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Improving the Presumptive Disability 

Decision-Making Process for Veterans 

Committee on Evaluation of the Presumptive Disability 

Decision-Making Process for Veterans, Jonathan M. 

Samet and Catherine C. Bodurow, Editors 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

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Committee on Evaluation of the Presumptive Disability

Decision-Making Process for Veterans

Board on Military and Veterans Health

Jonathan M. Samet and Catherine C. Bodurow, Editors
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“Knowing is not enough; we must apply.

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Advising the Nation. Improving Health.
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The National Academy of Sciences is a private, nonprofit, self-perpetuating society 

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COMMITTEE ON EVALUATION OF THE PRESUMPTIVE 

DISABILITY DECISION-MAKING PROCESS FOR VETERANS

JONATHAN M. SAMET (Chair), Professor and Chair, Department of 

Epidemiology, Jacob I. and Irene B. Fabrikant Professor in Health, 

Risk, and Society, Johns Hopkins University, Bloomberg School of 

Public Health, Baltimore, MD

MARGARET A. BERGER, Suzanne J. and Norman Miles Professor of 

Law, Brooklyn Law School, NY

KIRSTEN BIBBINS-DOMINGO, Assistant Professor of Medicine and of 

Epidemiology, Biostatistics, University of California, San Francisco

ERIC G. BING, Endowed Professor of Global Health and HIV, Charles R. 

Drew University of Medicine and Science, Los Angeles, CA

BERNARD D. GOLDSTEIN, Professor of Environmental and 

Occupational Health, Graduate School of Public Health, University 

of Pittsburgh, PA

GUY H. McMICHAEL III, President, GHM Consulting, Washington, DC

JOHN R. MULHAUSEN, Director, Corporate Safety and Industrial 

Hygiene, 3M Company, St. Paul, MN

RICHARD P. SCHEINES, Professor and Head, Department of 

Philosophy, Carnegie Mellon University, Pittsburgh, PA

KENNETH R. STILL, President and Scientific Director, Occupational 

Toxicology Associates, Inc., Hillsboro, OR

DUNCAN C. THOMAS, Verna Richter Chair in Cancer Research, 

Professor, and Director, Biostatistics Division, Department of 

Preventive Medicine, Keck School of Medicine, University of 

Southern California, Los Angeles

SVERRE VEDAL, Professor, Department of Environmental and 

Occupational Health Sciences, University of Washington School of 

Public Health and Community Medicine, Seattle

ALLEN J. WILCOX, Senior Investigator, Epidemiology Branch, National 

Institute of Environmental Health Sciences, and Editor-in-Chief of 

Epidemiology, Durham, NC

SCOTT L. ZEGER, Frank Hurley-Catharine Dorrier Professor and Chair, 

Department of Biostatistics, Bloomberg School of Public Health, 

Johns Hopkins University, Baltimore, MD

LAUREN ZEISE, Chief, Reproductive and Cancer Hazard Assessment 

Branch, Office of Environmental Health Hazard Assessment, 

California Environmental Protection Agency, Oakland
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Improving the Presumptive Disability Decision-Making Process for Veterans 

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vi

Volunteer Scientific Consultant

MELISSA McDIARMID, Professor of Medicine, Occupational Health 

Program, University of Maryland School of Medicine, Baltimore

Consultant

ROBERT J. EPLEY, Independent Consultant, Waxhaw, NC

Staff

CATHERINE BODUROW, Study Director

MORGAN A. FORD, Program Officer (May-August 2007)

LESLIE SIM, Program Officer (February-May 2006)

ALICE VOROSMARTI, Research Associate (May-August 2007)

CARA JAMES, Research Associate (June 2006-May 2007)

ANISHA DHARSHI, Research Associate (June 2006-January 2007)

KRISTEN BUTLER, Research Assistant (March-July 2007)

KRISTEN GILBERTSON, Research Assistant (February-July 2006)

JON Q. SANDERS, Program Associate (March 2006-May 2007)

REINE Y. HOMAWOO, Senior Program Assistant (May-August 2007)

VERA DIAZ, Intern (February-April 2007) 
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vii

BOARD ON MILITARY AND VETERANS HEALTH

ROBERT B. WALLACE (Chair), Professor of Epidemiology and Internal 

Medicine, and Director, Center on Aging, College of Public Health, 

University of Iowa, Iowa City

GEORGE K. ANDERSON, Executive Director, Association of Military 

Surgeons in the United States, Bethesda, MD

MICHAEL S. ASCHER, Senior Medical Advisor, Defense Biology 

Biosciences Directorate, Lawrence Livermore National Laboratory, 

Livermore, CA

ARTHUR J. BARSKY, Professor of Psychiatry, Harvard Medical 

School, and Director of Psychiatric Research, Brigham and Women’s 

Hospital, Boston, MA

DIANA D. CARDENAS, Professor and Chair, Department of 

Rehabilitation Medicine, University of Miami, FL

LINDA D. COWAN, Professor, University of Oklahoma College of Public 

Health, Oklahoma City

TIMOTHY R. GERRITY, Senior Partner, Noventus Medical, Worcester, 

MA

KATHERINE L. HEILPERN, Acting Chair, Department of Emergency 

Medicine, Emory School of Medicine, Atlanta, GA

MYRON M. LEVINE, Head, Division of Geographic Medicine, and 

Director, Center for Vaccine Development, University of Maryland 

School of Medicine, Baltimore

SUSAN H. MATHER, Department of Veterans Affairs (Retired), Bowie, 

MD

MATTHEW L. PUGLISI, Director, Business Development, Aptima, Inc., 

Washington, DC

PHYLLIS W. SHARPS, Professor and Director, Master’s Program, Johns 

Hopkins University School of Nursing, Baltimore, MD

ERNEST T. TAKAFUJI, Director, Office of Biodefense Research, 

National Institute of Allergy and Infectious Diseases, Bethesda, MD

Board Staff

FREDERICK ERDTMANN, Director

PAMELA RAMEY-McCRAY, Administrative Assistant

ANDREA COHEN, Financial Associate

IOM boards do not review or approve individual reports and are not asked to endorse 

conclusions and recommendations. The responsibility for the content of the reports rests with 

the authoring committee and the institution.
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Copyright © National Academy of Sciences. All rights reserved.

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ix

This report has been reviewed in draft form by individuals chosen 

for their diverse perspectives and technical expertise, in accordance with 

procedures approved by the National Research Council’s Report Review 

Committee. The purpose of this independent review is to provide candid 

and critical comments that will assist the institution in making its published 

report as sound as possible and to ensure that the report meets institutional 

standards for objectivity, evidence, and responsiveness to the study charge. 

The review comments and draft manuscript remain confidential to protect 

the integrity of the deliberative process. We wish to thank the following 

individuals for their review of this report:

Dan G. Blazer, Duke University Medical Center

Mark R. Cullen, Yale University School of Medicine

Lynn R. Goldman, Johns Hopkins Bloomberg School of Public Health

Steven N. Goodman, Johns Hopkins University School of Medicine

Robert F. Herrick, Harvard School of Public Health

Susan H. Mather, Department of Veterans Affairs (Retired)

Francis L. O’Donnell, Department of Defense’s Force Health 

Protection and Readiness Programs

Louise M. Ryan, Harvard School of Public Health

Patrick Ryan, PricewaterhouseCoopers

David A. Savitz, Mount Sinai School of Medicine

Harold C. Sox, American College of Physicians and Internal Medicine

Michael A. Stoto, Georgetown University

Reviewers
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REVIEWERS

Judith P. Swazey, The Acadia Institute

Joseph Thompson, Aequus, Inc.

Although the reviewers listed above have provided many constructive 

comments and suggestions, they were not asked to endorse the conclusions 

or recommendations nor did they see the final draft of the report before 

its release. The review of this report was overseen by Gilbert S. Omenn,

University of Michigan Medical School, and Willard G. Manning, University of Chicago. Appointed by the National Research Council and Institute 

of Medicine, respectively, they were responsible for making certain that 

an independent examination of this report was carried out in accordance 

with institutional procedures and that all review comments were carefully 

considered. Responsibility for the final content of this report rests entirely 

with the authoring committee and the institution.
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xi

Preface

This committee, the Committee on Evaluation of the Presumptive Disability Decision-Making Process for Veterans (Committee), was charged 

with describing the current process for how presumptive decisions are made 

for veterans who have health conditions arising from military service and 

with proposing a scientific framework for making such presumptive decisions in the future. Although an individual veteran can establish a direct 

service connection for an illness, the needed information on the responsible 

exposure received during military service may be unavailable or incomplete. Additionally, there may be scientific uncertainty as to whether the 

exposure is known to cause the health condition. To ensure that veterans 

are compensated when information for direct service connection is needed 

but unavailable, Congress or the Secretary of the Department of Veterans 

Affairs (VA) can decide to service connect entire groups of veterans for 

specific health conditions due to exposures received during service. This 

decision to compensate particular groups of veterans is called a presumptive disability service-connection decision or, simply, a presumption. A presumption may address unavailable or incomplete information on exposure 

or gaps in the evidence as to whether the exposure increases risk for the 

health condition.

Each veteran identified as eligible for coverage under a presumptive 

decision will have a separate, individual disability rating conducted by the 

VA and will be eligible for disability compensation based on the nature and 

severity of the health condition. That is, the presumptive disability serviceconnection decision is separate from the rating evaluation and compensation process.
Copyright © National Academy of Sciences. All rights reserved.

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xii PREFACE

The Committee took on the task of addressing presumptions while the 

United States was involved in conflict in Iraq and Afghanistan and veterans 

from prior conflicts were developing health conditions linked to service in 

Vietnam and the 1990 Persian Gulf War. The Committee’s charge involved 

examination of the processes used by all participants in the presumptive disability decision-making process for veterans—Congress, VA, the National 

Academies (National Research Council [NRC] and Institute of Medicine 

[IOM]), veterans service organizations, and veterans. The Committee examined the processes used by the NRC and IOM to evaluate scientific evidence 

in support of presumptive disability decision-making by the VA and how 

the VA used the syntheses and scientific classifications of the NRC and 

IOM, along with other information, to establish presumptive decisions. 

The Committee was asked to describe the current process. The Committee’s 

approach involved a series of case studies, intended to draw out “lessons 

learned” that would inform the development of a new approach. The case 

studies are not intended as criticisms about the work of past NRC or IOM 

committees or previously established presumptive decisions by Congress 

and VA. Rather the case studies serve as an appropriate and informative 

foundation for proposing an approach for the future. 

The Committee concluded that the presumptive disability decisionmaking process should be based on evidence about veterans’ health and 

how their health had been affected by military service. The Committee 

proposes a framework for the future that will be based on findings about 

the health of veterans that come from careful charting of Service member 

exposures during military service and tracking of their health at entry into, 

during, at separation from and after military service. The proposed framework may be applied to all types of exposures (e.g., chemical, biological, 

infectious, physical, and psychological); however, we recognize that characterizing psychological stressors, particularly under combat circumstances, 

is particularly difficult, although highly relevant to the chronic neuropsychiatric disorders faced by veterans. The Committee offers its framework 

for evaluation of the resulting evidence and for considering the evidence 

from studies of veterans in the context of all other relevant lines of scientific 

evidence. The Committee recommends a two-step approach for evaluation 

of scientific evidence on exposures of military personnel and risks to health. 

The first step is to determine the strength of evidence in support of causation and to classify the strength of the causal classification. The second step 

is to describe the magnitude of the disease burden caused by the exposure 

in a specific group of veterans.

Presumptive decisions, while based in evidence on risks to health status, 

are also affected by other considerations. The report acknowledges these 

considerations. The Committee recognizes that its proposed framework for 

the future will be applied in a context set by many considerations beyond 
Copyright © National Academy of Sciences. All rights reserved.

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PREFACE xiii

the scope of scientific evidence and its classification with regard to the 

strength of evidence for causality. Nonetheless, the Committee respectfully 

hopes that the Veterans’ Disability Benefits Commission will recommend 

and that Congress and the VA will adhere to an evidence-based approach 

for the future presumptive disability decision-making process for veterans. 

I am highly appreciative of the dedication and work of the members 

of the Committee on Evaluation of the Presumptive Disability DecisionMaking Process for Veterans. They willingly took on this important effort 

at a time when every American is aware of the great sacrifices that military 

service men and women and our veterans have and do make each day. The 

Committee addressed its charge with great dedication and worked tirelessly 

to consider all of the relevant information, to deliberate at length in committee meetings and conference calls. Of course, each committee member 

invested substantial time in this effort, reflective of its importance and of its 

challenging nature. The proposed scientific framework, levels for strength 

of evidence, and other recommendations in this report reflect the thoughtful and carefully considered conclusions of the Committee. The Committee 

wishes to express its appreciation for the valuable support of its dedicated 

staff directed by Catherine Bodurow. This report would not have been possible without their contributions.

Veterans have sacrificed a great deal for our nation. We owe them the 

best possible process for ensuring that those having service-related health 

conditions are properly identified, treated, and compensated.

Jonathan M. Samet, M.D., M.S.

Chair, Committee on Evaluation of the Presumptive 

Disability Decision-Making Process for Veterans
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Copyright © National Academy of Sciences. All rights reserved.

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xv

Acknowledgments

The Committee on Evaluation of the Presumptive Disability DecisionMaking Process for Veterans (Committee) and Institute of Medicine (IOM) 

staff would like to thank many individuals for providing information, 

data, discussions, and comments throughout this study. The Committee 

and IOM staff are indebted to these individuals for their assistance and 

contributions.

The Committee and IOM staff would like to acknowledge and thank 

members of the Veterans’ Disability Benefits Commission (VDBC) for 

taking time to attend and participate at the Committee’s open session 

meetings. The commissioners include: James T. Scott (VDBC’s Chairman), 

John Grady, Rick Surratt, and Joe Wynn. We would also like to recognize 

the VDBC Staff for their attendance and participation at the Committee’s 

open session meetings as well as any needed technical assistance throughout the study. These individuals include: Ray Wilburn (VDBC’s Executive 

Director), Jacqueline Garrick, Kathleen Greve, Steve Riddle, Jim Wear, 

and Donald Zeglin. IOM staff is appreciative of the assistance provided 

by Marcelle Habibion (Department of Veterans Affairs’ [VA] Director of 

Program Evaluation Service in the Office of Policy and Planning) during 

the course of the study. Many others from VA also provided information, 

presented at Committee meetings or participated in meetings with the Committee Chair and IOM staff. They are recognized, as follows, in alphabetical 

order: David Barrans, Mark Brown, Douglas Dembling, Lawrence Deyton, 

Patrick Dunne (VA’s Assistant Secretary for Policy and Planning), George 

Fitzelle, Duane Fleming, Bradley Flohr, Paul Hutter (VA’s Acting General 
Copyright © National Academy of Sciences. All rights reserved.

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xvi ACKNOWLEDGMENTS

Counsel), P. Craig Hyams, Patrick Joyce, Gordon Mansfield (VA’s Deputy 

Secretary), David McLenachen, Thomas Pamperin, and Joseph Salvatore.

The Committee benefited greatly from the knowledge, information, 

and views of presenters and panelists at its three open session meetings. 

The Committee would like to recognize the following individuals from its 

open session meeting on May 31, 2006 (listed in order of their presentation): John Grady (VDBC), Rick Surratt (VDBC), Joe Wynn (VDBC), Ray 

Wilburn (VDBC), Thomas Pamperin (VA), David Barrans (VA), Mark 

Brown (VA), Patrick Joyce (VA), and Bradley Flohr (VA). The Committee 

would like to recognize the following individuals who presented at its 

second open session meeting on July 27, 2006 (listed in order of their 

presentation): Rose Marie Martinez (IOM), Han Kang (VA), Lawrence 

Deyton (VA), R. Craig Postlewaite (DoD), Jack M. Heller (DoD), John 

Seibert (DoD), Cathy Wiblemo (The American Legion), Leonard Selfon 

(United Spinal Association), Quentin Kinderman (Veterans of Foreign Wars 

of the United States), and Rick Weidman (Vietnam Veterans of America). 

Finally, the Committee would like to recognize the following individuals 

who presented at its third open session meeting on October 4, 2006 (listed 

in order of their presentation): Laura Petrou, Patrick Ryan, Edward Scott,

Chris Yoder, Nhan Do (DoD), Cliff Freeman (VA), and James T. Scott 

(VDBC’s Chairman). In addition, several congressional staffers joined a 

panel discussion in person or by phone. They are recognized in alphabetical order, as follows: William Brew, Kelly Craven, Mary Ellen McCarthy, 

Paige McManus, Dahlia Melendrez, Kingston Smith, Jon Towers, and Lupe 

Wissel.

Representatives of the Department of Defense (DoD) contributed to the 

Committee’s efforts by attending and presenting at open session meetings, 

participating in conference calls, and providing written responses to Committee questions. The Committee and IOM staff would like to thank Ellen 

Embrey (DoD’s Deputy Assistant Secretary of Defense for Force Health Protection and Readiness), along with Michael Kilpatrick and George Johnson 

of her office, for making the assistance and expertise of many in DoD available to the Committee and IOM staff. IOM staff would like to acknowledge 

Craig Postlewaite who facilitated and participated in each of the DoD, 

Committee, and IOM staff interactions. The following individuals (listed 

in alphabetical order) contributed substantial time and effort to providing 

the Committee documents, answers to questions and participating at panel 

discussions during open session meetings: Kenneth Cox, Donna Doganiero, 

Jack Heller, Brad Hutchens, Jack Jeter, Bill Monk, Christine Moser, John 

Seibert, Becky Sobel, and Hew Wolf.

Throughout the course of the study, the Committee received written 

comments from veterans service organizations, individual veterans, and the 

public. These comments served to heighten awareness of important issues 
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ACKNOWLEDGMENTS xvii

that the Committee considered during its deliberations of the proposed 

levels for strength of evidence, proposed framework for the presumptive 

disability decision-making process, and recommendations. The Committee 

and IOM staff are grateful for the level of interest demonstrated and information that was shared.

IOM staff assembled an extensive electronic library of public laws, 

Federal Register notices, and all related presumptive disability decision 

documents with the assistance of librarians and experts at the Library of 

Congress. These individuals provided assistance in assembling an enormous 

knowledge base—from microfiche to electronic files—for the Committee, 

which was extensively researched and used throughout the study process. 

IOM staff is greatly indebted to the staff at the Library of Congress for 

these efforts.

The Committee was provided invaluable background information and 

expertise from IOM staff, including Rose Marie Martinez, David Butler, 

Jennifer Cohen, Carolyn Fulco, Abigail Mitchell, and Mary Paxton, during the course of the study. The Committee would like to thank these individuals for their contributions. 

The Committee was fortunate to have the assistance of two knowledgeable consultants throughout the study. Melissa McDiarmid provided 

invaluable scientific input to the Committee’s efforts. Robert Epley provided 

guidance on VA processes and background. The Committee is indebted to 

both of these individuals for the time and efforts they contributed.

Finally, the Committee would like to acknowledge the support of 

the IOM staff. The Committee would like to recognize, in particular, the 

efforts of Catherine Bodurow (Study Director) who worked tirelessly over 

the course of the study. The Committee is also particularly appreciative of 

the efforts of Morgan Ford (Program Officer), Alice Vorosmarti (Research 

Associate), and Reine Homawoo (Senior Program Assistant) who supported the study at its conclusion and delivered this report. The Committee 

would also like to recognize Frederick Erdtmann (Board Director) who 

attended each of the Committee meetings and provided assistance throughout the study. There were many who provided part-time staff support to 

the committee’s efforts over the course of the study. These additional staff 

included: Leslie Sim (Program Officer), Cara James (Research Associate), 

Anisha Dharshi (Research Associate), Kristen Butler (Research Assistant), 

Kristen Gilbertson (Research Assistant), Jon Sanders (Program Associate), 

and Vera Diaz (Intern). Additional staff support included assistance from: 

Andrea Cohen (Financial Associate), Pamela Ramey-McCray (Administrative Assistant), Lara Andersen (Office of Reports and Communication), 

and Mark Goodin (Copyeditor). The staff would also like to acknowledge 

William McLeod (Senior Librarian, The National Academies) who provided 

invaluable support throughout the study.
Copyright © National Academy of Sciences. All rights reserved.

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Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

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xix

Contents

Acronyms and Abbreviations xxv

General Summary 1 

Summary 7

1 Introduction 27

2 A Brief History of Presumptive Disability Decisions for Veterans 36

3 The Presumptive Disability Decision-Making Process 52

4 Legislative Background on Presumptions 70

5 Case Studies Summary Chapter 83

6 Establishing an Evidence-Based Framework 136

7 Scientific Evidence for Causation in the Population 150

8 Synthesizing the Evidence for Causation 175

9 Applying Population-Based Results to Individuals: From 

Observational Studies to Personal Compensation 198

10 Health and Exposure Data Infrastructure to Improve the 

Scientific Basis of Presumptions 237

11 Governmental Classification and Secrecy 298

12 The Way Forward 309

13 Recommendations 329
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xx CONTENTS

Appendixes1

A Statement of the Veterans’ Disability Benefits Commission to 

the Institute of Medicine’s Committee on the Presumptive 

Disability Decision-Making Process, May 31, 2006 339

B Committee on Evaluation of the Presumptive Disability 

Decision-­Making Process for Veterans Open Session 

Meeting Agendas 344

C Glossary 349

D Historical Background

E Arguments Favoring and Opposing Presumptions

F Tables: Summary of Presumptive Disability Decision-Making 

Legislative History

G VA’s White Paper on the Presumptive Disability Decision-Making 

Process

H IOM’s Statements of Task and Conclusions for Agent Orange and 

Gulf War Reports

I Case Studies

 1: Mental Disorders’ Presumptions

 2: Multiple Sclerosis Presumption

 3: Prisoners of War Presumptions

 4: Amputees and Cardiovascular Disease Presumption

 5: Radiation Presumptions

 6: Mustard Gas and Lewisite Presumptions

 7: Gulf War Presumptions

 8: Agent Orange and Prostate Cancer Presumption

 9: Agent Orange and Type 2 Diabetes Presumption

 10: Spina Bifida Program

J Causation and Statistical Causal Methods

K Sources of Health and Exposure Data for Veterans

L Additional Classification and Secrecy Information

M Biographical Sketches of Committee Members, Consultants, and 

Staff

1Appendixes D-M can be found on a CD attached to the back of the report cover.
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xxi

TABLES

2-1 Categories of Arguments Favoring and Opposing Presumptions, 42

2-2 Presumptive Categories and Their Designated Health Outcomes, 43

3-1 Presumptions in VA’s Disability Program, 62

5-1 List of Case Studies (in chronological order of when presumptions 

were established by Congress or VA), 84

6-1 Possible Decisions About Service-Attributable Diseases (SADs) with 

Associated Errors and Losses, 142

6-2 Hypothetical Example of the Estimation of Service-Attributable 

Disease, 144

7-1 Hypothetical Example of Military Radiation Exposure, Smoking, 

and Cancer, 167

8-1 IOM Categorization from the Executive Summary of Veterans and 

Agent Orange: Health Effects of Herbicides Used in Vietnam, 185

8-2 IOM Categorization from the Executive Summary of Gulf War and 

Health, Volume 1: Depleted Uranium, Pyridostigmine Bromide, 

Sarin, Vaccines, 186

Tables, Figures, and Boxes
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xxii TABLES, FIGURES, AND BOXES

9-1 Hypothetical Example of Risks from Multiple Causal 

Exposures, 209

9-2 Hypothetical PAFs Due to Smoking and Military Exposure, 210

9-3 True and False Positive and Negative Rates, 215

9-4 Comparing Sensitivity and Specificity of Two Hypothetical Sets of 

Compensation Criteria, 216

9-5 Hypothetical Scenario 1: PPV When AF = 50 Percent, 217

9-6 Hypothetical Scenario 2: PPV When AF = 9 Percent, 217

9-7 Hypothetical Scenario 3: PPV When AF = 2 Percent, 218

10-1 Timeline for Medical Surveillance and Exposure Data 

Collection, 242

10-2 Service-Specific Databases for Exposure, 257

10-3 Summary of VET Registry Projects, 267

10-4 National Academies’ and VA Medical Monographs on Veterans’ 

Health by Theater or Exposure, 268

10-5 VA Health Registries, 274

FIGURES

GS-1 Proposed framework for future presumptive disability decisionmaking process for veterans, 4

S-1 Roles of the participants involved in the presumptive disability 

decision-making process for veterans, 11

S-2 Proposed framework for future presumptive disability decisionmaking process for veterans, 17

3-1 Roles of the participants involved in the presumptive disability 

decision-making process for veterans, 53

6-1 Information gathering and its use in making general and specific 

compensation decisions, 139

7-1 Causal and spurious associations, 158

7-2 Scenario for causation without association, 158

7-3 The power of randomization, 161

7-4 Age as a confounder, 163

7-5 Unmeasured confounders, 163

7-6 TV and obesity, 163

7-7 Instrumental variable, 165

7-8 Rothman’s sufficient component causes model, 167
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TABLES, FIGURES, AND BOXES xxiii

8-1 Hypothetical illustrations, 179

8-2 Focusing on unmeasured confounders/covariates, or other sources 

of spurious association from bias, 180

8-3 IARC evaluation scheme, 184

8-4 Example posterior for Sufficient, 190

8-5 Example posterior for Equipoise and Above, 191

8-6 Example posterior for Below Equipoise, 192

8-7 Example posterior for Against, 193

9-1 Example of ROC curves, 219

9-2 “Economically rational” compensation plan, based on the 

attributable fraction, 225

9-3 Complete compensation (100 percent) for all exposed persons with 

disease, regardless of attributable fraction, 225

9-4 Complete compensation for all exposed persons only when 

attributable fraction is 50 percent or more, 226

9-5 Complete compensation for an AF of 50 percent or more, plus 

graduated compensation below 50 percent, 227

9-6 A rational process for determining veterans’ compensation, 228

10-1 Timeline for medical surveillance and exposure data collection, 241

10-2 DoD’s deployment health surveillance elements, 256

10-3 National Defense Occupational and Environmental Health 

Readiness System (DOEHRS), 258

12-1 Proposed framework for future presumptive disability decisionmaking process for veterans, 311

BOXES

3-1 Representatives at Each Tier of VA’s Internal Review of NAS 

Reports, 59
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xxv

ACB Army Classification Battery 

ACES-EM Automated Civil Engineering System-Environmental 

Management

ACHRE Advisory Committee on Human Radiation Experiments

ADA American Diabetes Association

AEC Atomic Energy Commission

AF Attributable fraction

AF-EMIS Air Force Environmental Management Information 

System

AFCESA Air Force Civil Engineer Support Agency

AFHLTA Armed Forces Health Longitudinal Technology 

Application

AFHS Air Force Health Study

AFHSC Armed Forces Health Surveillance Center

AHA American Heart Association

AHLTA Armed Forces Health Longitudinal Technology 

Application

AhR Aryl hydrocarbon receptor

AIDS Acquired immunodeficiency syndrome 

AIS Automated information systems

ALS Amyotrophic lateral sclerosis (Lou Gehrig’s disease)

AML Acute myelogenous leukemia

ANG Air National Guard

ANLL Acute non-lymphocytic leukemia

Acronyms and Abbreviations
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xxvi ACRONYMS AND ABBREVIATIONS

APIMS Air Program Information Management System

AS Assigned share

ASTM American Society for Testing and Materials

ATSDR Agency for Toxic Substances and Disease Registry

BEIR Biological Effects of Ionizing Radiation

BMI Body mass index

C&P Service Compensation and Pension Service 

CCB Configuration Control Board

CCS Command Core System (Air Force)

CDC Centers for Disease Control and Prevention

CDVA Commonwealth Department of Veterans’ Affairs

CERHR Center for the Evaluation of Risks to Human 

Reproduction

CES-D Centers for Epidemiological Studies-Depression Scale

CFR Code of Federal Regulations

CHD Coronary heart disease

CHF Congestive heart failure

CHPPM Center for Health Promotion and Preventive Medicine 

(Army)

CI Confidence interval

CIA Central Intelligence Agency

CIRRPC Committee on Interagency Radiation Research and 

Policy Coordination

CLL Chronic lymphocytic leukemia

CNS Central nervous system

COPD Chronic obstructive pulmonary disease

CRDP Concurrent Retirement and Disability Payments

CRS Congressional Research Service

CRSC Combat-Related Special Compensation 

CSM Cerebrospinal malformation 

CSP Cooperative Studies Program 

CVD Cardiovascular disease

DALY Disability-adjusted life year

DCI SCI Director of Central Intelligence Sensitive Compartmented 

Information Programs

DECC-D Defense Enterprise Computing Center-Detachment

DHHS Department of Health and Human Services

DISA Defense Information Systems Agency

DMDC Defense Manpower Data Center
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ACRONYMS AND ABBREVIATIONS xxvii

DMSS Defense Medical Surveillance System

DNBI Disease and nonbattle injury

DoA Department of the Army 

DoD Department of Defense

DoDI Department of Defense Instruction

DOE Department of Energy

DOEHRS Defense Occupational and Environmental Health 

Readiness System

DoL Department of Labor

DSM-III-R Diagnostic and Statistical Manual of Mental Disorders, 

Third Edition, Revised

DTAS Defense Theater Accountability Software

EA Exposure Assessment

EAR Excess absolute risk

EEOICPA Energy Employees Occupational Illness Compensation 

Program Act

EESOH-MIS Enterprise Environmental Safety and Occupational 

Health-Management Information System

EO Executive Order

EPA Environmental Protection Agency

EPCRA Emergency Planning and Community Right-to-Know Act

ERIC Epidemiologic Research and Information Center

ERR Excess relative risk

FECA Federal Employees’ Compensation Act

FERS Federal Employees Retirement System

FHIE Federal Health Information Exchange

FHP Force Health Protection

fMRI Functional magnetic resonance imaging

FN False negative

FNR False negative rate

FOUO For official use only 

FP False positive

FPR False positive rate 

FR Federal Register

FY Fiscal Year

GAF Global Assessment of Functioning

GAO Government Accountability Office

GBD General birth defect 

GBS Guillain-Barre syndrome
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xxviii ACRONYMS AND ABBREVIATIONS

GPS Global Positioning System

GT test General Technical test 

GW Gulf War

Gy Gray (measure of dose of irradiation)

HART Health Assessment Review Tool

HCFA Health Care Financing Administration

HEW U.S. Department of Health, Education, and Welfare

HHIM Health Hazard Information Module 

HIV Human immunodeficiency virus

HMMS Hazardous Materials Management System

HUS Hemolytic-uremic syndrome

IARC International Agency for Research on Cancer

ICD International Classification of Diseases

IH Industrial hygiene

IHIMS Industrial Hygiene Information Management System 

(Navy)

IOM Institute of Medicine

IQ Intelligence quotient

IREP Interactive RadioEpidemiological Program

IU Individual unemployability

LIMDIS Limited Dissemination

LMF Lovelace Medical Foundation

MDS Myelodysplastic syndrome

MFUA Medical Follow-up Agency

MMPI Minnesota Multiphasic Personality Inventory

MOA Memorandum of Agreement

MOS Military occupational specialty

MRI Magnetic resonance imaging 

MS Multiple sclerosis

MTF Military Treatment Facility

NAS National Academy of Sciences

NCEH National Center for Environmental Health

NCHS National Center for Health Statistics

NCI National Cancer Institute

NEHC Navy Environmental Health Center

NESHAP National Emission Standards for Hazardous Air Pollutants

NHANES National Health and Nutrition Examination Survey

NHL Non-Hodgkin’s lymphoma
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ACRONYMS AND ABBREVIATIONS xxix

NHLBI National Heart, Lung, and Blood Institute

NHS Nurses Health Study

NIH National Institutes of Health

NIOSH National Institute for Occupational Safety and Health

NOCONTRACT Not releasable to contractors

NOED Navy Occupational Exposure Database

NOFORN Not releasable to foreign nationals

NPV Negative predictive value

NRC National Research Council

NTP National Toxicology Program

NTS Nevada Test Site

OEF Operation Enduring Freedom

OEH Occupational and environmental health

OEHHA Office of Environmental Health Hazard Assessment

OEHS Occupational environmental health and safety 

OEL Occupational exposure limit

OGC Office of the General Counsel 

OH Occupational health

OHMIS Occupational Health Management Information System

OIF Operation Iraqi Freedom

OMB Office of Management and Budget

OPHEH Office of Public Health and Environmental Hazards 

OPM Office of Personnel Management

OR Odds ratio

ORCON Originator controlled dissemination and extraction of 

information

ORD Office of Research and Development

OSHA Occupational Safety and Health Administration

OSTP Office of Science and Technology Policy

PAF Population attributable fraction

PAR Population attributable risk

PC Probability of causation

PCB Polychlorinated biphenyl

PDDM Presumptive disability decision making

PHA Periodic health assessment

PKDL Post-kala-azar dermal leishmaniasis 

PL Public Law

POM Program Objectives Memorandum

POW Prisoner of War

PPB Parts per billion

PPG Pacific Proving Grounds
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xxx ACRONYMS AND ABBREVIATIONS

PPM Parts per million

PPV Positive predictive value

PSA Prostate-specific antigen

PSG II Professional Staffing Group II 

PTF Presidential Task Force

PTSD Posttraumatic stress disorder

PY Person-year

RADS Reactive airways dysfunction syndrome 

RCT Randomized controlled/clinical trial

RD Restricted data

ReA Reactive arthritis

RECA Radiation Exposure Compensation Act of 1990

RECAC Radiation Exposure Compensation Act Committee

REVCA Radiation-Exposed Veterans Compensation Act

RO Rey-Osterreith Test

ROC Receiver Operator Characteristics curve 

RR Relative risk/risk ratio

RTI Research Triangle Institute

SAD Service-attributable disease

SAF Service-attributable fraction

SANG Saudi Arabian National Guard

SAP Special Access Program

SCI Sensitive Compartmented Information

SCID Structured Clinical Interview for Diagnostic and 

Statistical Manual of Mental Disorders

SCL Symptoms Checklist

SEER Surveillance Epidemiology and End Results

SEG Similar exposure group

SES Socioeconomic status

SF Standard Form

SFFWG Shared Functions Focus Working Group

SHAD Project Shipboard Hazard and Defense

SMITREC Serious Mental Illness Treatment Research and 

Evaluation Center

SMR Standardized mortality ratio

SSA Social Security Administration

SSDI Social Security Disability Insurance

SSI Supplemental Security Income

TBI Traumatic brain injury

TCDD Tetrachlorodibenzo-p-dioxin
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ACRONYMS AND ABBREVIATIONS xxxi

TN True negative

TNR True negative rate

TP True positive

TPR True positive rate

UNSCEAR United Nations Scientific Committee on the Effects of 

Atomic Radiation

USC United States Code

USPSTF U.S. Preventive Health Services Task Force 

VA Department of Veterans Affairs 

VAO Veterans and Agent Orange

VASRD Veterans Administration Schedule for Rating Disabilities

VBA Veterans Benefits Administration

VDBC Veterans’ Disability Benefits Commission

VDRECSA Veterans’ Dioxin and Radiation Exposure Compensation 

Standards Act

VES Vietnam Experience Study 

VET (registry) Vietnam Era Twin (registry)

VHA Veterans Health Administration

VHI Veterans Health Initiative

VISTA Veterans Health Information Systems and Technology 

Architecture

VOC Volatile organic compound

VSO Veterans Service Organization

WAIS-R Wechsler Adult Intelligence Scale-Revised

WNINTEL Warning notice, intelligence sources, and methods 

involved

WRIISC War-Related Illness and Injury Study Centers

WWI World War I

WWII World War II

YLD Years of life lived with disability

YLL Years of life lost
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The United States has long recognized and honored the service and 

sacrifices of its military and veterans. Veterans who have been injured by 

their service (whether their injury appears during service or afterwards) are 

owed appropriate health care and disability compensation. For some medical conditions that develop after military service, the scientific information 

needed to connect the health conditions to the circumstances of service may 

be incomplete. When information is incomplete, Congress or the Department of Veterans Affairs (VA) may need to make a “presumption” of service 

connection so that a group of veterans can be appropriately compensated. 

The missing information may be about the specific exposures of the veterans, 

or there may be incomplete scientific evidence as to whether an exposure 

during service causes the health condition of concern. For example, when 

the exposures of military personnel in Vietnam to Agent Orange could not 

be clearly documented, a presumption was established that all those who 

set foot on Vietnam soil were exposed to Agent Orange.

The Institute of Medicine (IOM) Committee was charged with reviewing and describing how presumptions have been made in the past and, if 

needed, to make recommendations for an improved scientific framework 

that could be used in the future for determining if a presumption should 

be made. The Committee was asked to consider and describe the processes 

of all participants in the current presumptive disability decision-making 

process for veterans. The Committee was not asked to offer an opinion 

about past presumptive decisions or to suggest specific future presumptions. The Committee heard from a range of groups that figure into this 

decision-making process, including past and present staffers from Congress, 

General Summary
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 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

the VA, the IOM, veterans service organizations, and individual veterans. 

The Department of Defense (DoD) briefed the Committee about its current 

activities and plans to better track the exposures and health conditions of 

military personnel. The Committee further documented the current process 

by developing case studies around exposures and health conditions for 

which presumptions had been made. The Committee also reviewed general 

methods by which scientists, as well as government and other organizations, evaluate scientific evidence in order to determine if a specific exposure 

causes a health condition.

The history of presumptions is a fascinating and complex story. In 1921 

Congress empowered the VA Administrator (now Secretary) to establish 

presumptions of service connection for veterans. Only Congress and VA 

have the authority to establish presumptions for veterans. Since 1921, 

nearly 150 health outcomes have been service-connected on a presumptive basis by Congress and VA. This process has evolved over the years. 

The current process for making presumptions can be traced to the Agent 

Orange Act of 1991 (Public Law 102-4. 102d Cong., 2d Sess.), an act that 

established a model for decision making by VA that still stands today. In the 

1991 Act, Congress asked VA to contract with an independent organization 

to review the scientific evidence on Agent Orange. VA turned to the IOM of 

the National Academy of Sciences to carry out these reviews. Subsequently, 

VA turned to IOM for issues arising from the 1990 Gulf War. Based on 

the work of a committee, IOM provides VA with reports that describe the 

strength of evidence that links agents of concern with specific health conditions. VA uses IOM reports and other information in an internal decisionmaking process to decide whether a presumption will be made. 

The Committee carefully studied the current approach to presumptive disability decision making and examined a number of specific case 

examples. This assessment led to a number of recommendations to improve 

the process:

• As the case studies demonstrated, Congress could provide a clearer 

and more consistent charge on how much evidence is needed to make a 

presumption. There should be clarity as to whether the finding of an association in one or more studies is sufficient or the evidence should support 

causation.

• Due to lack of clarity and consistency in congressional language and 

VA’s charges to the committees, IOM committees have taken somewhat varying approaches since 1991 in reviewing the scientific evidence and in forming their opinions on the possibility that exposures during military service 

contributed to causing a health condition. Future committees could improve 

their review and classification of scientific evidence if they were given clear 

and consistent charges and followed uniform evaluation procedures. 
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GENERAL SUMMARY 

• The internal processes by which the VA makes its presumptive 

decisions following receipt of an IOM report have been unclear. VA should 

adopt transparent and consistent approaches for making these decisions. 

• Complete exposure data and health condition information for military personnel (both individuals and groups) usually have not been available 

from DoD in the past. Such information is one of the most critical pieces of 

evidence for improving the determination of links between exposures and 

health conditions.

All of these improvements are feasible over the longer term and are 

needed to ensure that the presumptive disability decision-making process 

for veterans is based on the best possible scientific evidence. Decisions 

about disability compensation and related benefits (e.g., medical care) for 

veterans should be based on the best possible documentation and evidence 

of their military exposures as well as on the best possible information on 

any health conditions caused by these exposures. While it is impossible to 

provide certainty in every case, a fresh approach could do much to improve 

the current process. The Committee’s recommended approach (Figure GS-1) 

has several parts: 

• An open process for nominating exposures and health conditions 

for review; involving all stakeholders in this process is critical

• A revised process for evaluating scientific information on whether 

a given exposure causes a health condition in veterans; this includes a new 

set of categories to assess the strength of the evidence for causation, and an 

estimate of the numbers of exposed veterans whose health condition can be 

attributed to their military exposure

• A consistent and transparent decision-making process by VA

• A system for tracking the exposures of military personnel (including chemical, biological, infectious, physical, and psychological stressors), 

and for monitoring the health conditions of all military personnel while in 

service and after separation 

• An organizational structure to support this process

To support the Committee’s recommendations, we suggest the creation 

of two panels. One is an Advisory Committee (advisory to VA), that would 

assemble, consider, and give priority to the exposures and health conditions 

proposed for possible presumptive evaluation. Nominations for presumptions could come from veterans and other stakeholders as well as from 

health tracking, surveillance, and research. The second panel would be a 

Science Review Board, an independent body, which would evaluate the 

strength of the evidence (based on causation) that links a health condition 

to a military exposure and then estimates the fraction of exposed veterans 
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 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Research/

Surveillance a

Stakeholder

Nominations b

Science Review

Boardd

VA Compensation

Decision Process

Advisory Committeec

Decisione

VA Secretary

VA Secretary

Report 

Charge 

Recommendations 

Initiates presumption 

consideration process 

FIGURE S-2

Vertical arrows have been shortened.

There is now a little over an inch of extra 

space at the bottom of 6 x 9 page

If more space is needed the figure will be

reduced in size in the page layout process

FIGURE GS-1 Proposed framework for future presumptive disability decisionmaking process for veterans.

a Includes research for classified or secret activities, exposures, etc. 

b Includes veterans, Veterans Service Organizations, federal agencies, scientists, 

general public, etc.

c

 This committee screens stakeholders’ proposals and research in support of evaluating evidence for presumptions and makes recommendations to the VA Secretary 

when full evidence review or additional research is appropriate. 

d The board conducts a two-step evidence review process (see report text for further 

detail).

e

 Final presumptive disability compensation decisions are made by the Secretary, 

Department of Veterans Affairs, unless legislated by Congress.
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GENERAL SUMMARY 

whose health condition could be attributed to their military exposure. The 

Science Review Board’s report and recommendations would go to VA for 

its consideration. VA would use explicit criteria to render a decision by the 

VA Secretary with regard to whether a presumption would be established. 

In addition, the Science Review Board would monitor information on the 

health of veterans as it accumulates over time in the DoD and VA tracking 

systems, and nominate new exposures or health conditions for evaluation 

as appropriate.

This Committee recommends that the following principles be adopted 

in establishing this new approach: 

1. Stakeholder inclusiveness

2. Evidence-based decisions

3. Transparent process

4. Flexibility

5. Consistency

6. Causation, not just association, as the target for decision making

The Committee suggests that its framework be considered as the model 

to guide the evolution of the current approach. While some aspects of the 

approach may appear challenging or infeasible at present, feasibility would 

be improved with the full implementation of the Committee’s recommendations, provision of appropriate resources to all of the participants in the 

presumptive disability decision-making process for veterans, and future 

methodological developments. DoD and VA have already been discussing 

various aspects of improving exposure and health tracking and how the two 

agencies can share data and information with each other. Veterans deserve 

to have these improvements accomplished as soon as possible. 
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INTRODUCTION

The United States has long recognized and honored military veterans’ 

service and sacrifices. Veterans injured by their service, becoming ill while 

in service, or having an illness after discharge as a long-term consequence of 

their service have been given healthcare coverage and disability compensation. As the complexity of exposures during combat has increased, the list of 

service-connected illnesses has grown. The Department of Veterans Affairs 

(VA) now provides disability compensation to approximately 2.6 million 

veterans for 7.7 million disabilities annually, expending approximately 

$24 billion for this purpose (VBA, 2006, pp. 19, 24, 27).

Disability compensation for military veterans requires that there be a 

service connection. A medical illness or injury that occurred while a member was in military service is considered service connected whether caused 

by or aggravated by an exposure or event during service or simply occurring coincidentally with military service. However, if a medical condition 

appears after the period of military service and it is presumed to be caused 

by or aggravated by an exposure or an event that occurred during military 

service, then veterans may receive compensation based on that presumption 

(Pamperin, 2006).

In making a decision to provide compensation, VA needs to determine 

whether the illness of concern can generally be caused by exposures received 

during service and whether the illness in a specific claimant was caused by 

the exposure. The answer to the general question of causality comes from 

a careful review of all available scientific information, while the answer 

Summary
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 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

to the question of causation in a specific person hinges on knowledge of 

the exposure received by that individual and of other factors that may be 

relevant. If the scientific evidence is incomplete, there may be uncertainty 

on the question of causation generally; if there is limited or no information 

on exposure of individual claimants or if other factors also contribute to 

disease causation, there may be uncertainty on the question of individual 

causation. 

To provide benefits to veterans in the face of these two broad types 

of uncertainty, Congress and VA make presumptive decisions that bridge 

gaps in the evidence related to causation and to exposure. Presumptions 

may relieve the veteran of persuading VA that the exposure produced the 

adverse health outcome and of proving that an exposure occurred during 

military service (Pamperin, 2006). Once a medical condition is service 

connected through presumptions, and the veteran can document military 

service consistent with having received the given exposure, the veteran 

only has to show the basic fact that he or she suffers from the condition 

in order to receive a disability payment and eligibility for medical care 

(Zeglin, 2006).

In 2004, Congress established the Veterans’ Disability Benefits Commission (the Commission), which was charged with “studying the benefits 

provided to compensate and assist veterans for disabilities attributable to 

military service” (VDBC, 2006, p. 1; as found in Appendix A). The Commission identified the presumptive disability decision-making process as 

a topic needing assessment and asked the Institute of Medicine (IOM) to 

establish a committee for this purpose that would be funded by VA. The 

resulting committee, the Committee on Evaluation of the Presumptive Disability Decision-Making Process for Veterans (the Committee), was given 

the following charge by VA:

• Describe and evaluate the current model used to recognize diseases 

that are subject to service connection on a presumptive basis.

• If appropriate, propose a scientific framework that would justify 

recognizing or not recognizing conditions as presumptive.

The Commission further elaborated the charge, asking the Committee to “help ensure that future veterans are granted service connection 

under a presumptive basis based on the best scientific evidence available” 

(VDBC, 2006, p. 4; as found in Appendix A). The Commission asked the 

Committee to “evaluate the current model used to determine diseases that 

qualify for service connection on a presumptive basis, and if appropriate, propose improvements in the model” (VDBC, 2006, p. 1; as found 

in Appendix A). The Commission emphasized that “having a method of 

granting service connection quickly and fairly based on a presumption is 
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SUMMARY 

of critical importance to our disabled veterans and their surviving spouses” 

and that “ensuring that future presumption processes reflect the then current medical knowledge about the causal relationship would benefit the 

entire veteran community” (VDBC, 2006, p. 4; as found in Appendix A). 

The Commission’s summary statement further commented that “[t]o the 

extent possible, suggestions that will avoid the necessity for many future 

presumptions by ensuring that exposure of service members is documented 

and scientific evidence is made available would be important” (VDBC, 

2006, p. 4; as found in Appendix A).

IOM appointed a 14-member committee that covered the broad scientific and medical areas of general, occupational, and psychiatric medicine; 

biostatistics; epidemiology; toxicology; industrial hygiene; and exposure 

and risk assessment. The Committee’s members also brought expertise 

in law, philosophy, causal decision making, and policy as well as knowledge of the Department of Defense (DoD) and VA’s approach to disability 

compensation. 

THE COMMITTEE’S APPROACH TO ITS CHARGE

In fulfilling its charge, the Committee first investigated and attempted 

to characterize Congress’ and VA’s recent approach to presumptive disability decision making, and then developed a conceptual framework for 

a new, more evidence-based process. It then constructed a way to move 

forward that builds on the framework and addresses deficiencies of the 

current process. 

The Committee held three open meetings to gather information on the 

current presumptive disability decision-making process. The Committee 

heard from past and present congressional staff members, representatives of 

VA, DoD, IOM, various stakeholder groups (e.g., veteran service organizations [VSOs]) and the general public. Committee members also participated 

in conference calls with DoD experts on medical surveillance and exposure 

data collection and exposure assessment systems. 

The Committee reviewed extensive background information including: 

documents provided by the Commission, public laws and supporting House 

and Senate reports, Federal Register notices, VA documents (e.g., cost estimates, a white paper on VA’s decision-making processes [found in Appendix G], and responses by VA to written questions from the Committee), 

DoD documents, and past IOM reports commissioned by DoD and VA. 

The Committee conducted 10 case study reviews—Mental Disorders’ Presumptions, Multiple Sclerosis Presumption, Prisoners of War Presumptions, 

Amputees and Cardiovascular Disease Presumption, Radiation Presumptions, Mustard Gas and Lewisite Presumptions, Gulf War Presumptions, 

Agent Orange and Prostate Cancer Presumption, Agent Orange and Type 2 
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10 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Diabetes Presumption, and Spina Bifida Program (not a presumption but a 

VA program area)—that cover a wide variety of circumstances for which 

presumptions have been established by Congress and VA since 1921. The 

case studies were a foundation for the Committee’s efforts in understanding past practices of all participants in the presumptive disability decisionmaking process (see Appendix I). 

The Committee also researched and considered capabilities and limitations of the exposure data and health outcome information available to 

DoD and VA for exposure assessment, surveillance, and research purposes. 

The Committee examined whether DoD and VA have a strategic research 

plan and vision for the necessary interface between the agencies, as well as 

with other, relevant research organizations. 

The Committee considered the use of scientific evidence in guiding the 

process for making presumptive decisions that affect the compensation of 

veterans. Drawing upon the Committee members’ expertise in epidemiology, medicine, toxicology, biostatistics, and causal decision making, the 

Committee covered the evaluation of evidence for inferring association and 

causation as well as methods for quantifying the contribution of an agent to 

disease causation in populations and extending this quantification to individuals. Using this framework, the Committee developed an evidence-based 

approach for making future decisions with regard to presumptions.

THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS 

FOR VETERANS

In 1921 Congress empowered the VA Administrator (now Secretary) 

to establish presumptions of service connection for veterans. Only Congress and the VA Secretary have the authority to establish presumptions. 

Over time, presumptions have been made to relieve veterans of the burden 

to prove that disability or illness was caused by a specific exposure that 

occurred during military service (e.g., Prisoners of War). Since 1921, nearly 

150 health outcomes have been service connected on a presumptive basis 

(see Appendix F). In February 2006, Congress codified all regulatory presumptions that VA had put in place to that time.

The current presumptive disability decision-making process for veterans involves several steps and several organizations. The process involves 

input from many parties—Congress, VA, the National Academies, and 

stake­holders (e.g., VSOs, advisory committees, and individual veterans) 

(Figure S-1). Congress has made presumptions itself. In the current model, 

Congress or stakeholders acting through Congress may call on VA to assess 

whether a presumption is needed. The VA turns to IOM for completion of a 

review of the scientific evidence. The findings of that evaluation are consid-
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11

Stakeholdersa

Congressb

VAc

The NationalAcademiesd

PRESUMPTION

Courts may interpret

presumption

Study Charge Report 

VA may appeal or

Congress may revise

Disputes 

FIGURE S-1

FIGURE S-1 Roles of the participants involved in the presumptive disability decision-making process for veterans.a Stakeholders include (but are not limited to) veterans service organizations (VSOs), veterans, advisory groups, federal agencies, and the general public; these stakeholders provide input into the presumptive process by communicating with Congress, VA, and independent organizations (e.g., the National Academies).b Congress has created many presumptions itself; in 1921, Congress also empowered the VA Secretary to create regulatory presumptions; on several occasions in the past, Congress has directed VA to contract with an independent organization (e.g., the National Academies) to conduct studies and then use the organization’s report in its deliberations of granting or not granting regulatory presumptions. c VA can establish regulatory presumptions; VA sometimes contracts with the National Academies to conduct studies and uses the organization’s report in its deliberations of granting or not granting regulatory presumptions. d The National Academies (Institute of Medicine and National Research Council) submit reports to VA based on requests and study charges from VA.
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12 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

ered by VA in its presumptive disability decision-making process. Decisions 

made in the courts have also influenced the current presumptive process.

Three major legislative actions by Congress have influenced the recent 

presumptive decisions—the Radiation Exposed Veterans Compensation Act 

of 1988 (Public Law 100-321. 100th Cong., 2d Sess.), the Agent Orange 

Act of 1991 (Public Law 102-4. 102d Cong., 1st Sess.), and the Persian 

Gulf War Acts of 1995 (Veterans’ Benefits Improvement Act of 1994. Public 

Law 103-446. 103rd Cong., 2d Sess.) and 1998 (Making Omnibus Consolidated and Emergency Appropriations for the Fiscal Year Ending September 

30, 1999, and for Other Purposes. Public Law 105-277. 105th Cong., 2d 

Sess.). The concept of “at least as likely as not” with regard to exposure 

potential was introduced for radiation exposures and its use has since 

been continued. The Agent Orange Act (Public Law 102-4. 102d Cong., 

1st Sess.) grew out of events following the Vietnam War, and its language 

expresses substantial and significant elements of the presumptive story. The 

presumptions put in place by Congress for Gulf War illnesses represent the 

first time that Congress produced a list of health outcomes that it defined 

as “undiagnosed illnesses” (Veterans Education and Benefits Expansion Act 

of 2001. Public Law 107-103. 107th Cong., 1st Sess.).

When Congress enacted the Agent Orange Act of 1991 (Public Law 

102-4. 102d Cong., 1st Sess.), it started a model for a decision-making 

process that is still in place. Congress asked VA to contract with an independent organization—VA contracted with IOM—to review the scientific evidence for Agent Orange. Since 1994, IOM has produced biennial 

reports on Agent Orange for VA to use as it considers making presumptive 

decisions (IOM, 1994, 1996, 1999, 2001, 2003b, 2005b). IOM has also 

delivered five volumes on the Gulf War (IOM, 2000a, 2003a, 2005a, 2006, 

2007). Congress requires VA to respond after receiving an IOM report with 

a determination as to whether VA will make a service connection for particular health outcomes on a presumptive basis. VA has described its internal 

decision-making processes to the Committee in a general fashion, and the 

Committee has reviewed VA’s Federal Register notices and documents (see 

Chapter 3). However, it remains unclear to the Committee how VA makes 

particular determinations with regard to weighing strength of evidence for 

causation and exposure potential in making its presumptive decisions. 

Analysis of the Agent Orange and Gulf War case studies (see Appendix I) shows important similarities and differences relevant to the overall presumptive process. One difference is that Agent Orange is a single 

product (actually a mixture of compounds that contains the contaminant 

dioxin), extensively researched for associated health outcomes, whereas the 

health consequences of the Gulf War are unlikely to be the result of any 

single agent. Military service men and women may have received a number 

of health-relevant exposures during service in the Persian Gulf, complicating the development of evidence reviews. For Agent Orange, there is one 
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SUMMARY 13

exposure of concern and a more constrained set of health indicators. There 

have been some differences in approaches of Agent Orange and Gulf War 

committees. The IOM Agent Orange reports (IOM, 1994, 1996, 1999, 

2001, 2003b, 2005b) did not explicitly include a causal category in their 

evaluations whereas recent Gulf War reports (IOM, 2000a, 2003a, 2005a, 

2006, 2007) did include a category for evidence sufficient to infer causation when characterizing the strength of evidence for agents evaluated. For 

neither set of reports does VA describe in its Federal Register notices how 

it accounted for exposure potential or magnitude in making its presumptive decisions.

FINDINGS OF CASE STUDIES

The case studies offered a diverse set of lessons learned and indicated 

elements of the current process that need to be addressed. In carrying out 

the case studies, this Committee had the opportunity to retrospectively 

examine the work of IOM committees as they grappled with the challenge 

of using uncertain evidence and of VA staff as they used the findings of 

IOM committees to make decisions about presumptions. The case studies 

demonstrate that the process has acted to serve the interests of veterans in 

many instances. Congress and VA have repeatedly acted to maximize the 

sensitivity of presumptive decisions so as to assure that no veteran who 

might have been affected is denied compensation. On the other hand, in 

maximizing sensitivity of presumptive disability decision making, substantial numbers of veterans whose illnesses may or may not have been actually 

service related are nonetheless compensated. There are both financial and 

nonfinancial costs to such decisions.

The case studies illustrate the use of presumptions to cover gaps in 

evidence, gaps that exist in part because of lack of information on exposures received by military personnel and inadequate surveillance of veterans 

for service-related illnesses. Secrecy is a particularly troubling source of 

incomplete information, as illustrated by the veterans who participated in 

studies of mustard gas and lewisite. Research carried out directly on the 

health of veterans has proved useful in some instances, leading to a decision, for example, on granting disability compensation for cardiovascular 

disease in amputees. But the research has not been systematic, and in the 

example of cardiovascular disease in amputees no further evidence relevant 

to a presumption made in 1979 has been collected. Research on radiation 

risks in veterans has been severely constrained by a lack of dose information, and the studies on radiation-exposed veterans have not been highly 

informative. 

Across the case studies, the Committee found variable approaches to 

synthesizing evidence on the health consequences of military service. The 

inferential target of scientific evidence reviews has not been consistent 
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14 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

and varied between causation (e.g., mustard gas and lewisite, Gulf War) 

and association alone (e.g., Agent Orange). The more recent IOM Agent 

Orange reports have emphasized findings of observational studies on association and interpretation that might have been enhanced by placing the 

findings within a biological framework strengthened by greater attention 

to other lines of evidence. In the Agent Orange case studies, the category 

“limited/­suggestive” for classifying evidence for association has been used 

for a broad range of evidence from indicating the mere possibility of an 

association to showing that an association is possibly causal. The “limited/

suggestive” evidence of association—on which the VA’s presumptive decisions to compensate type 2 diabetes and prostate cancer were made—may 

be below the level of certainty needed to support causation absent strong 

mechanistic understanding or to meet the congressional language of “if the 

credible evidence for the association is equal to or outweighs the credible 

evidence against the association,” which the Committee refers to “at least 

as likely as not.”

Both prostate cancer and type 2 diabetes illustrate situations in which 

the contribution of military exposures should be assessed against a background of disease risk that has other strong determinants: age in the case 

of prostate cancer and family history and obesity in the case of type 2 

diabetes, as indicated by the IOM committee in its report (IOM, 2000b). 

For both type 2 diabetes and prostate cancer, the magnitude of the relative risks observed for pesticide exposure implies that the contribution of 

military exposures is likely to be small in comparison to those of the other 

contributing factors. In such circumstances, an estimation of the proportion of cases attributable to military exposures could be helpful to the VA 

in considering whether or not to presumptively service-connect disabilities. 

The Committee recognizes that development of such estimations is a complicated process dependent on acquiring better exposure data, which may 

not be available for some period of time.

In the case studies, the Committee’s analyses were based on the very 

general information provided by VA about its internal decision-making processes. The case studies and VA’s decision to withhold documents related to 

specific decisions from the Committee did make clear, however, that these 

processes are not fully transparent. VA believes that access to predecisional 

documents by outside sources could stifle candid staff discussions on issues. 

Once IOM carries out its reviews and provides VA with reports documenting the extent of evidence available on associations, the internal processes 

of VA that follow are not fully open to scrutiny. This closed process could 

reduce trust of veterans in the presumptive disability decision-making process and may hinder efforts to optimize the use of scientific evidence. The 

Committee also found inconsistency in the decision-making process.
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SUMMARY 15

SCIENTIFIC FOUNDATION FOR 

PRESUMPTIVE DISABILITY DECISION MAKING

In developing a future approach for presumptive disability decision 

making, the Committee first gave extensive consideration to causal inference and the processes used to make causal judgments. In other words, 

the Committee considered how scientific evidence is used to determine if

exposure causes some disease. These determinations are generally made 

by expert committees that examine all relevant evidence for strengths and 

weaknesses and then synthesize the evidence to make a summary judgment. 

The Committee defines “exposure” in a broad manner to include chemical, biological, infectious, physical, and psychological stressors. The Committee recognizes that psychological stressors may be particularly difficult 

to describe, let alone measure and quantify.

The Committee then considered the quantification of the contribution 

of a particular exposure to disease causation. This second issue addresses 

the question of how much of the observed disease in a group, in both absolute and relative terms, is caused by the exposure. 

Provision of compensation to veterans on a presumptive basis, or to 

any other group that has been injured, requires a general decision as to 

whether the agent or exposure of concern has the potential to cause the 

condition or disease for which compensation is to be provided in at least 

some indi­viduals, and a specific decision as to whether the agent or exposure has caused the condition or disease in a particular individual. The 

determination of causation in general is based in a review and evaluation of 

all relevant evidence including (1) data on exposures of military personnel 

during service; (2) evidence on risks for disease coming from observational 

(epidemiologic) studies of military personnel; (3) other relevant epidemiologic evidence, including findings from studies of nonmilitary populations 

exposed to the agent of interest or similar agents; and (4) findings relevant 

to plausibility from experimental and laboratory research. The determination of causation in a particular case is based first on the general determination as to whether the exposure can cause disease, then on information 

about the exposures of the individual being evaluated for compensation, 

and on any other relevant information about the individual. 

The Committee considered the properties of a decision-making process, recognizing the possibility of two types of systematic errors: making a 

decision to compensate when the exposure has not caused the illness (false 

positive) and to not compensate when the exposure has actually caused 

the illness (false negative). The Committee recommends that any decision 

process consider the trade-off between these two errors and attempt to 

optimize both the sensitivity (i.e., minimize the false negatives) and the 

specificity (i.e., minimize the false positives). Generally, higher sensitivity 
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16 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

cannot be achieved without lower specificity. These errors have costs. False 

positive errors result in the expenditure of funds for cases of disease not 

caused by military service while false negative errors leave deserving veterans uncompensated. The appropriate balancing of these costs also needs 

consideration.

The Committee considered ways to classify evidence, reaching the 

conclusion that a broader and more inclusive evidence review process is 

needed. It found that IOM reviews could be enhanced if a broader array 

of epidemiologic and other evidence (e.g., animal and mechanistic data) 

was considered. The Committee also found that the target of inference had 

varied from causation (e.g., mustard gas and lewisite, Gulf War) to association (e.g., Agent Orange). Consequently, the Committee recommends 

that categories of evidence for reviews be established to make clear those 

relationships that are at least as likely as not to be causal. The Committee has concluded that a categorization of evidence is needed that gives a 

scientifically coherent rendering of the language employed by Congress in 

calling for review of available scientific evidence. The Committee proposes 

a four-level hierarchy that classifies the strength of evidence for causation, 

not just association, and that incorporates the concept of equipoise: that is, 

whether the weight of scientific evidence makes causation at least as likely 

as not in the judgment of the reviewing group. 

The Committee also gave consideration to the quantification of the 

burden of disease attributable to an exposure. This quantification would 

be made to provide an evaluation of the numbers of veterans to be compensated, but it would not be a component of the evidence evaluation for 

causation. For the purpose of quantification, the attributable risk, termed 

the service-attributable fraction, can be calculated if the needed information 

is available on the relative risk of disease among exposed individuals. For 

those exposures meeting the necessary level of evidence for compensation, 

the Committee recommends that the service-attributable fraction should be 

estimated overall and for subgroups of veterans, perhaps grouped by level 

of exposure, if the requisite data are available. Until more complete exposure information becomes available in the future, such calculations may not 

be possible for all conditions for which presumptions are made.

COMMITTEE’S RECOMMENDED APPROACH FOR THE FUTURE

Overview

The Committee’s recommended approach for the future (Figure S-2) 

has multiple new elements: a process for proposing exposures and illnesses 

for review; a systematic evidence review process incorporating a new evidence classification scheme and quantification of the extent of disease 
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SUMMARY 17

Research/

Surveillance a

Stakeholder

Nominations b

Science Review

Boardd

VA Compensation

Decision Process

Advisory Committeec

Decisione

VA Secretary

VA Secretary

Report 

Charge 

Recommendations 

Initiates presumption 

consideration process 

FIGURE S-2

Vertical arrows have been shortened.

There is now a little over an inch of extra 

space at the bottom of 6 x 9 page

If more space is needed the figure will be

reduced in size in the page layout process

FIGURE S-2 Proposed framework for future presumptive disability decision-­making 

process for veterans.

a Includes research for classified or secret activities, exposures, etc. 

b Includes veterans, Veterans Service Organizations, federal agencies, scientists, 

general public, etc.

c

 This committee screens stakeholders’ proposals and research in support of evaluating evidence for presumptions and makes recommendations to the VA Secretary 

when full evidence review or additional research is appropriate. 

d The board conducts a two-step evidence review process (see report text for further 

detail).

e Final presumptive disability compensation decisions are made by the Secretary, 

Department of Veterans Affairs, unless legislated by Congress.
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18 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

attributable to an exposure; a transparent decision-making process by VA; 

and an organizational structure to support the process. The Committee also 

calls for comprehensive tracking of exposures of military personnel and 

monitoring of their health while in service and subsequently.

Organizational Structure

The Committee recommends the creation by Congress of two new permanent boards: the Advisory Committee, serving in an advisory capacity to 

VA, and the Science Review Board (independent from VA). The Advisory 

Committee would consider the exposures and illnesses that might be a basis 

for presumptions and recommend to the VA Secretary exposures and illnesses needing further consideration. It would also consider research needs 

and assist VA with strategic research planning. The Science Review Board 

would evaluate the evidence for causation and, if warranted, estimate the 

service-attributable fraction of disease in veterans. One critical element 

in the deliberations of the Science Review Board would be evidence from 

monitoring the exposures and health of the veterans. The Science Review 

Board would provide VA with input for its presumptive decisions, including a summary report of the available scientific evidence in a standardized 

classification scheme. 

Congress and VA may find alternative processes to achieve the overall 

objective of the Committee’s recommendations: an evidence-based approach 

to making presumptive disability decisions. The Committee recognizes that 

specific elements of its proposal (e.g., the call for carrying out exposure 

assessments and making exposure estimates) are not yet fully practicable 

and would take time to develop and implement. However, future methodologic developments should enhance the feasibility of some of the challenging 

elements of this proposal. The Committee believes that this proposal can 

significantly improve the presumptive disability decision-making process 

for veterans and, therefore, the process for implementing it should begin 

without delay. 

Underlying Principles

VA’s decision to make a presumption may involve weighing difficult and 

incomplete scientific evidence, in the context of veterans’ concerns and society’s obligations to the affected veterans, and potential costs. Although the 

potential complexity of the decision-making process may make a complete 

codification difficult, the underlying principles can be clearly expressed. 

The Committee suggests the following six principles as a foundation for its 

proposed framework: (1) stakeholder inclusiveness; (2) evidence-based decisions; (3) transparent process; (4) flexibility; (5) consistency; and (6) using 
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SUMMARY 19

causation, not just association, as the basis for decision making. Flexibility 

and consistency are not contradictory constructs here. Flexibility refers to 

the ability to be adaptable through time in evaluating scientific evidence, 

and consistency refers to being consistent in the process of evaluating 

evidence and making consistent decisions based on a comparable level of 

certainty based on the scientific evidence.

Proposals to Review for Potential Presumption

In this process, conditions and causative agents or circumstances would 

be proposed for review based on evidence of a connection between the 

condition and military service and evidence that a sizable or well-defined 

group of veterans is likely to be affected. The possibility of a need for a 

presumption might arise from surveillance of veterans or active military 

personnel, laboratory research discoveries, or findings from studies of 

exposed workers. The process would be open, with proposals accepted 

from any source (e.g., veterans, veterans’ families, VSOs, VA, DoD, other 

governmental bodies, researchers, the general public). Proposals accepted 

by the VA Secretary would be sent to the Science Review Board for full, 

comprehensive scientific evaluation. 

Science Review Board

The Committee recommends a two-step process for scientific evaluation by the Science Review Board. The first step would involve a systematic 

review of all relevant data to decide the strength of evidence for causation, 

using one of four categories:

1. Sufficient: The evidence is sufficient to conclude that a causal relationship exists.

2. Equipoise and Above: The evidence is sufficient to conclude that a 

causal relationship is at least as likely as not, but not sufficient to conclude 

that a causal relationship exists. 

3. Below Equipoise: The evidence is not sufficient to conclude that a 

causal relationship is at least as likely as not, or is not sufficient to make a 

scientifically informed judgment.

4. Against: The evidence suggests the lack of a causal relationship.

 If the evidence for causation were categorized as Sufficient or at Equipoise and Above, then we anticipate that VA would consider a presumptive 

service connection based upon causal evidence categorization and its consideration of the service-attributable fraction if available (to be estimated 

in the second step of the process, described below). As is current VA policy, 
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20 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

if the evidence is at Equipoise, the benefit of the doubt would be given to 

the veteran. If the evidence were categorized as Against, then we anticipate 

that VA would not consider a presumptive service-connection. If, however, 

the evidence were categorized as Below Equipoise, then we anticipate that 

VA would, after carefully considering the prospects and recommendations 

for future research, decide on an appropriate time frame for the subsequent 

scientific review of the evidence, with the expectation that the evidence 

would then be sufficient to resolve matters either for or against the causal 

claim at that time. Such information would be considered by the Advisory 

Committee serving in its capacity as overseer of the overall process and 

advisor to the VA Secretary. 

If the VA Secretary were to decide that a presumption would not be 

established for evidence categorized as Below Equipoise or, for other reasons, for evidence categorized as Equipoise and Above, then during the 

period of further evidence development and gathering and prior to the 

subsequent scientific review of the evidence, VA should consider providing 

some support to potentially affected veterans, such as providing provisional 

access to medical care. 

As evidence accumulates, the balance might move to strengthen or 

to weaken the case for causality. Importantly, the Science Review Board 

should be free to upgrade the level of evidence, to downgrade the level of 

evidence, or to leave it as the same categorization. For evidence that has 

reached the classification of Sufficient, we would not anticipate a potential 

lowering of the classification, if the original determination was correctly 

made and based on sound scientific evidence. 

If the strength of the evidence reaches Sufficient or Equipoise and 

Above, then the evaluation would move to step two, the calculation of the 

service-attributable fraction of disease when required data and information are available. This calculation is independent of the classification of 

the strength of evidence for causation, and the magnitude of the serviceattributable fraction is not considered in the application of the four-level 

schema for categorizing evidence. Rather, the service-attributable fraction 

would be of value for decision making, giving an understanding of the 

scope of the population to be covered by a presumption. 

In step two, the Science Review Board would consider the extent of 

exposure among veterans and subgroups of veterans, as well as doseresponse relationships. When such information is available, the board 

would estimate the service-attributable fraction and its related uncertainty. 

The purpose of step two is to convey the impact of the exposure on veterans 

as a whole for the purpose of decision making and planning, but not to 

serve inappropriately as an estimate of probability of causation for individuals. Some exposures may contribute greatly to the disease burden of 

veterans, while other exposure (even with a known causal effect) may have 
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SUMMARY 21

a small impact overall. This additional information would be useful to VA 

in its decision making as to whether a presumption should be made for the 

veteran population in general, for subgroups, or not at all. In the absence 

of service-attributable fraction data, as will likely occur for many exposures 

over the short term, we assume the VA would consider presumptions on the 

information contained in step one. 

Expanding the Evidence Base

In the Committee’s view, the best scientific decisions about presumptions can be made only with comprehensive exposure and health surveillance of military personnel. Data collection should begin on entry into the 

military and continue through discharge, and when harmful exposures are 

suspected surveillance should be extended indefinitely. Surveillance refers 

to the ongoing collection, analysis, and use of data relevant to the health 

of a population. Elements of a surveillance system are already in place, but 

fall short of what is required. A fully functioning surveillance system would 

track military exposures and health outcomes, during military service and 

after discharge, and maintain a repository of data and biological specimens 

so that emerging and unanticipated questions could be retrospectively 

addressed. The system needs to be seamless in following military personnel, 

including National Guard and reservists, from active duty as they transition 

and become civilians. 

This surveillance system should also track job and deployment history 

for each Service member through the period of service, with exposure 

assessment and monitoring for a range of job categories. Information on 

disease risk factors more generally could also be tracked. Use of personal 

biological samples for individual monitoring also holds promise.

Assessing exposures relevant to the neuropsychiatric disorders that 

are frequent among veterans of recent and current combats is particularly 

problematic. Documentation of stress is requisite to the diagnosis of posttraumatic stress disorder (PTSD), but approaches for capturing exposures to 

such stressors and to the circumstances of combat have not yet been developed and put into place. Research is needed for this purpose that builds on 

existing approaches so that data become available over the long-term. 

In addition to surveillance, the Committee recommends an effort to 

coordinate and focus research on the health effects of military exposures. 

Associations identified in the surveillance data might need follow-up through 

more focused epidemiologic studies or exposure assessments. Toxicological 

research might be indicated to explore the mechanistic basis for an association between an exposure and a health condition.
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22 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

VA Procedures

Ultimately, the decision regarding which proposed topics for potential 

presumptions deserve full evaluation resides with VA. In the Committee’s 

proposed process, VA also receives scientific input from the Science Review 

Board. We recommend that VA establish a uniform and transparent process 

for making decisions regarding presumptions following receipt of evidence 

reviews. VA should establish procedures with input from the many stakeholders, and a clear, evidence-based rationale should be offered for all decisions. The Committee’s recommendations are aimed at providing a sound 

scientific framework for the presumptive disability decision-making process. 

The Committee clearly recognizes that there are social, economic, political, 

and legal factors beyond the scope of scientific evidence that may influence 

the presumptive disability decision-making process for veterans and the 

presumptive decisions that are established by Congress and VA.

Scientific evidence is not static, and it often is less than certain. Given 

that the scientific basis for presumptive decisions will change over time, the 

Committee recommends that VA should be able to adjust future decisions 

when such change is scientifically justified. This does not mean that the Committee recommends that benefits previously granted should be terminated. 

The Committee is aware that disabled veterans and their families are often 

dependent on such payments and that it could create a hardship to remove 

them, a matter that VA disability policy recognizes in other situations.

SPECIFIC RECOMMENDATIONS

Based on its evaluation of the current process for establishing presumptive disability decisions and its consideration of alternatives, the Committee 

has specific recommendations for an approach that would build stronger 

scientific evidence into the decision-making process and, at the same time, 

be even more responsive and open to veterans. We propose a transformation of the current presumptive disability decision-making process. We recognize that considerable time would be needed to implement some of these 

recommendations as would additional investment to create systems needed 

to track exposures and health status of currently serving military service 

personnel and veterans. Progress depends on greater research capacity and 

improvements in the evaluation and utilization of scientific evidence in making compensation decisions. We find that there are elements of the current 

process that could be changed quickly and we recommend that VA consider 

prompt action as it moves toward implementation of a new approach. The 

recommendations that follow are based around the Committee’s proposed 

framework for making presumptive decisions. We list the recommendations 

in relation to the appropriate body. 
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SUMMARY 23

Congress

Recommendation 1. Congress should create a formal advisory committee (Advisory Committee) to VA to consider and advise the VA 

Secretary on disability-related questions requiring scientific research 

and review to assist in the consideration of possible presumptions.

Recommendation 2. Congress should authorize a permanent independent review body (Science Review Board) operating with a well-defined 

process that will use evaluation criteria as outlined in this Committee’s 

recommendations to evaluate scientific evidence for VA’s use in considering future service-connected presumptions.

Department of Veterans Affairs

Recommendation 3. VA should develop and publish a formal process 

for consideration of disability presumptions that is uniform and transparent and clearly sets forth all evidence considered and the reasons 

for the decisions reached.

Science Review Board

The recommendations that follow are directed towards the proposed, 

future Science Review Board, the entity to be established in the Committee’s 

proposed approach.

Recommendation 4. The Committee recommends that the goal of the 

presumptive disability decision-making process be to ensure compensation for veterans whose diseases are caused by military service and 

that this goal must serve as the foundation for the work of the Science 

Review Board. The Committee recommends that the Science Review 

Board implement its proposed two-step process.

Recommendation 5. The Committee recommends that the Science 

Review Board use the proposed four-level classification scheme, as 

follows, in the first step of its evaluation. The Committee recommends 

that a standard be adopted for “causal effect” such that if there is at 

least as much evidence in favor of the exposure having a causal effect 

on the frequency or severity of disease as there is evidence against, then 

a service-connected presumption will be considered.

1. Sufficient: The evidence is sufficient to conclude that a causal relationship exists.
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24 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

2. Equipoise and Above: The evidence is sufficient to conclude that a 

causal relationship is at least as likely as not, but not sufficient to 

conclude that a causal relationship exists. 

3. Below Equipoise: The evidence is not sufficient to conclude that a 

causal relationship is at least as likely as not, or is not sufficient to 

make a scientifically informed judgment.

4. Against: The evidence suggests the lack of a causal relationship.

Recommendation 6. The Committee recommends that a broad spectrum of evidence, including epidemiologic, animal, and mechanistic 

data, be considered when evaluating causation. 

Recommendation 7. When the causal evidence is at Equipoise and 

Above or Sufficient, the Committee recommends that an estimate also 

be made of the size of the causal effect among those exposed. 

Recommendation 8. The Committee recommends that, as the second 

part of the two-step evaluation, the relative risk and exposure prevalence be used to estimate an attributable fraction for the disease in the 

military setting (i.e., service-attributable fraction).

Department of Defense and Department of Veterans Affairs

The following recommendations are intended to improve the evidence 

on exposures and health status of veterans:

Recommendation 9. Inventory research related to the health of veterans, 

including research funded by DoD and VA, and research funded by the 

National Institutes of Health and other organizations.

Recommendation 10. Develop a strategic plan for research on the 

health of veterans, particularly those returning from conflicts in the 

Gulf and Afghanistan.

Recommendation 11. Develop a plan for augmenting research capability 

within DoD and VA to more systematically generate evidence on the 

health of veterans.

Recommendation 12. Assess the potential for enhancing research 

through record linkage using DoD and VA administrative and health 

record databases.
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SUMMARY 25

Recommendation 13. Conduct a critical evaluation of Gulf War troop 

tracking and environmental exposure monitoring data so that improvements can be made in this key DoD strategy for characterizing exposures during deployment.

Recommendation 14. Establish registries of Service members and 

veterans based on exposure, deployment, and disease histories.

Recommendation 15. Develop a plan for an overall integrated surveillance strategy for the health of Service members and veterans. 

Recommendation 16. Improve the data linkage between the electronic 

health record data systems used by DoD and VA—including capabilities 

for handling individual Service member exposure information that is 

included as part of the individual’s health record.

Recommendation 17. Ensure implementation of the DoD strategy for 

improved exposure assessment and exposure data collection.

Recommendation 18. Develop a data interface that allows VA to access 

the electronic exposure data systems used by DoD.

Recommendation 19. DoD and VA should establish and implement 

mechanisms to identify, monitor, track, and medically treat individuals 

involved in research and other activities that have been classified and 

are secret.

REFERENCES

IOM (Institute of Medicine). 1994. Veterans and Agent Orange: Health effects of herbicides 

used in Vietnam. Washington, DC: National Academy Press. 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy 

Press. 

IOM. 1999. Veterans and Agent Orange: Update 1998. Washington, DC: National Academy 

Press. 

IOM. 2000a. Gulf War and health, volume 1: Depleted uranium, pyridostigmine bromide, 

sarin, vaccines. Washington, DC: National Academy Press. 

IOM. 2000b. Veterans and Agent Orange: Herbicide/dioxin exposure and type 2 diabetes. 

Washington, DC: National Academy Press. 

IOM. 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy 

Press. 

IOM. 2003a. Gulf War and health, volume 2: Insecticides and solvents. Washington, DC: The 

National Academies Press. 
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26 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

IOM. 2003b. Veterans and Agent Orange: Update 2002. Washington, DC: The National 

Academies Press. 

IOM. 2005a. Gulf War and health, volume 3: Fuels, combustion products, and propellants. 

Washington, DC: The National Academies Press. 

IOM. 2005b. Veterans and Agent Orange: Update 2004. Washington, DC: The National 

Academies Press. 

IOM. 2006. Gulf War and health, volume 4: Health effects of serving in the Gulf War. Washington, DC: The National Academies Press. 

IOM. 2007. Gulf War and health, volume 5: Infectious diseases. Washington, DC: The 

National Academies Press. 

Pamperin, T. J. 2006. An overview of the Disability Benefits Program and presumptions affecting veterans’ benefits. Paper presented at the first meeting of the IOM’s Committee 

on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans, 

Washington, DC. 

VBA (Veterans Benefits Administration). 2006. Annual benefits report fiscal year 2005. http://

www.vba.va.gov/bln/dmo/reports/fy2005/2005_abr.pdf (accessed February 26, 2007).

VDBC (Veterans Disability Benefits Commission). 2006. Statement of the Veterans’ Disability 

Benefits Commission to the IOM’s Committee on Presumptive Disability DecisionMaking Process. Washington, DC: VDBC. 

Zeglin, D. E. 2006. Presumptions of service connection. Paper prepared for the Veterans’ Disability Benefits Commission. https://www.1888932-2946.ws/vetscommission/

e-documentmanager/gallery/Documents/Reference_Materials/Presumption-Paper_3-7-

06.pdf (accessed March 8, 2007).
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27

1

Introduction

Veterans and their families have served the American people and our 

country in ways that cannot easily be summarized or measured. Our nation 

has long recognized and honored military veterans’ service and sacrifices. 

From the very beginning, benefits have been provided to those whose illnesses were incurred or aggravated by their military service. Ascertaining 

whether an illness is service connected is not unduly difficult when the illness emerges while the person is engaged in military service. But when an 

adverse health effect becomes manifest after military service, at times many 

years later, determining and proving a service connection may raise complex 

scientific and policy questions. 

Presumptions enable veterans to be granted service connection who, 

through no fault of their own, are unable to establish that the injury was 

caused by their military service. Since 1921, Congress and the Department 

of Veterans Affairs (VA) have created numerous presumptions to assist 

veterans in establishing that they have a service-connected disease entitling 

them to disability payments (see Appendix D for an historical overview). 

Much has happened since 1921 that has made the presumptive disability decision-making process more critical and complex. Fortunately, 

a far greater percentage of service men and women are surviving combat 

injuries, and the life expectancy of all veterans has greatly increased. As a 

result, disability payments are made for much longer periods, and recipients 

may develop medical complications that were much less frequent when presumptions were first employed. In addition, warfare has changed. Service 

personnel are subjected to numerous new types of exposures, about some 

of which we know very little. On the other hand, we understand a good 
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28 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

deal more now about disease processes because of recent research based in 

epidemiology, toxicology, and genetics. This report proposes a framework 

for presumptive disability decision making that would employ our best 

scientific understanding while protecting the interests of veterans and other 

stakeholders by including them in the decision-making process. It provides 

findings from a committee convened to assess the current approach of the 

presumptive disability decision-making process for veterans and to provide 

a framework for a future approach. The committee was appointed by the 

Institute of Medicine (IOM) of the National Academies at the request of a 

special congressional commission (see below). 

VETERANS’ DISABILITY BENEFITS COMMISSION

The Veterans’ Disability Benefits Commission (Commission) was created 

by the National Defense Authorization Act of 2004 (Public Law 108-136. 

108th Cong., 1st Sess.). The Commission is charged with “studying the 

benefits provided to compensate and assist veterans for disabilities attributable to military service. The Commission was mandated to consult with 

the Institute of Medicine (IOM) of the National Academy of Sciences with 

respect to the medical aspects of contemporary disability compensation policies” (VDBC, 2006, p. 1; as found in Appendix A). The Commission was 

asked to evaluate and assess the following:

• The appropriateness of benefits

• The appropriateness of the level of those benefits

• The appropriate standard(s) for determining whether the disability 

should be compensated (VDBC, 2006, p. 1; as found in Appendix A) 

To meet its goals, “the Commission produced a list of 31 research 

questions to be answered during its investigation” (VDBC, 2006, p. 1; as 

found in Appendix A). The Commission requested two studies from IOM. 

This report will address the issue of presumptions. Another committee, 

the Committee on Medical Evaluation of Veterans for Disability Compensation, issued a report entitled A 21st Century System for Evaluating 

Veterans for Disability Benefits, in June 2007. That report made recommendations to the Commission on how several components of VA’s medical evaluation and disability rating process for veterans could be updated 

and improved. 

The independent Commission “consists of 13 members who were 

appointed by the President and the leaders of Congress” (VDBC, 2006, 

p. 1; as found in Appendix A) and is funded by VA. Twelve of the commissioners have served in the military. Nine members have combat experience. 

“The Commission is charged to submit its report by October 1, 2007, to 
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INTRODUCTION 29

the President and Congress” (VDBC, 2006, p. 1; as found in Appendix A). 

The Commission’s website is www.vetscommission.org.

IOM COMMITTEE CHARGE AND APPROACH

In response to a request from the Veterans’ Disability Benefits Commission, IOM constituted the Committee on Evaluation of the Presumptive 

Disability Decision-Making Process for Veterans (Committee). To address 

the charge from the Commission, IOM assembled 14 full committee members, 1 volunteer scientific consultant, and 1 paid consultant—all with 

diverse backgrounds and expertise. The Committee’s website is www.iom.

edu/pddm.

As the independent Commission does not have its own funding source, 

this study was funded by VA. The task order description provided by VA 

is to (1) describe and evaluate the current model used to recognize diseases 

that are subject to service connection on a presumptive basis; and (2) if 

appropriate, propose a scientific framework that would justify recognizing 

or not recognizing conditions as presumptive.

The Committee gained many insights from a four-page statement clarifying the task order that was presented to the Committee at its first meeting by Commissioner John Grady (Grady, 2006; VDBC, 2006; as found in 

Appendix A). The statement emphasized that the granting of a presumptive service connection be “based on the best scientific evidence available” 

(VDBC, 2006, p. 4; as found in Appendix A). The Commission asked the 

Committee to “evaluate the current model used to determine diseases that 

qualify for service connection on a presumptive basis, and if appropriate, propose improvements in the model” (VDBC, 2006, p. 1; as found 

in Appendix A). The Commission emphasized that “having a method of 

granting service connection quickly and fairly based on a presumption is of 

critical importance to our disabled veterans and their surviving spouses,” 

and asked the Committee to consider process improvements to address the 

long periods of elapsed time before presumptions are established (VDBC, 

2006, pp. 3-4; as found in Appendix A). 

During the first meeting, the Committee asked questions of the commissioners to further clarify the charge. In responding, the Commission 

indicated that it did not expect a full, exhaustive review of all presumptions 

established since 1921 and that a review of case studies would facilitate 

the Committee’s understanding of the current process. The Commission 

also clarified the scope of the evaluation, indicating that it would like the 

Committee to evaluate all participants in the current process—including 

Congress, VA, IOM, veterans stakeholders, and any others—and to thoroughly assess the processes currently used to make presumptions, as well as 

in the past, since an understanding of past processes would be instructive in 
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30 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

considering possible future processes (as stated during Commission Panel 

discussion on May 31, 2006; VDBC, 2006, as found in Appendix A). The 

Committee approached the review of present and past processes and practice, including the roles and responsibilities of the different parties involved, 

through a series of case studies (see Appendix I). The Commission asked 

if there should “be a defined process in place at VA to review and establish presumptions” and if “the same or a different process should be used 

periodically to review existing presumptions” (VDBC, 2006, p. 3; as found 

in Appendix A). The Committee deliberated the case studies to learn the 

past processes of presumptive decisions and to develop its proposed framework for the future of the presumptive disability decision-making process. 

At the heart of such processes are the principles used by participants 

for evaluating evidence on whether or not an effect was caused by military 

service. The Commission therefore asked about the “amount of increase 

in occurrence rate . . . to warrant compensation” and for “advice, from 

an epidemiologic and statistical standpoint, on what strength of evidence 

would be the appropriate requirement when the Secretary of Veterans 

Affairs considers whether to establish a presumption” (VDBC, 2006, p. 3; 

as found in Appendix A). These requests address considerations of magnitude of risk and strength of evidence in making presumptive decisions, 

and the methodology used in determining causal relationships. These issues 

became a cornerstone for future Committee discussions regarding the use of 

causation versus association, interpretation of population versus individual 

risks, and use of attributable fraction or probability of causation for compensation purposes.

An important legal definition the Committee discussed throughout the 

study process was that “an association is considered ‘positive’ if the credible 

evidence for the association is equal to or outweighs the credible evidence 

against the association” (VA, 1996, p. 41368). This legal definition was an 

important part of deliberations for the Committee and became the foundation for the Committee’s proposed strength of evidence categories. 

Finally, the Commission asked the Committee to address some specific 

issues. First, several presumptions have been established “because it was 

not possible to document exposure to biological, chemical, radiological, or 

other environmental agents by accurate information on the exact locations 

to which military [S]ervice members were assigned during precise periods 

of time” (VDBC, 2006, p. 2; as found in Appendix A). The Commission 

stated the Committee “may be able to provide substantive advice concerning how to ensure that this situation is not repeated in the future” (VDBC, 

2006, p. 3; as found in Appendix A). Second, in its statement, the Commission asked if the case of Vietnam veterans with diabetes and prostate 

cancer was fully supported by medical evidence for these presumptions 

(VDBC, 2006; as found in Appendix A). When the Committee questioned 
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INTRODUCTION 31

the commissioners whether the intent was for the Committee to reevaluate 

the body of evidence for these presumptions, it was determined that this 

was beyond the charge of the Committee (as stated during Commission 

Panel discussion on May 31, 2006; VDBC, 2006; as found in Appendix 

A). However, the Committee did decide to include these two presumptions 

as part of the case study series to learn more about the processes that put 

these presumptions in place.

INFORMATION GATHERING BY THE COMMITTEE

The Committee engaged in extensive information gathering while conducting its inquiries. This enabled the Committee to develop the case study 

series, review the work and processes of VA and of the National Academies’ (IOM and National Research Council [NRC]) committees, consider 

congressional mandates and intent, consider future possible approaches 

for making presumptions, and review the underlying current and planned 

Service member and veteran surveillance systems at the Department of 

Defense (DoD) and VA that could support the presumptive decision-making 

process. The Committee collected and reviewed hundreds of public laws, 

congressional committee reports, federal government reports, National 

Academies’ (IOM and NRC) reports, as well as other documents.

The Committee also held three open session meetings—on May 31, 

July 27, and October 4, 2006—for information gathering purposes. The 

agendas for these meetings may be found in Appendix B. The Committee 

heard from the key participants in the presumptive disability decisionmaking process for veterans during these meetings—past and present 

congressional staff, VA representatives, IOM representatives, DoD representatives, veterans service organizations (VSOs), veterans, and the general 

public. Among the VSOs the Committee heard from were the American 

Legion, AMVETS, NAM-POWS Corporation, Non-Commissioned Officers Association, Texas Veterans Commission, United Spinal Association, 

Veterans for America, Veterans of Foreign Wars of the United States, and 

Vietnam Veterans of America. The individuals who participated are noted 

in the acknowledgments. 

To better and more clearly understand VA’s process and how it uses the 

National Academies’ (IOM and NRC) reports, the Committee asked VA for 

task force reports, working group documents, and cost estimate documents 

that related to specific, past presumptive decisions. VA declined the request 

to release these documents on the basis of the predecisional nature of the 

documents (Mansfield, 2006). As an alternative, VA offered to respond to 

questions offered by the Committee. A list of questions was prepared in 

writing by the Committee. VA did not respond to all of the Committee’s 

questions and cited similar reasons for not responding as were expressed 
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32 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

previously with regard to release of VA’s task force documents (Dunne, 

2006). 

Availability of VA Documents

The IOM Committee sought to review VA’s decision-making documents 

to better understand the factors considered in making recommendations by 

the working group and task force. These were not made available because 

VA considered them to be predecisional and possibly sensitive. As an alternative, VA prepared a white paper (found in Appendix G) that provides 

a general description of VA’s decision process following the receipt of an 

IOM report on Agent Orange or the Gulf War. VA also offered to respond 

to Committee questions regarding VA’s presumptive decision-­making procedures. The Committee submitted questions, and VA responded to several 

but not all of them (VA, 2006). In a letter to the Committee Chair, VA 

explained it was reluctant to respond to some of the questions for the 

following reasons:1

• The requested answers would cause VA to describe the contents of 

memoranda and notes of internal meetings that are pre-decisional, 

and reflective of internal deliberations of VA personnel who advise the 

Secretary of Veterans Affairs on matters of policy and law.

• In order to ensure that the Secretary receives the best possible advice, 

VA personnel must remain free to engage in vigorous discussion of 

important issues facing the Department without the constraints that 

necessarily would apply, if their deliberations were subject to external 

review.

• Statements made in the context of robust deliberations, if viewed apart 

from that context, may be misconstrued or misrepresented.

• The possibility of public disclosure may inhibit free discussion in future 

deliberations and needlessly limit the thorough and thoughtful consideration that must attend the formulation of policies affecting our 

Nation’s veterans.

• Providing the requested answers to the Presumptions Committee may 

effectively waive any protections VA would have against broader public 

disclosure of this pre-decisional information.

It should be noted that the Committee offered to receive redacted documents in accordance with the provisions of the Freedom of Information 

Act, but that offer was not accepted by VA. Similar reasons were given for 

not providing working group and task force reports to the Committee. In 

a separate letter to IOM, the Deputy Secretary of Veterans Affairs, Gordon 

1Personal communication, P. W. Dunne, Department of Veterans Affairs, December 2006.
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INTRODUCTION 33

H. Mansfield, indicated VA was “concerned that statements made in the 

context of robust deliberations, if viewed apart from that context, may be 

misconstrued or misrepresented for purposes of litigation or other ends.”2

The Committee believes that this report has been limited to some degree 

by lack of access to requested documents, to an extent we cannot assess 

without actually seeing the documents.

ORGANIZATION OF THE REPORT

This report is organized into 13 chapters with supporting appendixes. 

Chapters 2 through 5 address the historical and current presumptive disability decision-making process for veterans and describe how it is working. 

An overview of presumptive disability decisions established by Congress 

and VA since 1921 is found in Chapter 2. Chapter 3 describes the current 

presumptive disability decision-making process, and the roles of Congress, 

VA, and IOM. The legislative background pursuant to the more current 

presumptions of Radiation, Agent Orange, and Gulf War is included in 

Chapter 4. Chapter 5 summarizes the past and current practices found in 

the Committee’s 10 case studies (see Appendix I):

• Mental Disorders’ Presumptions

• Multiple Sclerosis Presumption

• Prisoners of War Presumptions

• Amputees and Cardiovascular Disease Presumption

• Radiation Presumptions

• Mustard Gas and Lewisite Presumptions

• Gulf War Presumptions

• Agent Orange and Prostate Cancer Presumption

• Agent Orange and Type 2 Diabetes Presumption 

• Spina Bifida Program (VA program but not a presumption) 

The lessons learned from these case studies provided valuable insights 

into past and current processes, as well as presenting opportunities for 

process improvements by all participants in the presumptive disability 

decision-making process.

The second part of the report (Chapters 6-13) focuses on methodological aspects of the process, laying the foundation for a path forward, and 

proposes a process for establishing presumptions in the future. Following 

an overview of an evidence-based framework for making presumptive decisions in Chapter 6, Chapters 7 and 8 lay the groundwork for developing 

2 Personal communication, G. H. Mansfield, Department of Veterans Affairs, December 

2006.
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34 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

methods to consider whether a substance or exposure may cause a specific 

health condition of concern. Chapter 9 then focuses on to what extent military service could be responsible for a specific health condition in veterans 

(in general or in a group of veterans)—taking as a given that an exposure 

during military service can cause the illness. Accurate evidence is critical for 

the process of conducting the assessments discussed in Chapters 7 through 

9. Chapter 10 summarizes health and exposure data systems within DoD 

for collecting exposure, incidence, and health status information during 

service, and within VA and other organizations for following military 

personnel after they leave service and through the remainder of their lives. 

Chapter 10 offers suggestions for improved research and surveillance to 

better support the presumptive disability decision-making process. Secrecy 

leads to gaps in evidence, and Chapter 11 therefore addresses governmental 

classification and secrecy. These earlier chapters are preparatory to Chapter 

12, which introduces “The Way Forward” with the Committee’s proposed 

framework for the future of presumptive disability decision making for veterans. Chapter 13 presents the Committee’s recommendations to Congress, 

VA, a Science Review Board, and DoD.

The appendixes contain information organized by the Committee and 

IOM staff that may assist the reader who wishes to further delve into 

the issues and historical background on presumptions. In addition to the 

appendix material introduced earlier (i.e., Commission statement, meeting 

agendas), the appendixes include acronyms, abbreviations, and a glossary 

(Appendix C), an overview of the current compensation system and its historical context (Appendix D), summary tables of the presumptive decisions 

established by Congress and VA since 1921 (Appendix F), VA’s White Paper 

(Appendix G), IOM’s Agent Orange and Gulf War Statements of Tasks 

and Conclusions (Appendix H), the complete series of case study chapters 

(Appendix I), additional background material on causation and statistical 

causal methods (Appendix J), additional background material on exposure 

and health data for veterans (Appendix K), and additional classification and 

secrecy information (Appendix L). Finally, Appendix M provides brief biographical information for Committee members, consultants, and selected 

staff responsible for this effort.

The Committee was not asked to and did not make judgments regarding specific cases in which individual veterans have claimed injuries and illnesses. This report neither supports nor criticizes the presumptive decisions 

Congress and VA have established since 1921. As well, the Committee did 

not make recommendations for any new, specific presumptions. These areas 

were beyond the Committee’s charge. However, the Committee did review, 

analyze, and report on the available information regarding the presumptive 

disability decision-making process for veterans.
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INTRODUCTION 35

COMMITTEE MEMBERS’ COMMITMENT TO VETERANS

All Committee members agreed to serve on this effort because of the 

importance of the issue and because of their deep gratitude and respect for 

those serving in the military and veterans who have served in the past. We 

submit this report with the hope that our effort will be to the benefit of 

those who have served in the past and who will serve in the future.

REFERENCES

Dunne, P. W. 2006. Department of Veterans Affairs responses: Questions following from the 

Veteran’s Disability Benefits Commission’s charge. Letter to Jonathan M. Samet. 

Grady, J. 2006. Statement presented at the first committee meeting of the IOM’s Committee 

on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans.

Washington, DC.

Mansfield, G. H. 2006. Internal VA process for reviewing reports on the Institute of Medicine 

under the Agent Orange Act of 1991 and the Persian Gulf War Veterans Act of 1998. 

Letter to Susanne A. Stoiber. 

VA (Department of Veterans Affairs). 1996. Diseases associated with exposure to certain 

herbicide agents. Proposed Rule. Federal Register 61(154):41368-41371.

VA. 2006. Department of Veterans Affairs responses: Questions following from the Veteran’s 

Disability Benefits Commission’s charge. Washington, DC: Department of Veterans 

Affairs. 

VDBC (Veterans Disability Benefits Commission). 2006. Statement of the Veterans’ Disability 

Benefits Commission to the IOM’s Committee on Presumptive Disability Decision 

Making Process. Washington, DC.
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36

2

A Brief History of Presumptive Disability 

Decisions for Veterans

INTRODUCTION

Presumptions have played an important role in both the conceptual 

basis for service connection and the actual administration of the Department of Veterans Affairs (VA) compensation program. Presumptions are 

used to bridge gaps in scientific and medical knowledge, as well as to resolve 

complex policy questions and simplify determinations of service connection 

for VA (VA, 1993a). This chapter offers a brief history of the presumptive 

disability decisions established for veterans since 1921. It is not intended as 

a comprehensive or exhaustive account of all presumptive decisions; rather, 

it provides background on presumptions—it explains how they operate, 

why they are used, and their role in making disability compensation available to veterans. The chapter focuses on presumptions for health outcomes 

rather than administrative presumptions. For a comprehensive review of 

presumptive decisions, the reader is referred to Analysis of Presumptions 

of Service Connection (VA, 1993a), Presumptions of Service Connection

(Zeglin, 2006), VA Disability Compensation Program: Legislative History

(Economic Systems Inc., 2004a), and VA Disability Compensation Program: Literature Review (Economic Systems Inc., 2004b).

What Is a Presumption?

In the law, there is general agreement about what a presumption is, 

although there is considerable controversy about what a presumption does. 

A presumption is a procedural device that dictates that once basic fact A is 
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A BRIEF HISTORY 37

established, the existence of fact B must be assumed unless the presumed 

fact is rebutted. A presumption therefore operates to relieve a party of the 

burden of establishing facts that it would otherwise be required to prove 

in order to prevail on its claim. A presumption that cannot be rebutted is a 

rule of substantive law; it does not satisfy the definition of a presumption 

because fact B must be assumed conclusively rather than conditionally. It 

does not allow for the possibility that fact B can be disproved.

A legislature has numerous choices when drafting a presumption; there 

is no uniform terminology that must be employed. To ensure passage, presumptions are often couched in somewhat ambiguous terms, particularly 

when they deal with sensitive and controversial policy issues. The result 

may be a deliberate fuzziness and ambiguity in the language that governs a particular presumption that will ultimately require recourse to the 

courts (Allen, 1980). Consequently, it is not always simple to determine 

precisely why a particular presumption was adopted or how it should be 

interpreted.

Why Are Presumptions Created?

Presumptions are created for a number of reasons. They promote 

fairness by simplifying proceedings and by making it less burdensome for 

claimants to gather evidence that is more accessible to the party against 

whom the claim is asserted. When the probability of the presumed fact’s 

existence is high if the basic fact exists, presumptions eliminate the expense 

and time that would be required to establish the presumed fact by direct evidence. Sometimes presumptions are established for policy reasons because 

of a desire to make it easier for particular types of claimants to establish 

their claims. This may for instance be true for veterans’ claims when information needed for an epidemiologic assessment, such as exposure data, 

is unavailable because it was not collected at the relevant time. Gratitude 

and sympathy for those who served their country obviously also play an 

important role (Reagan, 1988).

What Does a Presumption Do?

A true presumption affects the burden of proof. This can, however, 

mean different things as legislators, administrators, and judges do not 

always use consistent terminology to express their intentions. Burden of 

proof is a term used to label two different concepts: the burden of production and the burden of persuasion (Director, Office of Workers’ Compensation Programs, Department of Labor v. Greenwich Collieries et al., 1994. 

512 U.S. Supreme Court 267, Case No. 93-744). See 512 U.S. Supreme 

Court 267, Case No. 93-744, for an extensive discussion of the evolution 
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38 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

of the term burden of proof. A claimant or plaintiff ordinarily begins with 

both burdens. For instance, a veteran who relies on direct proof to show 

that he has a service-connected disability must generally both (1) produce 

evidence on that issue, and (2) persuade VA that the service connection 

exists. 

Types and Categories of Presumptions

There are two major types of presumptions. Type 1 presumptions 

shift both the burden of production and the burden of persuasion. Type 2 

presumptions have a lesser effect. For type 2 presumptions, establishment 

of the basic fact does not shift to the other party the burden of persuading 

the adjudicator that the presumed fact does not exist. The other party of 

the presumption only has to produce evidence that is contrary to, or meets 

the presumption. If the other party does so, the presumption vanishes, 

and the party with the original burden of persuasion—the party that had 

to establish the basic fact—continues to have the burden of proving the 

presumed fact. 

The difference between type 1 and 2 presumptions can be illustrated 

by the presumption of death after an unexplained absence of 7 years. If 

the presumption is a type 2 presumption, as it would be under the Federal 

Rules of Evidence unless Congress provides otherwise (Federal Rules of 

Evidence: Rule 301: Presumptions in General Civil Actions and Proceedings. 1975. Public Law 93-595. 93rd Cong., 2nd Sess.), the plaintiff would 

prove an absence of 7 years, the basic facts needed for the presumption to 

apply. Under Rule 301 if the opponent of the presumption introduces a witness to testify that she saw the absentee 1 year after his disappearance, the 

presumption vanishes, and the plaintiff has the burden of proving death as 

though there had never been a presumption. If this is a type 1 presumption, 

as it is in presuming death for veterans after a 7-year absence (Seven-Year 

Absence Presumption of Death. 2006. 38 U.S.C. § 108), the basic facts 

establish death unless VA has sufficient evidence to show that the veteran 

is alive.

Presumptions for Veterans

There are several reasons justifying the widespread use of presumptions 

in the adjudication of VA benefit claims. Presumptions may simplify and 

streamline the adjudication process by eliminating the need to obtain evidence and decide complex issues. Presumptions also promote accuracy and 

consistency in adjudications by requiring similar treatment in similar cases. 

Presumptions may relieve claimants and VA of the necessity of producing 

direct evidence when it is impractical or unduly burdensome to do so. 
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“Finally, presumptions may implement policy judgments that the burdens 

arising in certain cases be borne by the government rather than the veteran 

claimants notwithstanding the uncertainty surrounding the issue of whether 

the claimants’ disabilities were, in fact, incurred or aggravated by service” 

(Zeglin, 2006, p. 3).

To establish direct service connection for a VA disability compensation claim, a veteran must demonstrate the following: (1) that a disability 

currently exists, (2) that an event of disease or injury occurred or was 

aggravated in the military, and (3) that a medical connection can be shown 

between the service event and the existing disability (as stated in Barrans, 

2006). Presumptions lighten the burden of proof when patterns of circumstances impair veterans’ abilities to establish direct service connection. A 

presumption relieves the veteran of proving one or more of the requirements for direct service connection. The only difference between direct 

and presumptive service connection is the amount of proof required. All 

entitlements under presumptive service connection are identical to those 

under direct service connection (VA, 2006c).

There are both statutory and regulatory presumptions. Some presumptions relate to particular medical health outcomes, and others are 

administrative in nature (Pamperin, 2006). For example, there are several 

well-known presumptions of an administrative nature: presumption of 

death, presumption of sound condition, presumption of service connection 

due to aggravation, and presumption of total disability. The definitions of 

these presumptions are as follows:

• Presumption of death: Presumption of death upon 7 years of unexplained absence (Seven-Year Absence Presumption of Death. 38 U.S.C. § 

108[b])

• Presumption of sound condition: “Every veteran shall be taken to 

have been in sound condition when examined, accepted, and enrolled for 

service except as to defects, infirmities, or disorders noted at the time of the 

examination, acceptance, and enrollment, or where clear and unmistakable 

evidence demonstrates that the injury or disease existed before acceptance 

and enrollment and was not aggravated by such service.” (Presumption of 

Sound Condition. 38 U.S.C. § 1111)

• Presumption of service connection—Aggravation: “A preexisting 

injury or disease will be considered to have been aggravated by active 

military, naval, or air service, where there is an increase in disability during 

such [active] service, unless there is a specific finding that the increase in 

disability is due to the natural progress of the disease.” (Compensation for 

Service-Connected Disability or Death. Aggravation. 38 U.S.C. § 1153)

• Presumption of total disability: “A person shall be considered to be 

permanently and totally disabled if such person is . . . suffering from any 
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40 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

disability which is sufficient to render it impossible for the average person 

to follow a substantially gainful occupation, but only if it is reasonably 

certain that such disability will continue throughout the life of the person.” 

(Veterans’ Benefits. Determination with Respect to Disability. 38 U.S.C. § 

1502)

Medical health outcome presumptions have generally been adopted 

after periods of war and have been driven by the concerns of and for returning Service members. Military service is demanding, and those serving often 

do not know where they will be stationed and to which agents they will 

be exposed. In addition, military personnel are governed by the “line of 

duty” clause. VA will cover disability for a veteran “resulting from personal 

injury suffered or disease contracted in line of duty, or for aggravation of 

a pre-existing injury suffered or disease contracted in line of duty, in the 

active military, naval, or air service,” unless such injury or disease was “a 

result of the veteran’s own willful misconduct or abuse of alcohol or drugs” 

(Compensation for Service-Connected Disability or Death. Basic Entitlement. 38 U.S.C. § 1110). 

Presumptions established by Congress and VA have generally been 

defined by or linked to a location (e.g., service in Persian Gulf, Vietnam) 

or an activity (e.g., detonation of a nuclear device). Presumptions have 

also been defined by categories of disease. In general, VA categorizes medical health outcome presumptive decisions into the following categories: 

Chronic Diseases, Tropical Diseases, Former Prisoners of War (POWs), 

Radiation, Herbicide Agents, Mustard Gas/Lewisite, and Persian Gulf War 

(Zeglin, 2006).

Veterans are entitled to compensation for certain medical conditions 

that become manifest to a degree of 10 percent or more disability after 

they leave the military service, if there is a relationship between service and 

the condition being claimed (Presumptions Relating to Certain Diseases 

and Disabilities. 38 U.S.C. § 1112). The health outcomes for presumptions 

must be rated at least at a 10 percent level in order for a veteran to receive 

compensation for a specific presumption (Presumptions Relating to Certain 

Diseases and Disabilities. 38 U.S.C. § 1112). In addition, a veteran must 

establish the presumptive relationship within the prescribed presumptive 

period set by Congress or VA. The presumptive period is the allowable 

period after active duty period in which a veteran must develop a disease in 

order to be eligible for compensation. In the past, most presumptive periods 

were set at 1 year. Recently, the presumptive periods associated with certain 

diseases have been greatly lengthened to accommodate the long latency 

periods associated with some health outcomes (e.g., cancers), the considerable time required to resolve disability, the problems caused by governmentmandated secrecy about some exposures (e.g., mustard gas during WWII) 
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A BRIEF HISTORY 41

(see Appendix F, Table 1). Personal habits (e.g., tobacco use, alcohol and 

substance abuse) can be used to rebut presumptions, but in practice this 

is infrequently done (as stated in Barrans, 2006). Only subsequent to the 

diagnosis of mental health disorders will VA cover a veteran’s alcohol and 

substance abuse treatment (as stated in Pamperin, 2006).

The last extensive study of the use of presumptions was performed by 

the Bradley Commission in the 1950s. The Bradley Commission recommended that the existing presumptions for service connection should be 

withdrawn. They felt that “there is otherwise in the law sufficient protection for the veteran to establish service connection of any and all diseases” 

(President’s Commission on Veterans’ Pensions, 1956, p. 178). The Bradley 

Commission noted that several diseases that were presumptively service 

connected were probably caused by old age, not necessarily service. It also 

believed that some diseases that were presumptively service connected had 

little to do with service in the military and in fact would be developed 

regardless of active duty. In addition to this, the specialists believed that 

more thorough medical exams should be given to Service members after 

military service to better classify health status after active duty. Overall, 

they believed that the list of chronic diseases at the time needed to be 

completely resurveyed to more accurately reflect the most updated medical 

knowledge. They noted advancements in treatment and diagnosing methods 

to support their theory. One criticism was that the system for presumptive conditions was outdated and overly simplistic. The findings not only 

called for a change in methods but also demanded much stricter guidelines 

for rating presumptive conditions. In addition, the Bradley Commission 

stated that medical principles should allow direct service connection rather 

than having to resort to presumptions in many instances. The analysis 

cited changes in medical knowledge and improving technology as reasons 

for updating the rating system and urged VA to completely change its 

policy of expansive presumptive periods to reflect the current situation of 

the medical world (President’s Commission on Veterans’ Pensions, 1956). 

Congressional hearings on the report were held, but no favorable action 

was taken on these recommendations.

THE PUBLIC POLICY DEBATE SURROUNDING PRESUMPTIONS

Members of Congress, representatives of VA, veterans service organizations (VSOs), and individual veterans have long debated the basis for and 

application of presumptions of service connection (VA, 2006b). The general 

categories of arguments favoring and opposing presumptions can be found 

in Table 2-1. Appendix E provides quotations that support these categories 

of arguments favoring and opposing presumptions.
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42 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 2-1 Categories of Arguments Favoring and Opposing 

Presumptions 

Categories of Arguments 

Favoring Presumptions

Categories of Arguments 

Opposing Presumptions

1. Medical uncertainty. Onset of illness 

vs. appearance of symptoms. Doctors 

disagree over relationship to service. 

2. Inadequacy of service records and 

examinations.

3. Excessive burden of proof on veteran. 

Unfair to veteran to require medical 

proof when medical science is uncertain. 

Unreasonable to expect veterans afflicted 

with mental disability to prove SC.

4. Incidence of disease among veteran 

population. 

5. Difficult/delayed Diagnoses. Only 

medical specialists are likely to 

diagnose disease (MS) in early stages. 

Average person is unlikely to consult 

for original symptoms. 

6. Social benefits. Treatment of disease 

has broad social benefits. Treatment 

and compensation improve health of 

the nation generally. 

7. Enforce Congress’s view. Congress 

disagreed with findings of VA doctors. 

8. Association with risk factors. A disease 

associated with a known military risk 

factor and not associated with other 

risk factors. 

9. Promote health. Providing disability 

benefits relieves veterans of the need 

to perform work that could further 

compromise their health. 

10. Conditions of service. Long-range harm 

can be caused by particularly harsh 

conditions of service, such as those 

experienced by POWs. 

1. Questions of fact. Each case should be 

considered on its own merits. Service 

connection should be a question of fact 

rather than a question of law. 

2. Relationship to service. Presumptive 

disabilities cannot be shown to be related 

to circumstances of military service. 

3. Administrative function. Selecting 

diseases for inclusion as presumptive 

disabilities involves detailed medical 

and adjudicatory determinations best 

addressed administratively. 

4. Improved military procedures/records. 

Modern facilities, procedures, and 

record keeping allow case-by-case 

determinations.

5. Advances in medical science. 

Advancements in medical science (since 

WWI) facilitate detection and diagnosis 

of diseases. Accepted medical principles 

can reasonably and accurately establish 

onset of disease. 

6. Philosophy of program. Statutory 

presumptions for disabilities that 

cannot be shown to be related to service 

are inconsistent with the theory of 

compensation. 

7. Elevates cases without merit. Puts cases 

without merit (from standpoint of 

service connection) on a par with those 

proven to be service connected. 

8. Provisions are adequate without 

presumptions. Reasonable doubt to be 

resolved in favor of veteran eliminates 

need for presumption.

9. Qualifying criteria excessively liberal. In 

some cases, a bill’s language is seen as 

overly inclusive. 

SOURCE: VA (Veterans Administration). 2006b (unpublished). Presumption of service 

connection: The public policy debate. Washington, DC: VA. 
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A BRIEF HISTORY 43

BRIEF CHRONOLOGICAL HISTORY OF PRESUMPTIONS

This section summarizes presumptions that were established by Congress and VA from the 1920s to present. The health outcomes covered can 

generally be organized into the following presumptive categories: Chronic 

Diseases, Tropical Diseases, Former Prisoners of War, Radiation, Herbicide 

Agents, Mustard Gas/Lewisite, and Persian Gulf War. Table 2-2 summarizes all of the health outcomes that have been service connected for these 

presumptive categories to date. The information in this table was compiled 

from the health outcomes found in Tables F-1 and F-2 of Appendix F, 

which list all of the appropriate public laws and statutory citations. There 

are nearly 150 health outcomes that have been presumptively connected by 

Congress and VA since 1921.

TABLE 2-2 Presumptive Categories and Their Designated Health 

Outcomes

Presumptive 

Categories Health Outcomes (in alphabetical order)

Chronic 

Diseases

Anemia; arteriosclerosis; arthritis; atrophy; brain hemorrhage; brain 

thrombosis; bronchiectasis; calculi of the kidney, bladder, or gallbladder; 

cardiovascular-renal disease including hypertension; cirrhosis of the 

liver; coccidioidomycosis; diabetes mellitus; encephalitis lethargica 

residuals; endocarditis; endocrinopathies; epilepsies; Hansen’s disease; 

Hodgkin’s disease; leukemia; lupus erythematosus, systemic; myasthenia 

gravis; myelitis; myocarditis; nephritis; other organic diseases of the 

nervous system; osteitis deformans; osteomalacia; palsy, bulbar; paralysis 

agitans; psychoses; purpura idiopathic, hemorrhagic; Raynaud’s disease; 

sarcoidosis; scleroderma; sclerosis, amyotrophic lateral; sclerosis, multiple; 

syringomyelia; thromboangiitis obliterans (Buerger’s disease); tuberculosis, 

active; tumors, malignant, or of the brain or spinal cord or peripheral 

nerves; ulcers

Tropical 

Diseases

Amebiasis; blackwater fever; cholera; dracontiasis; dysentery; filariasis; 

leishmaniasis, including kala-azar; loiasis; malaria; onchocerciasis; Oroya 

fever; pinta; plague; schistosomiasis; yaws; yellow fever

Former 

Prisoners 

of War

Atherosclerotic heart disease and hypertensive vascular disease, including 

hypertensive heart disease; avitaminosis; beriberi; chronic dysentery; 

cirrhosis of the liver; dysthymic disorder (or depressive neurosis); 

helminthiasis; irritable bowel syndrome; malnutrition; organic residuals of 

frostbite; pellagra; peptic ulcer disease; peripheral neuropathy; posttraumatic 

osteoarthritis; psychosis; stroke; any other nutritional deficiency; any of the 

anxiety states

continued
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44 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Presumptive 

Categories Health Outcomes (in alphabetical order)

Radiation Bronchiolo-alveolar carcinoma; cancer of the bile ducts, bone, brain, breast, 

colon, esophagus, gall bladder, lung, ovary, pancreas, pharynx, salivary 

gland, small intestine, stomach, thyroid, and urinary tract; leukemia; 

lymphomas; multiple myeloma; primary liver cancer 

Herbicide 

Agents

Acute and subacute peripheral neuropathy; chloracne; chronic lymphocytic 

leukemia; Hodgkin’s disease; multiple myeloma; non-Hodgkin’s lymphoma; 

porphyria cutanea tarda; prostate cancer; respiratory cancers; soft-tissue 

sarcoma, including: adult fibrosarcoma, dermatofibrosarcoma protuberans, 

malignant fibrous histiocytoma, liposarcoma, leiomyosarcoma, epithelioid 

leiomyosarcoma, rhabdomyosarcoma, ectomesenchymoma, angiosarcoma, 

proliferating angioendotheliomatosis, malignant glomus tumor, malignant 

hemangiopericytoma, synovial sarcoma, malignant giant cell tumor of 

tendon sheath, malignant schwannoma, malignant mesenchymoma, 

malignant granular cell tumor, alveolar soft part sarcoma, epithelioid 

sarcoma, clear cell sarcoma of tendons and aponeuroses, extraskeletal 

Ewing’s sarcoma, congenital and infantile fibrosarcoma, malignant 

ganglioneuroma; type 2 diabetes

Mustard 

Gas and 

Lewisite

Acute nonlymphocytic leukemia; cancers (nasopharyngeal, laryngeal, lung 

[except mesothelioma], squamous cell carcinoma of the skin); chronic 

conjunctivitis; chronic form of laryngitis, bronchitis, emphysema, and 

asthma; chronic obstructive pulmonary disease; corneal opacities; keratitis; 

scar formation

Persian 

Gulf War

An undiagnosed illness, which may be associated with the following chronic 

symptoms: fatigue; symptoms involving skin, headache, muscle pain, joint 

pain, neurological symptoms, neuropsychological symptoms; symptoms 

involving the respiratory system, sleep disturbances, gastrointestinal 

symptoms, cardiovascular symptoms, abnormal weight loss, or menstrual 

symptoms. Also included are the following medically unexplained chronic 

multisymptom illnesses that are defined by a cluster of signs or symptoms: 

Chronic Fatigue Syndrome, Fibromyalgia, and Irritable Bowel Syndrome

SOURCE: Appendix F, Tables F-1 and F-2.

TABLE 2-2 Continued

1920s

The first presumptions were established in 1921: “In my opinion, that 

provision of the law which places the burden upon the disabled veteran 

of connecting his disease with his service has been responsible for more 

complaints, dissatisfaction and disappointment . . . than any other single 

provision. . . . Consequently, I propose to offer an amendment to section 

18 which will shift the burden of proof in the case of two classes of disease 
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A BRIEF HISTORY 45

only—tubercular and neuropsychiatric. I propose that when it is proved 

by an incapacitated soldier that he has either of these two types of disease 

he shall immediately be entitled to compensation unless the Government 

proves—the burden thus being shifted to the Government—that he has 

contracted the disease since the time of his discharge and it is not traceable 

to service in line of duty” (Senator Walsh, 61 Cong. Rec. 4105, 1921, as 

referenced in VA, 1993a, p. 7, and as found in Appendix E).

Neuropsychiatric disease (later called psychoses) and active pulmonary 

tuberculosis were the first two presumptions established on August 9, 1921 

(Veterans’ Bureau. Public Law 67-47. 1921. 67th Cong., 1st Sess.). These 

health outcomes must have manifested to 10 percent or more within 2 years 

of separation from active military service and must have been contracted 

during military service. On November 12, 1921, the first list of chronic constitutional diseases (later referred to as Chronic Diseases) was established 

(VA, 1921). These must have manifested within 1 year after the date of separation from service. The list included anemia (primary), arterio­sclerosis, 

beriberi, diabetes insipidus, diabetes mellitus, endocrinopathies, gout, hemochromatosis, hemoglobinuria (paroxysmal), hemophilia, Hodgkin’s disease, 

leukemia (all types), ochronosis, pellagra, polycythemia (erythremia), purpura, rickets, and scurvy. The category of Chronic Diseases was expanded 

in 1924 (World War Veterans’ Act, 1924. Public Law 68-242. 68th Cong., 

1st Sess.), 1925 (VA, 1925), and 1928 (VA, 1928).

1930s

In 1933, epilepsies and organic diseases of the nervous system were 

added to the Chronic Diseases category, and requirements for the manifestation of tuberculosis were more specifically characterized (Executive Order 

6089. Instruction No. 2, Implementing Vet. Reg. No. 1. April 12, 1933). 

Osteitis deformans (Paget’s disease) was added in 1935 (Executive Order 

6089. Instruction No. 2-A, Implementing Vet. Reg. No. 1. August 14, 

1935). 

1940s

The 1940s saw the growth in the number of presumptions and the 

addition of one new presumptive category—Tropical Diseases. The first 

tropical disease for which a presumption was made was malaria in 1945 

(VA, 1945). Malaria must have been contracted during active service with 

a presumptive period of 1 year after separation from active military service. 

The Tropical Diseases category was greatly expanded in 1946 (VA, 1947) 

and 1948 (Act of June 24, 1948. Public Law 80-748. 80th Cong., 2d Sess.) 

with clarifications appearing in 1949 (VA, 1949a). As well, the number 
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46 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

of presumptions in the category of Chronic Diseases increased greatly in 

1948 (Act of June 24, 1948. Public Law 80-748. 80th Cong., 2d Sess.) and 

1949 (VA, 1949a,b). The increase in the number of presumptions during 

this decade was related to the high incidence of such diseases observed in 

returning veterans from WWII.

1950s

The 1950s were not very active in establishing new presumptions. Sarcoidosis was added to the Chronic Diseases category, and amebiasis was 

added to the Tropical Diseases category in 1950 (VA, 1950). Clarifications 

on the dates of service, locations, and presumptive periods occurred in 1957 

(Veterans’ Benefits Act of 1957. Public Law 85-56. Sec. 301. 85th Cong., 

1st Sess.). It should be noted that the Bradley Commission, which reviewed 

the presumptive process and decisions, issued its report in 1956 (President’s 

Commission on Veterans’ Pensions, 1956).

1960s

In 1961, criteria for the presumptions in the Chronic Diseases and 

Tropical Diseases categories appeared (VA, 1961). No new presumptions 

were created during this decade.

1970s

A new presumptive category was established in the 1970s—Former 

Prisoners of War (POWs). POWs from WWII, the Korean War, and the 

Vietnam era were specifically connected for various physical and mental 

health outcomes in 1970 (Public Law 91-376. Sec. 3. 91st Cong., 2d Sess., 

1970). “Problems with nutrition, forced labor, and other inhumane treatment were deemed to be strong reasons to presume that the conditions 

were the direct result of captivity” (Economic Systems Inc., 2004a, p. 20). 

Clarification for the presumptive periods of Hansen’s disease (leprosy) and 

tuberculosis to 3 years as well as multiple sclerosis to 7 years from date of 

separation occurred in 1970 (VA, 1970). In 1979, ischemic heart disease 

(or other cardio­vascular disease) was presumptively associated with service 

amputation of one lower extremity at or above the knee or service-connected 

amputations of both lower extremities at or above the ankles (VA, 1979).

1980s

The decade demonstrated an expansion of presumptions with in the 

categories of POWs, Herbicide Agents, and Radiation. In 1981, the POW 
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A BRIEF HISTORY 47

imprisonment requirement of 90 days or more was reduced to 30 days or 

more (Former Prisoner of War Benefits Act of 1981. Public Law 97-37. 

97th Cong., 1st Sess.). In 1985, chloracne was presumptively connected 

with dioxin exposure (VA, 1985). In that same year, presumptions for 

exposure to ionizing radiation in Hiroshima or Nagasaki, Japan (September 

1945 until July 1946) and all forms of leukemia (except chronic lymphatic 

leukemia), many cancers, and multiple myeloma were made (VA, 1985). 

For POWs, organic residuals of frostbite and posttraumatic osteoarthritis 

were added in 1986 (Veterans’ Benefits Improvements and Health-Care 

Authorization Act of 1986. Public Law 99-576. 99th Cong., 2d Sess.). In 

1988, the scope of presumptive service connection law expanded dramatically when Congress passed a law providing a 40-year presumptive period 

for a long list of cancers associated with nuclear testing during the 1940s 

(Veterans’ Benefits and Services Act of 1988. Public Law 100-322. 100th 

Cong., 2d Sess.). This law introduced the phrases “radiation-exposed veteran” and “radiation-risk activity,” and added to the list POWs who were 

being held in Japan at the time of the nuclear detonations. 

1990s

The generation of presumptions accelerated in the decade of the 1990s. 

Each year of this decade new presumptions or clarifications of presumptive periods were established by Congress or VA. The Radiation Exposure 

Compensation Act of 1990 (Public Law 101-426. 101st Cong., 2d Sess.) 

added presumptions for downwinders to the Radiation category, but it did 

not cover veterans. Also in 1990, non-Hodgkin’s lymphoma was presumptively connected for Vietnam service (VA, 1990). In 1991, Congress passed 

the Agent Orange Act (Public Law 102-4. 102d Cong., 1st Sess.). This act 

added non-Hodgkin’s lymphoma, soft-tissue sarcomas, and chloracne (or 

other acneform disease) in the presumptive category of Herbicide Agents. 

Presumptions for the Mustard Gas/Lewisite category, stemming from WWII 

full-body, field, or chamber experiments, were established in 1992 (VA, 

1992a). Also in 1992, peripheral neuropathy was presumptively connected to 

the Herbicide Agents category (VA, 1992b), and cancer of the salivary gland 

and urinary tract were added to the Radiation category (Veterans’ Radiation Exposure Amendments of 1992. Public Law 102-578. 102d Cong., 2d 

Sess.). Both ovarian cancer and parathyroid cancer were presumptively connected to the Radiation category in 1993 (VA, 1993b). During that same 

year, posttraumatic stress disorder was presumptively connected for military 

service and former POWs (VA, 1993c). Finally, several additional diseases 

associated with service in Vietnam were added in 1993 (VA, 1993d).

In 1994, numerous additions occurred in the presumptive categories 

of Mustard Gas/Lewisite (VA, 1994a), Herbicide Agents (VA, 1994d,e; 
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48 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Veterans’ Benefits Improvements Act of 1994. Public Law 103-446. 

103d Cong., 2d. Sess.), and Radiation (VA, 1994b). Also in 1994, the 

Persian Gulf War undiagnosed illnesses were proposed (VA, 1994c). 

The Persian Gulf War undiagnosed illnesses were finalized in the 1995 

Compensation for Certain Undiagnosed Illnesses rule, the first time 

that Congress had made a presumption for a list of medical terms (VA, 

1995b). Additional presumptions in the Radiation category were added 

for cancer of the rectum and lymphomas (other than Hodgkin’s disease) 

later that year (VA, 1995a). In 1996, prostate cancer as well as acute and 

subacute peripheral neuropathy were presumptively connected under 

the category of Herbicide Agents (VA, 1996). The presumptive period 

for undiagnosed illnesses to manifest within 2 years after service was 

extended to December 31, 2001, in 1997 (VA, 1997). Prostate cancer 

and any other cancer were presumptively connected for the Radiation 

category in 1998 (VA, 1998). The Persian Gulf War Veterans Act of 

1998 (Public Law 105-277. 105th Cong., 2d Sess.) established service 

connection for diseases associated with exposure to biological, chemical, or toxic agents; environmental or wartime hazards; or preventive 

medicines or vaccines associated with service in the southwest Asia 

theater of operations during the Persian Gulf War. Finally, the Veterans 

Millennium Health Care and Benefits Act of 1999 (Public Law 106-

117. 106th Cong., 1st Sess.) established a presumption for bronchioloalveolar carcinoma and radiation exposure.

2000 to Present

The final Veterans Millennium Health Care and Benefits Act presumptively connected bronchiolo-alveolar carcinoma to radiation exposure in 

2000 (VA, 2000). In April 2001, VA published a final rule stating that 

veterans’ use of tobacco products and associated adverse health outcomes 

would not be considered service connected (VA, 2001a). In May 2001, 

VA presumptively connected type 2 diabetes with herbicide exposure (VA, 

2001b). In the same year, additional presumptions for the Radiation category were established (VA, 2001c) and clarifications for presumptive 

periods relating to Persian Gulf War and Vietnam service were published 

(VA, 2001d; Veterans Education and Benefits Expansion Act of 2001. 

Public Law 107-103. 107th Cong., 1st Sess.). Additional cancer presumptions were added for radiation-risk activities in 2002 (VA, 2002). Cirrhosis 

of the liver was presumptively connected in 2003 for former POWs (VA, 

2003b), and chronic lymphocytic leukemia was presumptively connected 

the same year for herbicide exposures (VA, 2003a). The list of diseases presumptively connected for POWs was expanded in 2003 (Veterans Benefits 

Act of 2003. Public Law 108-183. 108th Cong., 1st Sess.), and additional 
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A BRIEF HISTORY 49

diseases were presumptively connected for POWs in 2004 (VA, 2004). The 

definition of radiation-risk activity was clarified in 2004 to include service 

in a capacity if performed as an employee of the Department of Energy 

(Veterans Benefits Improvement Act of 2004. Public Law 108-454. 108th 

Cong., 2d Sess.). Once again, additional health outcomes were presumptively connected for POWs in 2005 (VA, 2005). In early 2006, Congress 

codified all presumptions established to date (Veterans’ Benefits. Title 38 

U.S.C.). In 2006, VA published an interim final rule that the presumptive 

period for undiagnosed illnesses to manifest within 2 years after service 

would be extended to December 31, 2011 (VA, 2006a).

SUMMARY

Many presumptive decisions have been made since the first presumptions were established in 1921. These decisions reflect the complexity of 

exposures during service. The increased longevity of veterans means that 

there are many more diseases from which veterans may suffer and which 

may have originated in military service. In the 50 years since the Bradley 

Commission’s report was released (President’s Commission on Veterans’ 

Pensions, 1956), there have been substantial changes in medical care and 

in the evidence relevant to making presumptions. However, a need for 

presumptions has persisted, and the creation of new presumptions has 

increased rapidly in the last two decades.

REFERENCES

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Barrans, D. 2006. History of presumptions of service connection. Paper presented to the 

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Economic Systems Inc. 2004a. VA Disability Compensation Program: Legislative history. 

Washington, DC: VA Office of Policy, Planning and Preparedness. 

Economic Systems Inc. 2004b. VA Disability Compensation Program: Literature review. 

Washington, DC: VA Office of Policy, Planning and Preparedness. 

Pamperin, T. J. 2006. An overview of the Disability Benefits Program and presumptions affecting veterans’ benefits. Presented to the Institute of Medicine’s Committee on Evaluation 

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President’s Commission on Veterans’ Pensions. 1956. A report to the president: Veterans 

benefits in the United States: Findings and recommendations. Vol. 1, Parts I and II. 

Washington, DC: Government Printing Office. 

Reagan, R. 1988. Statement on signing the Radiation-Exposed Veterans Compensation Act of 

1988. Weekly Compilation of Presidential Documents 24(20):641-642.

VA (Veterans Administration). 1921. Internal memorandum implementing Veteran’s Bureau 

Regulation No. 11. Washington, DC: VA.

VA. 1925. Schedule for rating disabilities. Washington, DC: VA. P. 75. Washington, DC: VA. P. 75.

VA. 1928. Schedule of disability ratings. Extension 6. Washington, DC: VA.
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50 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

VA. 1945. Veterans Administration Circular No. 8. Section I. Washington, DC: VA.

VA. 1947. Disability ratings for malaria and chronic diseases characteristically tropical in 

origin. Veterans Administration Technical Bulletin 8-6. Washington, DC: VA.

VA. 1949a. Pensions, bonuses, and veterans’ relief: Veterans’ claims; miscellaneous amendments. Part 3. Federal Register 14(26):568-578.

VA. 1949b. Pensions, bonuses, and veterans’ relief: Veterans’ claims; miscellaneous amendments. Part 3. Federal Register 14(197):6174-6180.

VA. 1950. Pensions, bonuses, and veterans’ relief: Veterans’ claims; miscellaneous amendments. Part 3. Federal Register 15(169):5902-5910.

VA. 1961. Disease subject to presumptive service connection. Federal Register

26(36):1581-1582.

VA. 1970. Pensions, bonuses, and veterans’ relief. Part 3: Adjudication. Subpart A: Pension, compensation, and dependency and indemnity compensation. Federal Register

35(232):18280-18283.

VA. 1979. Pension, compensation, and dependency and indemnity compensation, proximate 

results, secondary conditions. Federal Register 44(168):50339-50340.

VA. 1985. Adjudication of claims based on exposure to dioxin or ionizing radiation. Final 

rules. Federal Register 50(165):34452-34461.

VA. 1990. Claims based on service in Vietnam. Final regulations. Federal Register

55(208):43123-43125.

VA. 1992a. Claims based on chronic effects of exposure to mustard gas. Final rule. Federal 

Register 57(148):33875-33877.

VA. 1992b. Claims based on exposure to herbicides containing dioxin (peripheral neuropathy/

lung cancer). Proposed rule. Federal Register 57(13):2236-2238.

VA. 1993a. Analysis of presumptions of service connection. Washington, DC: VA. Washington, DC: VA. 

VA. 1993b. Claims based on exposure to ionizing radiation. Final rule. Claims based on exposure to ionizing radiation. Final rule. Federal Register

58(57):16358-16359.

VA. 1993c. Direct service connection (post-traumatic stress disorder). Final rule. Federal 

Register 58(95):29109-29110.

VA. 1993d. Diseases associated with service in the Republic of Vietnam. Final rule. Federal 

Register 58(95):29107-29109.

VA. 1994a. Claims based on chronic effects of exposure to mustard gas or lewisite. Final rule. 

Federal Register 59(159):42497-42500.

VA. 1994b. Claims based on exposure to ionizing radiation. Final rule. Federal Register 

59(171):45975.

VA. 1994c. Compensation for certain undiagnosed illnesses. Proposed rule. Federal Register

59(235):63283-63285.

VA. 1994d. Disease associated with exposure to certain herbicide agents. Final rule. Federal 

Register 59(23):5106-5107.

VA. 1994e. Disease associated with exposure to certain herbicide agents (multiple myeloma 

and respiratory cancers). Final rule. Federal Register 59(110):29723-29724.

VA. 1995a. Claims based on exposure to ionizing radiation (lymphomas other than Hodgkin’s 

disease and cancer of the rectum). Final rule. Federal Register 60(198):53276-53277.

VA. 1995b. Compensation for certain undiagnosed illnesses. Final rule. Federal Register

60(23):6660-6666.

VA. 1996. Diseases associated with exposure to certain herbicide agents (prostate 

cancer and acute and subacute peripheral neuropathy). Final rule. Federal Register

61(217):57586-57589.

VA. 1997. Compensation for certain undiagnosed illnesses. Interim rule with request for comments. Federal Register 62(82):23138-23139.
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A BRIEF HISTORY 51

VA. 1998. Claims based on exposure to ionizing radiation (prostate cancer and any other 

cancer). Final rule. Federal Register 63(185):50993-50995.

VA. 2000. Veterans Millennium Health Care and Benefits Act. Final rule. Federal Register

65(136):43699-43700.

VA. 2001a. Claims based on the effects of tobacco products. Final rule. Federal Register

66(67):18195-18198.

VA. 2001b. Disease associated with exposure to certain herbicide agents: Type 2 diabetes. Final 

rule. Federal Register 66(89):23166-23169.

VA. 2001c. Diseases specific to radiation-exposed veterans. Proposed rule. Federal Register

66(153):41483-41485.

VA. 2001d. Extension of the presumptive period for compensation for Gulf War veterans’ 

undiagnosed illnesses. Interim final rule with request for comments. Federal Register

66(218):56614-56615.

VA. 2002. Diseases specific to radiation-exposed veterans. Final rule. Federal Register

67(17):3612-3616.

VA. 2003a. Disease associated with exposure to certain herbicide agents: Chronic lymphocytic 

leukemia. Final rule. Federal Register 68(200):59540-59542.

VA. 2003b. Presumption of service connection for cirrhosis of the liver in former prisoners of 

war. Final rule. Federal Register 68(138):42602-42603.

VA. 2004. Presumptions of service connection for diseases associated with service involving detention or internment as a prisoner of war. Interim final rule. Federal Register

69(194):60083-60090.

VA. 2005. Presumptions of service connection for diseases associated with service involving 

detention or internment as a prisoner of war. Affirmation of interim final rule as final 

rule. Federal Register 70(123):37040-37042.

VA. 2006a. Extension of the presumptive period for compensation for Gulf War veterans. 

Interim final rule. Federal Register 7(242):75669-75672.

VA. 2006b (unpublished). Presumption of service connection: The public policy debate.

Washington, DC: VA.

VA. 2006c (unpublished). Presumptions of service connection. Washington, DC: VA. Washington, DC: VA.

Zeglin, D. E. 2006. Presumptions of service connection. Paper prepared for the Veterans’ Disability Benefits Commission. https://www.1888932-2946.ws/vetscommission/

e-documentmanager/gallery/Documents/Reference_Materials/Presumption-Paper_3-7-

06.pdf (accessed March 8, 2007).
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52

3

The Presumptive Disability 

Decision-Making Process

This chapter describes the current presumptive disability decisionmaking process for veterans and outlines the roles of various participants 

in the process. The description is based on presentations at the Committee’s 

open sessions, public documents, documents provided by the Department of 

Veterans Affairs (VA), the Institute of Medicine (IOM) reports, and other 

relevant materials. 

SUMMARY OF THE PROCESS

The current presumptive disability decision-making process for veterans involves multiple parties and is not controlled by any single entity or 

organization. The process involves input from Congress, VA, the National 

Academies (IOM and National Research Council [NRC]) and the veteran 

community. Decisions made in the courts have also influenced the current presumptive process. Figure 3-1 depicts roles of participants in the 

current process. Although the number and extent of presumptions have 

varied over the last 80 years, it appears that the presumptive decisions 

established since the early 1990s have led to growing concerns and questions about the presumptive process itself. 

When Congress enacted the Agent Orange Act of 1991 (Public Law 

102-4. 102d Cong., 1st Sess.), it started a model for a decision-making 

process that is still in place today. Congress asked VA to contract with an 

independent organization—VA contracted with IOM—to review the scientific evidence related to Agent Orange and disease. The process begins with 

VA supplying a study charge to the IOM committee carrying out the review, 
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53

Stakeholdersa

Congressb

VAc

The NationalAcademiesd

PRESUMPTION

Courts may interpret

presumption

Study Charge Report 

VA may appeal or

Congress may revise

Disputes 

FIGURE 3-1

FIGURE 3-1 Roles of the participants involved in the presumptive disability decision-making process for veterans.a Stakeholders include (but are not limited to) veterans service organizations (VSOs), veterans, advisory groups, federal agencies, and the general public; these stakeholders provide input into the presumptive process by communicating with Congress, VA, and independent organizations (e.g., the National Academies).b Congress has created many presumptions itself; in 1921, Congress also empowered the VA Secretary to create regulatory presumptions; on several occasions in the past, Congress has directed VA to contract with an independent organization (e.g., the National Academies) to conduct studies and then use the organization’s report in its deliberations of granting or not granting regulatory presumptions. c VA can establish regulatory presumptions; VA sometimes contracts with the National Academies to conduct studies and uses the organization’s report in its deliberations of granting or not granting regulatory presumptions. d The National Academies (Institute of Medicine and National Research Council) submit reports to VA based on requests and study charges from VA.
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54 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

and it ends with the IOM committee responding with a report, based on 

a comprehensive review, that addresses the charge. Since 1994, IOM has 

produced six biennial reports on Agent Orange (IOM, 1994, 1996, 1999, 

2001, 2003b, 2005b) and five volumes on the Gulf War (IOM, 2000a, 

2003a, 2005a, 2006b, 2007a) for VA to use in its deliberations when 

making presumptive decisions. 

Through this process, health outcomes, such as prostate cancer and 

type 2 diabetes, have been presumptively service connected to Agent Orange 

exposure in Vietnam. The process for establishing presumptions continued 

to evolve in recent years to respond to veterans who were deployed to the 

Persian Gulf during or shortly following the Gulf War in 1990. Although the 

focus for presumptions among Vietnam veterans centered on their exposure 

and health outcomes relating to the dioxin-contaminated herbicide Agent 

Orange, the Gulf War has added new challenges caused by the multiple and 

various agents to which Service members were exposed. The IOM report 

process has responded to the multiplicity of agents of concern by developing 

reports on large groups of similar agents, such as combustion products (IOM, 

2000a, 2003a, 2005a).This chapter reviews the roles of each major participant in the presumptive disability decision-making process for veterans.

DESCRIPTION OF ROLES FOR SPECIFIC PARTICIPANTS 

(IN ALPHABETICAL ORDER)

Role of Congress

The power to compensate veterans for their service-connected adverse 

health effects resides in Congress. Consequently, Congress has the power 

to create presumptions that make it easier for a veteran to establish service 

connection (see Chapter 2). Congress has sometimes exercised its power 

through legislation; at other times Congress has delegated its authority to 

the VA Secretary to prescribe “all rules and regulations . . . with respect to

the nature and extent of proof and evidence and the method of taking and 

furnishing them in order to establish the right to benefits under such laws” 

(Rules and Regulations. 2003. 38 U.S.C. § 501(a); emphasis added). This 

general authority has been used sparingly by VA over the years to establish 

presumptions. 

The vast majority of presumptions have resulted from public laws 

that specifically identify a disability or disease and set forth the conditions 

under which a presumption of service connection attaches (see Appendix F). 

Subsequent legislative enactments often modify the conditions under which 

these specific presumptions apply. As a matter of law, most presumptions 

can be rebutted by competent evidence (see Chapter 2) although this rarely 

occurs in practice.
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THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS 55

Beginning in the 1980s, Congress has also legislated procedures to 

be employed in responding to service-related claims initially concerning 

herbicide and radiation exposures and later with respect to various exposures encountered during the Gulf War (see Appendix F). The procedures 

that Congress has established essentially involve review by a committee 

from the National Academies (e.g., IOM and NRC) of medical and scientific evidence concerning the relationship of disabilities or diseases to certain 

exposure agents. On a periodic basis, IOM furnishes findings for Agent 

Orange and Gulf War to the VA Secretary who must then decide whether 

or not to grant a presumption within a specified number of days of receipt 

of a report (Agent Orange Act of 1991. Public Law 102-4. 102d Cong., 1st 

Sess.; Veterans Programs Enhancement Act of 1998. Public Law 105-368. 

105th Cong., 2d Sess.). 

The formal role of Congress in establishing these presumptions follows 

a comparatively transparent process. Issues are brought to the attention of 

Congress by individual constituents seeking assistance from members in 

securing veteran benefits for which they claim entitlement, and by veteran 

service organizations (VSOs) that represent their interests. Media attention 

concerning veteran issues can also engage the interest of Congress. Finally, 

legislation concerning presumptions can also be initiated at the request of 

the executive branch, although this has been a rare occurrence. 

A bill to establish a presumption is introduced in one or both houses of 

Congress, and it is usually accompanied by the sponsors’ floor statements 

setting forth the reasons why it should be enacted. Public hearings are held 

by one or both of the veterans affairs committees and testimony is received 

from a variety of witnesses including VSOs and individual veterans who 

are often constituents of various committee members. VA’s position on the 

legislation along with cost estimates prepared by the Director of the Congressional Budget Office, where applicable, are also received and considered 

by Congress (Johnson, 2003). 

The Veterans Affairs Committee considering the legislation next moves 

to consider the legislation and amendments thereto in executive session. 

At one time these meetings were closed to the public, but they have been 

conducted in open session for approximately the past 30 years. After consideration of any amendments, the measure, if approved by the committee, 

is ordered to the floor for consideration by the entire Senate or House. The 

bill as amended is accompanied by a report prepared by the committee’s 

majority staff that sets forth the rationale for the legislation. The report 

also includes a summary of testimony received and information considered 

together with the administration’s position and cost estimates (Johnson, 

2003). The report may also include separate and minority views, although 

this has been infrequent with veterans legislation that is more often than 

not reported unanimously. 
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56 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Floor debate on the pending bill is televised and transcribed in the 

Congressional Record. Procedures for considering legislation on the floor, 

however, differ substantially between the House and the Senate. The 

amount of debate and the ability to consider amendments to the measure 

on the floor of the House is for the most part limited, which enhances the 

authority of the House Committee on Veterans Affairs. In the Senate the 

ability to attach amendments and to have extensive debate is rarely constricted (Johnson, 2003). Because of the frequent need to keep the “trains 

moving on time,” an individual Senator need not be a member of the 

Veterans Affairs Committee to exercise considerable influence in shaping 

veterans legislation. 

It should be observed parenthetically that historically the House Veterans Affairs Committee has been the initiator of most veterans legislation. This resulted from the fact that until 1971 only the House had a full 

standing committee on veterans affairs. The Committee enjoyed a stable, 

“tenured” leadership and staff for long periods of time that enabled it to 

develop considerable expertise in veterans’ matters. Given House floor procedures, committee views were rarely challenged and invariably prevailed 

(Carr, 2001). In the Senate, by contrast, veterans legislation—depending 

on its content—was handled either by the Committee on Finance or the 

Committee on Labor and Public Welfare (SOURCE: http://veterans.­senate.

gov/index.cfm?FuseAction=About.CommitteeHistory), both of which had 

numerous other issues that engaged the committee members’ time and 

interest. As a result, the Senate frequently deferred to the position of the 

House in veterans’ matters prior to 1971.

The creation of the Senate Committee on Veterans Affairs in 1971 

amid concern generated about treatment of returning Vietnam veterans 

altered the status quo as the Senate developed a larger voice in veterans’ 

matters (SOURCE: http://veterans.senate.gov/index.cfm?FuseAction=About (SOURCE: http://veterans.senate.gov/index.cfm?FuseAction=About..CommitteeHistory). This contributed to changes in how presumptions were This contributed to changes in how presumptions were 

created as the issue of Agent Orange exposure grew in intensity. 

In situations where the two houses have not adopted identical measures, 

the differences need to be resolved often through a formal House-­Senate 

conference committee. The veterans affairs committees, however, rarely 

resort to the formal conference committee process. Instead they negotiate 

their differences in informal, nonpublic meetings that frequently involve 

committee staff acting as surrogates for the members. Once agreement is 

reached, an amended version is reported to the floor of either the House 

or the Senate where it is passed and sent to the other body, which accepts 

the measure as amended causing it to be transmitted to the President for 

action. Both committees insert an identical joint explanatory statement in 

the Congressional Record that sets forth the changes made and the parties’ 

understanding and rationale of the compromise measure (Johnson, 2003). 
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THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS 57

As this description of the congressional process indicates, an extensive 

public record is developed with respect to the consideration and adoption 

of presumptions. Whether this record is a complete and accurate description of why a presumption was or was not adopted or why processes or 

standards were crafted in the manner they were is another matter. The politics of an issue often are not openly acknowledged in the public record. The 

personal views of key individual members can often have enormous weight. 

“Horse trading” on other matters often affects the shape and outcome of 

a particular bill. Moreover, substantive differences are sometimes papered 

over with ambiguous language to gain approval of the legislation, which 

presents a variety of problems to those who are charged with implementing 

their provisions. All of this suggests that the science justifying a presumption is but one factor considered by Congress in the enactment of the legislation. For additional information and analysis of the role of Congress in 

the development of presumptions, the reader is directed to the case studies, 

in particular the discussion of Agent Orange and Gulf War presumptions, 

found in Appendix I.

Congressional Perspective

The Committee received views from a panel of former congressional 

staff members, most of whom had served on either the Senate or the House 

Veterans Affairs committees in the 1980s and 1990s at a time when there 

were intense concern and questions about the effect of service exposures on 

the subsequent health of veterans (presentations made to the Committee on 

October 5, 2006). Among the factors arguably affecting the enactment of 

presumption legislation were (1) increasing concern about federal budget 

problems, (2) the perceived strength of key members of Congress considering the legislation, and (3) the continuing reminder of American Service 

members who had been recently killed or wounded and the debt our society 

owed them (Petrou, 2006; Ryan, 2006; Scott, 2006; Yoder, 2006). 

It was observed that “scientific integrity is critical” in the presumptive 

disability compensation process and that if it was “lacking, the quality of 

the decisions [would] suffer, and veterans and the American people [would] 

lose faith in the decision-making process” (Petrou, 2006, p. 8). At the same 

time, faced with the claims of veterans with many real disabilities and diseases, it was acknowledged that presumptive decisions were shaped by the 

perceived “need to make ‘yes or no’ decisions in the face of pervasive uncertainty” with regards to the level, if any, of exposure and the likely health 

effects resulting therefrom (Yoder, 2006, p. 1). Panel members were critical of insufficient efforts to monitor the health of Service members. They 

noted the absence of predeployment health assessments and inadequate 

surveillance of environmental exposures that troops may have encountered 
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58 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

during the Gulf War notwithstanding lessons that should have been learned 

from Agent Orange and Vietnam (Petrou, 2006; Ryan, 2006; Scott, 2006; 

Yoder, 2006). Although there was disagreement as to its wisdom, there was 

uniform agreement that if a connection between exposure and disease were 

established, Congress has a strong bias in favor of compensating all veterans even if the attributable risk was small and large numbers of false positives would result (Petrou, 2006; Ryan, 2006; Scott, 2006; Yoder, 2006).

Role of Department of Veterans Affairs (VA)

The Committee’s description of the VA process is based on presentations to the Committee as well as a general description provided by VA 

(see Appendix G). The Committee requested internal documents related to 

specific presumptions, but these were not provided (see Chapter 1). Based 

on the information available, the Committee found that VA has developed 

an ad hoc process for establishing presumptions that relies upon National 

Academies (e.g., IOM and NRC) reports, recommendations of advisory 

committees, and VA research findings (Barrans, 2006; Pamperin, 2006a). 

Currently, VA follows the process that began with the Agent Orange Act of 

1991 (Public Law 102-4. 102d Cong., 1st Sess.). Upon receipt of an IOM 

Veterans and Agent Orange (VAO) or Gulf War (GW) report, the VA Secretary is required to determine whether a presumption of service connection 

is warranted for any diseases discussed in the report. 

VA has not adopted formal procedures governing its internal review 

and utilization of findings of IOM reports. However, a general practice has 

developed that VA usually follows in conducting its internal review. The 

general practice involves a three-tiered review with a working group (tier 

1), a task force group (tier 2), and the VA Secretary (tier 3). Working group 

members include internal VA staff and outside experts as needed, with the 

option of seeking input from VSOs, Congress, and veterans (Deyton, 2006). 

Representatives at each tier are shown in Box 3-1.

The Working Group convenes after receiving the briefing from the IOM 

VAO or GW committee. “Prior to the meeting, VHA personnel usually will 

seek to identify, based on the IOM report and the committee briefing, the 

diseases that may warrant special consideration because IOM’s findings 

with respect to those diseases appear to be potentially significant. The . . . 

VHA generally provides the working group members with additional information concerning those diseases, including copies of any significant scientific studies identified in the IOM report and other information. . .” (VA, 

2006, p. 3; as found in Appendix G). 

“At the initial working group meeting, the OGC [Office of the General 

Counsel] representative briefs the working group on the legal standard 

governing the VA Secretary’s decision. . . . The working group will try to 
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BOX 3-1

Representatives at Each Tier of VA’s 

Internal Review of NAS Reports 

Tier 1: Working Group Representatives* 

• Veterans Health Administration (VHA) Office of Public Health and Environmental Hazards (OPHEH)

• Veterans Benefits Administration (VBA)—Compensation and Pension Service 

(C&P Service)

• Office of the General Counsel (OGC)—Professional Staff Group II 

• VHA personnel with specialized medical training or experience

• Outside technical experts such as National Institutes of Health (NIH), Centers 

for Disease Control and Prevention (CDC), and Environmental Protection 

Agency (EPA), as needed

Tier 2: Task Force Representatives**

• Under Secretary for Health 

• Under Secretary for Benefits 

• General Counsel

• Assistant Secretary for Policy and Planning 

• Other experts (CDC, EPA, as appropriate)

Tier 3: The VA Secretary

SOURCE: Deyton, 2006; VA, 2006; as found in Appendix G.

*The members generally are assigned to the working group by supervisory personnel within 

VHA, VBA, and OGC. The working group may receive input from outside content experts as 

well as veterans, VSOs, and Congress.

**Appointed by the VA Secretary.

reach consensus as to whether the scientific evidence appears to warrant 

a presumption of service connection for any diseases under the applicable 

legal standard” (VA, 2006, p. 3; as found in Appendix G). 

“If the Working Group concludes that the scientific evidence and legal 

standard do not provide a clear basis for recommending for or against 

establishing a presumption . . . the Working Group generally will agree to 

set forth a range of options for a decision by VA policy-making officials. In 

those circumstances, the Working Group will discuss the factors that preclude a clear recommendation, which may include ambiguity in the governing statutory standard as applied to certain IOM findings. . . . The Working 

Group will discuss the options available to the VA Secretary and may also 
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60 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

discuss the factors that may be relevant to the VA Secretary’s decision among 

those options” (VA, 2006, pp. 3-4; as found in Appendix G). The Working 

Group prepares a written report that typically includes the following: 

• A summary of the issues to be decided under applicable law and 

the IOM report

• A summary of the findings contained in the IOM report

• A summary of the legal standard governing VA’s decision

• A summary of the Working Group’s analysis of the medical evidence in relation to the legal standard, particularly with respect to any 

potentially significant findings in the IOM report 

• A statement of the Working Group’s recommendations or of the 

options identified by the Working Group 

In arriving at such recommendations, the Working Group generally 

does not prepare or obtain a cost estimate for the options. However, it may 

provide general information, for example, the prevalence rates of certain 

diseases under consideration. If the Working Group report lists a range of 

options available to the VA Secretary, it ordinarily would identify the scientific and legal considerations relevant to the VA Secretary’s choice among 

those options, and may also identify policy implications associated with 

various options” (VA, 2006, p. 4; as found in Appendix G). 

The VA task force receives this report and reviews its recommendations. 

“The Task Force often, though not always, provides a separate report to the 

VA Secretary that is . . . usually similar to the Working Group’s report in format and content. . . . [O]nce the report is drafted, it is circulated to the Task 

Force members for signature and is then transmitted to the VA Secretary” 

(VA, 2006, p. 4; as found in Appendix G).

“Based on the Task Force’s report, the VA Secretary determines whether 

to establish presumptions for any diseases discussed in the IOM report and 

directs appropriate action to implement the decision. . . . [I]f the VA Secretary determines that a presumption of service connection is warranted for 

any disease, VBA (through the C&P Service staff) will prepare proposed 

rules to establish such presumptions” and “an estimate of the costs associated with the rule. . . . VA will transmit the proposed rule and cost estimate 

to OMB [Office of Management and Budget] for review. If OMB approves 

the proposed rule, it will be transmitted to the VA Secretary for signature. 

VA will then transmit the rule to the Federal Register for publication. Once 

the period for providing public comments on the rule has ended, VBA will 

prepare a final rule. VA will submit the final rule to the Federal Register for 

publication” (VA, 2006, p. 5; as found in Appendix G). 

“If the VA Secretary determines that a presumption of service connection is not warranted for certain diseases, VBA will prepare a notice 
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THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS 61

explaining the scientific basis for that decision with respect to each such 

disease prior to publication” (VA, 2006, p. 5; as found in Appendix G). VA 

then publishes this notice in the Federal Register.

Presentations made at Committee open session meetings brought out 

several issues of importance to VA. The scientific, independent review 

process, as well as the breadth and thoroughness of IOM reports, provide 

credibility to the presumptive disability decision-making process. However, 

interpretation of the IOM reports can be problematic for VA. The difficulty 

lies not only in determining the effects of exposure but in separating the 

effects of a specific exposure of concern from the effects of other potential 

exposures. Past IOM committees have not been charged to provide guidance on this issue. VA is also hindered by not having exposure data for individuals. VA noted that some exposures known to contribute to conditions 

of concern are common in nonmilitary settings, complicating interpretation 

of studies of risks of military exposures for these outcomes.

VA, under statutes outlining the presumptive process for Agent Orange 

and Gulf War (Agent Orange Act of 1991. Public Law 102-4. 102d Cong., 

1st Sess.; Veterans Programs Enhancement Act of 1998. Public Law 105-

368. 105th Cong., 2d Sess.), is not required to consider any evidence on 

exposure magnitude that would be necessary for a direct service connection. 

It can offer little or no guidance for making decisions based on exposure 

magnitude or duration. VA is left to treat all exposures as equally likely 

to lead to an associated long-term health effect (Brown, 2006; Deyton, 

2006).

The Impact of Presumptions

VA does not track the number of presumptive service-connected disability claims granted and/or denied for each condition, nor are health 

outcomes within the VBA data systems coded in a manner that would 

permit VA to easily determine how many veterans are presumptively service 

connected (as stated in Pamperin, 2006b). For various categories of health 

conditions, some information regarding the number of presumptions may 

be determined. That is, if it is clear that the only or most readily anticipated 

method for connection is via presumption (and not direct service connection), then one may conclude that the number of cases for various categories of health conditions are presumptively service connected (Pamperin, 

2006b). The Committee was unable to obtain additional data on the number of presumptive cases or their impact to the overall VA system. Table 3-1 

provides data that were provided to the Committee during its first open 

session meeting (Pamperin, 2006b).

Because disability cases adjudicated on the bases of presumptive decisions are not routinely counted, the costs are not known with certainty. 
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62 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 3-1 Presumptions in VA’s Disability Program

Condition Number of Veterans Disability Severity Rating

Chronic Diseases

Arteriosclerosis Unknown Not differentiated

Arthritis Unknown Same

Leukemia Unknown Same

Raynaud’s disease Unknown Same

Tropical Diseases

Malaria 30,000 0%

Leishmaniasis 283 0%

Dysentery 872 0%

Plague 10 0%

Prisoners of War

Any anxiety Unknown Most rated 100%

Stroke and its complications Unknown 100%

Cirrhosis of the liver Unknown 100%

Peripheral neuropathy Unknown 100%

Radiation

Lung cancer Unknown Not differentiated

Colon cancer Unknown Same

Lymphomas Unknown Same

Stomach cancer Unknown Same

Herbicide Agents

Type II diabetes 197,000 Most are 10% and 20%

Prostate cancer 30,000 1/3 at 100%, average 40%

Respiratory cancer 5,000 Half at 100%

Non-Hodgkin’s and Hodgkin’s 5,000 Half at 100%, balance 50%

Gulf War

Undiagnosed illness 3,259 Typically a 10% evaluation

SOURCE: Pamperin, 2006b. 

However, estimates are made. VA estimated administrative costs for presumptive radiation decisions (bone, brain, colon, lung, and ovarian cancers) 

as $33,934,297 over 10 years with benefit costs of $768,601,698 over that 

same time period (McLenachen, 2005, slide 8). Estimated administrative 

costs for type 2 diabetes from 2001 through 2005 were $62 million with 

estimated benefit costs of $3.3 billion during that same time period. VA 

estimated that there would be 20,399 new type 2 diabetes awards in the 

first year and 179,000 over the next 5 years. The estimates did not include 

retroactive payments (McLenachen, 2005, slide 12). Today, the most frequent disability for which Vietnam veterans are receiving service-connected 

compensation is type 2 diabetes (VBA, 2006, p. 34). “At end of fiscal year 
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THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS 63

2006, nearly 248,000 veterans were service-connected for diabetes. More 

than 215,000 of these awards were based upon herbicide exposure in Vietnam” (VA, 2007, pp. 6B-13).

Role of Institute of Medicine (IOM)

The National Academies is a private, nonprofit, and independent entity 

that advises the nation on science, engineering, and health matters (NAS, 

2007a). The IOM is one of four entities within the National Academies. 

The other entities are the National Academy of Sciences, which was created 

by Congress during Abraham Lincoln’s presidency, the National Academy 

of Engineering, and the National Research Council.

The National Academies convenes committees of its own members and 

“other experts to address the scientific and technical aspects of society’s 

most pressing problems” (NAS, 2007b, p. 2). All committee members serve 

without pay. Committee members are screened to ensure that they do not 

have conflicts of interest. The committees include “experts with the specific 

expertise and experience needed to address the study’s statement of task” 

(NAS, 2007b, p. 3). 

The National Academies use a systematic study process. Study committees typically gather information through “(1) meetings that are open to the 

public and that are announced in advance through the National Academies’ 

Web site; (2) the submission of information by outside parties; (3) reviews 

of scientific literature; and (4) the investigations of the committee members 

and staff” (NAS, 2007b, pp. 5-6). 

Committee deliberations are closed to the public and sponsors in order 

to “develop draft findings and recommendations free from outside influence. . . . All analyses and drafts of the report remain confidential” (NAS, 

2007b, p. 6). A rigorous external peer review by a separate group of volunteer experts is undertaken prior to completion of the study. The National 

Academies are responsible for the final products and their public release. 

For additional information on the National Academies and the committee 

process, see http://nationalacademies.org/.

IOM Perspective

The Committee heard from IOM staff about how studies requested by 

VA were conducted over several decades (Martinez, 2006). On each occasion that VA has asked IOM to conduct a new study for Agent Orange 

or the Gulf War in support of a possible presumption, a new committee 

was selected and convened. Each committee had access to the publically 

available information regarding the work of previous IOM committees 

but interpreted their statement of task independent of prior committees. 
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64 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

As a result, each committee’s operating assumptions and study plans were 

similar but not fully identical to those of prior committees. They were free 

to construct their own evidence criteria and ways to weigh the individual 

research studies that they considered (see Appendixes H-1 and H-2 for IOM 

Agent Orange and Gulf War committee study charges).

IOM has completed six full, biennial Veterans and Agent Orange (VAO) 

reviews (IOM, 1994, 1996, 1999, 2001, 2003b, 2005b) and three focused 

(IOM, 2000b, 2004b, 2006a) Agent Orange reviews (see Appendix H-1). 

A new VAO update report was recently published (IOM, 2007b); this VAO 

report was being drafted simultaneously and independently of this report. 

Each of the VAO committees was composed of experts with diverse backgrounds to address their charge. Because of the unique nature of the Agent 

Orange biennial reviews, some consistency of membership for subsequent 

reviews across committees has been sustained. As a result, approximately 

one-third of each VAO committee’s members had served on a previous 

committee and were familiar with the past literature on Agent Orange. This 

overlap of membership helped to provide historical perspective and some 

consistency throughout the review process. 

The IOM committees have been faced with significant challenges, 

including

• few directly applicable epidemiologic studies; 

• no contemporaneous exposure measurements; 

• uncertainty about which veterans were exposed to which agents; 

• multiple, possibly synergistic exposures; 

• possible long latency for health effects from some agents; and 

• significant confounders. (Martinez, 2006, slides 7-8)

Source reference material includes epidemiologic studies (e.g., occupational, environmental, veterans) and toxicologic studies (e.g., animal health 

effects, cellular-level mechanistic). 

The first IOM VAO committee categorized the strength of the evidence 

available into the following four categories: “(1) sufficient evidence of an 

association, (2) limited/suggestive evidence of an association, (3) inadequate/

insufficient evidence to determine whether an association exists, and 

(4) limited/suggestive evidence of no association” (IOM, 1994, pp. 6-7). 

Although there have been minor changes to the characterization of these 

categories over the past 15 years, each of the committees has continued to 

categorize evidence in this manner (IOM, 1996, 1999, 2001, 2003b, 2005b; 

see also Appendix H-3).

The committees carrying out the Gulf War (GW) studies requested by 

VA have approached their task somewhat differently. Similar to the process outlined for Agent Orange, VA requested IOM to “conduct a study 
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THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS 65

to evaluate the published scientific literature concerning the association 

between the agents to which the Gulf War veterans may have been exposed 

and adverse health effects” (IOM, 2000a, p. 2). The first IOM Gulf War 

committee began its work in January 1999 and identified an initial list of 

compounds of greatest concern to veterans. Two public laws (Veterans 

Programs Enhancement Act of 1998. Public Law 105-368. 105th Cong., 2d 

Sess.; Making Omnibus Consolidated and Emergency Appropriations for 

the Fiscal Year Ending September 30, 1999, and for other Purposes. 1998. 

Public Law 105-277. 105th Cong., 2d Sess.) mandated further studies.

 The first IOM Gulf War and Health Study committee decided to categorize strength of evidence into the following five categories: (1) sufficient 

evidence of a causal relationship, (2) sufficient evidence of an association, 

(3) limited/suggestive evidence of an association, (4) inadequate/insufficient 

evidence to determine whether an association does or does not exist, and 

(5) limited/suggestive evidence of no association (IOM, 2000a, pp. 4-5). 

Although there have been minor language changes to these categories 

or description of these categories, the individual, stand-alone committees have continued to categorize evidence in this manner (IOM, 2003a, 

2004a, 2005a, 2006b, 2007a; see also Appendix H-4). As in the case of 

the Agent Orange committees, there has been some overlap of committee 

membership in the Gulf War series. However, the nature of the individual 

Gulf War reports and specific statements of task have required less overlap 

of membership and increased the need for more specific scientific expertise 

and background in the various areas of biological, chemical, and infectious 

agents depending upon the specific charge to the committee.

These Agent Orange and Gulf War examples show important similarities 

and differences relevant to the overall presumptive process. Of note, Agent 

Orange reports by IOM did not explicitly include a causal category in the 

evaluation, whereas Gulf War reports did include a category of evidence sufficient to infer causation when characterizing the strength of evidence available for all agents evaluated. Consideration of the actual exposure potential 

for veterans was beyond the charges to the committees.

The statements of task and conclusions from each of the Agent Orange 

and Gulf War reports may be found in Appendix H.

Role of Veterans Service Organizations (VSOs)

There are numerous VSOs that voice their members’ concerns. VSOs 

and their advisory committees have played an important role in the evaluations and actions of Congress, VA, and the National Academies (e.g., 

IOM and NRC). There are also special veteran advisory groups, such as 

the Advisory Committee on Former POWs, with direct access to the VA 

Secretary. The impact and voices of the veteran community can be very 
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66 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

powerful. A review of the “Agent Orange Update,” which describes some 

of the actions and influence VSOs and other organizations had in moving 

the Agent Orange Act forward (Cranston, 1990), provides insight into the 

role VSOs played in that specific congressional action. 

The Committee received extremely helpful and diverse input from 

representatives of VSOs and individual veterans who attended open session 

committee meetings or who prepared written material to provide to the 

Committee for its consideration.

Veterans Perspective

The Committee heard that VSOs struggle with how scientific evidence 

that is uncertain and sometimes limited is used in evaluating cause and 

effect relationships. The VSO representatives wanted to make certain not 

only that the Committee considered past conflicts and practices but also 

that the Committee took into account what is occurring in today’s environment and what future veterans may be facing, including emerging problems 

such as traumatic brain injuries, a signature wound of the current Gulf 

conflict (Sullivan, 2006). 

Other issues raised included better data collection on exposures and 

health status during military service, the use of International Classification 

of Diseases codes for illness and injuries, and seamless transition to VA after 

discharge. The importance of collecting data for reservists and National 

Guard members identical to those serving active duty was emphasized 

(Sullivan, 2006).

The Committee repeatedly heard from representatives of VSOs and 

individual veterans that they expect a fair, equitable, and scientifically based 

system for establishing presumptions (Kinderman, 2006; Overstreet, 2006; 

Selfon, 2006). However, the Committee was also cautioned that more rigorous application of tests for cause and effect may not serve the process well 

(Violante, 2006).

Each of the VSOs reaffirmed the responsibility and commitment to 

care for all men and women who have served in our stead—past, present, 

and future. Each stakeholder brings an important perspective to the presumptive disability decision-making process for veterans. There are clearly 

factors other than science that are considered in these decisions especially 

when the science base is weak or absent. The future framework will seek 

to identify ways to improve information and the methods needed to make 

the best possible presumptive decisions.
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REFERENCES

Barrans, D. 2006. History of presumptions of service connection. Paper presented at the 

first meeting of the IOM’s Committee on the Evaluation of the Presumptive Disability 

Decision-Making Process for Veterans, Washington, DC. 

Brown, M. 2006. The role of science in Department of Veterans Affairs disability compensation policies for environmental and occupational illness and injuries. Paper presented at 

the first meeting of the IOM’s Committee on the Evaluation of the Presumptive Disability 

Decision-Making Process for Veterans, Washington, DC. 

Carr, T. P. 2001. CRS report for Congress. Parliamentary reference sources: House of 

Representatives. CRS report RL30787. Washington, DC: Congressional Research Service. http://lugar.senate.gov/CRS%20reports/Parliamentary_Reference_Sources_House.

pdf (accessed April 30, 2007).

Cranston, A. 1990. Agent Orange update. Senate Congressional Record 101st Cong., 2nd 

Sess. November 2. Presented by Scott, E. P., at the third meeting of the IOM’s Committee 

on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans, 

San Antonio, TX.

Deyton, L. 2006. Introduction to VA health care system and assessing environmental/occupational exposures. Paper presented at the second meeting of the IOM’s Committee 

on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans, 

Washington, DC. 

IOM (Institute of Medicine). 1994. Veterans and Agent Orange: Health effects of herbicides 

used in Vietnam. Washington, DC: National Academy Press. 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy 

Press. 

IOM. 1999. Veterans and Agent Orange: Update 1998. Washington, DC: National Academy 

Press. 

IOM. 2000a. Gulf War and health, volume 1: Depleted uranium, pyridostigmine bromide, 

sarin, and vaccines. Washington, DC: National Academy Press. 

IOM. 2000b. Veterans and Agent Orange: Herbicide/dioxin exposure and type 2 diabetes. 

Washington, DC: National Academy Press. 

IOM. 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy 

Press. 

IOM. 2003a. Gulf War and health, volume 2: Insecticides and solvents. Washington, DC: The 

National Academies Press. 

IOM. 2003b. Veterans and Agent Orange: Update 2002. Washington, DC: The National 

Academies Press. 

IOM. 2004a. Gulf War and health: Updated literature review of sarin. Washington, DC: The 

National Academies Press. 

IOM. 2004b. Veterans and Agent Orange: Length of presumptive period for association 

between exposure and respiratory cancer. Washington, DC: The National Academies 

Press. 

IOM. 2005a. Gulf War and health, volume 3: Fuels, combustion products, and propellants. 

Washington, DC: The National Academies Press. 

IOM. 2005b. Veterans and Agent Orange: Update 2004. Washington, DC: The National 

Academies Press. 

IOM. 2006a. Disposition of the Air Force Health Study. Washington, DC: The National 

Academies Press. 

IOM. 2006b. Gulf War and health, volume 4: Health effects of serving in the Gulf War. 

Washington, DC: The National Academies Press. 
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68 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

IOM. 2007a. Gulf War and health, volume 5: Infectious diseases. Washington, DC: The 

National Academies Press. 

IOM. 2007b. Veterans and Agent Orange: Update 2006. Washington, DC: The National 

Academies Press 

Johnson, C. W. 2003. How our laws are made, revised and updated. Washington, DC: Government Printing Office. http://www.senate.gov/reference/resources/ pdf/­howourlawsaremade.

pdf (accessed May 7, 2007).

Kinderman, Q. 2006. Statement presented at the second meeting of the IOM’s Committee 

on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans.

Washington, DC.

Martinez, R. 2006. Institute of Medicine: Agent Orange and Gulf War studies. Presented at the 

second meeting of the IOM’s Committee on the Evaluation of the Presumptive Disability 

Decision-Making Process for Veterans, Washington, DC. 

McLenachen, D. 2005. Presumptive service connection in VBA. Presented to Veterans’ Disability Benefits Commission, Washington, DC. 

NAS (The National Academies). 2007a. The National Academies: Advisors to the nation on 

science, engineering, and medicine. http://www.nationalacademies.org/ (accessed May 9, 

2007).

NAS. 2007b. The National Academies study process: Ensuring independent, objective advice. 

http://www.nationalacademies.org/studycommitteprocess.pdf (accessed May 9, 2007).

Overstreet, H. G. 2006. Statement presented at the third meeting of the IOM’s Committee 

on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans.

San Antonio, TX. 

Pamperin, T. J. 2006a. An overview of the disability benefits program and presumptions 

affecting veterans’ benefits. Paper presented at the first meeting of the IOM’s Committee 

on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans, 

Washington, DC. 

Pamperin, T. J. 2006b. Presumptions in VA’s disability program—The effect. Paper presented 

at the first meeting of the IOM’s Committee on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans, Washington, DC. 

Petrou, L. 2006. Statement presented at the third meeting of the IOM’s Committee on the 

Evaluation of the Presumptive Disability Decision-Making Process for Veterans. San 

Antonio, TX.

Ryan, P. 2006. Perspectives on veterans’ legislative disability presumptions. Paper presented 

at the third meeting of the IOM’s Committee on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans, San Antonio, TX.

Scott, E. P. 2006. Statement presented at the third meeting of the IOM’s Committee on the 

Evaluation of the Presumptive Disability Decision-Making Process for Veterans, San 

Antonio, TX.

Selfon, L. J. 2006. Statement from the United Spinal Association presented at the second meeting of the IOM’s Committee on the Evaluation of the Presumptive Disability DecisionMaking Process for Veterans, Washington, DC. 

Sullivan, P. 2006. Testimony presented at the third meeting of the IOM’s Committee on the 

Evaluation of the Presumptive Disability Decision-Making Process for Veterans, San 

Antonio, TX.

VA (Department of Veterans Affairs). 2006. Internal VA process for reviewing reports of the 

IOM under the Agent Orange Act of 1991 and the Persian Gulf War Veterans Acts of 

1998. Presented to the IOM’s Committee on the Evaluation of the Presumptive Disability 

Decision-Making Process for Veterans, Washington, DC.
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THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS 69

VA. 2007. Fiscal year 2008 budget submission. National cemetery administration, benefits 

program, and departmental administration. Vol. 2. Washington, DC: Department of 

Veterans Affairs. http://www.va.gov/budget/summary/ (accessed May 9, 2007).

VBA (Veterans Benefits Administration). 2006. Annual benefits report fiscal year 2005. Washington, DC: Department of Veterans Affairs. 

Violante, J. A. 2006. Public comments for the IOM’s Committee on the Evaluation of the 

Presumptive Disability Decision-Making Process for Veterans. San Antonio, TX. 

Yoder, C. 2006. Thoughts on presumptions of service-connection for veterans presumed to 

have been exposed to environmental hazards. Paper presented at the third meeting of 

the IOM’s Committee on the Evaluation of the Presumptive Disability Decision-Making 

Process for Veterans, San Antonio, TX.
Copyright © National Academy of Sciences. All rights reserved.

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70

4

Legislative Background on Presumptions

In previous chapters, the Committee has described the historical background for presumptions and the current approach as it has evolved to 

include Congress, the Department of Veterans Affairs (VA), the National 

Academies (Institute of Medicine [IOM] and National Research Council 

[NRC]) and stakeholders. This chapter addresses the legislative background, 

in greater depth, for three more recent issues that have been a focus for the 

National Academies (NRC and IOM) and VA: radiation exposure, Agent 

Orange, and the Gulf War. The same issues are also a focus for case studies 

that are summarized in the next chapter and provided in their entirety in 

Appendix I. The legislative materials covered in this chapter provide a picture of the concerns of veteran stakeholders and congressional responses 

and intent, as set out in specific legislation.

The complexities and perplexities that encumber the presumptive disability decision-making process are evident if we look at the evolution of 

presumptions governing radiation exposures, the Gulf War, and Agent 

Orange. We see a variety of approaches, not always consistent, a diverse 

group of participants—Congress, VA, the National Academies (NRC and 

IOM), stakeholders, and the courts—and somewhat opaque standards for 

making decisions. It should be noted that VA proposes to reorganize and 

rewrite all of its compensation and pension regulations (see 71 Fed. Reg. 

16464 [March 31, 2006]) (VA, 2006b). Notices of Proposed Rulemaking 

have been published and will continue to be published. The discussion that 

follows does not take these new rules into account. 
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LEGISLATIVE BACKGROUND ON PRESUMPTIONS 71

PRESUMPTIONS FOR VETERANS, IN GENERAL

VA clearly assumes that all congressional presumptions governing veterans’ benefits are type 1 presumptions (see Chapter 2 for an explanation 

of the difference between type 1 and type 2 presumptions) (Zeglin, 2006). 

Consequently, the veteran is relieved both of producing sufficient evidence 

of an exposure that is service connected and of persuading VA that his or 

her adverse health effect was incurred through a service-connected exposure 

(Basic Entitlement. 2006. 38 U.S.C. § 1110 provides for disability payments 

for illnesses that were “aggravated” or “incurred” during service). Once a 

medical condition is service connected through presumptions, and the veteran can document military service consistent with the given exposure or 

risk, the veteran only has to show the basic fact that he or she suffers from 

the condition in order to receive the specified disability payment. 

The discussion below will focus on the link between disease and 

service—the question to which scientific reviews are directed. Equally 

important to the compensation decision, however, is the creation of a 

presumption that relieves the veteran of having to provide evidence of 

a military exposure of sufficient magnitude to account for his or her illness 

or injury (Brown, 2005). See, for instance, 38 U.S.C.A. § 1116(f) (a veteran 

who served in Vietnam during a specified period is presumed to have been 

exposed to herbicide containing dioxin); 38 U.S.C. § 1116(f) (Presumptions 

of Service Connection for Diseases Associated with Exposure to Certain 

Herbicide Agents; Presumptions of Exposure for Veterans Who Served in 

the Republic of Vietnam. 2006. 38 U.S.C. § 1116(f); and Haas v. Nicholson

(2006). United States Court of Appeals for Veterans Claims, Case Number 

04-0491 § 1116[f]) is ambiguous as to whether it required veterans to have 

set foot in Vietnam, and the court extended the presumption to veterans 

serving in the waters near the shore of Vietnam. Often, as is evident in the 

case studies, exposure data are lacking, making it impossible to conduct 

epidemiologic studies of the veterans. In such cases, the medical evidence 

for the presumption that links the disease to the exposure will relate to a 

surrogate group, such as workers exposed to the substances at issue. For a 

discussion of this problem in connection with the Vietnam War presumptions, see Stellman and Stellman (2005).

In theory, all presumptions, including those that govern a veteran’s 

ability to show exposure, prove health outcomes, establish that a disability 

did not predate service (Wagner v. Principi. 2004. United States Court of 

Appeals for the Federal Circuit, Case Number 02-7347), or establish some 

other element of a claim, are rebuttable as provided in 38 U.S.C.S. § 1113 

(Presumptions Rebuttable. 2005. 38 U.S.C. § 1113). VA assumes that an 

individual was medically sound when entering military service. However, 

that presumption of soundness is sometimes challenged if evidence shows 
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72 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

a preexisting condition. See examples in the Veterans Benefits Manual (VA, 

2005). Federal circuit court has held that evidence rebutting a presumption 

must only meet a “preponderance of the evidence” standard unless Congress specifies a higher standard (Thomas v. Nicholson, 2005. United States 

Court of Appeals for the Federal Circuit, Case Number 05-7019).

In practice, presumptions establishing that a veteran’s adverse health 

effects are service connected are rarely rebutted. David Barrans of the VA 

Office of the General Counsel acknowledged in response to a question after 

his oral presentation at the July 2005 Veterans’ Disability Benefits Commission meeting that VA claims adjusters (veterans service representatives) 

generally do not seek to develop information to rebut presumptions. Accordingly, one does not see many claims rejected because of evidence that the 

disease predated the veteran’s military service or because the presumptive 

condition is found to stem from an intercurrent cause. VA does have provisions for developing evidence of “willful misconduct” if it may affect these 

claims (Basic Entitlement. 2006. 38 U.S.C. § 1110; Basic Entitlement. 2007. 

38 U.S.C. § 1131), but the limited provisions are rarely relevant to presumptive claims (see Presumptions Rebuttable. 2005. 38 U.S.C. § 1113; Line of 

Duty and Misconduct. 2005. 38 C.F.R. § 3.301). Accordingly, in practice 

the presumptions governing service connection are not rebutted and operate 

more as rules of law than procedural devices; they mandate finding a nexus 

between the veteran’s service and a specified disability or disease. 

If Congress wished, it could specify evidence that may or may not be 

used to rebut a presumption. It has done so in other statutes, unrelated to 

veterans’ benefits that rely on presumptions to establish benefits under a 

compensation scheme. For instance, the Back Lung Benefits Act (Congressional Findings and Declaration of purpose. 2007. 30 U.S.C. § 901, et seq.) 

contains a number of rebuttable type 2 presumptions that operate to prove 

that a miner was disabled due to pneumoconiosis and that this disability 

arose out of his employment in coal mines. The regulation accompanying 

this legislation specifically provides that certain items of evidence shall not 

suffice to rebut the presumption of disability (Presumption of Entitlement 

Applicable to Certain Death Claims. 2003. 20 C.F.R. § 718.306[d]). The 

courts have taken this to mean that a combination of items can be used 

to rebut the presumption. Similarly, the National Childhood Vaccine Act 

(Establishment. 2007. 42 U.S.C. § 300aa-1) contains a vaccine injury table 

(Vaccine Injury Table. 2007. 42 U.S.C. § 300aa-14) setting out presumptions that particular adverse health effects occurring within a specified 

period after a child was vaccinated were caused by the vaccination. The act 

also requires showing that “there is not a preponderance of the evidence” 

that the claimed injury “is due to factors unrelated to the administration 

of the vaccine” (Determination of Eligibility and Compensation. 1999. 42 

U.S.C.S. § 300aa-13[a][1][B]). These factors may, as shown by the claim-
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LEGISLATIVE BACKGROUND ON PRESUMPTIONS 73

ant’s evidence or other material in the record, “include infection, toxins, 

trauma (including birth trauma and related anoxia), or metabolic disturbances which have no known relation to the vaccine involved, but which in 

the particular case are shown to have been the agent or agents principally 

responsible for causing” the claimed injury (Determination of Eligibility 

and Compensation. 1999. 42 U.S.C. § 300aa-13[a][2][B]). 

The claims process becomes more complicated, less certain, and more 

expensive if evidence has to be scrutinized by a claims adjuster. The current system of creating presumptions that permit “automatic” awarding of 

benefits when a veteran suffers from a named presumptive disease promotes 

administrative efficiency. It means, however, that scientific input into decisions about a veteran’s entitlement to disability payments occurs only at 

the front end of the process when a decision is made whether or not to 

service connect.

PRESUMPTIONS GOVERNING RADIATION, AGENT ORANGE, 

AND GULF WAR EXPOSURES, IN GENERAL

Many veterans exposed to radiation or Agent Orange in Vietnam or 

who served in the Persian Gulf War1 alleged they suffered from adverse 

health effects incurred through military service. Eventually, as discussed 

below, Congress legislated with regard to all three situations. Some of this 

legislation lists specific illnesses and adverse health effects and authorizes 

VA to adopt presumptions through rule making that would relieve a veteran 

from having to prove a service connection. Although the statutes resemble 

each other in some respects, and may have influenced each other, the case 

studies indicate that the data, decisions, and decision makers underlying 

the presumptions are quite dissimilar. For example, both Congress and 

VA have established presumptions for radiation. Only VA has established 

presumptions for Agent Orange. And although VA was given the authority 

by Congress to do so, VA has not made presumptions of service connection 

to date for diseases incurred by Persian Gulf War veterans; however, VA 

administers compensation for Persian Gulf War veterans who are service 

connected by the congressionally established presumption of “undiagnosed 

illnesses” that may become manifest within a presumptive period after 

service in the Gulf. 

Although most radiation exposures occurred considerably earlier than 

the Agent Orange exposures during the Vietnam War, Congress started to 

pay attention to both problems at approximately the same time. 

1As defined in 38 U.S.C. § 101 (33), the term “Persian Gulf War” means “the period 

beginning on August 2, 1990, and ending on the date thereafter prescribed by presidential 

proclamation or by law.”
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74 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

The Radiation Presumptions

In 1984, Congress passed the Agent Orange and Atomic Veterans 

Relief Act (Public Law No. 98-592, 98 Stat. 2725 [1984] eventually became 

Veterans’ Dioxin and Radiation Exposure Compensation Standards Act. 

1984. Public Law 98-542. 98th Cong., 2d Sess.), which provided benefits 

for veterans who had participated either in atomic bomb testing or in the 

postwar occupation of Hiroshima or Nagasaki if they developed leukemia, 

polycythemia vera, or carcinoma of the thyroid. This was intended to be a 

temporary measure until further studies were completed (see HR, Report 

98-592, 98th Cong. 2d session, U.S. Congress, House of Representatives, 

1984). This act does not contain presumptions but directed VA to adopt 

regulations that would assist veterans who had been exposed to radiation.

In 1988, Congress passed the Radiation Exposed Veterans Compensation Act (1988. Public Law 100-321. 100th Cong., 2d Sess.). The act 

created a presumption that a veteran who suffered from one of 13 specified 

cancers, and who had participated in atomic bomb testing or the postwar 

Japanese occupation or was a Japanese prisoner of war during the specified 

time period, was entitled to disability benefits and free medical treatment. 

In 2002, an additional 5 cancers were added to the presumptive list (VA, 

2002). 

Regulations adopted pursuant to the Veterans’ Dioxin and Radiation Exposure Compensation Standards Act (Claims Based on Exposure 

to Ionizing Radiation. 2006. 38 C.F.R. § 3.311) were designed to assist 

veterans who are not suffering from one of the presumptive cancers. If the 

veteran is suffering from a “radiogenic” disease listed in the regulation, VA 

is required to assess the “size and nature of the radiation dose” that the 

veteran may have received. When VA receives dose information and the 

report reflects a range of possible exposure levels, then VA must presume 

exposure at the highest end of the reported exposure range in making its 

determination (Claims Based on Exposure to Ionizing Radiation. 2006. 38 

C.F.R. § 3.311[a]). Even if the disease is not listed as a “radiogenic” disease, 

VA is nevertheless required to “consider the claim under the provisions of 

this section provided that the claimant has cited or submitted competent 

scientific or medical evidence” of the disease’s being “radiogenic” (Claims 

Based on Exposure to Ionizing Radiation. 2006. 38 C.F.R. § 3.111[b][4]). 

Claims are referred to the Under Secretary for Benefits who must determine 

whether “sound scientific and medical evidence supports the conclusion” 

that “it is at least as likely as not the veteran’s disease resulted from exposure to radiation in service. ‘Sound scientific evidence’ means observations, 

findings, or conclusions that are statistically and epidemiologically valid, 

are statistically significant, are capable of replication, and able to withstand 

peer review, and ‘sound medical evidence’ means observations, findings, or 
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LEGISLATIVE BACKGROUND ON PRESUMPTIONS 75

conclusions that are consistent with current medical knowledge and are so 

reasonable and logical as to serve as the basis of management of a medical 

condition” (Claims Based on Exposure to Ionizing Radiation. 2006. 38 

C.F.R. § 3.111c). 

Of all the presumptions, those governing exposure to radiation probably rest on the firmest scientific evidentiary basis. As the case study indicates (see Appendix I), a great deal is known about the effects of radiation. 

Groups other than veterans who were exposed to radiation, such as downwinders, had exposures similar to the veterans, unlike the very different 

exposures experienced by workers who were treated as surrogates for 

veterans in studying the effects of dioxin exposures in factory accidents. 

Nevertheless, despite the presumptive diseases that have been established, many veterans have difficulty in establishing a service connection; 

they may be unable to furnish the required evidence of their exposure at a 

specified location and time, in part because such information may be classified as secret (Podgor, 2005). They may then seek compensation under the 

nonpresumptive regulations because those provide that if the veteran claims 

to have been in a specified location on a particular date and the government 

cannot prove otherwise, it must be assumed that the veteran participated 

in activities that would have given rise to a presumptive decision. However, because this is a nonpresumptive claim, the veteran will have to show 

adequate exposure (Podgor, 2005). In 2003, an NRC committee concluded 

that only about 50 nonpresumptive claims had been successful although 

thousands had been filed (NRC, 2003, p. 252). 

The Agent Orange Presumptions

The historical background that led to the Agent Orange presumptions 

is set out in Chapter 2. By 1984, the courts had rejected the veterans’ claims 

that their illnesses were caused by exposure to Agent Orange, and VA was 

not providing disability benefits except for cases of chloracne. The veterans 

had fared better with Congress, which in 1981 authorized VA to provide 

hospital and outpatient care for veterans whose health problems allegedly 

stemmed from Agent Orange exposures (Veterans’ Health Care, Training, 

and Small Business Loan Act. 1981. Public Law 97-72. 97th Cong., 1st 

Sess.). When in 1984 Congress acted again and passed the Veterans’ Dioxin 

and Radiation Exposure Compensation Standards Act (1984. Public Law 

98-542. 98th Cong., 2d Sess.), President Reagan observed in his signing 

statement that VA had already furnished medical care to over one million 

Vietnam veterans (Reagan, 1984).

The 1984 act took three steps toward creating service-connection 

presumptions for diseases suffered by Vietnam veterans (Murphy, 1986). 

First, the act created some interim presumptions by directing VA to grant 
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temporary disability benefits, lasting until September 30, 1986, to any 

veteran who contracted chloracne (a skin condition) or porphyria cutanea 

tarda (a liver disease) within one year of leaving Vietnam (Murphy, 1986). 

Second, the act required the Administrator of Veteran Affairs to promulgate 

guidelines and standards for determining whether claims based on exposure 

to Agent Orange were service connected (Murphy, 1986). Congress thereby 

authorized VA to handle dioxin claims via new procedures that it was to 

devise and promulgate through formal rule making rather than by adjudications in individual proceedings. Third, the act directed the formation of 

an advisory committee to collect and evaluate scientific studies relating to 

the possible health effects of exposure to Agent Orange (Veterans’ Dioxin 

and Radiation Exposure Compensation Standards Act. 1984. Public Law 

98-542. 98th Cong., 2d Sess.). 

In August 1985, after receiving input from the Veterans’ Advisory Committee on Environmental Hazards, VA issued final regulations relating to 

the 1984 act that set out a process for adjudicating claims based on Agent 

Orange exposure (VA, 1985). The regulations concluded that “sound medical and scientific evidence does not establish a cause-and-effect relationship 

between dioxin exposure” and any disease other than chloracne (Claims 

based on exposure to ionizing radiation. 1985. 38 C.F.R. § 3.311a[d]). 

In 1987, a number of veterans instituted a lawsuit challenging VA’s 

regulations as violating the 1984 act by adopting too high a standard for 

finding a connection between exposure to Agent Orange and manifestation of a particular disease (Nehmer v. United States, 1989, United States 

District Court for the Northern District of California, Case Number 86-

6160). The plaintiffs contended that “Congress intended only that there 

be a significant ‘statistical association’ between dioxin and a particular 

disease in order to grant service connection for that disease.” VA conceded 

that its regulation required “proof of a causal relationship to grant service 

connection.” The court, after explaining that the issue to be decided was 

legal—what was Congress’ intent—and not the scientific question of which 

test was scientifically valid, turned to the language of the 1984 act in order 

to determine congressional intentions (Nehmer v. United States, 1989, 

United States District Court for the Northern District of California, Case 

Number 86-6160, pp. 4-6).

The court first pieced together a number of different statements in the 

act because the applicable standard of proof was not directly addressed. 

The court found that “the language of the act is at best ambiguous, at worst 

silent” because Congress spoke in terms of both association and cause. 

Because the text was inconclusive, the court next looked at the legislative 

history to ascertain Congress’ purpose. After reviewing comments by members of House and Senate committees that had jurisdiction over the act, the 

court concluded “that Congress did not intend VA to use a causal relation-
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LEGISLATIVE BACKGROUND ON PRESUMPTIONS 77

ship,” but suggested that “service connection to be granted on the basis of 

‘an increased risk of incidence,’ or a ‘significant correlation’ between dioxin 

and various diseases.” According to the court, this standard was consistent 

with previous practices that had established presumptions of service connectedness for amputees and prisoners of war (Nehmer v. United States, 

1989, United States District Court for the Northern District of California, 

Case Number 86-6160, pp. 7-9). 

VA announced that it would not appeal the Nehmer decision and that 

it would abide by the court’s ruling and issue new Agent Orange regulations. The litigation has continued as to whether veterans denied benefits 

pre-Nehmer are entitled to receive benefits retroactively even for conditions 

that were service-connected after the date of Nehmer. The 9th Circuit Court 

of Appeals so held on July 19, 2007. Congress also took further steps. In 

1991, after numerous hearings and committee reports, it enacted the Agent 

Orange Act (Agent Orange Act of 1991. Public Law 102-4. 102d Cong., 

1st Sess.; codified, as amended, Presumptions of Service Connection for 

Diseases Associated with Exposure to Certain Herbicide Agents. 2006. 38 

U.S.C. § 1116).

The Agent Orange Act continued to use both association and causation language, albeit in a somewhat different form. It gave the VA Secretary 

authority to prescribe regulations providing for a presumption “[w]henever 

the Secretary determines, on the basis of sound medical and scientific evidence, that a positive association exists between” the Agent Orange exposure and a disease. The act states that

An association between the occurrence of a disease in humans and exposure to an herbicide agent shall be considered to be positive for the purposes of this section if the credible evidence for the association is equal to 

or outweighs the credible evidence against the association. (Agent Orange 

Act of 1991. Public Law 102-4. 102d Cong., 1st Sess.) 

Rather than relying on an advisory committee to furnish scientific 

input, the act directed VA to contract with the National Academy of 

Sciences (NAS) “to review and evaluate the available scientific evidence 

regarding associations between diseases and exposure to dioxin and other 

chemical compounds in herbicides” (Agent Orange Act of 1991. Public 

Law 102-4. 102d Cong., 1st Sess.). In making an association determination, the VA Secretary was instructed to consider the NAS reports and “all 

other sound medical and scientific information and analyses available to the 

Secretary,” and in evaluating any study, the VA Secretary is to “take into 

consideration whether the results are statistically significant, are capable of 

replication, and withstand peer review” (Agent Orange Act of 1991. Public 

Law 102-4. 102d Cong., 1st Sess.). 
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78 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Congress directed the committee to answer “to the extent that available 

scientific data permit meaningful determinations” (Scientific Determinations Concerning Disease. 2006. 38 U.S.C. § 1116.3[d][1]) about

1. whether a statistical association with herbicide exposure exists, 

taking into account the strength of the scientific evidence and the appropriateness of the statistical and epidemiologic methods used to detect the 

association;

2. the increased risk of disease among those exposed to herbicides 

during service in the Republic of Vietnam during the Vietnam era; and

3. whether there exists a plausible biological mechanism or other 

evidence of a causal relationship between herbicide exposure and disease. 

The first IOM Veterans and Agent Orange (VAO) committee that was 

convened to respond to these questions (IOM, 1994, p. 15) concluded that 

a lack of exposure data made it impossible to answer the second question. 

The other two questions required the committee to examine the cause of the 

particular health effect at issue. This is explicit in question 3, which mandates inquiry into a “causal relationship.” Question 1 also requires a causal 

inquiry, though it makes this request implicitly. As Dr. Hertz-­Picciotto, the 

chair of the 2000 and 2002 IOM committees explained: “[A]ny determination about the existence of ‘statistical association’ that takes into account 

‘strength’ of the evidence and ‘appropriateness’ of the methods examines 

the same concerns that enter into a consideration of evidence for causation” 

(Hertz-Picciotto, 2005, p. 556). 

The first IOM VAO committee began meeting in 1992 and issued its 

first review in 1994 (IOM, 1994). It decided to place the data it found 

and reviewed into one of four categories: sufficient evidence of an association; limited/suggestive evidence of an association; inadequate/insufficient 

evidence to determine whether an association exists; limited/suggestive evidence of no association. It was required to update its reports every 2 years 

or sooner. 

The IOM VAO committees at times changed the category for several 

particular health outcomes, as successive reviews considered additional 

evidence. VA’s response and establishment of a presumption to the IOM 

categorization of the particular health outcome was not necessarily consistent. For example, the VAO committees in 1994 and 1996 characterized the 

evidence linking Agent Orange to prostate cancer as limited/suggestive of 

an association (IOM, 1994, 1996). VA did not establish a presumption for 

prostate cancer in 1994. It was not until 1996 that VA decided that prostate 

cancer should be presumptively service-connected (VA, 1996). In another 

example, the 1994 IOM VAO committee characterized the evidence linking herbicides to type 2 diabetes to be inadequate/insufficient to determine 
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LEGISLATIVE BACKGROUND ON PRESUMPTIONS 79

if an association existed (IOM, 1994). In 2000, a special Agent Orange 

committee was constituted at the request of VA to evaluate type 2 diabetes 

independent of the IOM VAO biennial reviews (IOM, 2000b). The committee characterized the evidence as limited/suggestive of an association (IOM, 

2000b). VA then decided that type 2 diabetes should be presumptively 

service-connected (VA, 2001). It was not clear from the Federal Register

notice why VA concluded that the existence of limited/suggestive evidence 

was equivalent to the requirement of “credible evidence for the association 

is equal to or outweighs the credible evidence against the association” or a 

“positive association” as required by the Agent Orange Act of 1991 (Public 

Law 102-4. 102d Cong., 1st Sess.). The statement in the Federal Register

reporting the VA Secretary’s decision to presumptively service-connect (VA, 

2001) did not explicitly explain how these conclusions were reached.

The Persian Gulf War Presumptions

The Persian Gulf War was fought during a very short period in 1991. 

Almost immediately, veterans began to complain of numerous adverse 

health effects that they attributed to service in the Gulf. It immediately 

became evident to Congress and VA that the Persian Gulf veterans’ health 

complaints differed significantly from those voiced by the Vietnam veterans. 

The Vietnam veterans ascribed their medical woes to herbicides and Agent 

Orange, and they claimed that the numerous well-defined diseases from 

which they suffered, ranging from skin and liver diseases to a variety of 

cancers, could be attributed to exposure to herbicides and Agent Orange. 

The Persian Gulf War veterans, on the other hand, claimed to be suffering 

from syndromes and symptoms rather than established diseases, and they 

blamed these on exposures to a host of toxic environmental substances that 

were present in the Persian Gulf. Many of the exposures are no different 

than those experienced by civilians in the United States, and for the great 

majority of veterans, the magnitude of the exposures was small, and limited 

to a short period of time (Brown, 2005).

Congress began by authorizing VA to provide health-care services on a 

priority basis to Persian Gulf veterans (Priority VA Health Care for Persian 

Gulf Veterans. 1993. Public Law 103-210. 103d Cong., 1st Sess.). An effort 

was also undertaken to gather data about the nature of the illnesses and 

symptoms that veterans claimed to have, as well as to conduct research on 

environmental exposures that occurred during the war. In 1994, Congress 

passed the Veterans’ Benefits Improvements Act (Public Law 103-446. 

103rd Cong., 2d Sess., codified as Compensation for Disabilities Occurring 

in Persian Gulf War Veterans. 2006. 38 U.S.C. § 1117), which authorized 

VA to compensate veterans for certain chronic disabilities and illnesses 

that could not be attributed to any known clinical diagnosis. Originally, 
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80 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

these adverse health effects had to manifest within 2 years of service in the 

Persian Gulf in order for a veteran to receive compensation. This presumptive time period has, however, been extended a number of times. Most 

recently in December 2006, compensation is now available provided the 

disability of “undiagnosed illness” becomes manifest by December 31, 2011 

(VA, 2006a, p. 75672).

In 1998, Congress passed the Persian Gulf War Veterans Act of 1998 

(Public Law 105-277. 105th Cong., 2d Sess., codified, in part, as Presumptions of Service Connection for Illnesses Associated with Service in the 

Persian Gulf During the Persian Gulf War. 2006. 38 U.S.C. § 1118) and 

the Veterans Programs Enhancement Act of 1998 (Public Law 105-368. 

105th Cong., 2d Sess.). These acts, which are similar to the Vietnam War 

Agent Orange legislation, set up procedures for establishing presumptions 

of service connection for diseases incurred by Gulf War veterans. As in the 

Agent Orange legislation, “a positive association” is required between an 

environmental exposure associated with service in the Persian Gulf War 

and “the occurrence of a diagnosed or undiagnosed illness in humans or 

animals” (Presumptions of Service Connection for Illnesses Associated with 

Service in the Persian Gulf During the Persian Gulf War. 2006. 38 U.S.C. 

§ 1118[b][1][B][ii]). In addition, the Gulf War Act stated that an association “shall be considered to be positive . . . if the credible evidence for the 

association is equal to or outweighs the credible evidence against the association” (Presumptions of Service Connection for Illnesses Associated with 

Service in the Persian Gulf During the Persian Gulf War. 2006. 38 U.S.C. 

§ 1118[b][3]). The same review process as was set up for Agent Orange 

was established for Gulf War. An agreement was entered into with NAS to 

establish committees that were charged with answering similar questions 

as asked of the IOM VAO committees (Persian Gulf War Veterans Act of 

1998. Public Law 105-277. 105th Cong., 2d Sess.). As with Agent Orange, 

the IOM committee provides its Gulf War reports to VA, and the VA Secretary must then determine whether a presumption should be established 

and announce the decision in the Federal Register. IOM has issued several 

volumes of Gulf War reports (IOM, 2000a, 2003, 2005, 2006, 2007).

Although VA was given the authority by Congress to do so, VA has 

not made presumptions of service connection to date for diseases incurred 

by Persian Gulf War veterans pursuant to 38 U.S.C. § 1118 (Presumptions 

of Service Connection for Illnesses Associated with Service in the Persian 

Gulf During the Persian Gulf War. 2006. 38 U.S.C. § 1118). However, VA 

administers compensation for Persian Gulf War veterans who are service 

connected by the congressionally established presumption of “undiagnosed 

illnesses” that may become manifest within a presumptive period after 

service in the Gulf. In February 2006, the VA Secretary wrote to leaders of 

the House and Senate Veterans Affairs Committees advising them that the 
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LEGISLATIVE BACKGROUND ON PRESUMPTIONS 81

evidence currently available did not warrant the establishment of Persian 

Gulf presumptions and that VA would publish notices of its decision in the 

Federal Register “explaining the basis for that determination” (Nicholson 

letters on file with committee, 2006a,b,c,d). As of the time of report publication, no statement appears in the Federal Register, although such statements 

are required to be filed within 60 days of the receipt of an IOM report 

(Presumptions of Service Connection for Illnesses Associated with Service 

in the Persian Gulf During the Persian Gulf War. 2006. 38 U.S.C. § 1118). 

Although the presumptive service-connection mechanism has not been a 

major factor for Persian Gulf veterans, a comparatively large percentage of 

Persian Gulf veterans have, nonetheless, been able to collect compensation 

through the direct service-connection route (Brown, 2006). 

As of now, the Persian Gulf statutes would govern any presumptions 

dealing with current service in Iraq or any other area in the Gulf. 

REFERENCES

Brown, M. 2005. The role of science in Department of Veterans Affairs disability compensation policies for environmental and occupational illness and injuries. Journal of Law and 

Policy 13(2):593-612.

Brown, M. 2006. The role of science in Department of Veterans Affairs disability compensation policies for environmental and occupational illness and injuries. Paper presented 

to the IOM’s Committee on Evaluation of the Presumptive Disability Decision-Making 

Process for Veterans, Washington, DC. 

Hertz-Picciotto, I. 2005. How scientists view causality and assess evidence: A study of the Institute of Medicine’s evaluation of health effects in Vietnam veterans and Agent Orange. 

Journal of Law and Policy (Brooklyn Law School) 13(2):553-591. 

IOM (Institute of Medicine). 1994. Veterans and Agent Orange: Health effects of herbicides 

used in Vietnam. Washington, DC: National Academy Press. 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy 

Press. 

IOM. 2000a. Gulf War and health, volume 1: Depleted uranium, pyridostigmine bromide, 

sarin, vaccines. Washington, DC: National Academy Press. 

IOM. 2000b. Veterans and Agent Orange: Herbicide/dioxin exposure and type 2 diabetes. 

Washington, DC: National Academy Press. 

IOM. 2003. Gulf War and health, volume 2: Insecticides and solvents. Washington, DC: The 

National Academies Press. 

IOM. 2005. Gulf War and health, volume 3: Fuels, combustion products, and propellants. 

Washington, DC: The National Academies Press. 

IOM. 2006. Gulf War and health, volume 4: Health effects of serving in the Gulf War. Washington, DC: The National Academies Press. 

IOM. 2007. Gulf War and health, volume 5: Infectious diseases. Washington, DC: The 

National Academies Press. 

Murphy, S. 1986. A critique of the Veterans Administration claims process. Brooklyn Law 

Review 52:533-569. 

NRC (National Research Council). 2003. A review of the dose reconstruction program of the 

Defense Threat Reduction Agency. Washington, DC: The National Academies Press. 
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Podgor, M. F. 2005. The inability of World War II atomic veterans to obtain disability 

benefits: Time is running out on our chance to fix the system. Elder Law Journal

13(2):519-523.

Reagan, R. 1984. Statement on signing the Veterans’ Dioxin and Radiation Exposure Compensation Standards Act. http://www.presidency.ucsb.edu/ws/ index.php?pid=39308&st=&st1= 

(accessed May 15, 2007).

Stellman, J. M., and S. D. Stellman. 2005. Characterization of exposure to Agent Orange 

in Vietnam veterans as a basis for epidemiological studies. Journal of Law and Policy 

(Brooklyn Law School) 13(2):505-525. 

U.S. Congress, House of Representatives. 1984. Agent Orange and Atomic Veterans Relief 

Act. House Report 98-592. 98th Cong., 2nd Sess. January 25. 

VA (Department of Veterans Affairs). 1985. Adjudication of claims based on exposure to 

dioxin or ionizing radiation. Final rules. Federal Register 50(165):34452-34461.

VA. 1996. Diseases associated with exposure to certain herbicide agents (prostate 

cancer and acute and subacute peripheral neuropathy). Final rule. Federal Register

61(217):57586-57589.

VA. 2001. Diseases associated with exposure to certain herbicide agents: Type 2 diabetes. 

Federal Register 66(89):23166-23169.

VA. 2002. Diseases specific to radiation-exposed veterans. Final rule. Federal Register

67(17):3612-3616.

VA. 2005. VA M21-1MR Adjudication Procedures Manual Rewrite. Washington, DC: Department of Veterans Affairs. http://www.warms.vba.va.gov/M21_1MR.html (accessed 

May 14, 2007). 

VA. 2006a. Extension of the presumptive period for compensation for Gulf War veterans. 

Federal Register 71(242):75669-75672. 

VA. 2006b. General provisions. Proposed rule. Federal Register 71(62):16464-16475.

Zeglin, D. E. 2006. Presumptions of service connection. Paper prepared for the Veterans’ Disability Benefits Commission. https://www.1888932-2946.ws/vetscommission/

e-documentmanager/gallery/Documents/Reference_Materials/Presumption-Paper_3-7-

06.pdf (accessed March 8, 2007).
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83

5

Case Studies Summary Chapter

INTRODUCTION

In addressing its charge with regard to characterizing Congress’ and 

the Department of Veterans Affairs’ (VA’s) presumptive disability decisionmaking process for veterans, the Committee completed the set of case 

studies around specific exposures and illnesses listed in Table 5-1. The 

Committee determined that a thorough evaluation of selected case studies 

would capture past practices of all participants involved in the presumptive disability decision-making process for veterans—Congress, VA, the 

National Academies’ (Institute of Medicine [IOM] and National Research 

Council [NRC]), stakeholders, and the courts—and provide a basis for 

making sound and practical recommendations for the future of this process. 

The complete, specific case studies are found in Appendix I.

The case studies were selected to reflect the range of presumptive decisions established by Congress and VA, as they made decisions using evidence ranging from abundant and quite conclusive in the case of radiation 

to much more limited in cases such as Agent Orange and prostate cancer. 

The examples were also chosen to illustrate approaches taken by IOM and 

NRC committees in evaluating evidence related to presumptions. In the 

case studies, the Committee focused on examining the evidence foundation available for evaluation by Congress, the IOM or NRC, and VA; the 

approaches taken for reviewing the evidence; the schema used to classify the 

level of evidence for causation; and the translation of the scientific evidence 

through the conclusions of the IOM and NRC committees into a decision 

by VA. The case studies also provided insights into principles embedded in 

the presumptive disability decision-making process. 
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84 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 5-1 List of Case Studies (in chronological order of when 

presumptions were established by Congress or VA)

Mental Disorders’ Presumptions

Multiple Sclerosis Presumption

Prisoners of War (POWs) Presumptions

Amputees and Cardiovascular Disease Presumption

Radiation Presumptions

Mustard Gas and Lewisite Presumptions

Gulf War Presumptions

Agent Orange and Prostate Cancer Presumption

Agent Orange and Type 2 Diabetes Presumption

Spina Bifida Program*

*Because spina bifida is a condition that affects the children of veterans, it is not a presumptive 

decision for veterans; however, the children of Vietnam and Korean War veterans are covered 

by a VA program.

The case studies were based on detailed review of public laws, legislative background, research reports, National Academies’ IOM and NRC 

committees’ reports, and VA materials. However, as described in Chapter 1, 

the case studies were limited by VA’s response to the Committee’s request 

for information, documents, and responses to the Committee’s written 

questions. The case studies synthesize a large body of information. This 

body of information is summarized in Annex 5-1 at the end of this chapter, and the full case study series is in Appendix I. Additional materials 

on individual case studies and cost estimates are also referenced at the 

end of this chapter in Annexes 5-2 and 5-3. This chapter synthesizes the 

“lessons learned” from each of the case studies. We begin by summarizing 

each of the case studies and the particular lessons learned and then look 

across the case studies as a group for more general conclusions. The case 

studies are presented in chronological order as to when presumptions were 

established by Congress or VA. In drawing out these lessons as a basis for 

moving forward, the Committee’s commentary should not be construed as 

a critique of past activities and processes of Congress, VA, and National 

Academies’ IOM and NRC committees. This Committee recognizes that 

these activities took place over decades during which scientific research and 

evidence review processes were evolving and that tremendous efforts from 

all participants in the process went into producing all of the work that we 

summarize as follows.
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CASE STUDIES SUMMARY CHAPTER 85

MENTAL DISORDERS’ PRESUMPTIONS

Description

There have been two major types of presumptive disabilities for mental 

disorders among U.S. veterans: those presumed to be chronic and those 

among POWs. The diversity of these disorders has posed a challenge. The 

presumptive disabilities assigned to posttraumatic stress disorder (PTSD), 

depression, and any anxiety state for POWs are well grounded in the scientific literature (Beebe, 1975; CDC, 1988; Cohen and Cooper, 1954; Engdahl 

and Page, 1991; Keehn, 1980; Nefgzer, 1970; Page et al., 1997). The 

presumptive disability category for psychosis among veterans has a more 

limited base of evidence (Beebe, 1975; Keehn, 1980) and appears a consequence of its initial inclusion as a presumptive disability when presumptions 

first began in 1921. At that time, the disorder (then called neuropsychiatric 

disease) had no treatment and was considered to be chronic. 

Lessons Learned

Presumptive decisions for mental disorders have been made for veterans who are former POWs and veterans who developed chronic mental 

problems during or shortly after military service. Although legislation has 

been informed by the scientific evidence available at the time, the scientific 

evidence in some instances has been limited and with inconsistency around 

the disorders included. For example, if the strength of evidence classification of limited/suggestive evidence led to presumptive decisions for PTSD, 

dysthymia, and any anxiety state among former POWs, then there does not 

appear to be a clear basis for excluding other mental disorders with equal 

or stronger evidence of connection to being a POW, such as major depression. The presumptive decisions established with regard to the previously 

mentioned mental disorders make clear that these decisions have been 

influenced by not only scientific evidence but by political and social considerations that apply to these veterans (e.g., POWs) and the specific mental 

disorders they may manifest. The need to develop a stronger evidence 

base and consistent evaluation of the evidence base with regard to these 

mental disorders is great, particularly in light of the anticipated high rates 

of mental disorders among military personnel assigned to and returning 

from Iraq and Afghanistan. This case study also illustrates the need for a 

process to continually carry out research and update the scientific evidence 

base for presumptions.
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86 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

MULTIPLE SCLEROSIS PRESUMPTION

Description

This case study examines the 1962 decision to grant compensation for 

service-connected disability to veterans diagnosed with multiple sclerosis 

(MS) within 7 years of their separation from the military. This presumption stems from the VA’s interest in compensating disease and disability that 

has its onset during military service. Veterans with one of a defined list of 

chronic diseases may also be compensated if these are diagnosed within 

1 year of separation from the military. The rationale here is that these 

diseases are sufficiently insidious and the diagnosis sufficiently challenging 

so as to make it impossible to conclude with certainty that the true disease 

onset did not occur during the period of military service.

Multiple sclerosis was eventually singled out from the other chronic illnesses and the period of diagnosis extended from 1 year (Veterans’ Chronic 

and Tropical Diseases Act of 1948. Public Law 80-748. 80th Cong., 2d 

Sess.; VA, 1949), to 2 (Act of October 12, 1951. ch. 499, 65 Stat. 421 as 

cited in VA, 1993), to 3 years (Act of August 25, 1959. Public Law 86-

187. 86th Cong., 1st. Sess. as cited in VA, 1993), and eventually to 7 years 

(Veterans’ Disability Compensation Increase Act of 1962. Public Law 87-

645. 87th Cong., 2d Sess. as cited in VA, 1993) following separation from 

military service. The rationale for this extension was the growing scientific 

evidence (much of it generated by VA researchers studying veterans) of the 

long delay between the onset of MS symptoms and eventual diagnosis, as 

well as the possibility that environmental factors may play a role in the 

etiology of MS. However, these studies also failed to find evidence that 

military service contributes to MS risk, and veterans do not appear to have 

higher rates of MS than the general population (Berkowitz and Santangelo, 

1999; Kurtzke and Page, 1997; Kurtzke et al., 1979, 1985, 1992; Norman 

et al., 1983; Page et al., 1993, 1995; VA Multiple Sclerosis Study Group, 

1956, 1957; Wallin et al., 2000).

Lessons Learned

The rationale for the MS presumption reflects two lines of reasoning 

used in making presumptions. The first reflects the possibility that MS 

diagnosed after separation from the military may, in fact, have been present 

during military service, and therefore subject to the same compensation 

rules as other direct service-connection disabilities. The second acknowledges that the etiology of MS is unclear and may be related to an environmental exposure received during military service. Understanding that both 

of these arguments have been used in the MS case is important, because the 
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evidence required to support each is very different. In the first case, timing 

is the standard (specifically the possibility of disease onset during military 

service), and evidence for association between an exposure and outcome is 

not required. By contrast, in the second case, evidence from some association between exposure during service and future disease is necessary. 

Congress did not call for a systematic review of the scientific literature 

on this topic; such a review might have allowed for more evidentiary discussion of the premise behind this presumption and the type of evidence that 

might be necessary to support it. 

PRISONERS OF WAR PRESUMPTIONS

Description

Disability presumptions concerning American veterans who were captured and interned as POWs almost uniformly developed as a result of 

congressional initiatives prompted by concerns over the harsh treatment 

that POWs had endured and practical difficulties that they might encounter 

in establishing entitlement to benefits. Concerned that World War II POWs 

might lack official medical records and have difficulties establishing the 

conditions of their internment, Congress first instructed VA to give special 

consideration and apply liberal evidentiary standards to POWs’ claims. As 

details of the harsh nature of the POW experience became more widely 

known, and as members received complaints from some former POWs 

having difficulties establishing disability benefit claims, Congress began to 

enact statutory presumptions for certain nutritionally related conditions 

and mental illness. Studies of mortality and morbidity among POWs suggesting connections of the POW experience with certain diseases and conditions also served as impetus for additional legislation, notwithstanding 

scientific limitations noted in those studies (Keehn, 1980; Nefzger, 1970; 

Page and Miller, 2000; Page and Ostfeld, 1994; Page and Tanner, 2000; 

VA, 1993). Over the course of more than 50 years, certain preconditions 

that had to be met before a presumption could attach, such as length or 

internment or the time period in which a condition must first be manifested, 

were progressively liberalized or eliminated by statute. In 2004 VA established administrative standards for any new POW presumptions based on 

“limited/suggestive evidence” of an association of the disease with internment provided that it was “biologically plausible” (VA, 2004).

Lessons Learned

Americans and their elected representatives have long been concerned 

with the welfare of those who protected, defended, and sacrificed for their 
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88 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

country. The extensive system of veteran benefits and their liberalized rules 

for qualification are a manifestation of this concern. This concern is intensified when those veterans seeking assistance are viewed as having been 

subjected to extraordinary stresses and sacrifices, as have POWs. As VA 

declared in its 1980 study, the POW experience was an “extremely harsh 

and brutal experience,” “. . . characterized by starvation, diet, poor quality 

or nonexistent medical care, ‘death marches,’ executions, and torture” (VA, 

1980, p. 4).

Given this context, the creation of certain presumptions with respect to 

disabilities claimed to be connected with a veteran’s experience as a POW 

reflects long established concern for their welfare. These presumptions simplify adjudication for otherwise difficult cases because of the lack of specific 

evidence on exposures and the complexity of the health consequences of 

having been a POW. A difficult burden of proof for the veteran and VA is 

removed by a presumption. Presumptions have been particularly helpful in 

assessing POW claims for which information about individual conditions of 

internment and complete medical records were frequently unavailable. Presumptions have enabled greater consistency in decision making for POWs; 

a previous lack of consistency generated much discontent by veterans who 

strongly communicated their concerns to elected representatives. 

Research has been carried out on the health of former POWs (Beebe, 

1975; Brass and Page, 1996; Cohen and Cooper, 1954; IOM, 1992; Keehn, 

1980; Nefzger, 1970; Page and Brass, 2001; Page et al., 1991, 1997; VA, 

1980). The studies, which date back to the early 1950s, have slowly provided evidence on the POW experience, particularly about malnutrition, 

stress, and the psychological consequences. 

At the same time, evidence relevant to particular presumptions was 

sometimes limited by coming from a single study with a small sample size. 

Consequently, interpretations of most studies acknowledged the uncertainties of findings and urged caution at drawing unwarranted inferences. As 

described by one author, the mixture and interdependence of various factors 

of the POW experience and the variation of their relative intensities “from 

time to time, from place to place, and from man to man,” have “limit[ed] 

the scope and specificity of the inferences that may be drawn statistically” 

(Nefzger, 1970, p. 124). 

Given the suggestive but scientifically uncertain results of many studies, 

not surprisingly policy makers frequently decided to create service-­connected 

presumptions when faced with the pressing claims of genuinely sick and 

disabled former POWs. As one author observed of his 1992 study of POWs, 

the “descriptive” data obtained had “uses beyond the scientific,” specifically 

in the “discussion of military service-connected disabilities.” He added, 

“[d]espite the fact that sound inferences about the group of all former 

POWs cannot be drawn from the exam data in this report, policy­makers 
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who must deal with such issues should be able to review this descriptive 

information” (IOM, 1992, p. 5; emphasis added). VA in its 2004 Guidelines 

for POW Presumptions responds to uncertainty; while expressing an intent 

to base its determinations on “sound scientific and medical evidence,” it 

adopts a standard of “limited/suggestive evidence” of an association for 

former POWs and adds the additional caveat that “fairness to former 

POWs requires that VA fully evaluate the available data and not accord 

undue significance to the fact that such data are comparatively limited by 

the small size of the affected population” (VA, 2004, p. 60085).

The POW case study illustrates how uncertainties of the available 

scientific information have been relatively weighted against other driving 

factors for compensating POWs. Over time, the requirement that a presumptive decision be “based on sound scientific and medical evidence” has 

increasing been overshadowed by these other considerations, reflecting the 

determination to assure that compensation for former POWs has maximum 

sensitivity.

AMPUTEES AND CARDIOVASCULAR DISEASE PRESUMPTION

Description

This case study examines the 1979 presumption of service connection 

for cardiovascular disease that develops in veterans with certain types of 

service-related amputations. This case study was chosen to illustrate several important features. First, in contrast to many presumptions that exist 

because of the difficulty establishing exposure status among veterans, this 

presumption applies to a defined group of veterans for whom exposure (i.e., 

amputation) is not in question. Controversy regarding whether amputation 

was linked to cardiovascular disease prevented this complication from being 

compensated through standard individual claims and therefore necessitated 

the presumption. Second, this presumption was put in place through legislative action on the part of Congress, not administratively by VA, as is the 

case with many of the other presumptions. Third, the scientific basis for this 

presumption is a single Medical Follow-Up Agency (MFUA) study of World 

War II amputees and their mortality from cardiovascular disease (Hrubec 

and Ryder, 1980). During the more than 30 years of follow-up of the study 

population, 922 proximal amputees died; 714.1 deaths were expected based 

on the general U.S. male death rate. Compared with distal amputees and 

those with disfigurement, proximal amputees had a higher risk of all-cause 

mortality, diabetes, and cardiovascular disease, particularly atherosclerotic 

(ischemic) heart disease. 
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90 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Lessons Learned

The lessons from this case study center around the type of evidence 

necessary to put a presumption in place, specifically what level of evidence should be required for a presumption; how the scientific base of 

evidence is updated based on new studies; how to evaluate evidence 

regarding exposures, outcomes, and potential mediators; and what types 

of evidence might make the scientific basis for a presumption more robust. 

This presumption was put into place largely on the basis of one study and 

further studies on cardiovascular disease in amputees have not been carried out, even though the occurrence, management, and natural history 

of cardiovascular diseases have changed substantially in the subsequent 

three decades. In the decades since the presumption was implemented, 

many aspects of cardiovascular disease have changed; incidence rates have 

dropped, as has mortality; new preventive approaches are available, and 

treatments are increasingly effective. However, further studies have not been 

carried out on cardiovascular disease in subsequent cohorts of amputees, 

nor were data systems put in place to carry out surveillance for changing 

disease risks in the amputees. Special populations, such as the amputees, 

could be closely tracked through registries (i.e., specific cohort studies) to 

make certain that previous scientific observations hold and to assess if the 

establishment of additional presumptions is needed.

RADIATION PRESUMPTIONS

Description

The radiation case study is concerned with the experience of the 

“atomic veterans” who were exposed to ionizing radiation, mainly through 

participation in nuclear weapons tests. In this case study, unlike most of 

the others, there is an abundant literature—some relating to dose-response 

relationships in general populations, some specific to veterans—upon 

which to base compensation policy (CIRRPC, 1988; IARC, 2000; IOM, 

1996a, 2002; Lagakos and Mosteller, 1986; Lubin and Steindorf, 1995; 

NRC, 1980, 1984, 2003, 2005, 2006; Podgor, 2007; Prentice et al., 1983; 

RECAC, 1996; UNSCEAR, 2000). In general, most veterans for whom 

exposure estimates are available appear to have had relatively low doses, 

and a summary of the epidemiologic evidence suggests that the majority 

of cancers in this group were not caused by radiation. Despite this, there 

remain numerous uncertainties, particularly with respect to estimation 

of an individual’s exposures and with respect to the risk for specific rare 

cancers. These uncertainties in large part are responsible for the shift 

in emphasis from individual dose-based criteria for compensation in the 
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Veterans’ Dioxin and Radiation Exposure Compensation Standards Act 

of 1984 (Public Law 98-542. 98th Cong., 2d Sess.) to the establishment 

of presumptions in the Radiation-Exposed Veterans Compensation Act of 

1988 (Public Law 100-321. 100th Cong., 2d Sess.), illustrating the need for 

presumptions even in this relatively data-rich situation. It also illustrates 

that epidemiologic studies of veterans themselves can be less informative 

than other nonmilitary populations because of such issues as limited sample 

size, inadequate length of follow-up, low doses, poor dosimetry, other 

potential biases, and difficulties in teasing out the effects of modifiers such 

as smoking. Finally, the radiation story illustrates the practical difficulties 

posed by the secrecy under which these nuclear weapons test operations 

were conducted, posing difficulties both for researchers and for individual 

veterans seeking to document their claims.

Lessons Learned

For radiation exposure, in contrast to the factors considered in the 

other case studies, epidemiological evidence on risks is abundant and the 

dose-response relationships for cancer have been described with reasonable 

precision from such major studies as that of the atomic bomb survivors. 

Epidemiological studies have been carried out on radiation-exposed veterans 

specifically. General models have been developed for quantifying the probability of causation, given the level of exposure. Additionally, there is a 

substantial body of research on mechanisms by which radiation causes 

cancer. 

Nonetheless, uncertainties remain in extending this evidence to compensating particular veterans as their exposures are poorly estimated, disease outcomes lack specificity of cause, and for some rare cancers causation 

remains to be established. These uncertainties in large part appear responsible for the shift in emphasis from individual probability of causation 

(PC)-based criteria for compensation in the Veterans’ Dioxin and Radiation 

Exposure Compensation Standards Act of 1984 (Public Law 98-542. 98th 

Cong., 2d Sess.) to the establishment of presumptions in the RadiationExposed Veterans Compensation Act of 1988 (Public Law 100-321. 100th 

Cong., 2d Sess.). Still unresolved is whether, in light of the uncertainties 

about site-specific risk, perhaps all cancers in radiation-exposed veterans 

should be treated as presumptively caused by radiation, at least absent 

very convincing evidence that the specific cancer is not caused by radiation. Arguably, the only site that might be excluded on this basis would be 

chronic lymphatic leukemia.

While the Committee has called for research and surveillance on the 

health of veterans, the studies of radiation effects in veteran populations 

have proven of limited utility, in part because of the relatively small num-
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92 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

ber of excess cancers expected in the available cohorts and, importantly, 

because individual exposures were not tracked in a systematic manner. As a 

result an opportunity to carefully characterize radiation-related cancer risks 

among veterans may have been missed. Fortunately, there has long been a 

strong body of evidence from other populations, so that the weak evidence 

provided by the studies of veterans has not been construed as a basis for 

holding back on presumptions for radiation. The availability of strong epidemiologic data has made possible the construction of quantitative models 

to guide compensation policy for radiation-exposed veterans, which has 

often not been possible for other exposures. These models have not been 

used to quantify the burden of radiation-caused cancer among veterans.

Specificity is an issue in compensation of cancers in radiation-exposed 

individuals. Many cancers caused by radiation also have many other responsible risk factors, and cases caused by radiation cannot be distinguished 

from those caused by other factors. Additionally, for most radiation exposures received during military service, the probability of causation is low. 

In the example of smoking, which interacts with radiation for lung cancer, 

evidence-based policies can be developed based on an understanding of the 

joint effects of radiation and smoking. Potentially, if data are available, 

similar models could be developed for the interaction of radiation with 

other agents. 

Ultimately, much of the force behind the movement for compensation 

for the atomic veterans came from the fact that the government deliberately 

exposed them to harm, while having at least some knowledge of the risks 

involved at the time. Furthermore, the risks were often denied by government officials, both at the time of exposure when military personnel were 

not properly informed and later when diseases were manifest and attempts 

at redress were dismissed. On this basis, veterans consider that the case 

for their claims for compensation is enhanced by the culpability of the 

government.

MUSTARD GAS AND LEWISITE PRESUMPTIONS

Description

This case study examines the 1992 and 1994 decisions by VA to establish presumptive service connection for health outcomes related to mustard 

gas and lewisite exposures among World War II veterans. This case study, 

the first involving a congressional request for the IOM to develop a report, 

raises a series of still persistent issues. With the recognition that some World 

War II veterans had been exposed to mustard gas during laboratory studies, 

VA in 1992 proposed a presumptive service-connection decision covering 

this exposure (VA, 1992a). The presumption was based on four primary 
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factors: (1) the studies were classified, (2) participants were directed not 

to discuss their participation in the studies, (3) their medical records were 

sparse, and (4) no long term follow-up was conducted or provided for the 

participants (VA, 1992a). VA issued a final rule in July 1992 (VA, 1992b). 

As a result of public comment to the proposed rule as found in the 

final rule (VA, 1992a,b), VA contracted with IOM to write a report on the 

health effects of exposure to mustard gas and lewisite. In early 1994, VA 

revised the presumption based on the IOM study, Veterans at Risk: The 

Health Effects of Mustard Gas and Lewisite (IOM, 1993), and issued a 

proposed rule (VA, 1994a). The second presumptive service-connection 

rule was issued in August 1994. This rule amended the original proposal 

by (1) adding more diseases to the original list of diseases, (2) adding the 

compound lewisite to the rule, (3) adding veterans who might have been 

exposed during World War I and in studies after the end of World War II, 

and (4) clarifying the extent of exposure (VA, 1994b). 

Lessons Learned

A number of concerns are raised by this presumptive decision. Foremost is the unresolved problem raised by secrecy surrounding military/

governmental studies involving exposure of military personnel to warfare 

agents that may have immediate or delayed effects on their health (IOM, 

1993). Classifying warfare studies based on national security is necessary in 

many cases. However, this classification can lead to concerns about health 

that might not be resolved for decades. 

In the case of mustard and lewisite agents, national security took precedence over the long-term health risks to the study participants. Participants 

in these studies maintained their secrecy oaths for decades even though 

they developed health problems consequent to their exposures. As health 

consequences emerged there were problems in finding information about 

exposure to mustard gas or lewisite in their medical records. Consequently, 

health-care providers could not provide appropriately targeted screening 

and care and long-term medical follow-up was not provided to the study 

participants. A third area of concern is that this classification precluded 

health-care providers from being aware that symptoms of mustard gas or 

lewisite exposure might be exhibited by patients. As a result, the health-care 

providers did not look for these occupationally related symptoms (IOM, 

1993). 

The consequences of secreting information were partially recognized in 

several Information Letters from the VA Under Secretary for Health (VA, 

2002, 2005, 2006). As indicated in the Presidential Task Force 2003 report 

(President’s Task Force to Improve Health Care Delivery for Our Nation’s 

Veterans, 2003) and a recent Government Accountability Office (GAO) 
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94 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

report (GAO, 2006a), the health of our veterans must be considered in relation to all aspects of military service. The presidential task force specifically 

cited the lack of exposure data to a known environmental hazard as a root 

cause for not being able to determine compensatory issues for our veterans 

(GAO, 2006a,b). While it appears that DoD is addressing the tracking and 

recording of the Service members’ movements to link with exposure data 

that have been collected, both of these issues remain concerns for the veteran. Inadequate exposure data are collected, and the ability to vector these 

data to location and troop movement has limited attribution of disease to 

exposure agents for individual veterans. Exposure assessment is the key to 

disability benefits for veterans. A recent report (GAO, 2004) indicates that 

force health protection and surveillance policy are not as good as they could 

be, but are improving, especially with more current deployments. 

The final rule for mustard gas and lewisite (VA, 1994b), based upon 

the 1993 IOM report, outlined three categories of casual relationships for 

health consequences of exposure: indicated, suggested, and insufficient 

evidence of a relationship. VA acknowledged in the final rule that certain 

health consequences could be linked directly to mustard gas or lewisite 

exposure and that a second grouping of health consequences had a suggestive linkage based upon the 1993 IOM report. Although the IOM report 

recommended many diseases that could be associated with exposure to 

these agents, VA specifically eliminated several of the diseases as not being 

related to mustard gas or lewisite exposure. Consequently, a precedent was 

established by VA for causal health consequences associated with specific 

chemical agents as recommended by IOM. Lastly, this case study indicates 

an apparent lack of communication and coordination between DoD and 

VA regarding individual Service members and government workers involved 

in studies, chemical agents used in these studies, and any actual or potential exposure data for the individuals involved. This lack of coordination 

was emphatically pointed out in the 1993 report Veterans at Risk (IOM, 

1993).

GULF WAR PRESUMPTIONS

Description

While the Gulf War presumption process was heavily influenced by the 

Agent Orange presumptive history, the course of the Gulf War process was 

different from that of its predecessor. The lengthy Agent Orange process 

was a culmination of interactions between veterans and their advocates, 

Congress, the scientific community, the work of the IOM committees, and 

VA. However, when Congress established the initial Gulf War presumption 

termed “undiagnosed illnesses,” two of the aforementioned four groups—
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the scientific community and VA—were not involved in the decision-making 

process. This initial presumptive provision for “undiagnosed illnesses” by 

Congress was based on symptom complaints of returning Gulf War veterans 

and was not related to single organ systems or easily explained by a unifying exposure or mechanism. Rather, nonspecific signs and symptoms were 

grouped under the “undiagnosed illnesses” category for disability compensation. VA was directed by Congress to administer the program. 

After the first two provisions of the Gulf War presumptions had been 

enacted (unexplained illnesses and chronic multisymptom illness) by Congress, Congress instructed VA to commission a scientific review examining 

the candidate exposures in the Gulf theater that may have contributed to 

the health effects experienced by veterans. These reviews were performed 

by IOM committees and reported in a five-volume series titled Gulf War 

and Health (IOM, 2000a, 2003a, 2005a, 2006, 2007). The reviews found 

limited evidence of linkages between veterans’ health and specific environmental exposures during deployment. The majority of the scientific findings 

from the IOM Gulf War committees and subsequent decisions by the VA 

Secretary to presumptively service connect or not service connect have not 

yet appeared in the Federal Register as required by statute, and VA has not 

yet presumptively connected any health conditions with Gulf War service. 

Lessons Learned

Compensation presumptions mandated by Congress in the absence 

of certain scientific evidence that link Gulf War service to adverse health 

outcomes, while well intentioned, may have contributed to confusion and 

suspicion around the presumptive process. In addressing health problems 

in Gulf War veterans, Congress and VA faced the difficulty of providing 

compensation for a syndromic illness that had not been linked to specific 

exposures. Two approaches were followed. The earlier decision (1995), 

to make “presumptive” a list of conditions, signs, or symptoms clustered 

under the rubric of “undiagnosed illnesses” allowed medical care and other 

benefits to be provided to affected veterans by VA. The second approach 

departed from the initial symptom-based presumption model, and a 1998 

act mandated as “presumptive” any additional conditions or symptoms that 

could be linked to “a biological, chemical, or other toxic agent, environmental or wartime hazard or preventive medicine or vaccine,” extending 

the possible list of potential illnesses considered presumptively linked to 

service in the Gulf (Persian Gulf War Veterans Act of 1998. Public Law 

105-277. 105th Cong., 2d Sess. § 1602). Thus, the presumptive process for 

Gulf War Illnesses may have been driven by public expectations and pressure on Congress and VA to act more quickly than either Congress or VA 

had acted with regard to Agent Orange decisions. It was clear that Congress 
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did not want to wait very long to provide assistance to Gulf War veterans 

following the experience they had in establishing the Agent Orange Act.

In a politically charged and time-pressured context, decisions about 

qualification for the initial Gulf War presumption needed to be made, even 

though the base of scientific evidence was incomplete. Additionally, since 

Gulf War Illness comprised a symptom complex without any specific diagnostic features, a presumption was established largely in response to reports 

of numerous individual veterans with inexplicable symptomatology, whose 

health had deteriorated. Congress made a decision to accept the veteran’s 

self-reported symptom complaints as sufficient evidence and validation of 

a Gulf War service-connected illness. Congress then directed VA, through 

legislation, to provide service-connected benefits to veterans with qualifying 

health complaints.

Little consideration has been given to estimating exposures received by 

individual veterans and the levels of exposures, or to the potential for using 

such estimates, based on specific locations in theater, job title, or specific 

duties, in determining eligibility for a service-connected Gulf War condition. 

There has been a broad assumption of exposure to harmful agents that are 

associated with Gulf War Illness, even though the responsible exposures 

were uncertain. In this example, Congress directed VA to choose to include 

all possible claims, permitting high sensitivity (including all possible cases), 

but poor specificity (high false positive claims). These initial policies came 

from Congress and were implemented by VA with little scientific review. 

In subsequent decisions related to the Gulf War, VA has engaged IOM in 

producing reports that VA considers in the presumptive disability decisionmaking process. VA has asked IOM to examine adverse health effects rather 

than the existing “undiagnosed illness” or “chronic diseases” provisions 

established by Congress with relation to Gulf War service. These reviews 

have been the basis for subsequent decision making by VA, which has not 

yet established any presumptions for the Gulf War. 

A lack of exposure information has hindered evidence-based decision 

making. Information for retrospectively estimating troop exposures during 

military service has been limited by gaps in exposure information, a limitation receiving comment by IOM committees and other groups addressing 

service-connected disability determinations (IOM, 2000a, 2003a, 2005a).

There are obvious barriers to collecting such information, including the 

complexity of doing so during wartime deployments. On the other hand, 

there has been increasing understanding of the need for exposure assessment as an element of force health protection and readiness (DoD, 1997, 

2006). 

This case study also points to the potential for decision making without 

having a sufficient evidence base to lead to unintended, adverse consequences, including erosion of public trust and confidence in the decision-
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CASE STUDIES SUMMARY CHAPTER 97

making process. The Committee viewed the legislated presumption for 

Gulf War Unexplained Illness as having some negative consequences. The 

decision was not evidence-based and it gave credence to the existence of a 

still poorly characterized and poorly investigated illness complex. Absent 

research, the presumption may have strengthened the belief that some 

candidate toxicants, or a mixture of environmental hazards known or 

unknown, existed in the Gulf War theater and were pervasively present at 

sufficient concentration to affect the thousands of veterans with symptoms 

of unexplained illness. Despite acknowledging preventable exposures to 

environmental chemicals in the Gulf War theater, after several IOM inquires 

into these hazards, none of the IOM committee reports (IOM, 2000a, 

2003a, 2005a, 2006, 2007) has endorsed either a unifying candidate toxicant as a cause for unexplained Gulf War illness or a combination of causes 

as evidence for the presumptions established by Congress.

AGENT ORANGE AND PROSTATE CANCER PRESUMPTION

Description

Prostate cancer is the second most common cause of cancer deaths in 

U.S. men (SOURCE: http://seer.cancer.gov/csr/1975_2003/results_merged/

topic_mor_trends.pdf). Although the focus of extensive research, few 

specific etiologic factors that explain the occurrence of the disease have 

been identified, other than a very strong association with age. The observational evidence available on Agent Orange and prostate cancer risk comes 

from epidemiological studies of herbicide and dioxin exposed groups in 

the general population and military personnel exposed to Agent Orange in 

Vietnam (see Table 6-34 in IOM, 2005b, pp. 277-280). 

Beginning with the 1994 Agent Orange report, IOM committees consistently found “limited/suggestive” evidence associating prostate cancer 

with Agent Orange—with the results of one high-quality study indicating 

a positive and statistically significant association with phenoxy herbicide 

exposure, along with weaker evidence and less consistent findings from 

other studies (IOM, 1994, 1996b, 1999, 2001, 2003b, 2005b). In the 

populations that have been investigated with higher levels of exposure 

evidence, excess risk of prostate cancer has been found in some studies 

and not uniformly across these studies (IOM, 1994, 2005b). However, 

in addition to the dioxin contaminant, the chlorophenoxy herbicide is a 

potential causative agent. Based in part upon the IOM finding that there 

was “limited/­suggestive” evidence for association, VA established a presumption in 1996 that provides benefits to Vietnam veterans with prostate 

cancer (VA, 1996).
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98 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Lessons Learned

In this case study, the Committee focused on the use of the scientific 

evidence on Agent Orange and prostate cancer in the decision to establish a 

presumption. The Committee assessed the relationship of the congressional 

language to the IOM’s criteria for classifying evidence and the use of the 

IOM’s evidence evaluation for prostate cancer by VA. The Agent Orange 

Act of 1991 (Public Law 102-4. 102nd Cong., 1st Sess. Section 2[b][3]) 

states that a positive association is one for which “the credible evidence of 

the association is equal to or outweighs the credible evidence against the 

association.” This statement is not necessarily equivalent to the category of 

“limited/suggestive” evidence for association used by IOM committees. The 

IOM limited/suggestive category covers a broad range of epidemiological 

evidence from relatively weak to strongly suggestive. In the instance of 

Agent Orange and prostate cancer, VA made a presumption based on the 

IOM’s conclusion of “limited/suggestive” evidence for association; the evidence at the time was relatively limited, but did include one study showing 

a statistically significant excess and a number of other studies showing 

positive, but weak and non-significant associations. Because the Committee did not have documentation of the rationale for VA’s decision beyond 

the Federal Register notice (VA, 1996), the basis for making a presumption 

given the particular IOM conclusion and scope of evidence was unclear to 

the Committee.

 In reviewing evidence on Agent Orange, the 2005 IOM review considered biological and toxicological evidence when evaluating the biological 

plausibility of the association between prostate cancer and exposure to 

Agent Orange but did not integrate these other lines of evidence with epidemiological findings to come up with an overall evaluation (IOM, 2005b). 

In seeking to classify the strength of evidence, prior IOM committees have 

relied mostly on epidemiological findings, potentially leaving the resulting 

presumptions open to criticism for having insufficient scientific justification 

when viewed in a broader context. Additionally, there has been a relatively 

limited body of relevant toxicological literature on prostate cancer.

The criterion for reaching “limited/suggestive” evidence for association 

of Agent Orange used by the IOM is that the “[e]vidence is suggestive of 

an association between herbicides and the outcome but is limited because 

chance, bias, and confounding could not be ruled out with confidence. For 

example, at least one high-quality study shows a positive association, but 

the results of other studies are inconsistent” (IOM, 2005b, p. 8) The Agent 

Orange Committee evaluations for prostate cancer considered the totality 

of epidemiological evidence, but there were limitations of the exposure data 

available to aid in the evaluation of the studies considered. Previous Agent 

Orange committees also reviewed and reported on toxicological and mecha-
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CASE STUDIES SUMMARY CHAPTER 99

nistic information, but according to their interpretation of their charge, did 

not integrate this information with the epidemiological evidence to make 

conclusions about the overall weight of the evidence for causal association. 

Several studies were of worker groups and measures of exposure to either 

the chlorophenoxy compounds or dioxin were not available to enable comparisons across studies. Dose-response relationships could be considered for 

a few studies; for example, the relative risk “of prostate cancer in Ranch 

Hands correlated with putative exposure to Agent Orange (high 6.04 vs 

low 2.17 vs background 1.5; p = 0.01)” (IOM, 2005b, p. 282). The lack 

of accurate estimates of exposure from the military experience has limited 

the study of the association between prostate cancer and exposure to Agent 

Orange in veterans. 

AGENT ORANGE AND TYPE 2 DIABETES PRESUMPTION

Description

This case study examines the 2001 decision to establish presumptive 

service connection for type 2 diabetes among Vietnam veterans under the 

Agent Orange Act (Agent Orange Act of 1991. Public Law 102-4. 102nd 

Cong., 1st Sess.). This case study was chosen because of several features 

in the events leading to the presumption and because of the implications 

of this presumption for VA. First, although most of the Agent Orange presumptions have been the result of the biennial IOM review of the scientific 

literature, the scientific evaluation that resulted in this presumption was 

conducted by a special IOM panel commissioned by VA specifically for 

this topic, out of sequence with the biennial IOM reports (IOM, 2000b). 

Second, after its review, this special IOM committee determined that the 

evidence linking Agent Orange and diabetes would justify a change from 

the previous category of “inadequate/insufficient” to “limited/suggestive.” 

Third, VA issued a presumption for type 2 diabetes on the basis of this 

“limited/suggestive” category of evidence, rather than the using the “sufficient evidence” standard. Finally, as a consequence of this presumption, 

all veterans who served in Vietnam receive compensation for their type 2 

diabetes, as well as the associated complications of this morbid, chronic 

condition. This presumption will continue to have important financial 

consequences for VA as type 2 diabetes incidence generally increases with 

advancing age and as national rates of type 2 diabetes continue to rise in 

all segments of the population, fueled primarily by the high rates of obesity 

and inactivity.
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100 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Lessons Learned

This case study has several features in common with some of the other 

case studies. As for radiation and cancer, type 2 diabetes has multiple risk factors, including age, family history, inactivity, and obesity. The extent to which 

Agent Orange contributes to causation of type 2 diabetes in veterans is uncertain, but likely to be relatively small compared with these other factors.

Some IOM Agent Orange reports have commented on the extent that 

Agent Orange exposure may contribute to diabetes rates observed among 

Vietnam veterans: 

It must be noted, however, that these studies indicate that the increased 

risk, if any, from herbicide or dioxin exposure appears to be small. The 

known predictors of diabetes risk—family history, physical inactivity, and 

obesity—continue to greatly outweigh any suggested increased risk from 

wartime exposure to herbicides. (IOM, 2000b, pp. 3, 37)

Recognition of the relative contributions of multiple factors could be 

important for the identifying and compensating service-attributable type 

2 diabetes that develops among aging Vietnam veterans. The IOM Agent 

Orange committee reports have not attempted to quantify the attributable 

burden of disease, although such calculations would be useful for decision 

making, both to understand the potential burden of disease overall and to 

anticipate decisions about compensation for individual veterans. An additional explicit analysis of service-attributable risk that attempts to quantify 

the fraction of disease risk attributable to military service might be more 

useful to VA and Congress when making legislative and administrative 

decisions based on complex scientific evidence, although it is recognized 

that conducting such an analysis for this case would be a challenge given 

the lack of adequate research in this area and the limited data on exposures 

to herbicides.

Analyses of high-quality data for a representative cohort of veterans 

could have been informative for determining the existence of an association between exposures during military service and the risk of disease or 

disability. A well-designed cohort study might have contributed data for 

evaluating the link between Agent Orange and type 2 diabetes, particularly 

if the design had included accurate assessments of exposure during service, 

evaluation of other risk factors that may have been present during service 

or developed subsequently (e.g., obesity), and longitudinally assessed occurrence of this disease. In fact, the Vietnam Experience Study (VES) provided 

an opportunity to initiate a cohort study. Continuation of the study as a 

cohort might have proven informative for diabetes and other potential 

health consequences of service in Vietnam. 
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In evaluating the observational studies, specific and formal methodological protocols did not appear to be used for synthesizing findings of 

available studies and updating the classification of evidence as the findings 

of additional studies became available to successive committees. The type 

2 diabetes presumption came after the 2000 IOM committee “upgraded” 

the assessment of the existing evidence from “inadequate/insufficient” to 

“limited/suggestive” category. Although new studies were considered in this 

reassessment, no particular study was considered as providing conclusive 

evidence of association between Agent Orange and type 2 diabetes. Rather, 

the reclassification reflected the committee’s view of the cumulative weight 

of the evidence. Having a more detailed evidence review algorithm and 

classification approach, such as IARC (IARC, 2006), could enhance the 

consistency of assessment of evidence across different committees. 

The case study also points to a lack of transparency in the VA’s process where scientific evidence is applied to legislative and administrative 

decisions. The type 2 diabetes presumption signaled an important trend on 

the part of VA to assign presumption on the bases of “limited/suggestive” 

classification of the levels of evidence, rather than the highest standard of 

“sufficient” evidence. This decision may have been influenced by a variety 

of considerations beyond the scientific evidence, i.e., political, economic, 

and administrative factors. The interplay of these multiple factors and their 

relative weighting by VA were not described in any of the materials available to the Committee.

SPINA BIFIDA PROGRAM

Description

This case study examines the 1996 and 2003 decisions to grant monetary 

compensation and health benefits to children of Vietnam and Korean War 

veterans with spina bifida based on the scientific evidence suggesting an association between herbicide exposure in Vietnam and Korea and spina bifida in 

the children of exposed veterans. Reproductive health effects were considered 

by the first IOM veterans and Agent Orange report issued in 1994 (IOM, 

1994). The committee concluded that male exposure to toxins could plausibly be linked to adverse developmental consequences in their offspring:

Animal and human data indicate that the exposure of the male to various 

toxic agents may increase the risk of the full spectrum of adverse developmental endpoints from fetal loss to cancer. (IOM, 1994, p. 595)

But the committee found the evidence to support the link between 

Agent Orange and a range of birth defects to be “inadequate/insufficient” 
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102 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

(IOM, 1994, p. 6). In its response to the IOM report, VA noted that 

although reproductive effects were considered by the IOM committee, 

there was no mechanism within the existing VA compensation structure 

to award benefits to any party other than the veteran; providing compensation to children of veterans with developmental effects attributable to 

Agent Orange exposure would require additional legislative action (VA, 

1994c, p. 346). 

Based on new research findings, in the 1996 Agent Orange report, the 

IOM committee assessed the evidence for the association between Agent 

Orange and spina bifida as “limited/suggestive” (IOM, 1996b). This reclassification was based on a re-analysis of the Ranch Hand study, in response 

to a critique in the IOM’s 1994 report. In addition the committee considered three other studies, each of which had potential biases that were different and therefore unlikely to be responsible for demonstrating a consistent 

pattern of results (IOM, 1996b). 

Public Law 104-204 (Departments of Veterans Affairs and Housing 

and Urban Development, and Independent Agencies Appropriation Act, 

1997. 104th Cong., 2d Sess.) was passed in 1996, authorizing benefits for 

children born to Vietnam veterans with spina bifida. Additional legislation 

in 2000 (Veterans Benefits and Health Care Improvement Act of 2000. 

Public Law 106-419 § 401. 106th Cong., 2d Sess.) established benefits to 

children of “women Vietnam veterans” with birth defects; this law provided benefits to children of female veterans with a broad range of defects 

that might be attributable to maternal exposure during Vietnam service 

(excluding defects that were the result of familial predisposition or the 

injury suffered at birth). In 2003, these benefits were extended to children 

of veterans of the Korean War (Veterans Benefits Act of 2003. Public Law 

108-103. 108th Cong., 2d Sess.). 

Lessons Learned

Apart from the programs established by legislative action described 

above, there continues to be no overall mechanism for compensating offspring for health consequences attributable to maternal or paternal military service. Toxic exposures that occur during military service have the 

potential to cause adverse developmental effects, and all of the Agent 

Orange reports have described the biologically plausible mechanisms for 

these effects in both exposed female and male veterans. Given VA’s interest in compensating veterans for adverse health effects incurred as a result 

of military service and the possibility that such effects may extend to the 

health of veterans’ offspring, the absence of a clear and consistent policy 

on compensating affected offspring is notable. The need for a clear policy 

statement will continue to grow as VA considers the health effects of mili-
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CASE STUDIES SUMMARY CHAPTER 103

tary service in the large population of reproductive-aged veterans and the 

growing number of women in the armed services.

Although the public laws providing compensation for particular categories of offspring with birth defects may have been expedient for these 

affected individuals, the approach of addressing the more general policy 

gap described above with these programs runs counter to principles of 

consistency and equity that should inform the approach to presumptions. 

Any new adverse reproductive consequences of Agent Orange exposure 

identified in IOM reports would again require legislative action for these 

specific effects in order for compensation to be granted; the administrative 

route that has applied to all other Agent Orange presumptions is not available for reproductive consequences of exposure at present.

It should be noted that the evidence standard for the spina bifida 

presumption was “limited/suggestive,” not the more rigorous “sufficient” 

standard (IOM, 1996b). The difficulty with using this lesser standard as 

the basis for presumptions has been described in other case studies related 

to Agent Orange and type 2 diabetes and prostate cancer.

SYNTHESIS

These case studies offer a diverse set of lessons learned and indicate 

elements of the current presumptive disability decision-making process 

for veterans that need to be addressed moving forward. The case studies 

show that the process has acted to serve the interests of veterans in many 

instances. Overall, Congress and VA have repeatedly acted to maximize 

the sensitivity of presumptive decisions so as to ensure that specific groups 

of veterans are compensated. The particular interest in caring for veterans 

who have experienced the hardship of being a POW, for example, has led 

to a range of presumptions that apply to POWs. However, in maximizing 

the sensitivity of presumptive decision making for particular groups of 

veterans, substantial numbers of false positives may have resulted, as in 

the examples of Agent Orange and the Gulf War. Additionally, because no 

systematic process for approaching presumptive decision making exists, 

important omissions in this coverage remain without a clear mechanism for 

expanding coverage, as with potential reproductive health consequences of 

military service for the offspring of those who serve.

The case studies illustrate the use of presumptions to cover gaps in evidence, gaps that exist in part because of lack of information on exposures 

received by military personnel and inadequate surveillance of veterans for 

the occurrence of service-related illnesses. Secrecy is a particularly troubling 

source of incomplete information, as illustrated by the veterans who participated in studies of mustard gas and lewisite. Research has been carried out 

on the health of veterans, leading to the decision, for example, on cardio-
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104 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

vascular disease in amputees. But the research has not been systematic, 

and in the example of cardiovascular disease in amputees, further evidence 

relative to a presumption made in 1979 has not been collected. Research on 

radiation risks in veterans has been severely constrained by a lack of dose 

information, and the resulting studies have not been informative. A lack 

of exposure information has hindered research on other agents as well and 

led to a sweeping exposure presumption with regard to exposure to Agent 

Orange in Vietnam.

Across the case studies, the Committee believes that prior efforts did 

not optimally synthesize all of the evidence on the health consequences of 

military service. In some cases there has not been an independent body 

that reviews the scientific evidence and updates the medical knowledge and 

scientific evidence relevant for a specific presumptive decision over time. 

As a consequence, some presumptions appear inconsistent (as with the 

psychiatric illnesses) or even aberrant (as with multiple sclerosis) in the face 

of contemporary medical and scientific knowledge. In other cases where an 

independent body has reviewed the scientific evidence, the synthesis of the 

evidence has not always been optimally comprehensive and standardized. 

The inferential target in IOM reports has shifted between causation (e.g., 

mustard gas and lewisite, Gulf War) and association (e.g., Agent Orange), 

and the more recent IOM Agent Orange reports have emphasized findings 

of observational studies without full attention to other lines of evidence. In 

the Agent Orange case studies the category “limited/suggestive” for association has been used when the epidemiological evidence base was fairly weak, 

including only one study with statistically significant findings. In the case 

of type 2 diabetes, at the time of the Agent Orange and diabetes report, 

there were multiple studies that were all substantially limited by bias or 

confounding. The categorization of the evidence as “limited/­suggestive” 

by IOM has led to presumptions on the part of VA that appear to be irreversible once made, even though scientific evidence is dynamic. Stated in 

another way, even if further scientific evidence were unsupportive of previous research findings and a future IOM committee were to change its classification for strength of evidence, VA may not change its presumption. The 

Committee notes that presumptive decisions have been made to compensate 

health outcomes (e.g., type 2 diabetes, prostate cancer), based on evidence 

characterized by IOM committees as limited/suggestive for association, 

well below the evidence level needed to establish causation, absent strong 

mechanistic understanding. 

The case studies document the particular problem that arises with 

regard to presumptions related to common, chronic diseases with multiple 

causes, such as type 2 diabetes, prostate cancer, and cardiovascular disease. In seeking high sensitivity for presumptions in general, specificity is 

sacrificed, and the resulting number of false positives may be particularly 
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CASE STUDIES SUMMARY CHAPTER 105

large for common conditions with multiple etiologies. These false positives 

are associated with large attendant costs, both financial and non-financial. 

Determining the degree to which the onset of a common disease with 

multiple etiologies may be attributable to prior military service may be 

particularly useful for presumptions related to such conditions, but neither 

the IOM committees nor VA have given full consideration to whether the 

attributable fraction should be estimated for veterans. Later chapters of this 

report discuss how the attributable fraction might be estimated for veterans, and how such estimates would benefit VA in its presumptive disability 

decision-making process.

In the case studies, the Committee’s analyses were based on the very 

general information provided by VA about its internal decision-making 

processes. The case studies did make clear, however, that these processes are 

neither fully transparent nor consistent. This was further implied by VA’s 

decision to withhold task force documents from the Committee’s review, 

considering them pre-decisional in nature. VA believes that access to predecisional documents by outside sources would stifle candid staff opinions 

on issues. Once IOM carries out its reviews and provides VA with reports 

documenting the extent of evidence available on associations, the internal 

processes that follow are not fully open to scrutiny. This practice could 

degrade the trust of veterans in the presumptive disability decision-making 

process and may hinder efforts to optimize the use of scientific evidence.

In its proposed approach for future decision making, the Committee 

offers recommendations that address the strengths and challenges highlighted by the case studies.

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agents. Under Secretary for Health Information letter IL 10-2005-004. www.va.gov/environagents/docs/USHInfoLetterIL10-2005-004_March _14_2005.pfd (accessed February 27, 2007).

VA. 2006. Potential health effects among veterans involved in military chemical warfare agent 

experiments conducted from 1955 to 1975. Under Secretary for Health information letter 

IL 10-2006-010. Washington, DC: Department of Veterans Affairs. http://www1.va.gov/ 

environagents/docs/USHInfoLetterIL10-2006-010.pdf (accessed February 28, 2007).

VA Multiple Sclerosis Study Group. 1956. Isoniazid in the treatment of multiple sclerosis: 

Report on VA Cooperative Study. Transactions of the American Neurological Association

(81st meeting):128–131.

VA Multiple Sclerosis Study Group. 1957. Isoniazid in the treatment of multiple sclerosis: 

Report on Veterans Administration Cooperative Study. Journal of the American Medical 

Association 163(3):168-172. 

Wallin, M. T., W. F. Page, and J. F. Kurtzke. 2000. Epidemiology of multiple sclerosis in 

U.S. veterans: 8. Long-term survival after onset of multiple sclerosis. Brain 123(Pt. 

8):1677-1687.
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CONGRESS

EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Mental Health

Veterans’ Bureau Act of 1921World War Veterans’ Act, 1924Veterans, disability compensation, increase(1970)Former Prisoner of War Benefits Act of 1981Veterans’ Compensation and Program Improvements Amendments of 1984Veterans Benefits Act of 2003

PL 67-4742 STAT. 147, 153PL 68-24243 STAT. 607, 615PL 91-37684 STAT. 787, 788PL 97-3795 STAT. 935, 936PL 98-22398 STAT. 37, 40PL 108-183117 STAT. 2651

PL 91-376PL 97-37PL 98-223PL 108-183

HR 91-1166HR 97-28HR 98-228HR 98-425HR 108-211

SR 91-784SR 91-785SR 97-88SR 98-249SR 107-86SR 108-169

Pensions, Bonuses, and Veteran’s Relief (1949)Pensions, Bonuses, and Veterans’ Relief (1970)Veterans Benefits; Former Prisoners of War (1981)Veterans Benefits; Former Prisoners of War (1982) (final regulations) Direct Service Connection (Posttraumatic stress disorder) (1992) (proposed rule)Direct Service Connection (Posttraumatic stress disorder) (1993) (final rule) 

14 FR 57135 FR 1828046 FR 5757147 FR 1165557 FR 3453658 FR 29109

38 CFR Part 3Former 39 CFR 3.80, 3.8638 CFR Part 338 CFR Part 338 CFR Part 3

Compensation for Certain Undiagnosed Ill

(1994) 

59 FR 63283

38 CFR Part 3

ANNEX 5-1 Legislative Documents Referenced for Case Studies
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111

Act of 2003

117 STAT. 2651

SR 108-169

Connection (Posttraumatic stress disorder) (1993) (final rule) 

29109

Part 3

Compensation for Certain Undiagnosed Illnesses (1994) (proposed rule)

59 FR 63283

38 CFR Part 3

Compensation for Certain Undiagnosed Illnesses (1995) (final rule)

60 FR 6660

38 CFR Part 3

Multiple Sclerosis

Pensions, Bonuses, and Veterans’ Relief (1949)

14 FR 571 38 CFR 

3.86

Pensions, Bonuses, and Veterans’ Relief (1970)

35 FR 18280

38 CFR 3.307, 3.309

Compensation and Pension Provisions of the Veterans Education and Benefits Expansion Act of 2001 (2003) (final rule)

68 FR 34539

38 CFR Parts 3 and 13

Presumptions relating to certain diseases and disabilities (2006) (38 USC § 1112)

continued
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EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Prisoners of War

Veterans, disability compensation, increase (1970)

PL 91-37684 STAT. 787

PL 91-376 HR 91-1166 SR 91-784

SR 91-785

Former Prisoner of War Benefits Act of 1981

PL 97-3795 STAT. 935

PL 97-37 HR 97-28 SR 97-88

Veterans’ Compensation and Program Improvements Amendments of 1984

PL 98-22398 STAT. 37

PL 98-223 HR 98-228

HR 98-425

SR 98-249

Veterans’ Benefits Improvement and Health-Care Authorization Act of 1986

PL 99-576100 STAT. 3248

PL 99-576 HR 99-728

HR 99-729

SR 99-494SR 99-200SR 99-444

Veterans’ Benefits and Services Act of 1988

PL 100-322102 STAT. 487

PL 100-322 HR 100-191

HR 100-236HR 100-578

SR 100-15SR 100-215

Veterans Benefits Act of 2003

PL 108-183117 STAT. 2651

PL 108-183 HR 108-211 SR 107-86

SR 108-169

Amputees and Cardiovascular Disease

Veterans Disability Compensation and Survivor Benefit Act of 

PL 94-43390 STAT. 1374

PL 94-433 HR 94-1270 SR 94-1226 Pension, 

Compensation, and Dependency and Indemnity Compensation

44 FR 50339 

38 CFR Part 3

ANNEX 5-1 Continued
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113

of 1988

HR 100-578

Veterans Benefits Act of 2003

PL 108-183117 STAT. 2651

PL 108-183 HR 108-211 SR 107-86

SR 108-169

Amputees and Cardiovascular Disease

Veterans Disability Compensation and Survivor Benefit Act of 1976

PL 94-43390 STAT. 1374

PL 94-433 HR 94-1270 SR 94-1226 Pension, 

Compensation, and Dependency and Indemnity Compensation, Proximate Results, Secondary Conditions (1979) (final regulations)

44 FR 50339 

38 CFR Part 3

Radiation Veterans’ Dioxin 

and Radiation Exposure Compensation Standards Act of 1984RadiationExposed Veterans Compensation Act of 1988Radiation Exposure Compensation Act of 1990Veterans’ Benefits Programs Improvement Act of 1991

PL 98-54298 STAT. 2725PL 100-321102 STAT. 485PL 101-426104 STAT. 920PL 102-86105 STAT. 414

PL 98-542PL 100-321PL 101-426PL 102-86

HR 98-592HR 98-828HR 98-592HR 100-235HR 101-463HR 101-857HR 102-130

SR 97-89SR 100-215SR 101-264SR 101-379SR 102-139

Guidance for the Determination and Reporting of Nuclear Radiation Dose for DoD Participants in the Atmospheric Nuclear Test Program (1945-1962) (1982) Guidance for the Determination and Reporting of Nuclear Radiation Dose for DoD Participants in the Atmospheric Nuclear Test Program (1945-1962) (1983) (final rule)

47 FR 2185348 FR 10645

32 CFR Ch. 132 CFR Part 218

continued
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EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Radiation (continued)

Veterans’ Radiation Exposure Amendments of 1992Veterans’ Benefits Improvements Act of 1994Radiation Exposure Compensation Act Amendments of 2000Veterans Benefit Improvements Act of 2004

PL 102-578106 STAT. 4774PL 103-446108 STAT. 4645PL 106-245114 STAT. 501PL 108-454118 STAT. 3598

PL 102-578PL 103-446PL 106-245PL 108-454

HR 102-757HR 103-538HR 103-668HR 103-669HR 106-697HR 108-211HR 108-572

SR 101-379SR 102-139SR 103-280SR 103-385SR 103-386SR 106-397SR 108-169

Guidance for the Determination and Reporting of Nuclear Radiation Dose for DoD Participants in the Atmospheric Nuclear Test Program (1945-1962) (1985) (proposed amendment of final rule)

50 FR 19538

32 CFR Part 218

Adjudication of Claims Based on Exposure to Dioxin or Ionizing Radiation (1985) (final rules)

50 FR 34452 

38 CFR Parts 1 and 2

Claims Based on Exposure to Ionizing Radiation (1989) (final regulations)

54 FR 42802

38 CFR Part 3

Claims Based on Exposure to Ionizing Radiation (1992) (

d 

57 FR 10449

38 CFR Part 3

ANNEX 5-1 Continued
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115

Ionizing Radiation (1989) (final regulations)Claims Based on Exposure to Ionizing Radiation (1992) (proposed rule)

57 FR 10449

38 CFR Part 3

Claims Based on Exposure to Ionizing Radiation (Parathyroid Adenoma) (1992) (proposed rule)

57 FR 10853

38 CFR Part 3

Radiation Exposure Compensation Act of 1990 (1992)(proposed rule)

57 FR 40424

38 CFR Part 3

Claims Based on Exposure to Ionizing Radiation (1993) (final rule)

58 FR 16358

38 CFR Part 3

Radiation Exposure Compensation Act of 1990 (1993) (final rule)

58 FR 25564

38 CFR Part 3

Claims Based on Exposure to Ionizing Radiation (1994) (proposed rule)

59 FR 6607

38 CFR Part 3

continued
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Case Study

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EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Radiation (continued)

Claims Based on Exposure to Ionizing Radiation (1994) (final rule)

59 FR 45975

38 CFR Part 3

Claims Based on Exposure to Ionizing Radiation (Radiogenic Diseases) (1995) (final rule)

60 FR 9627

38 CFR Part 3

Claims Based on Exposure to Ionizing Radiation (Lymphomas other than Hodgkin’s Disease and Cancer of the Rectum) (1995) (final rule)

60 FR 53276

38 CFR Part 3

Claims Based on Exposure to Ionizing Radiation (Prostate Cancer 

61 FR 50264

38 CFR Part 3

ANNEX 5-1 Continued
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117

Claims Based on Exposure to Ionizing Radiation (Prostate Cancer and Any Other Cancer) (1996) (proposed rule)

61 FR 50264

38 CFR Part 3

Claims Based on Exposure to Ionizing Radiation (Prostate Cancer and Any Other Cancer) (1998) (final rule)

63 FR 50993

38 CFR Part 3

The Veterans Millennium Health Care and Benefits Act (2000) (final rule)

65 FR 43699

38 CFR Part 3

Diseases Specific to Radiation-Exposed Veterans (2001) (proposed rule)

66 FR 41483

38 CFR Part 3

Diseases Specific to RadiationExposed Veterans (2002) (final rule)

67 FR 3612

38 CFR Part 3

Claims Based on Exposure to Ionizing Radiation (2002) (final rule)

67 FR 6870

38 CFR Part 3

continued
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Case Study

CONGRESS

EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Mustard Gas/ Lewisite

Claims Based on Chronic Effects of Exposure to Mustard Gas (1992) (proposed rule)

57 FR 1699

38 CFR Part 3

Claims Based on Chronic Effects of Exposure to Mustard Gas (1992) (final rule)

57 FR 33875

38 CFR Part 3

Claims Based on Chronic Effects of Exposure to Vesicant Agents (1994) (proposed rule)

59 FR 3532

38 CFR 3.307(b)

Claims Based on Chronic Effects of Exposure to Mustard Gas or Lewisite (1994) (final rule)

59 FR 42497

38 CFR Part 3

Gulf War Omnibus 

Consolidated and Emergency Supplemental 

PL 105-277112 STAT. 2681

PL 105-277

HR 105-626

SR 105-362

Compensation for Certain Undiagnosed Illnesses (1994) 

59 FR 63283

38 CFR Part 3

ANNEX 5-1 Continued
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119

Lewisite (1994) (final rule)

Gulf War Omnibus 

Consolidated and Emergency Supplemental Appropriations Act, 1999Veterans Education and Benefits Expansion Act of 2001

PL 105-277112 STAT. 2681PL 107-103115 STAT. 976

PL 105-277PL 107-103

HR 105-626HR 107-156

SR 105-362SR 107-86SR 106-122

Compensation for Certain Undiagnosed Illnesses (1994) (proposed rule)Compensation for Certain Undiagnosed Illnesses (1995) (final rule)Compensation for Certain Undiagnosed Illnesses (1997) (interim rule)Compensation for Certain Undiagnosed Illnesses (1998) (final rule)Illnesses Not Associated with Service in the Gulf during the Gulf War (2001) (notice)

59 FR 6328360 FR 666062 FR 2313863 FR 1112266 FR 35702

38 CFR Part 338 CFR Part 338 CFR Part 338 CFR Part 3

continued
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EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Gulf War(continued)

Extension of the Presumptive Period for Compensation for Gulf War Veterans’ Undiagnosed Illnesses (2001) (interim final rule)

66 FR 56614

38 CFR Part 3

Extension of the Presumptive Period for Compensation for Gulf War Veterans’ Undiagnosed Illnesses (2002) (final rule)

67 FR 78979

38 CFR Part 3

Compensation and Pension Provisions of the Veterans Education and Benefits Expansion Act of 2001 (2003) (final rule)

68 FR 34539

38 CFR Parts 3 and 13

Agent Orange and P

Veterans’ Dioxin and Radiation Exposure C

i

PL 98-54298 STAT. 2725

PL 98-542 HR 98-592

HR 98-828

SR 97-89 Adjudication of 

Claims based on Exposure to Di

i

I

i

i

50 FR 34452

38 CFR Parts 1 and 3

ANNEX 5-1 Continued
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Education and Benefits Expansion Act of 2001 (2003) (final rule)

Agent Orange and Prostate Cancer

Veterans’ Dioxin and Radiation Exposure Compensation Standards Act of 1984

PL 98-54298 STAT. 2725

PL 98-542 HR 98-592

HR 98-828

SR 97-89 Adjudication of 

Claims based on Exposure to Dioxin or Ionizing Radiation (1985) (final rules)

50 FR 34452

38 CFR Parts 1 and 3

Agent Orange Act of 1991

PL 102-4105 STAT. 11

PL 102-4 HR 101-672

HR 101-857

SR 100-215SR 100-439SR 101-82SR 101-379

Claims Based on Service in Vietnam (1990) (proposed regulations)

55 FR 25339

38 CFR Parts 3 and 4

Veterans’ Benefits Improvements Act of 1994

PL 103-446108 STAT. 4645

PL 103-446 HR 103-538

HR 103-668HR 103-669

SR 103-280SR 103-385SR 103-386

Claims Based on Service in Vietnam (1990) (final regulations)

55 FR 43123

38 CFR Parts 3 and 4

Veterans’ Benefits Improvements Act of 1996

PL 104-275110 STAT. 3322

PL 104-275 HR 104-649 SR 99-101

SR 100-439SR 104-371

Claims Based on Exposure to Herbicides Containing Dioxin (SoftTissue Sarcomas) (1991) (proposed regulations)

56 FR 7632

38 CFR Parts 3 and 4

Claims Based on Exposure to Herbicides Containing Dioxin (Soft-Tissue Sarcomas) (1991) (final regulation)

56 FR 51651

38 CFR Parts 3 and 4

continued
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Case Study

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EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Agent Orange and Prostate Cancer(continued)

Claims Based on Exposure to Herbicides Containing Dioxin (Peripheral Neuropathy/Lung Cancer) (1992) (proposed rule)

57 FR 2236

38 CFR Part 3

Diseases Associated with Service in the Republic of Vietnam (1992) (proposed rule)

57 FR 30707

38 CFR Part 3

Diseases Associated with Service in the Republic of Vietnam (1993) (final rule)

58 FR 29107

38 CFR 3.309(e)

Disease Associated with Exposure to Certain Herbicide Agents (1993) (proposed rule)

58 FR 50528

38 CFR Part 3

Diseases Not Associated with Exposure to Certain Herbicide 

59 FR 341

ANNEX 5-1 Continued
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with Exposure to Certain Herbicide Agents (1993) (proposed rule)

50528

Part 3

Diseases Not Associated with Exposure to Certain Herbicide Agents (1994) (notice)

59 FR 341

Disease Associated with Exposure to Certain Herbicide Agents (1994) (final rule)

59 FR 5106

38 CFR Part 3

Disease Associated with Exposure to Certain Herbicide Agents (Multiple Myeloma and Respiratory Cancers) (1994) (proposed rule)

59 FR 5161

38 CFR Part 3

Disease Associated with Exposure to Certain Herbicide Agents (Multiple Myeloma and Respiratory cancers) (1994) (final rule)

59 FR 29723

38 CFR Part 3

continued
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124ANNEX 5-1 Continued

Case Study

CONGRESS

EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Agent Orange and Prostate Cancer(continued)

Diseases Associated with Exposure to Certain Herbicide Agents (Prostate Cancer and Acute and Subacute Peripheral Neuropathy) (1996) (proposed rule) 

61 FR 41368

38 CFR Part 3

Disease Not Associated with Exposure to Certain Herbicide Agents (1996) (notice)

61 FR 41442

Diseases Associated with Exposure to Certain Herbicide 

61 FR 57586

CFR Part 3
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Diseases Associated with Exposure to Certain Herbicide Agents (Prostate Cancer and Acute and Subacute Peripheral Neuropathy) (1996) (final rule)

61 FR 57586

CFR Part 3

Veterans’ Benefits Improvements Act of 1996 (1997) (final rule)

62 FR 35421

38 CFR Part 3

Diseases Not Associated with Exposure to Certain Herbicide Agents (1999) (notice)

64 FR 59232

Diseases Not Associated with Exposure to Certain Herbicide Agents (2002) (notice)

67 FR 4 2600

continued
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ANNEX 5-1 Continued

Case Study

CONGRESS

EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Agent Orange and Prostate Cancer(continued)

Disease Associated with Exposure to Certain Herbicide Agents: Chronic Lymphocytic Leukemia (2003) (proposed rule)

68 FR 14567

38 CFR Part 3

Compensation and Pension Provisions of the Veterans Education and Benefits Expansion Act of 2001 (2003) (final rule)

68 FR 34539

38 CFR Parts 3 and 13

Disease Associated with Exposure to Certain Herbicide Agents: Chronic Lymphocytic Leukemia (2003) (final rule)

68 FR 59540

38 CFR Part 3

Agent Orange and Type 2 

b

Veterans’ Dioxin and Radiation Exposure 

PL 98-54298 STAT. 2725

PL 98-542

HR 98-592HR 98-828

SR 97-89

Adjudication of Claims based on Exposure to 

50 FR 34452

38 CFR Parts 1 and 3
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Agent Orange and Type 2 Diabetes

Veterans’ Dioxin and Radiation Exposure Compensation Standards Act of 1984Agent Orange Act of 1991Veterans’ Benefits Improvements Act of 1994Veterans’ Benefits Improvements Act of 1996Veterans Education and Benefits Expansion Act of 2001

PL 98-54298 STAT. 2725PL 102-4105 STAT. 11PL 103-446108 STAT. 4645PL 104-275110 STAT. 3322PL 107-103115 STAT. 976

PL 98-542PL 102-4PL 103-446PL 104-275PL 107-103

HR 98-592HR 98-828HR 101-672HR 101-857HR 103-538HR 103-668HR 103-669HR 104-649HR 107-156

SR 97-89SR 100-215SR 100-439SR 101-82SR 101-379SR 103-280SR 103-385SR 103-386SR 99-101SR 100-439SR 104-371SR 107-86SR 106-122

Adjudication of Claims based on Exposure to Dioxin or Ionizing Radiation (1985) (final rules)Claims based on Service in Vietnam (1990) (proposed regulation)Claims based on Service in Vietnam (1990) (final regulation)Claims Based on Exposure to Herbicides Containing Dioxin (Soft Tissue Sarcomas) (1991) (proposed regulation)Claims Based on Exposure to Herbicides Containing Dioxin (Soft Tissue Sarcomas) (1991) (final regulation)

50 FR 3445255 FR 2533955 FR 4312356 FR 763256 FR 51651

38 CFR Parts 1 and 338 Parts 3 and 438 Parts 3 and 438 Parts 3 and 438 Parts 3 and 4

continued
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EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Agent Orange and Type 2 Diabetes(continued)

Claims Based on Exposure to Herbicides containing Dioxin (Peripheral Neuropathy/Lung Cancer) (1992) (proposed rule)

57 FR 2236

38 CFR Part 3

Diseases Associated with Service in the Republic of Vietnam (1992) (proposed rule)

57 FR 30707

38 CFR Part 3

Diseases Associated with Service in the Republic of Vietnam (1993) (final rule)

58 FR 29107

38 CFR 3.309(e)

Disease Associated with Exposure to Certain Herbicide Agents (1993) (proposed rule)

58 FR 50528

38 CFR Part 3

Disease Associated with Exposure to 

59 FR 5106

38 CFR Part 3

ANNEX 5-1 Continued
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with Exposure to Certain Herbicide Agents (1993) (proposed rule)

50528

Part 3

Disease Associated with Exposure to Certain Herbicide Agents (1994) (final rule)

59 FR 5106

38 CFR Part 3

Disease Associated with Exposure to Certain Herbicide Agents (Multiple Myeloma and Respiratory Cancers) (1994) (final rule)

59 FR 29723

38 CFR Part 3

Veterans’ Benefits Improvements Act of 1996 (1997) (final rule)

62 FR 35421

38 CFR Part 3

Diseases Not Associated with Exposure to Certain Herbicide Agents (1999) (notice)

64 FR 59232

continued
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Case Study

CONGRESS

EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Agent Orange and Type 2 Diabetes(continued)

Disease Associated with Exposure to Certain Herbicide Agents: Type 2 Diabetes (2001) (proposed rule)

66 FR 2376

38 CFR Part 3

Disease Associated with Exposure to Certain Herbicide Agents: Type 2 Diabetes (2001) (final rule)

66 FR 23166

38 CFR Part 3

Disease Associated with Exposure to Certain Herbicide Agents: Chronic Lymphocytic Leukemia (2003) (proposed rule)

68 FR 14567

38 CFR Part 3

Compensation and Pension Provisions of the Veterans Education and 

68 FR 34539

38 CFR Parts 3 and 13

ANNEX 5-1 Continued
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Compensation and Pension Provisions of the Veterans Education and Benefits Expansion Act of 2001 (2003) (final rule)

68 FR 34539

38 CFR Parts 3 and 13

Disease Associated with Exposure to Certain Herbicide Agents: Chronic Lymphocytic Leukemia (2003) (final rule)

68 FR 59540

38 CFR Part 3

Change of Effective Date of Rule Adding a Disease Associated with Exposure to Certain Herbicide Agents: Type 2 Diabetes (2004) (final rule)

69 FR 31882

38 CFR Part 3

continued
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EXECUTIVE BRANCH (DEPARTMENT OF VETERANS AFFAIRS)

Public Law Name

Public LawStatute CIS Index

House Report 

Senate Report Rule Name

Federal Register

Code of Federal Regulations

Spina Bifida

Disease Not Associated with Exposure to Certain Herbicide Agents (1994) (notice)

59 FR 341

Disease Not Associated with Exposure to Certain Herbicide Agents (1996) (notice)

61 FR 41442

ANNEX 5-1 Continued
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CASE STUDIES SUMMARY CHAPTER 133

ANNEX 5-2

The following National Academies’ reports were evaluated by committee members for inclusion in the individual case studies (see Appendix I). 

The reports appear below in chronological order:

NRC (National Research Council). 1982. Possible long-term health effects of short-term exposure to chemical agents. Vol. 1. Washington, DC: National Academy Press.

NRC. 1984. Assigned share for radiation as a cause of cancer: Review of radioepidemiological 

tables, assigning probabilities of causation. Washington, DC: National Academy Press.

NRC. 1984. Possible long-term health effects of short-term exposure to chemical agents: Cholinesterase reactivators, psychochemicals and irritants and vesicants. Vol. 2. Washington, 

DC: National Academy Press.

NRC. 1985. Mortality of nuclear weapons test participants. Washington, DC: National 

Academy Press.

NRC. 1985. Possible long-term health effects of short-term exposure to chemical agents: 

Final report. Current health status of test subjects. Vol. 3. Washington, DC: National 

Academy Press.

NRC. 1988. Overview. In Health risks of radon and other alpha-emitters: BEIR IV. Washington, DC: National Academy Press.

NRC. 1990. Health effects of exposure to low levels of ionizing radiation: BEIR V. Washington, DC: National Academy Press.

IOM (Institute of Medicine). 1991. Epidemiology in military and veteran populations: Proceedings of the Second Biennial Conference, March 7, 1990. Washington, DC: National 

Academy Press.

IOM. 1992. The health of former prisoners of war. Washington, DC: National Academy 

Press.

IOM. 1993. Veterans at risk: The health effects of mustard gas and lewisite. Washington, DC: 

National Academy Press.

IOM. 1994. Health effects of herbicides used in Vietnam. Washington, DC: National Academy 

Press.

IOM. 1994. Veterans and Agent Orange: Health effects of herbicides used in Vietnam. Washington, DC: National Academy Press.

IOM. 1995. Health consequences of service during the Persian Gulf War: Initial findings and 

recommendations for immediate action. Washington, DC: National Academy Press.

IOM. 1995. Recommendations for research on the health of military women: Bibliographies. 

Washington, DC: National Academy Press.

IOM. 1995. A review of the dosimetry data available in the Nuclear Test Personnel Review 

(NTPR) Program. Washington, DC: National Academy Press.

IOM. 1996. Health consequences of service during the Persian Gulf War: Recommendations 

for research and information systems. Washington, DC: National Academy Press. 

IOM. 1996. Interactions of drugs, biologics, and chemicals in U.S. military forces. Washington, DC: National Academy Press.

IOM. 1996. Mortality of veteran participants in the Crossroads nuclear test. Washington, DC: 

National Academy Press.

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy 

Press.

IOM. 1997. Characterizing exposure of veterans to Agent Orange and other herbicides used 

in Vietnam: Scientific considerations regarding a request for proposals for research. 

Washington, DC: National Academy Press.
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134 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

IOM. 1997. An evaluation of radiation exposure guidance for military operations: Interim 

Report. Washington, DC: National Academy Press.

IOM. 1998. Adequacy of the VA Persian Gulf registry and uniform case assessment protocol. 

Washington, DC: National Academy Press.

IOM. 1998. Assessing readiness in military women: The relationship of body, composition, 

nutrition, and health. Washington, DC: National Academy Press.

IOM. 1998. Measuring the health of Persian Gulf veterans: Workshop summary. Washington, 

DC: National Academy Press.

IOM. 1999. Gulf War veterans: Measuring health. Washington, DC: National Academy 

Press.

NRC. 1999. Health effects of exposure to radon: BEIR VI. Washington, DC: National Academy Press.

IOM. 1999. Potential radiation exposure in military operations: Protecting the soldier before, 

during, and after. Washington, DC: National Academy Press.

IOM. 1999. Veterans and Agent Orange: Update 1998. Washington, DC: National Academy 

Press.

IOM. 2000. The Five Series Study: Mortality of military participants in U.S. nuclear weapons 

tests. Washington, DC: National Academy Press.

IOM. 2000. Gulf War and health, volume 1: Depleted uranium, pyridostigmine bromide, 

sarin, vaccines. Washington, DC: National Academy Press.

NRC. 2000. A review of the draft report of the NCI-CDC working group to revise the 1985

radioepidemiological tables. Washington, DC: National Academy Press.

IOM. 2000. Veterans and Agent Orange: Herbicide/dioxin exposure and type 2 diabetes. 

Washington, DC: National Academy Press.

IOM. 2001. Gulf War veterans: Treating symptoms and syndromes. Washington, DC: National 

Academy Press.

IOM. 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy 

Press.

IOM. 2002. Veterans and Agent Orange: Herbicide/dioxin exposure and acute myelogenous 

leukemia in the children of Vietnam veterans. Washington, DC: National Academy 

Press.

IOM. 2003. Characterizing exposure of veterans to Agent Orange and other herbicides used 

in Vietnam: Interim findings and recommendations. Washington, DC: The National 

Academies Press.

IOM. 2003. Characterizing exposure of veterans to Agent Orange and other herbicides used 

in Vietnam: Final report. Washington, DC: The National Academies Press.

IOM. 2003. Gulf War and health, volume 2: Insecticide and solvents. Washington, DC: The 

National Academies Press.

IOM. 2003. Veterans and Agent Orange: Update 2002. Washington, DC: The National 

Academies Press.

NRC. 2003. A review of the dose reconstruction program of the Defense Threat Reduction 

Agency. Washington, DC: The National Academies Press.

IOM. 2004. Gulf War and health: Updated literature review of sarin. Washington, DC: The 

National Academies Press

IOM. 2004. Veterans and Agent Orange: Length of presumptive period for association 

between exposure and respiratory cancer. Washington, DC: The National Academies 

Press.

NRC. 2004. Review of the Army’s technical guides on assessing and managing chemical 

hazards to deployed personnel. Washington, DC: The National Academies Press.

IOM. 2005. Gulf War and health, volume 3: Fuels, combustion products, and propellants. 

Washington, DC: The National Academies Press.
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CASE STUDIES SUMMARY CHAPTER 135

IOM. 2005. Veterans and Agent Orange: Update 2004. Washington, DC: The National 

Academies Press.

NRC. 2005. Assessment of the scientific information for the Radiation Exposure Screening 

and Education Program. Washington, DC: The National Academies Press.

IOM. 2006. Amyotrophic lateral sclerosis in veterans: Review of scientific literature. Washington, DC: The National Academies Press.

IOM. 2006. Disposition of the Air Force Health Study. Washington, DC: The National 

Academies Press.

IOM. 2006. Gulf War and health, volume 4: Health effects of serving in the Gulf War. Washington: The National Academies Press.

IOM. 2006. Gulf War and health, volume 5: Infectious diseases. Washington, DC: The 

National Academies Press.

NRC. 2006. Health risks from exposure to low levels of ionizing radiation: BEIR VII Phase 

2. Washington, DC: The National Academies Press.

IOM. 2006. Posttraumatic stress disorder: Diagnosis and assessment. Washington, DC: The 

National Academies Press.

NRC. 2006. Toxicity testing for assessment of environmental agents interim report. Washington, DC: The National Academies Press.

ANNEX 5-3

The VA provided the Committee with the following cost estimates (in 

chronological order):

VA (Department of Veterans Affairs). 1988. Cost estimate of Agent Orange legislation: NonHodgkin’s lymphoma. Washington, DC: VA. 

VA. 1996. Cost estimate for regulation on claims based on exposure to herbicides: Estimated 

benefit and administrative costs. Adding prostate cancer and peripheral neuropathy to list 

of diseases for which VA will provide presumptive service connection based on herbicide 

exposure. Washington, DC: VA.

VA. 1996. Memorandum: Costing for regulation on claims based on exposure to herbicides. 

Washington, DC: VA.

VA. 1999. Costing of H.R. 690: Adding bronchiolo-alveolar carcinoma to list of diseases presumed service connected for certain radiation-exposed veterans. Washington, DC: VA. 

VA. 2000. Costing of regulation RIN 2900-AK63: Disease associated with exposure to certain 

herbicide agents: Type 2 diabetes. Washington, DC: VA. 

VA. 2001. Costing of regulation RIN 2900-AK83: Presumption of service connection for 

cirrhosis of the liver in former prisoners of war. Washington, DC: VA.

VA. 2003. Costing of RIN 2900-AL55: To establish a presumption of service connection for 

chronic lymphocytic leukemia (CLL). Washington, DC: VA.

VA. 2004. Costing of RIN 2900-AM09: Additional presumptions for former POWs. Washington, DC: VA.
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136

6

Establishing an Evidence-Based 

Framework

OVERVIEW

The Committee’s review of Congress’ and the Department of Veterans 

Affairs’ (VA’s) approach to establishing presumptions has identified multiple elements of the process for reconsideration. In the next four chapters, 

the Committee develops a conceptual foundation for implementing an 

evidence-based system for compensation and offers recommendations for 

future approaches in Chapter 12. This chapter serves as an introduction to 

this section of the report, offering general considerations on the basis for 

making presumptions and their role in compensation by VA.

There are two ideas that underpin these four chapters:

• Decisions about presumptions should be grounded in a scientific 

evaluation of the full range of evidence that the exposure of interest causes

the disease or disability.

• If there is sufficient evidence to infer a causal relationship, the 

amount of disease attributable to the exposure should be estimated.

Chapters 7 and 8 address the first question of whether a causal relationship exists. Chapter 7 makes explicit what is meant by cause in contrast to 

statistical association and details the sources of evidence necessary to reach 

a conclusion as to whether there is a causal relationship. Chapter 8 then 

discusses quantitative and qualitative approaches for integrating epidemiological, laboratory, and other kinds of evidence to reach conclusions about 

the strength of evidence for association and causation. This background 
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ESTABLISHING AN EVIDENCE-BASED FRAMEWORK 137

provides a foundation for the Committee’s specific recommendations in 

Chapter 12, which outlines a classification system for characterizing the 

strength of evidence in support of a general causal relationship. Assuming 

that such a causal relationship has been established, Chapter 9 discusses 

how to quantify the strength of the causal effect, using measures most 

relevant to compensation decisions under the presumptive process: the 

attributable fraction for the population of exposed veterans, and the probability of causation for an individual. Chapter 10 covers the various types 

of data necessary to assess the existence of a causal relationship and to 

quantify the size of the causal effect. It proposes future comprehensive 

exposure and health data collection strategies for military personnel and 

veterans.

Provision of compensation to a veteran, or to any other individual 

who has been injured, on a presumptive basis requires a general decision 

as to whether the agent or exposure of concern has the potential to cause

the condition or disease for which compensation is to be provided, in at 

least some individuals, and a specific decision as to whether the agent or 

exposure has caused the condition or disease in the particular individual or 

group of individuals. The determination of causation for veterans is based 

on review and evaluation of all relevant evidence including (1) measurements and estimates of exposures of military personnel during their service, 

if available; (2) direct evidence on risks for disease in relation to exposure from epidemiologic studies of military personnel; (3) other relevant 

evidence, including findings from epidemiologic studies of nonmilitary 

populations who have had exposure to the agent of interest or to similar 

agents; and (4) findings relevant to plausibility from experimental and laboratory research. Scientists and scientific organizations, such as the Institute 

of Medicine (IOM), have developed approaches for reviewing evidence 

and determining if causation can be inferred. Typically, these approaches 

involve a comprehensive review and the judgment of a panel of experts as to 

whether the evidence supports causation and with what degree of strength. 

The determination of causation for a particular veteran is based first on the 

general determination as to whether the exposure causes disease, and then 

on information on the exposures and possibly on clinical features of the 

individual being evaluated for compensation. 

Compensation decisions critically depend on determinations of cause, 

but the information available for determining general or specific causation may be incomplete or inconclusive. For a group, the evidence may be 

insufficient or still evolving, and for an individual, information on exposure 

may be lacking, or there may be uncertainty as to the role of service-related 

factors versus the roles of other factors in causation. In the Agent Orange 

example, information on cancer risk in exposed veterans was not available 

until they had been followed for a sufficient time, reflective of the latency 
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138 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

between exposure and disease risk for carcinogens. For individual Vietnam 

veterans, exposure to Agent Orange cannot be estimated with any certainty, 

and VA has made a presumption with regard to exposure of Vietnam 

veterans to Agent Orange (VA, 2002). VA has also presumptively linked 

certain outcomes, such as prostate cancer and type 2 diabetes, based on 

evidence for association to Agent Orange exposure. By contrast, presumptions are not needed for combat-related casualties for which there is no 

uncertainty as to causation. 

The role of presumptions becomes evident when the complete suite of 

information needed by VA for making compensation decisions for groups 

and for particular individuals is considered. Figure 6-1 describes information gathering and how information may be used for making general and 

specific judgments about causation and for making evidence-based decisions with regard to compensation. The schema in the figure assumes that 

the availability of information for making these determinations, as well as 

the roles of factors beyond the scientific evidence, such as costs and political considerations, are all figured into the process. Presumptions are made 

when there are gaps in the information related to exposure and causal 

classification. Factors other than the evidence relevant to the causal classification may affect the compensation decision.

If complete information were available, the process in the table could 

flow without presumptions, but the review of presumptions in Chapter 2 

shows that this ideal has been infrequent and many presumptions have been 

made. The military workplace and particularly combat can lead to many 

exposures that may affect future health status and disease occurrence. Military personnel sustain a variety of exposures, some specific to the military 

and others not, that may increase risk for disease. If exposures of potential 

concern were tracked during military service and disease surveillance were 

in place and maintained, even for those who have left active duty, evidence 

could be generated directly relevant to the causation of disease in veterans. 

Disease rates could be compared in exposed and nonexposed veterans, for 

example. Lacking such evidence, reviewing groups turn to epidemiologic 

studies of other populations and gauge the relevance of the findings for the 

exposures of veterans. Such groups also give consideration to toxicological 

and other research information. For a specific individual, the determination 

of eligibility for compensation would be based ideally in full knowledge of 

that individual’s risk and an estimation of his or her probability of causation, given exposure history and observational information on the associated risk from similarly exposed people. However, this level of information 

and scientific understanding has not yet been fully achieved for individual 

causation for any agent. 
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ESTABLISHING AN EVIDENCE-BASED FRAMEWORK 139

FIGURE 6-1

Exposure Measurements for

Military Personnel

Compensation Decision

Causal Classification

Evidence Review

Biomedical Knowledge

(Including Studies of

Veterans)

Exposed Group Eligible for

Compensation

Exposed Individuals

Individual exposure

Other risk factors

Other considerations

FIGURE 6-1 Information gathering and its use in making general and specific 

compensation decisions.

A FRAMEWORK FOR PRESUMPTIONS

For all veterans or a particular group of veterans, the evidence may be 

sufficient to identify a causal relationship between an exposure and a health 

outcome. However, certainty as to whether an individual veteran’s service 

caused his or her disability or illness will vary depending on clinical characteristics and the availability of information on the veteran’s exposures 

during service. 
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140 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

In decisions to award compensation, two types of errors may occur: 

giving compensation to a veteran whose illness was not caused by the 

service-related factor (false positive) and denying compensation to a veteran 

whose illness was caused by the factor (false negative). These two types of 

errors need consideration in the design of compensation schemes. 

This section establishes a framework for reasoning about compensation for service-attributable disability and illness and for making presumptions, and discusses the concept of a disability or illness being service 

attributable—that is, caused by a veteran’s service. (A more detailed discussion of models of causation is presented in Chapter 8 and Appendix J.) This 

section also describes the types of errors that can be made and the potential 

costs of each. It then addresses presumptions, viewed as one approach to 

completing gaps in the evidence needed for making decisions about compensation. The Committee emphasizes the need to address the false positive 

and false negative rates of particular decisions. 

To simplify this chapter, the Committee considers the onset of a particular definable disease, a dichotomous outcome. Of course, some diseases are 

non-specific in their characteristics and the extent of disability associated 

with a particular disease may be a continuum from mild to very severe. 

Service-Attributable Disease

In the circumstance that a veteran has a specific medical disease, the 

primary question for presumptive compensation is whether the disease is 

attributable, that is, caused by exposures during military service. We ask 

whether, absent service, the disease would have occurred at all or would 

have been less severe. The answer for any particular veteran can never be 

known exactly because it is not possible to observe the same person as 

exposed and non-exposed. The needed comparison for what would have 

happened to the exposed person, had they not been exposed, is referred to 

as the “counterfactual”—in other words, counter to the actual facts. We 

use information from unexposed but similar persons to describe the counterfactual. For example, the rate of posttraumatic stress disorder (PTSD) in 

former prisoners of war (POWs) could be compared to the rate in veterans 

with combat service who had not been POWs. There is an implicit assumption that the rate in non-POWs represents the rate in POWs, had they not 

been POWs. The excess in the POWs reflects the contribution of having 

been a POW.

The degree of certainty as to whether a disease is caused by service will 

vary substantially across different exposures and diseases. At one extreme, if 

the health problem is the direct result of an event during service, such as a battle wound, then full service attribution can be made with certainty. For chronic 

diseases with multiple causes there may be much less certainty. For example, 
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ESTABLISHING AN EVIDENCE-BASED FRAMEWORK 141

consider a Vietnam veteran who develops diabetes. His service has been established as a potential risk factor based on findings of epidemiologic studies and 

knowledge that some Vietnam veterans were exposed to Agent Orange, leading 

to a presumption of exposure of all Vietnam veterans. However, other factors, 

such as obesity and age, also contribute to the development of diabetes. Service 

attribution for diabetes in this particular veteran is much more uncertain than 

for disability from the battle wound. The uncertainty comes both from gaps 

in the general evidence linking Agent Orange to diabetes and from limitations 

of the information available on exposure and other relevant characteristics for 

the particular veteran. 

In deciding whether to compensate a group of veterans on a presumptive basis, review is needed of all relevant data to assess if the disease is 

service attributable, including information about wartime exposures and 

other risk factors (such as obesity, age, and gender, in the example of diabetes). This information would then be used to estimate the likelihood, 

that is, the chance that exposure during military service contributed to the 

disease in the group. Currently, with the exception of radiation for which 

quantitative risk approaches are available, VA takes a more qualitative 

approach to determining service attribution, while using information about 

the exposure and other factors, as available. For some diseases of current 

concern with several causes, the causal agents contributing in a particular 

individual cannot be known with certainty so that presumptions will lead 

to false positive and negative errors. 

Errors

The two possible errors that can be made in deciding service attribution (assuming knowledge of whether or not a veteran’s disease was caused 

by exposures during service) are summarized in Table 6-1. A false positive 

decision is made when the veteran’s disease is not caused by his or her 

service, but VA decides that it was. A false negative decision is made when 

the disease is caused by service, but VA does not determine it to be service 

attributable.

The rates of correct decisions are called the sensitivity or true positive 

rate (TPR) and the specificity or the true negative rate (TNR). In other 

words, the proportion of all truly service caused cases that are correctly 

classified as service attributable is called sensitivity, whereas the proportion of all truly non-service caused cases that are correctly judged not to 

be service attributable is called specificity. Sensitivity is the probability of 

correctly deciding that a person’s disease was caused by service. Specificity 

is the probability of correctly deciding that it was not. 

The example above addresses the correct classification of veterans with 

regard to the causation of disease by exposures during military service. The 
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142 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 6-1 Possible Decisions About Service-Attributable Diseases 

(SADs) with Associated Errors and Losses 

Decision Truth Error Rate of Error Loss

Disease NOT 

caused by 

service

Disease NOT 

caused by 

service

No error Specificity

[True 

Negative Rate 

(TNR)]

0

Disease NOT 

caused by 

service

Disease IS 

caused by 

service

Failure to 

attribute 

disease to 

service

1-Specificity

[False 

Negative Rate 

(FNR)]

Failure to cover veteran 

with SAD

• Monetary loss to 

veteran

• Injustice to veteran

Disease IS 

caused by 

service

Disease NOT 

caused by 

service

False 

attribution 

of disease to 

service

1-Sensitivity

[False positive 

rate (FPR)]

• Monetary loss to 

society 

• Incorrect disease label 

and consequences

Disease IS 

caused by 

service

Disease IS 

caused by 

service

No error Sensitivity

[True positive 

rate (TPR)]

0

same concept and terminology is used with regard to classification of exposures and diseases. Exposure status is often classified on the basis of incomplete or imperfect information so that some persons designated as exposed 

were not (false positives) and some designated as non-exposed were (false 

negatives). The same considerations extend to disease classification. For 

some diseases, there are relatively specific and firm diagnostic criteria (e.g., 

type 2 diabetes), while for others, the diagnostic picture is more ambiguous, 

(e.g., some neuropsychiatric disorders), and both false positive and false 

negative errors of diagnostic classification may be made. 

Losses

As is nearly always the case, errors of classification have associated costs 

or losses. False negative errors are readily understood: a veteran who should 

receive compensation does not. The consequences of false negative errors 

elicit strongly motivated responses from all parties: veterans, VA, Congress, 

and society in general. Because there is strong motivation to avoid false 

negative decisions, a compensation scheme may be constructed to minimize the risk of making them by maximizing sensitivity (the probability of 

deciding in favor of compensation when a service-attributable disease has 
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ESTABLISHING AN EVIDENCE-BASED FRAMEWORK 143

occurred). In avoiding false negatives, however, there is usually a trade-off 

with the numbers of false positives, as increasing sensitivity will generally 

reduce specificity. In other words, planning for as few false negatives as possible increases the number of false positives. In balancing the risks of false 

negative decisions against numbers of false positives, VA presenters and past 

congressional staffers at public Committee meetings indicated a strong motivation to compensate veterans who may have been harmed by their military 

service, even if false positives are incurred (as stated during Pamperin, 2006; 

as stated during Petrou, 2006; as stated during Ryan, 2006; as stated during 

Scott, 2006; as stated during Yoder, 2006). 

However, false positive errors may also come with losses. These include 

the injustice of inappropriately awarding compensation to veterans not 

actually harmed by their service and the unnecessary expenditure of public 

funds. A compensation system that tends to have a high false positive rate 

may become generally suspect, particularly if compensation costs escalate 

rapidly. Uncompensated veterans may be troubled by the seemingly high 

rate of compensation among fellow veterans. Balancing the losses of false 

negatives and false positives is difficult, as the loss from a false negative is 

the injustice done to deserving but uncompensated veterans and that from 

false positives includes economic costs along with non-economic consequences of having a non-specific system.

Service-Attributable Fraction of Disease

In public health, calculations have long been made on the amount 

of disease caused by a factor. One well-known example is the number of 

deaths each year in the United States attributable to cigarette smoking. 

Similarly, it is possible to estimate the amount of disease among veterans 

with a given exposure and given risk profile that exceeds what is observed 

in otherwise similar, but unexposed persons. That is, one can compare the 

rate of disease in exposed veterans to the rate in otherwise similar persons 

who were known not to be exposed. If there is a difference between these 

two rates, and the assumption is that the difference is due to a causal 

effect of the exposure on disease occurrence, then the fraction of disease 

attributable to the exposure can be quantified. If for a subgroup of veterans 

with a homogeneous risk profile, the rates of disease among exposed and 

unexposed are r1 and r0, respectively, then the fraction of disease attributable to service is the relative increase associated with exposure expressed 

as a fraction of the rate among the exposed. That is, assuming causation, 

the service-attributable fraction (SAF) can be calculated by the following 

equation: 

SAF = (r1 – r0)/r1 or = 1 – r0/r1
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144 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

As r1—the additional risk from exposure—increases, the term r1 becomes 

smaller and the SAF increases towards 1.0. Consider again the examples of 

battle wounds and diabetes. Because all battle wounds occur only among 

those in combat, r0 = 0 so that the attributable fraction is 1.0 for battle 

wounds. For diabetes, however, the fraction of cases attributable to service 

in Vietnam is likely to be much smaller than 1.0, given the existence and 

strength of other factors (e.g., obesity) that contribute to its causation.

Rates of disease for exposed veterans and for otherwise similar veterans 

who were not exposed are required to estimate the SAF of disease for a 

population of exposed veterans. The rates are needed for each subgroup as 

defined by the exposure of interest, other risk factors, and perhaps other 

covariates. Of course, taking account of all the various subgroups defined 

by the resulting array of variables is likely to be difficult or even impossible in practice. If relevant data are available, an analytic approach using a 

statistical model can be used for taking the covariates into account so that 

the SAF can be calculated for each subgroup. 

To illustrate the estimation of service-attributable disease, consider the 

hypothetical data in Table 6-2 showing diabetes occurrence in 5,000 veterans 

exposed to Agent Orange and 5,000 otherwise similar, but unexposed, 

persons in a particular stratum of demographic and other risk factors.

In this hypothetical example, 150 of the 10,000 veterans have diabetes. 

Again in this example, only 100 of the diabetics were exposed to the 

putative cause, and thus 100/150 = 67 percent of the total funds spent on 

diabetes are for exposed individuals. Even among the exposed veterans, not 

all cases of diabetes were caused by the exposure, as 50 would be expected 

absent exposure, based on the experience of the unexposed veterans of 

whom 50 of 5,000 developed diabetes. Therefore, we can assume, absent 

exposure (i.e., the counterfactual), that 50 of the 100 cases among the 

exposed veterans would have occurred, even if those veterans had not been 

exposed. Hence, only the remaining 50 or 50/100 = 50 percent are attributable to the exposure associated with service in Vietnam. In this example, 

providing compensation for all exposed veterans with diabetes means that 

the false positive rate is 50 percent. 

TABLE 6-2 Hypothetical Example of the Estimation of ServiceAttributable Disease

Diabetes No Diabetes Total

Exposed veterans 100 4,900 5,000

Unexposed veterans 50 4,950 5,000

Total 150 9,850 10,000
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ESTABLISHING AN EVIDENCE-BASED FRAMEWORK 145

In this example, the costs of compensation can be apportioned between 

the true positives and false positives. Assume funds of $10,000 per person 

compensated and three scenarios: (1) knowledge of who is exposed and 

has disease caused by exposure, (2) knowledge of who is exposed and no 

knowledge of which cases were caused by exposure, and (3) no knowledge 

of who is exposed or which cases were caused by exposure. In the first situation, $500,000 would be awarded, only to true positives. In the second, if 

the exposure status of specific individuals were known but individual causation not known, $1,000,000 would be awarded. With a SAF of 50 percent, 

$500,000 would be for true positives and $500,000 for false positives. If 

exposure status were unknown for all individuals, then the compensation 

scheme would award $1,500,000 including $1,000,000 for false positives. 

Applying the SAF of 33 percent (67 × 50 percent) to the total disability costs 

(150 × $10,000) again gives $500,000 in costs attributable to the exposure. 

In the first situation, with known exposures and disease causation, only 

those exposed receive payment, while, in the third, all with disease receive 

payment. 

This simple example shows that the attributable costs for a population 

with a given set of characteristics are determined by two fractions: 

• Probability that a veteran was actually exposed to the putative 

cause given that he or she has the disease and given his or her estimated or 

measured exposure data and information on other relevant factors

• Probability that the disease in an exposed veteran was caused by 

his or her exposure given that the veteran has the disease, and given his or 

her estimated or measured exposure information and information on other 

relevant factors

These probabilities can be estimated, if the requisite data are available; 

otherwise, values must be assumed. Presumptions for exposure or causation, as currently implemented by VA, correspond to assuming that these 

probabilities are equal to 1.0. Service in a particular theater may lead to a 

presumption of exposure, an assumption meaning that the probability of 

exposure is 1.0; with regard to causation, there may be a further assumption that the disease is caused by the exposure, again acting as though the 

second probability is 1.0. If either of these two probabilities were assumed 

to be 0, then compensation would not be awarded. 

In the illustration above, we calculated a single SAF from the rates of 

disease among exposed and otherwise similar unexposed veterans. This 

calculation is based upon the assumption that we are comparing like to 

like persons, except for the exposure. It can be difficult to form groups 

of exposed and unexposed veterans that are the same with respect to 
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146 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

other factors affecting the disease process. Typically, statistical methods for 

adjustment are used to attempt to achieve this comparability.

Statistical methods, however, are only as good as the data to which they 

are applied. Accurate and precise estimates of SAFs depend on detailed data 

on exposure, key covariates, and disease outcomes. Chapter 10 provides a 

detailed discussion of approaches to compiling such data as an element of 

surveillance of veterans. To the extent that data are incomplete, a frequent 

situation, the estimates of the SAF will be subject to uncertainty to a degree 

that will depend on the extent of missing data.

Making Presumptions

To this point, we have described the concept of service-attributable disease for a population and for an individual. We have indicated that application of a presumption can be thought of as equivalent to acting as though the 

probability of exposure and/or the probability that an exposed veteran’s disease is caused by his or her service are equal to 1.0. We show that any scheme 

may lead to two types of error and that avoiding false negatives, a desirable 

property of a compensation system, may increase the false positive rate. One 

key consideration is the basis for setting the sensitivity of the approach. We 

have set out the losses associated with each of the two types of error. When a 

veteran’s illness is not attributed to a service-related exposure when it should 

be, he or she is denied benefits to which entitled, and an injustice is rendered. 

When a veteran’s illness is attributed to a service-related exposure even when 

he or she was not exposed (or, if exposed, the disability was not caused by 

that exposure), compensation is provided that is not truly warranted. 

Uncertainty

Uncertainty, lack of complete and perfect knowledge, inherently affects 

the presumptive disability decision-making process. Presumptions are 

needed because information is incomplete, in relation both to causation 

generally and to whether specific individuals have an illness caused by service in the military. Because uncertainty is inevitably present, a vocabulary 

to express its extent, including adjectives such as unknown, improbable, 

possible, likely, or certain is needed. In using uncertain scientific evidence 

for decision making, we depend upon quantification of uncertainty for 

guidance on how to weigh more and less certain evidence. 

In attributing disease to military service, uncertainty may be unavoidable for some exposures, although obviously not for others, such as a 

wound and its consequences. As described in Chapters 7 and 8, one necessary step in the presumptive disability decision-making process is to determine whether a disease was caused by factors related to military service. 
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ESTABLISHING AN EVIDENCE-BASED FRAMEWORK 147

The counterfactual notion of cause compares disease occurrence in two 

worlds, one with and the other without the exposure. Because only one of 

these worlds is observable, the likelihood of an event in the other must be 

predicted, and the outcome of the prediction is inherently uncertain. 

The determination of whether a particular military exposure has the 

potential to cause a disease or condition is often subject to substantial 

uncertainty. Experimental studies have the advantage of having an explicit 

comparison group selected at random so that the counterfactual state is 

experimentally established. However, data from controlled experiments 

in human populations are generally not available and would generally 

not be applicable to exposures that cause disease only after a substantial 

period of time, as is true for many chemicals and risk for cancer. Findings 

from observational or epidemiologic studies of risk in exposed compared 

to unexposed persons, while attempting to control for other factors, are 

often used instead. The effort to control for other factors and to thereby 

assure comparability of exposed and nonexposed persons may not be fully 

successful, and other sources of bias may also add to uncertainty in results 

of observational studies. Typically, results of in vitro and animal studies of 

biological mechanisms are also considered. However, in using the results 

of such research, uncertainty arises from the extrapolation of results from 

cells, animals, or other systems to humans. Approaches for quantifying 

these diverse sources of uncertainty about causation have been developed 

but do not fully reflect the scope of the uncertainty and its implications for 

decision making. Most often, judgment of expert panels to gauge the degree 

of uncertainty is used as a guide to decision making. 

Even if general causation is established, assignment of causation in a 

particular veteran may still be subject to uncertainty. Limited or no information may be available on exposure. Exposures in a war theater may 

vary greatly over space and time, and without detailed information on the 

spatiotemporal profiles of exposure and on locations of individual Service 

members, exposure estimates will be imprecise and possibly invalid. 

Uncertainty as to individual causation would not be eliminated by 

having “perfect” exposure data. Conditions and diseases often have multiple causes, each possibly causing some proportion of the observed cases. 

Absent some marker that indicates that a particular case of disease was 

attributable to a specific factor, uncertainty as to causation by military 

service, when other factors also contribute to etiology, is inherent. Variation in susceptibility to an exposure is a further source of uncertainty in 

considering causation in individuals. 

Uncertainty also affects the SAF, a statistic recommended by the Committee as an index of the extent of disease that is attributable to an exposure. The attributable fraction is defined as the fraction of an exposed and 

diseased population whose disease was caused by the exposure, meaning it 
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148 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

is the fraction of the population who, but for the exposure, would not have 

developed the disease. The value of the attributable fraction may depend on 

multiple factors, including the level and the timing of exposure, the doseresponse curve, the time since exposure, and the baseline susceptibility of 

the population. The true function relating the attributable fraction to exposure is unknown in terms of both its general form and its specific values. 

We estimate the function describing the attributable fraction from finite 

data that are subject to variability. Hence, there is typically uncertainty in 

estimates of the attributable fraction used to describe the burden of disease 

attributable to an exposure and to assess whether disease in an individual 

veteran was caused by service.

Scientists have constructed mathematical systems to quantify uncertainty; the theory of probability is the most widely applied. There are two 

distinct notions of probability: frequentist and subjectivist. In the former, 

probability represents the long-run frequency of events. For example, the 

probability of a heads or tails represents the fraction of heads or tails out of 

a large number of coin tosses. Subjectivist probability is instead an expression of belief about the likelihood of an event. For example, we represent 

an individual’s risk of disease as a probability between 0, indicating no 

chance, and 1, indicating certainty. For either notion, there is the same 

precise calculus for representing, combining, and manipulating probabilities 

as measures of uncertainty. 

In subsequent chapters, the Committee sets out concepts related to 

general and specific causation that are critical for improving the current 

approach to making presumptions.

SUMMARY

This chapter introduces some of the key concepts involved in using 

scientific evidence as the basis for compensation of groups of exposed individuals. It sets out the need to determine general causation and to consider 

how much disease is attributable to exposure. These concepts are elaborated in subsequent chapters. Gaps in the scientific evidence on exposure 

and causation lead to a need for presumptions. Chapters 10 and 11 address 

how surveillance of exposures and disease among active duty personnel and 

veterans could reduce these gaps.

REFERENCES

Pamperin, T. J. 2006. An overview of the disability benefits program and presumptions affecting veterans’ benefits. Paper presented at the first meeting of the IOM’s Committee on 

the Evaluation of the Presumptive Disability Decision-Making Process for Veterans, 

Washington, DC. 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html

ESTABLISHING AN EVIDENCE-BASED FRAMEWORK 149

Petrou, L. 2006. Statement presented at the third meeting of the IOM’s Committee on the 

Evaluation of the Presumptive Disability Decision-Making Process for Veterans. San 

Antonio, TX.

Ryan, P. 2006. Perspectives on veterans’ legislative disability presumptions. Paper presented 

at the third meeting of the IOM’s Committee on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans, San Antonio, TX.

Scott, E. P. 2006. Statement presented at the third meeting of the IOM’s Committee on the 

Evaluation of the Presumptive Disability Decision-Making Process for Veterans. San 

Antonio, TX.

VA (Department of Veterans Affairs). 2002. Veterans health initiative. Independent study 

course. Vietnam veterans and Agent Orange exposure. Washington, DC: Department of 

Veterans Affairs. http://www1.va.gov/agentorange/docs/VHIagentorange.pdf (accessed 

May 12, 2007).

Yoder, C. 2006. Thoughts on presumptions of service-connection for veterans presumed to 

have been exposed to environmental hazards. Paper presented at the third meeting of 

the IOM’s Committee on the Evaluation of the Presumptive Disability Decision-Making 

Process for Veterans, San Antonio, TX.
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150

7

Scientific Evidence for 

Causation in the Population

INTRODUCTION

This chapter describes the kinds of scientific evidence used for establishing a general causal relationship between exposure and disease, an important input to presumptive service-connection decisions. Unlike individual 

service-connection claims, in which a particular veteran has to make a case 

that a particular condition affecting him or her was caused by or aggravated 

by military service, a presumptive service connection applies to a group, or 

population of veterans. Presumptive service connections remove the burden 

of proof from individual veterans, but establishing presumptions necessitates an assessment of the scientific evidence for population causal claims

(i.e., was some group of veterans exposed to conditions or substances that 

aggravated existing or caused new health problems after service separation). 

More specifically, the goal is often to establish whether, in a population of 

individuals, exposures received by members of the population resulted in 

a change in the frequency of occurrence or in the average severity of a disease. For example, we might ask whether the frequency of non-Hodgkin’s 

lymphoma (NHL) among Vietnam veterans who were exposed to benzene 

during service is higher than the frequency among those who were not. If 

so, then we might assert that exposure to benzene is capable of causing

NHL. The causal claim about the population does not mean that every 

veteran exposed to benzene during service will develop NHL or that every 

case of NHL would not have happened but for benzene exposure. On the 

population level, causal claims typically involve how risk (the probability

of disease) changes in response to exposure. 
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SCIENTIFIC EVIDENCE FOR CAUSATION IN THE POPULATION 151

In this chapter we will focus on the scientific issues involved in 

establishing these sorts of causal claims. We will review the issues facing 

scientists or others who review evidence to collectively decide on population causal claims. The next chapter provides a framework for doing so. 

At the start of this chapter, we discuss the types of scientific information 

considered in evaluating the strength of evidence for inferring causation. 

Then we discuss how epidemiologists define and assess association and 

how association differs from causation. This distinction is essential to 

understanding prior approaches to presumptive disability decision making 

and also this Committee’s proposed approach. In Appendix J, we offer an 

extended discussion of what we mean by causation and how it is modeled 

statistically. We have placed this material in an appendix, not as a reflection of its importance, but because the topic is too complicated to cover 

in a short section. 

Next we discuss the scientific strategies used to establish association, 

and lastly we discuss the scientific strategies used to move beyond just 

determining the presence of an association to inferring causation. We 

conclude the chapter by discussing uncertainty—both with respect to 

association and with respect to causation. We leave to the next chapter 

a discussion of strategies for synthesizing potentially diverse sources of 

evidence into a single overall judgment of the strength of evidence for a 

causal claim. 

SOURCES OF EVIDENCE

Evidence about population causal claims (hereafter just “causal 

claims”) comes from a variety of sources. In some cases, we have extensive knowledge about the mechanism by which exposure causes disease. 

For example, we do not need a randomized clinical trial to establish that 

bullet or s­hrapnel wounds have a deleterious effect on health. In other 

cases, such as low levels of exposure to lead and cognitive deficits in children, we know much less about the mechanisms and turn to other types of 

scientific evidence including findings of epidemiologic studies. Any scientific assessment of a causal claim combines the mechanistic knowledge and 

statistical evidence from epidemiologic studies. In this section we briefly 

survey the types of statistical evidence used to establish causal claims, 

and then we sketch the types of toxicologic, biologic, and mechanistic 

knowledge used to support or reject causal claims. By statistical evidence 

we mean the quantitative relationships between a set of measured variables in a sample. Case reports about individual patients may be useful 

for suggesting etiologic hypotheses, particularly with exposures that are 

followed quickly by disease onset.
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152 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Randomized Clinical Trials

The most persuasive human evidence for establishing a causal relationship comes through experimental studies in which investigators control 

exposure. Randomized clinical trials (RCTs) are the counterpart in humans 

to the controlled laboratory experiment with animals. In clinical trials, 

the exposure (usually considered as potentially beneficial, such as a new 

medication) is allocated randomly to the study population in such a way 

that the treated and untreated groups are otherwise equivalent, at least in 

expectation. If the randomization process has been successful, then any differences between the treated and comparison groups should reflect a causal 

relationship between treatment and disease (or outcome) risk. Randomization assures comparability of the two groups on factors that may affect the 

occurrence of the outcome.

Although the RCT is simple in concept, proper execution in human 

populations is often quite challenging and complicated. Even if randomization is successful in assuring comparability of exposed and comparison 

groups, validity of results for causal inference is not assured. For example, 

there are powerful placebo effects that operate in humans, which can be 

eliminated, in some instances, by concealing treatment status from the 

study participants. More subtle problems can arise when the doctors or 

others administering the treatment and collecting the outcome data are 

aware of treatment status. This potential for bias has prompted the use of 

the “double-blind” design, in which neither the study personnel in contact 

with participants nor the participants themselves know the treatment status. 

A refinement of this design is the crossover study, in which treatment and 

nontreatment are given in random order to each participant, allowing each 

person in the study group to be his or her own control. This design illustrates the kind of evidence we would like to have to draw causal claims, 

since we directly observe the response of the same person when they are 

treated and not treated, so that the treatment can be reasonably inferred 

to be the “cause” of any differences in response under the two conditions. 

Unfortunately, crossover trials are a practical approach only for studying 

short-term responses to agents for non-fatal conditions, so that they cannot be used for assessing effects of environmental exposures on chronic 

diseases.

In most other designs, including RCTs of standard design and most 

observational studies, we have to base such conclusions on differences 

in rates between exposed and unexposed groups of different individuals, 

rather than on the responses of the same individual in exposed and unexposed states. Interpretation of differences in outcome frequency as a causal 

effect when comparisons are made between different groups requires a 

form of inference known as “counterfactual.” Using the counterfactual (i.e., 
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counter to the facts) we infer what would have happened in the exposed 

group had the exposure been some alternative by making a comparison 

with the outcomes of others who actually experienced the different exposure. The counterfactual approach needs comparability of the exposed and 

comparison groups. 

RCTs and other experiments involving humans are ethically limited in 

the range of questions to which they can be applied. Many of the major 

questions of public health—for example, the effects of air pollution or 

pesticides on human health—cannot be addressed through RCTs because it 

is not ethical to expose humans experimentally to substances in quantities 

that are presumed harmful. For such questions, we are limited to passively 

observing the health of people “naturally” exposed—that is, to observational studies. Nonetheless, the model of the RCT remains useful as a 

framework for considering limitations of findings of observational studies. 

Randomized interventions can be ethically carried out to reduce exposure 

to harmful agents (e.g., tobacco use).

Observational Studies

In an observational study, the investigator does not control exposure of 

the people in the study and does not intervene in any way in the population 

under study. Although observational studies may lack the comparability of 

exposed and non-exposed characteristic of controlled experiments, they are 

nonetheless capable of providing evidence about the relationship between 

exposure and health and are generally the only option available to obtaining human evidence of the effect of potentially harmful exposures. 

Broadly speaking, observational study designs fall into three categories: 

cross-sectional studies, cohort studies, and case-control studies. In crosssectional studies, a variety of factors are recorded at a particular point in 

time. In cohort studies, persons exposed or unexposed to a given factor are 

observed over a period of time for health effects related to the exposure. 

The case-control study compares persons with a given disease (cases) to 

those without the disease (controls) with regard to their history of exposure. Each of these general designs has appropriate analytic strategies, and 

each design has its own strengths and weaknesses. There are variations 

of each of these approaches, and a few additional approaches as well (for 

example, case-crossover studies). These designs are well described in standard epidemiologic references. 

One general difficulty of observational studies, regardless of design, 

is that exposure is not randomized. Rather, exposure status may be determined by where people live or work, what they eat, what social group they 

belong to, or by a host of other factors that can be associated with disease 

risk. As a consequence of these other factors, associations between expo-
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154 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

sures and disease risk may occur even if the exposure does not cause the 

disease. Conversely, no association may be measured when the exposure 

actually does cause disease because these factors act to reduce the effect.

Toxicologic, Mechanistic, and Biologic Knowledge

In addition to randomized clinical trials and observational studies, 

which provide statistical evidence of a relationship between exposure and 

disease, a wide variety of other types of scientific evidence may be crucial 

for inferring a causal relationship between exposure and disease (IOM, 

2006a,b; IOM/NRC, 2005). Controlled laboratory experiments with animals and research in in vitro systems and other relevant biological, physical, or even social data can be used to assess the likelihood that a given 

substance or circumstance can cause a particular human health effect. 

Approaches to assessing the combined evidence from human and animal 

investigations, as well as from in vitro systems, have been formulated by 

a number of agencies including the International Agency for Research on 

Cancer (IARC, 2006b), the Institute of Medicine (IOM) (IOM, 2006b; 

IOM/NRC, 2005), and the Environmental Protection Agency (EPA, 2005). 

These formalized approaches offer guidance on assessment of evidence and 

relative weighting of various lines of evidence.

Even without statistical evidence from epidemiologic studies, the findings of animal studies and mechanistic investigations on how an agent 

causes a health effect can be sufficiently convincing to support a causal 

conclusion. For example, IARC identified benzo(a)pyrene as a human 

carcinogen primarily based on non-epidemiologic evidence (Straif et al., 

2005). However, we infrequently amass this level of biological understanding for agents affecting human health. More typically, non-epidemiologic 

lines of research are considered to support the conclusion that a substance, 

or chemical, “probably” causes, or is “likely” or “reasonably anticipated” 

to cause an adverse effect such as cancer or other health endpoints (e.g., 

EPA, 2005; IARC, 2006b; NTP, 2005; NTP CERHR, 2003, 2005). When 

there are epidemiologic findings supporting an association between an agent 

and disease, however, experimental or other biological evidence may provide sufficient weight and understanding for scientists to conclude that the 

association is due to a causal relationship. For example, in several species 

the agent may produce the same effect as observed in human studies, and 

by a mechanism that is conserved and relevant across species with key features of the mechanism observed through experiments in human cell lines 

or other systems. 

As a case in point, epidemiologic, animal, and mechanistic data were all 

considered in establishing that industrial exposure to butadiene can cause 

lymphohematopoietic cancers (IARC, 1999). Epidemiologists showed that 
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styrene-butadiene exposed rubber workers had elevated lymphohematopoietic cancer rates. Toxicologists showed that potentially carcinogenic 

metabolites of butadiene in butadiene-exposed workers activated potential 

oncogenes, providing mechanistic knowledge on carcinogenesis, and biologists induced tumors in mice and rats, both with exposure to butadiene and 

to a known metabolite that occurs in humans and mice and rats, providing 

animal evidence. 

Formaldehyde provides a contrasting example. IARC (2006a, sec. 5-2) 

noted that epidemiologic studies found “strong but not sufficient evidence 

for a causal association” between formaldehyde exposure and leukemia. 

Their interpretation of the finding as causal was guarded because of some 

limitations in the several positive studies (e.g., small numbers of deaths) and 

lack of finding of effect in a high-quality study. There was uncertainty with 

regard to possible underlying mechanisms. The IARC monograph noted 

lack of good rodent models for human acute myeloid leukemia. It also 

considered various possible mechanisms, “such as clastogenic damage to 

circulatory stem cells” (IARC, 2006a, sec. 5-4). Unable to identify a mechanism for the induction of leukemia in humans from formaldehyde and data 

to support it, IARC did not conclude that formaldehyde was a known cause 

of human leukemia. Golden et al. (2006) have advanced arguments that 

the relationship could not be causal. For example, they argued that inhaled 

formaldehyde is so reactive that it is unlikely to travel as formaldehyde 

from the upper airways to the bone marrow; also they argued that “there is 

no indication that formaldehyde is toxic to the bone marrow/hematopoietic 

system” as are other known leukemogens benzene, ionizing radiation, and 

chemotherapeutic agents (Golden et al., 2006, p. 146).

ASSOCIATION AND CAUSATION

Association

Absent strong mechanistic understanding, the first step towards establishing a causal relationship between exposure experienced by people and 

a disease is to establish a statistical association between exposure and the 

disease. Exposure and disease are positively associated in a group if the incidence of disease among those exposed is higher than the incidence among 

those not exposed. For example, in the early 1950s Doll and Hill demonstrated that tobacco smoking and lung cancer mortality were associated. 

In a cohort of British physicians, lung cancer mortality was much higher 

among people who smoked 25 g of tobacco daily compared with those 

who didn’t smoke (Doll and Hill, 1954, p. 1530). Even though a detailed 

mechanism between inhaling smoke and contracting lung cancer was not 

evident, a vague but plausible mechanism based on the carcinogenic proper-
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156 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

ties of tobacco tar allowed scientists to hypothesize that the association was 

produced by a causal relationship. Had there been no observed difference in 

lung cancer mortality between smokers and nonsmokers, they would have 

likely assumed that smoking had no causal influence on lung cancer.

The strength of association between exposure and disease is typically 

measured with a statistic called the relative risk (RR). RR is the ratio 

of the incidence of disease among the exposed over the incidence in the 

unexposed:

RR incidence

incidence = = ( )( )

exposed

unexposed

# exposed with disease / # exposed

# not exposed with disease / # not exposed

An RR of 1.0 means that the frequency of disease among the exposed 

is the same as among the unexposed. An RR of 10 means that the rate of 

disease among the exposed is 10 times as high as among the unexposed. 

A high RR does not imply a high absolute risk in the population. If, 

for example, one in a million unexposed individuals and 10 in a million 

exposed individuals get the disease, then the RR is 10, even though the 

chances of getting the disease among those exposed is only 1 in 100,000. 

Another measure of association, commonly used in case-control 

studies, is the odds ratio (OR): 

OR = # with disease & exposed / # with disease & not exposed

# without disease & exposed / # without disease & not exposed

# with = disease & exposed / # without disease & exposed

# with disease & not exposed / # without disease & not exposed

From this formula, it can readily be seen that the OR, expressed in the 

first line as the odds of exposure in cases divided by the odds of exposure 

in controls, is also (second line) the odds of disease in the exposed divided 

by the odds of disease in the unexposed. The OR has the desirable property 

of being approximately equal to the RR if the disease is rare (Greenland 

and Thomas, 1982). This is true even though the absolute risks in exposed 

and unexposed cannot be estimated from case-control studies. 

Association Is Not Causation

Association is not the same as causation. It is prima facie evidence 

for causation, but not sufficient by itself for proving a causal relationship 

between exposure and disease. For example, although they did not record 

its presence, Doll and Hill would presumably have found a high positive 
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SCIENTIFIC EVIDENCE FOR CAUSATION IN THE POPULATION 157

association between having tar-stained fingers and lung cancer mortality 

in their study. Clearly having tar stains on one’s fingers does not by itself 

cause lung cancer, but it could be associated with lung cancer risk because 

heavier smokers, at greater risk for lung cancer, would also be more likely 

to have tar-stained fingers. 

Unlike associations, causal claims support making counterfactual claims, 

that is, claims about what the world would have been like had something 

been different, or changed. For example, what would have been the rate of 

lung cancer mortality among a group of smokers had they been prevented 

from smoking? For this, the counterfactual claim would be the rate of lung 

cancer mortality among never smokers. What would have been the rate of 

lung cancer mortality among those with tar-stained fingers had we eliminated their stains with special soap? Although tar stains and smoking are 

both associated with lung cancer, we can answer these questions because we 

know the causal mechanisms: smoking is a common cause of tar stains and 

lung cancer, but tar stains by themselves have no effect on lung cancer mortality. Service-connection claims require the same attention to counterfactual 

questions: what would have been the rate of adult-onset type 2 diabetes had 

Vietnam veterans not been exposed to Agent Orange, for example. 

Claims about association alone do not support the sorts of claim that 

must underlie presumptive service connections, while causal claims do. We 

call an association that arises in a population from an exposure that causes 

disease a causal association. Associations are termed spurious if they arise 

for some other reason. For example, the association between tar-stained 

fingers and lung cancer is spurious.

Spurious associations can arise in many ways. One is from a common 

factor (confounder) that is associated with the exposure under study and 

also a cause of the disease of interest, and another is from reverse causality 

(the disease is a cause of exposure) as depicted in Figure 7-1. 

 In the context of presumptive service connections, exposure typically 

occurs prior to the medical condition under consideration. Thus, we can 

almost always rule out the possibility that a medical condition was a cause 

of exposure, but the development of disease may influence apparent exposure. For example, it has been speculated that early subclinical manifestations of diabetes could increase storage of polychlorinated biphenyls (PCBs) 

in the body, leading to apparent associations of PCBs with diabetes even 

when the exposure is measured years before the emergence of the disease. 

More intuitively, people developing asthma might choose to not have cats 

if the presence of a cat exacerbated their asthma. The inverse association 

that would be observed between asthma and cat ownership would represent reverse causation and not a causal, protective effect of cats on risk for 

asthma. Thus, reverse causation may produce a spurious association even 

with carefully collected prospective data. 
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158 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Common

Cause

Exposure Disease

Exposure Disease

Exposure Disease

Causal

Association

Spurious

Association

Reverse

Causality

FIGURE 7-1

FIGURE 7-1 Causal and spurious associations.

If we can measure potential confounders (i.e., common causes) that 

might give rise to spurious association, then statistical adjustment can be 

used to remove the part of the observed association that arises spuriously 

from confounders. We discuss this strategy in a later section. 

There is also the possibility that exposure causes disease, but that the 

two are not associated in the population under study. For example, if a 

confounder produces negative association between exposure and disease, 

but the true causal relationship produces positive association, and the two 

associations (true and confounded) are of roughly same magnitude, then 

the observed association will be small as represented in Figure 7-2. Note 

that dropouts are excluded from this example. Fortunately, because hiding a 

causal association requires a spurious association of similar magnitude but 

opposite sign as the causal association, this situation occurs infrequently. 

Confounder

Exposure Disease

+

+ –

FIGURE 7-2

FIGURE 7-2 Scenario for causation without association.
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The Problem of Bias

Even if confounding and reverse causation can be ruled out (or statistically controlled for, as we discuss below), observational studies might still 

be affected by other forms of bias, including information bias and selection bias. Bias in this context does not suggest prejudice on the part of the 

researcher, but rather denotes systematic error arising from the collection 

of information or the selection of participants that produces an observed 

association not attributable to an underlying causal relationship between 

exposure and disease. For example, systematic error might occur in a casecontrol study of patients with pancreatic cancer in which most of the cases 

have died before they could be interviewed. If the interviewer relies on 

family members for information about exposures of the dead person but 

on living controls themselves, then the quality of the exposure information 

is likely to differ for the cases and the controls. Differential quality of data 

for cases and controls can in turn easily distort the true association between 

an exposure and a disease. This would be an example of information bias, 

a broad class of bias that relates to the quality of data collected. Another 

kind of bias is selection bias, which occurs when the selection process 

by which the study sample is derived distorts the relationship between 

exposure and outcome. For example, suppose half of the patients in the 

treatment arm of an RCT drop out of the study from side effects, while no 

one from the control arm drops out, and suppose that the dropouts are the 

ones who began the study in worse health. Even if the treatment has no 

benefit whatsoever on the outcome, the treated group will appear to fare 

better than the untreated group. Once possible biases are identified, their 

possible impact on the results can be assessed through sensitivity analysis 

(discussed below). 

EVIDENCE FOR ASSOCIATION

Although it is not sufficient for establishing causation, association is 

nevertheless prima facie evidence for causation, and the lack of association 

is prima facie evidence for lack of causation. Thus, if mechanistic knowledge is insufficient to settle the issue, a first stage in any evidence-based 

approach to presumptive service connection is to empirically establish and 

quantify the level of association in the service population under consideration, or in similarly exposed populations. 

Epidemiologists (e.g., Rothman, 2002) use risk measures such as the 

RR and the OR to quantify the association between exposure and disease 

in a population. Other measures might also be of interest, such as the 

attributable fraction (AF)—the proportion of disease in either the total 

population or an exposed subgroup that is caused by exposure—which is 
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160 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

particularly relevant for compensation policy (see next chapter). This report 

uses the terminology service-attributable fraction (SAF) when the subgroup 

of interest is a military population. More complex conceptual and statistical 

models are needed when there are several risk factors to be considered in 

combination, as will be discussed later in this chapter. 

Risk measures are estimated by applying statistical techniques to data 

from a particular sample drawn from the population of interest (e.g., a 

study of 1,000 randomly selected veterans of a particular conflict). The 

result of this process is an estimate of the population risk measure (e.g., 

the RR), together with a measure of the uncertainty in those estimates (a 

standard error or confidence interval) caused by the inherent variability in 

a random sampling process. Note that these uncertainty estimates usually 

account only for random variation, not the consequences of any bias. 

Statistical techniques are also used to test specific hypotheses, particularly the null hypothesis that there is no association between exposure and 

disease in the population. The null hypothesis is of particular interest—

unless it can be rejected, there is insufficient empiric evidence to conclude 

the existence of an association in the population. 

The statistical tests related to the null hypothesis are referred to as significance tests, and the test results are commonly expressed in the form of 

a P value, the probability of observing a sample result at least as extreme 

as that observed in the sample if the null hypothesis were true. Note that 

the P value does not provide the probability that the null hypothesis is true 

given the observed data. That would require specification of one’s prior 

belief in the null hypothesis before seeing the data. Additionally, failing 

to find the P value needed to reject the null hypothesis at some level of 

probability does not exclude the possibility of an association. There should 

be enough precision to rule out a counter explanation that the study was 

inadequate to detect a meaningful effect size. 

EVIDENCE FOR GOING BEYOND ASSOCIATION TO CAUSATION

If an association has been established, the next (and more difficult) 

task is to assess the evidence for causation by trying to eliminate alternative 

explanations to causality for the association. For example, tobacco companies and some academic researchers initially dismissed the association 

between smoking and lung cancer by proposing explanations other than 

causation. Arguments were advanced such as: perhaps a poor economic 

background would expose someone to conditions besides smoking that 

would lead to lung cancer and would also make them more likely to smoke 

or perhaps there are genes that dispose people to smoke and also to be 

more susceptible to lung cancer. Only after some years of epidemiologic 

research, animal studies, and scientific debate did the scientific community 
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SCIENTIFIC EVIDENCE FOR CAUSATION IN THE POPULATION 161

reject all alternative explanations and conclude that the association between 

smoking and cancer is causal. Postulating and eliminating alternatives are 

core skills in observational research. This process can use data from many 

sources, including the basic sciences and toxicology. If reasonable alternatives are possible, then we cannot move beyond association to a firm causal 

conclusion.

Experimental Control: Inferring Causation in RCTs

Randomized clinical trials remove two of the possible alternative explanations of an observed association: confounding and reverse causality. By 

assigning treatment (exposure) randomly, the design removes the influence 

of any confounder that might influence exposure (Figure 7-3a), and the 

influence of the outcome on exposure, if there is any (Figure 7-3b). Done 

properly, and setting aside the play of chance, only a causal relationship 

from exposure to health outcome should produce observed association in an 

RCT (Figure 7-3c). However, RCTs are generally not possible for the kinds 

of causal questions facing VA in presumptive disability decision making.

Statistical Control: Inferring Causation from Observational Studies

Adjusting for Confounding

When associations are found in observational studies, the first approach 

for removing spurious associations from confounders is statistical control 

of characteristics that may differ between exposed and unexposed persons 

(i.e., adjustment). Multiple regression models are one way to estimate the 

association between exposure and outcome after adjusting for characExposure

Health

Outcome Randomizer

Confounder

Exposure

Health

Outcome

Randomizer

Exposure

Health

Outcome

Randomizer (a) (b)

(c)

FIGURE 7-3

FIGURE 7-3 The power of randomization.
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162 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

teristics of participants that might confound the results. If investigators 

have successfully measured characteristics that distort the results, then 

adjustment of these factors will help separate a spurious from a causal 

association. 

For example, suppose we conduct an observational study of veterans, 

each exposed during service to some level of a toxin that can permanently 

degrade respiratory function. Suppose further that older veterans are more 

likely to have been exposed to more of the toxin, as it was used more frequently in the early segment of a war. Since age (after military service) also 

naturally degrades respiratory function, it is a confounder of the association 

between the exposure and respiratory function in this study (Figure 7-4) 

and must be included as a covariate in a multiple regression to adjust for 

its biasing effect. If age is the only such confounder in the study, and it is 

measured accurately, then we can indeed separate the spurious from the 

causal association statistically.1

Two problems are common in such an approach, however. First, unlike 

randomization, which can eliminate the influence of all confounders without 

having to identify and measure any of them, appropriate statistical adjustment for confounders requires identifying and measuring all of them. If, 

for example, age were not the only confounder of the association of exposure with respiratory function (Figure 7-5), then the association between 

exposure and respiratory function, statistically adjusted for age, would still 

combine both spurious and causal association, and thus present a misleading estimate of the effect of exposure on respiratory function. 

Deciding which variables to control for in a statistical analysis of the 

association between exposure and disease depends upon knowledge about 

the possible mechanisms connecting them. For example, dozens of observational studies, some involving thousands of subjects, have shown an 

association between watching TV and childhood obesity (IOM, 2006a). 

Can we move beyond an association and say that watching TV causes 

childhood obesity? 

These studies include a variety of statistical adjustments, depending on 

the mechanisms the researchers consider important. The primary mechanisms thought to connect TV and obesity are shown in Figure 7-6. Thus, 

several studies controlled for socioeconomic status (SES), as a child from a 

low socioeconomic status home might be allowed to watch more TV and 

also allowed to eat a higher proportion of high-calorie/low-nutrition foods 

1Assuming all relations are linear, that is, Respiratory Function = β1Exposure + β2Age + an 

“error” term ε ∼ N(0,σ2), and all boxed variates standard normal, then the expected observed 

covariance (association) between exposure and respiratory function is β1 + β2φ. The expectation of the estimate of the association between exposure and respiratory function adjusting 

for age in fact equals β1. 
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B

Age

Exposure

Respiratory

Function

B F

FIGURE 7-4

B

Age

Exposure

Respiratory

Function

B F

Unmeasured

Confounders

FIGURE 7-5

SES

TV

Obesity

Junk Food

Commercials

Caloric

Intake

Junk

Food

Exercise

Appetite

-

-

FIGURE 7-6

FIGURE 7-6 TV and obesity.

FIGURE 7-4 Age as a confounder.

FIGURE 7-5 Unmeasured confounders.
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164 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

(“junk” foods). Several studies attempted to separate out the potential contribution of TV to obesity through replacing or suppressing exercise, which 

in turn would lead to more obesity, or by increasing caloric intake, either 

through increasing exposure to food marketing, or by increasing appetite 

through other means (e.g., people like to snack when they are relaxing 

passively in front of a TV). Being able to identify these mechanisms allows 

us to identify and control for potential sources of spurious association and 

also to tease apart the importance of a variety of possible mechanisms. 

Measurement Error

A further problem in adjusting for spurious associations involves measurement error. If a confounder has been included in the statistical analysis 

as a covariate but has been measured poorly, then the included variable 

is only a surrogate for the true variable. This is equivalent to partially 

omitting the variable and thus does not allow all confounding bias to be 

removed from the estimate of the causal association (Kennedy, 2003). The 

more measurement error in the confounding variables the greater the potential for incomplete control of bias. 

Another problem similar to measurement error occurs when covariates 

are measured too coarsely. If, for example, TV was not measured in minutes 

per day, but rather as high, medium, and low, then differences in TV watching levels within these coarse categories could still affect the probabilities of 

exposure to junk food commercials. Statistically adjusting for this imprecise 

measure of TV would fail to remove all confounding. 

To summarize, statistically adjusting for confounders can separate the 

causal from the spurious association between exposure and disease, but it 

can do so completely only if all confounders have been identified, measured 

accurately, and represented in a valid statistical model. Thus, in assessing 

a report on a study that claims that adjustment for confounding has been 

made, the adjusted association estimates the causal association if the study 

has

• included all reasonable confounders, 

• measured them with reasonable precision and accuracy, and

• used them in a valid statistical model.

Instrumental Variables 

An alternative to measuring and adjusting for confounders is instru­mental 

variable estimation, a technique favored by econometricians (Kennedy, 2003) 

but not yet widely used in epidemiology (Greenland, 2000). An instrumental 

variable must be related directly to the putative cause but independent of all 
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potential confounders. Under this condition, we can separate variation in 

the cause that might spuriously come from the confounders or from reverse 

causation from true variation in the cause that will translate to variation in 

the effect. By using the instrument to show how much of the variation is not

from the confounders and not from reverse causation, we can then statistically adjust the observed association between cause and effect without even 

measuring the confounders or being concerned about reverse causation. 

An example of an instrumental variable might be distance from the 

hypocenter for veterans of a nuclear weapons test. The true causal variable 

here would be their ionizing radiation exposure. For some participants this 

may have been measured by a film badge dosimeter, but these measurements are incomplete and inaccurate. However, one could use the mean of 

the measured doses for all participants located at the same distance from 

the hypocenter as an instrumental variable for assigning dose to all participants, and then examine the relationship between these assigned doses 

and subsequent cancer risk. Assuming a Service member’s assignment to a 

particular location during the test was effectively at random with respect to 

potential confounders (Service members weren’t assigned to locations based 

on their future cancer risks), this would be expected to yield an unbiased 

assessment of the exposure-response relationship (Figure 7-7). 

Although instrumental variable estimation is a potentially powerful 

strategy for separating causal from spurious association, it depends heavily 

on the availability of an informative instrumental variable and on the untestable assumption that the instrument is independent of all the other potential 

confounders and not an independent risk factor for disease given radiation 

dose. Thus, its practical applications in epidemiologic research are limited.

Other Guides to Causal Knowledge

There have been several attempts to create sets of criteria to guide 

scientific judgments when moving beyond observed association to causaDisease:

cancer

Exposure:

ionizing

radiation

dose

Unmeasured

Confounders

Instrument:

distance

from the

hypocenter

FIGURE 7-7

FIGURE 7-7 Instrumental variable.
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166 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

tion. Some of these criteria can be traced to the “canons of inference” 

proposed by John Stuart Mill (1862). In the early days of microbiology, 

Koch developed his famous “postulates” as formal criteria for establishing 

a causal association of a clinical infectious disease with a micro­organism. 

Koch’s postulates include the identification of the suspect causal organism in people with the disease and the causation of the illness in an animal by infection with the organism (Koch, 1884). Unfortunately, such 

experimentally based criteria are of little help in establishing the causality 

of an environmental exposure with a chronic disease. The version of the 

criteria most familiar to epidemiologists and other public health researchers 

is the Bradford-Hill criteria, which are: the strength of the association, consistency, specificity, temporality (logical time sequence), dose-response (biologic gradient), plausibility, coherence, experimental evidence, and analogy 

(Hill, 1965). Although each of these criteria has limitations or exceptions, 

they can be useful guides to assessing the overall evidence. For example, see 

the introductory chapter in the 2004 Surgeon General’s report on smoking 

(DHHS/CDC, 2004). 

As we discussed above, background knowledge about the biologic 

mechanisms by which an exposure might or might not cause disease can 

prove crucial in establishing a causal claim or its negation. The tools of 

experimental biology have been extraordinarily valuable in developing 

insights into human physiology and pathology. Such laboratory tools have 

been extended to explore the effects of putative toxins on human health, 

especially through the study of model systems in other species. The field of 

toxicology has flourished in recent decades, allowing arguments of plausibility to be developed for a range of environmental toxicants. At the 

same time, species can differ in fundamental aspects of physiology (e.g., 

metabolism, hormonal regulation) that limit extrapolation from one species 

to another. 

REALISTIC CAUSAL INFERENCE

Multifactorial Causation

Epidemiologists have long recognized that most chronic diseases, such 

as cancer or coronary heart disease, result from a complex “web of causation,” whereby one or more external agents (exposures) taken into the body 

initiate a disease process, the outcome of which could depend upon many 

factors including age, genetic susceptibility, nutritional status, immune competence, social factors, and others. Exposures may occur over an extended 

period of time with some cumulative effect, and exposure to multiple agents 

together could result in synergistic or antagonistic effects different from 

what might result from each separately. These general notions were formal-
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ized by Rothman (1976) in a “sufficient component causes model,” which 

postulates that disease can result from a number of different constellations 

of causal factors, each of which may comprise several components (e.g., 

exposure plus susceptibility plus timing) that are all necessary to make them 

a complete cause. This framework is useful in thinking about exposure to 

multiple causal factors. For example, consider the diagram in Figure 7-8. 

Consider the data from a hypothetical epidemiologic study of veterans exposed to some particular exposure illustrated in Table 7-1. In this 

hypothetical example, smoking is a much larger contributor to risk than 

is the military exposure of the participants, but the two factors are not 

confounded, since among the population at risk, the proportion of smokers is the same in the exposed and unexposed. It is also evident that the 

two effects on risk are multiplicative, since individuals with both factors 

Background causes Radiation alone Smoking alone Radiation and

smoking jointly

FIGURE 7-8

TABLE 7-1 Hypothetical Example of Military Radiation Exposure, 

Smoking, and Cancer

Military 

Radiation

Exposure Smoking Habit Number at Risk Cancer Cases Relative Risk

No Never 1,000 10 1

No Current 1,000 100 10

Yes Never 1,000 30 3

Yes Current 1,000 300 30

FIGURE 7-8 Rothman’s sufficient component causes model.

NOTE: Each circle represents a different constellation of factors that is sufficient to produce disease; within any circle, the sectors represent specific factors 

that are all necessary to comprise a complete cause. Blank space represents host 

susceptibility plus background exposures; vertical bars, ionizing radiation; horizontal 

bars, tobacco smoking; cross-hatched, joint action of smoking and radiation.

SOURCE: Rothman, 1976.
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168 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

have an RR of 30, the product of the RR for smoking (10) and for military 

exposure (3). In other exposure situations, the pattern of combined effects 

could be less than multiplicative, or greater. Two specific models have special relevance to compensation policy. The first is the multiplicative model 

just illustrated, which can be represented mathematically as

RRmult = RRE × RRS ,

where RRE is the RR for exposed nonsmokers relative to nonexposed nonsmokers, and RRS is the RR for unexposed smokers relative to unexposed 

nonsmokers. Under this model, the effect of exposure is the same in both 

nonsmokers (RRE|NS = 3) and smokers (RRE|S = 30/10 = 3). The other 

important situation is an additive model of the form:

RRadd = 1 + (RRE − 1) + (RRS − 1)

= RRE + RRS − 1

In other words, the risk from exposure to both factors is the background 

risk plus the sum of the additional risks from each factor separately. Thus, in 

our hypothetical example, if the single-factor risks were as before, we would 

have expected an RR for exposed smokers of 1 + (10 − 1) + (3 − 1) = 12, 

rather than 30 as above. Under this model, the excess RR (ERR = RR − 1) 

for exposure is the same in nonsmokers (ERRE|NS = 3 − 1 = 2) and smokers 

(ERRE|S = 12 − 10 = 2). Of course, the actual joint effect could be different 

from either of these specific models. The effect when both exposures are 

present could be less than additive (e.g., a joint RR of 11), greater than 

multiplicative (e.g., 50), or in between (e.g., 20).

Models for Interaction

Epidemiologists use the term interaction (or effect modification) to 

denote the departure of the observed joint risk from what might be expected 

based on the separate effects of the factors. However, any estimate of interaction is model specific, meaning it depends on what model of interaction 

we expect (multiplicative, additive, or some other). In claiming interaction, 

one must therefore specify the model for the combined effect from which 

the observed data deviate. For example, one could define a multiplicative 

interaction RR as

RR

RR

RR RR Int(mult)

joint

E S

= × ,
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or an additive interaction RR as RRInt(add) = RRjoint − RRE − RRS + 1. For 

the data illustrated in the table above, RRInt(mult) = 30/(3 × 10) = 1 and 

RRInt(add) = 30 – 3 – 10 + 1 = 18, indicating no departure from a multiplicative model but a large positive deviation from an additive model. Likewise, 

if the joint RR were 12, the multiplicative interaction RR would have been 

0.4 and the additive interaction would have been 0, indicating a less than 

multiplicative joint effect and no departure from an additive model. These 

concepts have natural extensions to more than two risk factors, such as the 

inclusion of main effects and interactions in the widely used logistic regression model (which assumes a multiplicative model). The following chapter 

will describe how these parameters can be used to estimate the proportion 

of disease among exposed individuals that is attributable to the separate or 

joint action of each factor or other unknown factors, and the relevance and 

limitations of such estimates for attributing causation in individuals. 

The previous example presumes that there is no causal connection 

between the military exposure and smoking—that prior smoking did not 

cause the individual’s exposure in the military or vice versa. If this assumption did not hold, a very different analysis would be required. For example, 

suppose a nonsmoking recruit received a serious battle wound leading to 

amputation, which subsequently caused him or her to take up smoking 

for self-medication, and he or she ultimately developed lung cancer. In this 

case, one might wish to estimate the direct effect of battle trauma on lung 

cancer risk and the indirect effect mediated through smoking. However, as 

a policy matter, one might conclude that both routes were ultimately the 

consequence of battle trauma and should not be distinguished for the purpose of deciding on compensation. In other words, an individual’s smoking 

history would be irrelevant.

UNCERTAINTY

The science of estimating the causal influence of an exposure on disease, especially in cases where controlled experiments are not feasible, is 

fraught with uncertainty. Dealing with uncertainty in a principled way is 

one of the goals of statistics, however, and it need not stop us from rational analysis. In this section we provide a framework for dealing with the 

uncertainty inherent in assessing population causal claims. 

There are three levels of uncertainty in making a case for a service 

connection:

1. Uncertainty as to the correct causal model 

2. Uncertainty as to the statistical (parameter) estimates within each 

model

3. Uncertainty about the specifics of a given individual within a group
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170 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

The uncertainty about the correct causal model involves uncertainty 

about whether exposure in fact causes disease at all, about the set of 

confounders that are associated with exposure and cause disease, about 

whether there is reverse causation, about what are the correct parametric 

forms of the relations of the exposure and confounders with outcome, and 

about whether there are other forms of bias affecting the evidence. One 

currently used method for making this uncertainty clear is to draw a set of 

causal graphs, each of which represents a particular causal hypothesis, and 

then consider evidence insofar as it favors one or more of these hypotheses 

and related graphs over the others. We explain this approach in more detail 

in Appendix J. 

Uncertainty about the model is not just limited to the qualitative causal 

structure; however, it also involves uncertainty about the parametric form 

of the model specified, the variables included, whether or not measurement 

error is modeled, and so on. When mechanistic knowledge exists, this sort 

of uncertainty is mitigated. Nevertheless, model uncertainty is perhaps the 

most important level of uncertainty.

By comparison, uncertainty about the parameter estimates (regression coefficients) for a given model is a well-studied problem. When the 

news­paper reports that a political poll is accurate to “within 3 percentage points,” it is attempting to report the uncertainty about the estimates 

reported by the poll. When a regression analysis produces an OR with a 

confidence interval (or a P value for the null hypothesis that the adjusted 

association is 0), it is quantifying the uncertainty caused by the random 

variation that we can expect from one sample to another. The important 

point is that these reports of uncertainty are conditional on the model 

being a sufficiently adequate approximation to reality so that the inferences 

drawn are valid. The overall scientific inference involves uncertainty about 

the model and uncertainty about the parameter estimates given each model. 

It would be misleading to neglect the uncertainty in the model, and act as if 

the P values and confidence intervals delimit and make precise our overall 

scientific uncertainty. 

Beyond model uncertainty and parameter estimate uncertainty, we still 

face uncertainty in applying causal models to individuals. Typically, causal 

models will provide a prediction about the chances or severity of a disease, 

given a particular level of exposure and particular levels of the covariates, 

such as age or social class. For a given individual, we might be highly 

uncertain about the level and duration of exposure, as well as uncertain 

about the levels of covariates. This level of uncertainty is also important to 

presumptive service-connection claims, as will be discussed in the follow­ing 

chapter. 

There are two systematic, quantitative approaches for including uncertainty about the model into an assessment of overall uncertainty about a 
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causal inference. The first is sensitivity analysis, and the second is model 

averaging. In sensitivity analysis we attempt to quantify the sensitivity of 

the parameter estimate to assumptions about the model. In model averaging, we attempt to provide an overall uncertainty to our estimate by calculating the estimate of a common parameter or target and its uncertainty 

for each model we consider plausible, and then by weighting the estimates 

and the uncertainties by the likelihood of each model. It is essential that 

the target have the same interpretation in each model, or the combination 

of the estimates has no meaning.

Sensitivity Analysis

In general, sensitivity analysis is the attempt to systematically explore 

the sensitivity of a particular parameter estimate, such as the size of the 

causal effect of exposure on disease, to any assumption made in the model 

that itself can be parameterized. For example, in estimating the effect of 

cumulative exposure to lead on a child’s IQ, cumulative lead exposure for a 

child can be estimated by measuring the concentration of lead in the child’s 

shed baby teeth. Although this is an improvement over blood lead, it still 

involves error. The estimate of the effect of lead on IQ is sensitive to the 

amount of measurement error for lead, and the measurement error can be 

parameterized by the proportion of the variance of the measure thought to 

come from actual lead as opposed to error. A sensitivity analysis can then 

be performed by estimating the effect under a progression of levels of this 

proportion. This provides an assessment of how sensitive the causal estimate is to various possibilities of measurement error, and provides a more 

specific statement of what we must assume about measurement error in 

order to reach the causal conclusion.

Paul Rosenbaum (2002), along with Charles Manski (1995), has developed a formal technique for dealing with unmeasured confounding or bias 

called sensitivity analysis. The essential idea is to make reasonable guesses 

as to the range of distortion introduced by possible bias, or the extent of 

the associations underlying the possible confounding, and then to use those 

ranges to estimate the extent to which the outcome is changed under those 

assumptions. If the outcome turns out to be highly sensitive to such perturbations, one cannot rule out the possibility that the observed association is 

an artifact. Greenland (1996) has advocated a more quantitative approach 

to directly modeling multiple sources of bias.

Model Averaging

Given the inevitable uncertainty about the true model form, one might 

ask how one should estimate the RR (or any other epidemiologic effect 
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172 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

parameter derived from it) and an “honest” confidence interval for it that 

allows for this possibility of model specification error. There is an extensive 

statistical literature on this question (see, for example, Leamer, 1978, for 

a review), but in practice the problem is frequently ignored. Frequently, an 

investigator conducts a number of different analyses and ends up reporting only a single best-fitting model, or the one model in which he or she 

holds the strongest belief, and reports confidence limits on the parameters 

of that model, as if it were the “true” model. Sometimes, an investigator 

may acknowledge this uncertainty about model form by reporting a range 

of alternative models in the spirit of sensitivity analyses. This can leave the 

reader uncertain as to which specific set of estimates to use, particularly 

if several models fit the data more or less equally well, yet yield different estimates and confidence intervals. There are, however, a number of 

formal approaches to this problem from both a frequentist and a Bayesian 

perspective. 

Here we summarize briefly just one of them, known as Bayesian 

model averaging (Hoeting et al., 1999). Suppose we have a parameter 

of interest β (measuring the effect of interest) and a range of alternative models m = 1, . . . M, yielding estimates ˆ

βm and variances estimates 

V M m = = var( ) β

ˆ m of this same parameter under different models (for this 

purpose, we must assume that the parameter β has the same interpretation 

under each of the different models, i.e., the effect of exposure, conditional on 

different choices of adjustment variables). Let π m = = Pr( ) M m D denote the 

posterior probability of model m, conditional on the observed data D. Then 

a natural estimator of β that takes account of model uncertainty might be 

a simple weighted average of the model-specific estimators, β β = ∑ π ˆ m m m

with variance var( ) β = + ( ) β − β π . ∑m (Vm m ) m

2

This formal approach has 

seldom been applied in practice, although there are some examples in the 

epidemiologic literature. It also has some potential for misuse, as when 

many highly correlated variables are considered in the same model. In 

model averaging, we attempt to deal with model uncertainty by calculating 

the estimate of a common parameter or target and its uncertainty for each 

model we consider plausible, and then by weighting the estimates and the 

uncertainties by the likelihood of each model. 

SUMMARY

Presumptive service-connection decisions depend on population-level 

causal questions, such as “Were some cases of type 2 diabetes among Vietnam veterans caused by exposure to dioxin in Agent Orange during military 

service?” Assessing such claims scientifically involves review of statistical 
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SCIENTIFIC EVIDENCE FOR CAUSATION IN THE POPULATION 173

evidence from epidemiologic studies, evidence from experiments in other 

animals, and mechanistic evidence from basic biologic science. 

Because a statistical association between exposure and disease does 

not prove causation, plausible alternative hypotheses must be eliminated 

by careful statistical adjustment and/or consideration of all relevant scientific knowledge. Epidemiologic studies that show an association after such 

adjustment, for example through multiple regression or instrumental variable estimation, and that are reasonably free of bias and further confounding, provide evidence but not proof of causation. Mechanistic knowledge 

about how particular agents might produce adverse health effects provides 

further evidence. For example, ionizing radiation is known to cause mutations in DNA that can result in cancer. Animal studies may provide further 

evidence by showing that an agent may induce in several different species 

the same effect observed in human studies, and by a mechanism that is 

conserved across species with key features of the mechanism observed. 

Uncertainty about a causal claim can arise because of uncertainty 

about which among a set of plausible models is correct, or because of 

uncertainty about study design and execution, or it can arise because of 

uncertainty caused by simple sampling variability, or it can arise because 

of uncertainty in the basic science required to analyze other evidence. The 

overall uncertainty about the claim in question is some combination of all 

of these uncertainties.

Additional information on causation and statistical causal methods can 

be found in Appendix J.

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Doll, R., and A. B. Hill. 1954. The mortality of doctors in relation to their smoking habits; A 

preliminary report. British Medical Journal 1(4877):1451-1455.

EPA (Environmental Protection Agency). 2005. Guidelines for carcinogen risk assessment. 

EPA/630/P-03/001B. Washington, DC: Environmental Protection Agency. http://www.

epa.gov/IRIS/cancer032505.pdf (accessed March 1, 2007).

Golden, R., D. Pyatt, and P. G. Shields. 2006. Formaldehyde as a potential human leukemogen: 

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fr/ENG/Preamble/CurrentPreamble.pdf (accessed March 1, 2007).

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175

8

Synthesizing the Evidence for Causation

In Chapter 7 we discussed the challenges of inferring a causal relationship between an exposure and a health outcome, and the range of evidence 

typically considered in making such inferences. In this chapter we discuss 

the problem of combining potentially diverse types of evidence in making 

a single, overall judgment about whether an exposure causes a health outcome. We begin by discussing the problem of integrating the evidence from 

multiple epidemiologic studies. We then describe a framework for combining epidemiologic and other evidence into a single quantitative judgment 

about the strength of causation. Next we discuss qualitative frameworks 

that have been used by expert committees for categorizing the overall 

strength of evidence for or against a causal claim. And lastly we propose 

a qualitative framework for causal reference to be used in the presumptive 

disability decision-making process.

We include this material because the scientific group that we propose 

in our new approach will review evidence on the health of veterans and 

will have the task of integrating an accumulating stream of results and 

interpreting new findings in the context set by previous findings and prior 

reviews. The successive Institute of Medicine (IOM) Agent Orange committees are illustrative. While the methods are presented in a theoretical 

fashion, they would be key components of the approach recommended by 

this Com­mittee and, in reality, they are already inherent to the approaches 

used by the IOM committees. 
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176 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

META-ANALYSIS: COMBINING EVIDENCE FROM 

MULTIPLE STUDIES

Scientific evidence relevant to causal relationships between exposure 

and disease comes from different types of investigation, including randomized clinical trials (RCTs) on humans, epidemiologic studies, animal experiments, and cell studies, and also from fundamental biological knowledge. 

We use the term human studies to refer to RCTs or observational studies 

involving people. Although an evidence-based approach must combine all 

forms of scientific evidence, in this section we limit our discussion to the 

problem of synthesizing the information from multiple human studies.

The idea of pooling information from multiple studies has a long tradition in statistics that goes back at least to Karl Pearson in 1904. A metaanalysis involves gathering all studies with evidence related to a particular 

question, and statistically combining the results of these studies. In many 

contexts, health researchers have mathematically combined the results from 

multiple, yet comparable RCTs to derive a summary estimate of the effect 

of some substance on health; the estimate appropriately combines the 

results of all the individual studies. Such summaries are often carried out, 

for example, to determine if there is a benefit of a drug or perhaps an 

excess occurrence of an unwanted side effect. One approach for combining 

evidence, random effects meta-analysis, allows for heterogeneity between 

studies; with this technique, a meta-analysis is not strictly limited to studies 

involving similar populations. 

In observational studies, there may be more variability in findings from 

study to study because study variables are not under the investigator’s control. The populations studied may vary considerably in their characteristics, 

and the variables measured as covariates for statistical adjustment may also 

differ. Nevertheless, meta-analysis is applied to observational study results 

as well as to RCT data. Meta-regression (Greenland and O’Rourke, 2001) 

allows pooling of data across observational studies with some unexplained 

heterogeneity, and recent work by E. Kaizar (2005) improves on metaregression for situations with data available from both RCTs and observational studies. 

Although the development of meta-analytic methods has generated 

extensive methodological discussion (see, for example, Berlin and Antman, 

1994; Berlin and Chalmers, 1988; Dickersin and Berlin, 1992; Greenland, 

1994a,b; Stram, 1996; Stroup et al., 2000), it is a technique that can be 

quite useful when there are multiple studies on the same question. For 

example, for each of a number of different cancers, the 2006 IOM Committee on Asbestos and Selected Cancers (IOM, 2006a) did a quantitative 

meta-analysis on studies that combined the effect of asbestos exposure on 

risk based on multiple studies for each of a set of cancers. The report pre-
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SYNTHESIZING THE EVIDENCE FOR CAUSATION 177

sented the results of individual studies as well as an overall estimate that 

came from the combination of the estimates from the individual studies. 

THE BAYESIAN APPROACH

No matter how sophisticated the meta-analytic technique, it is still 

limited to combining statistical evidence from different studies into a single statistical estimate of the effect size. As we discussed in Chapter 7, 

the scientific evidence germane to causal claims also includes mechanistic 

knowledge, findings of animal or cell and molecular studies, and other 

knowledge relevant to biological plausibility. A technique for combining all 

the available evidence into a single judgment needs to accommodate these 

other types of information. One approach for combining all the evidence 

available into a single quantitative judgment uses a Bayesian approach.

Bayesian methodology conceives of probability as degrees of belief. Any 

proposition can be given a degree of belief. For example, one person might 

have a personal degree of belief of 0.30 (30 percent) in the proposition 

that garlic prevents colds, while another might give the proposition 0.80. 

The Bayesian approach provides a rule for updating the existing degree of 

belief in response to additional evidence (Bayes’ rule, see below). Provided 

that no experts are inflexible in their belief,1 a group of experts who update 

their beliefs by Bayes’ rule will almost certainly converge to the same 

degree of belief after considering enough of the same relevant evidence.2

Thus, a group of scientists considering the overall evidence for a causal 

claim such as “formaldehyde causes leukemia” might begin with a prior

degree of belief about the claim and then update their belief in the light of 

accumulating evidence, regardless of the type of evidence. In more detail, if 

we consider each separate causal model relating formaldehyde (exposure) 

and leukemia as a separate hypothesis, Hi, then we can begin by using 

background knowledge or the results of previous studies, to assign a prior 

probability to each such hypothesis. 

The Bayesian approach then seeks to compute the posterior probability

Pr(Hi | D), namely the probability of (i.e., degree of belief in) hypothesis 

Hi given the new observed data D. The computation of these posterior 

probabilities is given by the famous rule first described by the Rev. Thomas 

Bayes, known as Bayes’ theorem or rule, which in simple form is

P H D

P H P D H

P D i

i i ( ) = ( ) ( )

( ) .

1That is, assigns degree of belief 0 to what turns out to be the “true” proposition. 

2And a raft of other assumptions—see Howson and Urbach, 1989.
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178 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Loosely translated, this formula reflects the prior probability for the 

hypothesis P(Hi), the likelihood, meaning the probability of the data D

given the hypothesis Hi is true, and P(D), the probability of the data before 

any hypothesis. 

The Bayesian framework provides a useful perspective on how weak 

additional evidence may have little impact on a strong prior probability 

or strong additional evidence may have substantial impact on a weak 

prior probability. For example, assume that we have very strong prior 

radiobiological and epidemiologic evidence that ionizing radiation can 

cause cancer, but a study of veterans who participated in nuclear weapons 

testing maneuvers fails to provide strong evidence of an association. In 

this example, assume that the data from the study do not lead to rejection 

of the null hypothesis of no association in a study of veterans exposed to 

radiation. This null finding might arise because the available sample size or 

length of follow-up was too small to yield an adequate number of cancers 

in the study group or because of inherent biases in the study design, such 

as inaccuracy of the available radiation dose information. If the veterans’ 

data are highly uncertain, then a null result might change the prior estimate 

of population radiation risk (e.g., the synthesis of the world literature by 

expert committees such as the National Research Council’s [NRC] Biological Effects of Ionizing Radiation [BEIR] committee) downward for this 

group, but by only a very modest amount. The posterior probability would 

still strongly favor a presumption (Figure 8-1a).

On the other hand, assume that there was very little prior knowledge 

about the effect of dioxins on cancer risk and a large, well-designed study of 

Vietnam veterans yielded a large and highly significant positive relative risk 

for non-Hodgkin’s lymphoma (NHL) (Figure 8-1b). In this case the absence 

of prior knowledge would have little influence on the degree of judgment 

given to the estimates from the veterans’ study. 

A further example is provided by the National Research Council’s 

Biological Effects of Ionizing Radiation (BEIR) IV Committee (NAS, 1988), 

which addressed the cancer risk of plutonium in humans. The available 

human data were very limited: no bone cancers were observed among 

18 patients injected with plutonium for experimental purposes or among a 

small number of others occupationally exposed in the Manhattan Project. 

The BEIR IV committee adopted an empirical Bayes approach that assumed 

that the ratio of carcinogenic potencies of plutonium to various other radionuclides would be roughly constant across species. As there are substantially 

more human data about the carcinogenicity of various isotopes of radium 

and extensive animal data about plutonium, radium, and other radionuclides, 

it was possible to estimate the risk of plutonium in humans from a combined 

analysis that incorporated animal and human data. The committee carried 

out an uncertainty analysis that incorporated the variability in the ratios 
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SYNTHESIZING THE EVIDENCE FOR CAUSATION 179

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

0 2 4 6 

Relative risk Relative risk Probability density

(a) (b) 

FIGURE 8-1 

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

0 2 4 6 8 10

Probability density

Prior

Data

Posterior

the requested lines have been redrawn and have been 

equated with the "Data" line in legend

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

0 2 4 6 8 10

Relative risk Relative risk Probability density

(a) (b) 

FIGURE 8-1 

2 4 6 8 10

Prior

Data

Posterior

Prior

Data

Posterior

the requested lines have been redrawn and have been 

equated with the "Data" line in legend

FIGURE 8-1 Hypothetical illustrations.

NOTE: Hypothetical illustrations of the combination of prior knowledge or judgment with study data to yield posterior estimates of a causal parameter, here the 

relative risk: (a) strong prior probability for a nonnull effect combined with weak 

data showing little or no effect in the study sample, and (b) weak prior probability 

combined with strong data showing a major effect.
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180 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

of the relative carcinogenicities of the radionuclides across species. In this 

analysis, the limited human data for plutonium shifted the posterior probability distribution of the carcinogenicity estimates only slightly downward 

relative to the prediction resulting from the animal data.

The Bayesian approach can also focus scientific attention as new evidence becomes available. For example, as discussed in Chapter 7, there are 

many ways to generate an observed association between an exposure and a 

health outcome. The association might be the result of the exposure causing 

the health outcome, confounding, other forms of bias or of chance. In carrying out an observational study, epidemiologists try to measure and adjust 

for confounders and eliminate bias with good study design and appropriate 

data analysis. Scientific opinion about how much of the adjusted association might still be from unmeasured confounding or bias is useful in judging 

the degree of confidence about the estimate of an association.

To illustrate, consider the diagram in Figure 8-2, which graphically 

depicts the epidemiologists’ concerns. Assuming a simple linear model, 

for illustration, the parameter β represents the causal association, that is, 

the amount of observed association between exposure and health due to 

the causal influence of exposure on health. The parameter α represents the 

amount of association from confounding that we can statistically adjust for, 

G G

B

Measured

Confounders/Covariates

Exposure to

Substance

Health

Outcome

Unmeasured Confounders/Covariates, or

Other Sources of Spurious Association from Bias

A

FIGURE 8-2

FIGURE 8-2 Focusing on unmeasured confounders/covariates, or other sources of 

spurious association from bias.
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SYNTHESIZING THE EVIDENCE FOR CAUSATION 181

given the right model, and the parameter γ represents the amount of spurious association that we cannot statistically adjust for. Because the estimate 

of the causal association β will be biased in proportion to the size of γ, 

scientific attention should be focused on γ. In a Bayesian approach, we can 

encode scientific opinion about the size of γ into a prior probability, and 

then compute a posterior probability over β that appropriately takes into 

account uncertainty over γ. 

In principle, then, the Bayesian approach provides an entirely quantitative framework for combining theoretical beliefs and evidence from 

previous studies along with the data at hand to update estimates of model 

parameters or of the probability that a particular hypothesis is true. In principle, each researcher undertaking a new study would apply the procedure 

to interpret the new evidence from the study in the context of already existing evidence, arriving at a posterior probability that is a methodologically 

appropriate combination of prior beliefs and accumulated evidence. 

In practice, however, the Bayesian approach is far from a panacea for 

the complex task of combining diverse types of evidence. In typical scientific contexts, it may be difficult to move from fairly inchoate and diverse 

sorts of background knowledge to a communal “prior.” By their nature, 

these prior odds are a matter of judgment, about which consensus amongst 

scientists can be difficult to obtain. 

Further, although “updating” a posterior probability from certain kinds 

of evidence is reasonably straightforward, updating from other kinds of evidence is not. For example, consider estimating the relative risk of leukemia 

as a function of benzene exposure. After specifying a prior probability 

over this function, updating from a new sample of 400 veterans who were 

exposed to twice the usual level of benzene and who have a relative risk 

of 1.8 for leukemia is fairly straightforward mathematically. How are we 

to update based on experimental evidence showing that rats exposed to 

50 times the background level of benzene develop leukemia at 3 times 

the rate of those exposed to background levels? What is the likelihood of 

this evidence, assuming any particular hypothesis about humans? Here we 

move beyond mathematics and statistics and into opinion about the comparability of leukemia and its causation in rats and humans. 

QUALITATIVE FRAMEWORKS USED BY EXPERT COMMITTEES

Faced with diverse mechanistic and biological evidence that cannot be 

incorporated into a single statistical meta-analysis, and with opinions and 

judgments too varied and vague to employ a formal Bayesian approach, 

expert committees have resorted to qualitative categorizations of the 

strength of evidence for causation. There is a lengthy history of doing so, 

dating back to the 1950s as evidence began to develop on disease causa-
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182 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

tion by radiation and tobacco smoking (Bayne-Jones et al., 1964). Judgments as to the level of evidence for causation can have substantial impact 

and often have regulatory implications. For example, the International 

Agency for Research on Cancer (IARC) (2006b), the U.S. Environmental 

Protection Agency (EPA) (2005), and the National Toxicology Program 

(NTP) (NTP, 2005) have developed systems for classifying the level of 

evidence in support of a causal relationship between chemicals and cancer. 

Similar classification systems have been developed for causal relationships 

for other health-specific effects such as reproductive outcomes (see e.g., 

NTP CERHR, 2003, 2005; Shelby, 2005), or between agents and health 

outcomes in general (IOM/NRC, 2005), or between smoking and disease 

(DHHS/CDC, 2004). 

Each of these classification systems relies on evidence from a variety of 

research sources: epidemiologic, toxicological, and biological. The approach 

of combining diverse sources into an overall judgment on the strength of 

evidence for general causation, at least in a public health context, can be 

traced back to the 1964 Report of the Advisory Committee to the Surgeon 

General on Smoking and Health (Bayne-Jones et al., 1964), as well as other 

early summary reports on smoking and health. In the introductory chapters 

to the 1964 report, the committee described the different sorts of evidence 

to be considered. They specifically listed animal experiments, clinical and 

autopsy studies, and population studies, but were expansive in the evidence 

considered. They described the importance of expert evaluations of the 

quality of published reports, wrote two pages on their working definition 

of causation, and codified a subset of Sir Bradford Hill’s criteria for establishing causation in epidemiology and public health contexts: consistency 

of the association, strength of the association, specificity of the association, 

temporality of the association, and the coherence of the association. The 

report that followed was an extended attempt to review all the evidence 

then available and synthesize it into an overall judgment: smoking causes 

lung cancer, bronchitis, emphysema, and is a “health hazard of sufficient 

importance in the United States to warrant appropriate remedial action” 

(Bayne-Jones et al., 1964, p. 33). 

Although the Surgeon General’s 1964 report did not explicitly categorize the level of evidential support for any of its conclusions, the 2004 

Surgeon General’s report does, as do recent reports from IARC (2006b) and 

IOM (2006a). A variety of categorizations exist. For example, the 2004 

Surgeon General’s report on smoking (DHHS/CDC, 2004), as well as the 

2006 IOM Committee on Asbestos (IOM, 2006a, p. 20), employed a fourlevel categorization of the strength of evidence of causation (the latter was 

based on the 2004 Surgeon General’s Report on Smoking [DHHS/CDC, 

2004]):
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SYNTHESIZING THE EVIDENCE FOR CAUSATION 183

1. Sufficient to infer a causal relationship

2. Suggestive but not sufficient to infer a causal relationship

3. Inadequate to infer the presence or absence of a causal relationship

4. Suggestive of no causal relationship 

IARC forms expert committees and instructs them to first categorize the level of evidence within three subcategories—human, animal, and 

mechanistic—and then to synthesize the subcategories of evidence into 

an overall evaluation on a five-category scale ranging from carcinogenic 

to probably not carcinogenic. Figure 8-3 depicts the IARC evaluation 

scheme.

Several groups, including some IOM committees on Agent Orange 

(IOM, 1994, 1996, 1999, 2001, 2003b, 2005b) and other veterans’ health 

issues, have based their approaches on the IARC (2006b) system for classifying the evidence in the subcategory pertaining only to human evidence. 

Within this subcategory, IARC systematically reviews available epidemiologic studies, considering study quality, relevance, and strength of findings. 

It then classifies the overall epidemiologic evidence as sufficient evidence if 

there is a finding that “a positive relationship has been observed between 

the exposure and cancer in studies in which chance, bias, and confounding 

could be ruled out with reasonable confidence” (IARC, 2006b, p. 19). For 

limited evidence, a “positive association has been observed between exposure to the agent and cancer for which a causal interpretation is considered 

by the working group to be credible, but chance, bias, or confounding could 

not be ruled out with reasonable confidence” (IARC, 2006b, pp. 19-20). 

With inadequate evidence, either there are no epidemiologic data or study 

quality, or power, or consistency across studies precludes a conclusion 

regarding causal association. 

The IOM committees assessing the impact of Agent Orange have published biennial reports since 1994. Table 8-1 contains the four-level categorization for the strength of epidemiologic evidence used in the 1994 report 

(IOM, 1994), which is quite similar to IARC’s subcategory scheme for 

human evidence (IARC, 2006b). Subsequent reports have used a similar 

classification scheme.

IOM committees (IOM, 2000, 2003a, 2004, 2005a, 2006b, 2007) 

examining Gulf War and health have added a causal category to those used 

by the IOM Agent Orange committees (IOM, 1994, 1996, 1999, 2001, 

2003b, 2005b). Table 8-2 shows the classification scheme from Volume 1 

of the Gulf War and Health series (IOM, 2000). The additional category 

makes causation explicit and includes evidence beyond that found in just 

epidemiologic studies. 

The IOM Agent Orange categorization (IOM, 1994, 1996, 1999, 2001, 

2003b, 2005b) relies less on mechanistic and animal evidence and more 
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184

Cancer in

humans

 Sufficient evidence Limited evidence Inadequate evidence Evidence suggesting

lack of carcinogenicity

Cancer in

experimental animals

 Sufficient evidence Limited evidence Inadequate evidence Evidence suggesting

lack of carcinogenicity

Mechanistic and

other relevant data

 Mechanistic data

“weak,” “moderate,” or“strong”?

 Mechanism likely to be

operative in humans?

Overall evaluation

 Group 1 Carcinogenic to humans Group 2A Probably carcinogenic to humans Group 2B Possibly carcinogenic to humans Group 3 Not classifiable as to its carcinogenicity to humans Group 4 Probably not carcinogenic to humans

FIGURE 8-3

FIGURE 8-3 IARC evaluation scheme.SOURCE: Adapted from Cogliano, 2006.
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SYNTHESIZING THE EVIDENCE FOR CAUSATION 185

TABLE 8-1 IOM Categorization from the Executive Summary of Veterans 

and Agent Orange: Health Effects of Herbicides Used in Vietnam

Sufficient Evidence of an 

Association

Evidence is sufficient to conclude that there is a positive 

association. That is, a positive association has been observed 

between herbicides and the outcome in studies in which 

chance, bias, and confounding could be ruled out with 

reasonable confidence. For example, if several small studies 

that are free from bias and confounding show an association 

that is consistent in magnitude and direction, there may be 

sufficient evidence of an association.

Limited/Suggestive

Evidence of an Association

Evidence is suggestive of an association between herbicides 

and the outcome but is limited because chance, bias, and 

confounding could not be ruled out with confidence. For 

example, at least one high-quality study shows a positive 

association, but the results of other studies are inconsistent.

Inadequate/Insufficient

Evidence to Determine 

Whether an Association 

Exists

The available studies are of insufficient quality, consistency, 

or statistical power to permit a conclusion regarding the 

presence or absence of an association. For example, studies 

fail to control for confounding, have inadequate exposure 

assessment, or fail to address latency.

Limited/Suggestive

Evidence of No Association

Several adequate studies, covering the full range of levels of 

exposure that human beings are known to encounter, are 

mutually consistent in not showing a positive association 

between exposure to herbicides and the outcome at any level 

of exposure. A conclusion of “no association” is inevitably 

limited to the conditions, level of exposure, and length of 

observation covered by the available studies. In addition, the 

possibility of a very small elevation in risk at the levels of 

exposure studied can never be excluded.

SOURCE: IOM, 1994.

on epidemiologic data than do the IARC, NTP, or EPA models. As there 

may be many cases relevant to presumptive service connection in which the 

epidemiologic evidence on veterans specifically is extremely thin or even 

non-existent, giving animal and mechanistic evidence a more prominent and 

systematic role in the overall evaluation scheme is warranted. The causal 

category added by the Gulf War committees is a step in this direction. 

Previous IOM Agent Orange committees also reviewed and reported on 

toxicological and mechanistic information, but according to their interpretation of their charge, did not figure this information into the conclusions 

about the strength of evidence for association and causation.
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186 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 8-2 IOM Categorization from the Executive Summary of Gulf 

War and Health, Volume 1: Depleted Uranium, Pyridostigmine Bromide, 

Sarin, Vaccines

Sufficient Evidence of a 

Causal Relationship

Evidence is sufficient to conclude that a causal relationship 

exists between the exposure to a specific agent and a health 

outcome in humans. The evidence fulfills the criteria for 

sufficient evidence of an association (below) and satisfies 

several of the criteria used to assess causality: strength 

of association, dose-response relationship, consistency of 

association, temporal relationship, specificity of association, 

and biological plausibility.

Sufficient Evidence of an 

Association

Evidence is sufficient to conclude that there is a positive 

association. That is, a positive association has been observed 

between an exposure to a specific agent and a health outcome 

in human studies in which chance, bias, and confounding 

could be ruled out with reasonable confidence.

Limited/Suggestive 

Evidence of an Association

Evidence is suggestive of an association between exposure 

to a specific agent and a health outcome in humans, but is 

limited because chance, bias, and confounding could not be 

ruled out with confidence.

Inadequate/Insufficient 

Evidence to Determine 

Whether an Association 

Does or Does Not Exist

The available studies are of insufficient quality, consistency, 

or statistical power to permit a conclusion regarding the 

presence or absence of an association between an exposure to 

a specific agent and a health outcome in humans.

Limited/Suggestive 

Evidence of No Association

There are several adequate studies covering the full range of 

levels of exposure that humans are known to encounter, that 

are mutually consistent in not showing a positive association 

between exposure to a specific agent and a health outcome 

at any level of exposure. A conclusion of no association is 

inevitably limited to the conditions, levels of exposure, and 

length of observation covered by the available studies. In 

addition, the possibility of a very small elevation in risk at 

the levels of exposure studied can never be excluded.

SOURCE: IOM, 2000.

A PROPOSED QUALITATIVE FRAMEWORK FOR 

EVALUATING CAUSAL CLAIMS

Incorporating the Full Range of Evidence

The new process recommended by this Committee involves a categorization of the strength of evidence in support of a causal claim that incorporates the full weight of all evidence, including expert opinion, findings from 
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SYNTHESIZING THE EVIDENCE FOR CAUSATION 187

epidemiologic and animal studies, and mechanistic knowledge. Reliance 

on the broad range of pertinent scientific data is also in keeping with the 

original congressional language that specifies consideration by NAS of the 

biological plausibility of any association. Before describing our proposed 

classification scheme, we briefly consider the consequences of extending the 

range of evidence considered. One issue is whether a seemingly more rigorous bar of evidence would reduce the likelihood of reaching a classification 

level at which compensation is made.

We approach this issue through case studies. Incorporating information derived from mechanistic studies and animal toxicology can lead to 

an upgrading or downgrading of a classification based on the weight of 

evidence classification. Some examples are described below.

Particulate Air Matter

Deployed personnel in the first Gulf conflict were exposed to airborne particles from the oil fires in Kuwait, exhaust from military vehicles 

and other combustion sources, and dust stirred by troop movements. The 

health effects of airborne particles are of general concern and the scientific 

evidence is subject to periodic review in the setting of the National Ambient Air Quality Standard (NAAQS) by the U.S. Environmental Protection 

Agency (SOURCE: http://epa.gov/pm/naaqsrev2006.html). The standard is 

evidence-based and the process of setting a new NAAQS involves a comprehensive review of all relevant scientific evidence, including epidemiologic 

and toxicological data as well as information on exposure patterns. For 

the last two reviews of the NAAQS, 1996 and 2006, the epidemiological 

evidence has been extensive, showing significant associations of airborne 

particles with increased risk for premature mortality and morbidity. The 

effects are relatively small, however, and biological plausibility has been a 

major consideration in evaluating the evidence and determining if the associations can be judged as causal. Information relevant to the plausibility of 

the associations comes from studies of the chemical and physical properties 

of particles and from toxicological studies that have addressed responses 

to particles in in vitro and in vivo models. Using a “weight of evidence” 

approach, the Environmental Protection Agency has judged the associations 

of airborne particles with adverse effects to be causal (SOURCE: http://epa.

gov/pm/naaqsrev2006.html).

2,3,7,8-Tetrachlorodibenzo-para-dioxin (TCDD)

TCDD, a potent dioxin, was listed in 1997 as a Group 1 carcinogen by 

IARC based on limited evidence in humans, sufficient evidence in experimental animals, and abundant mechanistic information including data 
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188 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

demonstrating that TCDD acts through the aryl hydrocarbon receptor 

(AhR), which is present in both humans and animals (IARC, 1997).

Formaldehyde 

IARC has recently concluded that formaldehyde should be added to 

that group of agents that are carcinogenic to humans (Group 1 carcinogen) 

(IARC, 2004, p. 1). This upgrade was based upon new epidemiologic evidence of an association with nasopharyngeal cancer. “[T]here is now sufficient evidence that formaldehyde causes nasopharyngeal cancer in humans, 

a rare cancer in developed countries” (IARC, 2004, p. 1). Previous laboratory, animal, and mechanistic evidence supported this association. The 

IARC found “strong but not sufficient evidence for a causal association 

between leukemia and occupational exposure to formaldehyde,” falling 

“slightly short of being fully persuasive because” of limitations in the 

cohort and conflict with nonpositive findings in another cohort (IARC, 

2006a, p. 5). IARC noted findings of lymphomas and leukemias in one 

study in male rats, and several possible mechanisms for the induction of 

human leukemia, such as clastogenic damage to circulatory stem cells. 

However IARC also noted the lack of good rodent models that simulate 

the occurrence of acute myeloid leukemia in humans, and did not identify 

a mechanism for its induction in humans (IARC, 2006a). 

Saccharin 

Saccharin was originally classified as “reasonably anticipated to be a 

human carcinogen” by NTP (NIH, 2000, p. 1) and “possibly carcinogenic 

to humans” by IARC (IARC, 1987, p. 334) based on data clearly showing bladder cancer in rats. Although there was some limited epidemiologic evidence associating bladder cancer with saccharin sweeteners, the 

epidemiologic evidence was classified by IARC as inadequate. Subsequent 

mechanistic studies attributed the animal cancer findings as being due to 

a mechanism that would only occur at high doses in rats. “Saccharin produces urothelial bladder tumours in rats by a non-DNA-reactive mechanism 

that involves the formation of a urinary calcium phosphate-containing 

precipitate, cytotoxicity and enhanced cell proliferation. This mechanism is 

not relevant to humans because of critical interspecies differences in urine 

composition” (IARC, 1999, p. 50). Saccharin has since been delisted as a 

reasonably anticipated carcinogen by NTP and deemed “not classifiable 

as to its carcinogenicity to humans” by IARC (IARC, 1999, p. 50; NIH, 

2000).

These case studies illustrate the potential contributions of mechanistic 

information as evidence relevant to causation is evaluated. A certain under-
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SYNTHESIZING THE EVIDENCE FOR CAUSATION 189

standing of mechanism of action may have substantial impact in considering the overall weight of evidence.

Committee Recommended Categories for the 

Level of Evidence for Causation

In light of the categorizations used by other health organizations and 

agencies as well as considering the particular challenges of the presumptive 

disability decision-making process, we propose a four-level categorization 

of the strength of the overall evidence for or against a causal relationship

from exposure to disease:

1. Sufficient: The evidence is sufficient to conclude that a causal relationship exists.

2. Equipoise and Above: The evidence is sufficient to conclude that a 

causal relationship is at least as likely as not, but not sufficient to conclude 

that a causal relationship exists.

3. Below Equipoise: The evidence is not sufficient to conclude that a 

causal relationship is at least as likely as not, or is not sufficient to make a 

scientifically informed judgment.

4. Against: The evidence suggests the lack of a causal relationship.

We use the term “equipoise” to refer to the point at which the evidence is in balance between favoring and not favoring causation. The term 

“equipoise” is widely used in the biomedical literature, is a concept familiar 

to those concerned with evidence-based decision making, and is used in 

VA processes for rating purposes as well as being a familiar term in the 

veterans’ community.

Below we elaborate on the four-level categorization that the Committee 

recommends. 

Sufficient

If the overall evidence for a causal relationship is categorized as Sufficient, then it should be scientifically compelling. It might include

• replicated and consistent evidence of a causal association: that is, 

evidence of an association from several high-quality epidemiologic studies 

that cannot be explained by plausible noncausal alternatives (e.g., chance, 

bias, or confounding), or 

• evidence of causation from animal studies and mechanistic knowledge, or 

• compelling evidence from animal studies and strong mechanistic 
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190 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

evidence from studies in exposed humans, consistent with (i.e., not contradicted by) the epidemiologic evidence. 

Using the Bayesian framework to illustrate the evidential support and 

the resulting state of communal scientific opinion needed for reaching the 

Sufficient category (and the lower categories that follow), consider again 

the causal diagram in Figure 8-2. In this model, used to help clarify matters 

conceptually, the observed association between exposure and health is the 

result of (1) measured confounding, parameterized by α; (2) the causal relation, parameterized by β; and (3) other, unmeasured sources such as bias or 

unmeasured confounding, parameterized by γ. The belief of interest, after 

all the evidence has been weighed, is in the size of the causal parameter β. 

Thus, for decision making, what matters is how strongly the evidence supports the proposition that β is above 0. As it is extremely unlikely that the 

types of exposures considered for presumptions reduce the risk of developing disease, we exclude values of β below 0. If we consider the evidence as 

supporting degrees of belief about the size of β, and we have a posterior 

distribution over the possible size of β, then a posterior like Figure 8-4 

illustrates a belief state that might result when the evidence for causation 

is considered Sufficient.

As the “mass” over a positive effect (the area under the curve to the 

right of the zero) vastly “outweighs” the small mass over no effect (zero), 

the evidence is considered sufficient to conclude that the association is 

causal. Put another way, even though the scientific community might be 

uncertain as to the size of β, after weighing all the evidence, it is highly 

confident that the probability that β is greater than zero is substantial; that 

is, that exposure causes disease. 

Posterior

Over β

Posterior

Mass Over

an Effect

0 Size of the Causal Effect β

P(β)

8-4

redrawn

FIGURE 8-4 Example posterior for Sufficient.
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SYNTHESIZING THE EVIDENCE FOR CAUSATION 191

Equipoise and Above

To be categorized as Equipoise and Above, the scientific community 

should categorize the overall evidence as making it more confident in the 

existence of a causal relationship than in the non-existence of a causal 

relationship, but not sufficient to conclude causation. 

For example, if there are several high-quality epidemiologic studies, 

the preponderance of which show evidence of an association that cannot 

readily be explained by plausible noncausal alternatives (e.g., chance, bias, 

or confounding), and the causal relationship is consistent with the animal 

evidence and biological knowledge, then the overall evidence might be categorized as Equipoise and Above. Alternatively, if there is strong evidence 

from animal studies or mechanistic evidence, not contradicted by human or 

other evidence, then the overall evidence might be categorized as Equipoise 

and Above. Equipoise is a common term employed by VA and the courts 

in deciding disability claims (see Appendix D).

Again, using the Bayesian model to illustrate the idea of Equipoise 

and Above, Figure 8-5 shows a posterior probability distribution that is an 

example of belief compatible with the category Equipoise and Above.

In this figure, unlike the one for evidence classified as Sufficient, there is 

considerable mass over zero, which means that the scientific community has 

considerable uncertainty as to whether exposure causes disease at all; that 

is, whether β is greater than zero. At least half of the mass is to the right of 

the zero, however, so the community judges causation to be at least as likely 

as not, after they have seen and combined all the evidence available. 

Posterior

Over β

Posterior

Mass Over

an Effect

P(β)

0 Size of the Causal Effect β

8-5

redrawn

FIGURE 8-5 Example posterior for Equipoise and Above.
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192 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Below Equipoise

To be categorized as Below Equipoise, the overall evidence for a causal 

relationship should either be judged not to make causation at least as likely 

as not, or not sufficient to make a scientifically informed judgment.

This might occur

1. when the human evidence is consistent in showing an association, 

but the evidence is limited by the inability to rule out chance, bias, or confounding with confidence, and animal or mechanistic evidence is weak, or 

2. when animal evidence suggests a causal relationship, but human 

and mechanistic evidence is weak or inconsistent, or 

3. when mechanistic evidence is suggestive but animal and human 

evidence is weak or inconsistent, or

4. when the evidence base is very thin.

Figure 8-6 shows a posterior probability distribution that is an example 

of belief compatible with the category Below Equipoise.

Against

 To be categorized as Against, the overall evidence should favor belief 

that there is no causal relationship from exposure to disease. For example, 

if there is human evidence from multiple studies covering the full range 

of exposures encountered by humans that are consistent in showing no 

causal association, or there is animal or mechanistic evidence supporting 

the lack of a causal relationship, and combining all of the evidence results 

Posterior

Over β

Posterior

Mass Over

an Effect

0 Size of the Causal Effect β

P(β)

8-6

redrawn

FIGURE 8-6 Example posterior for Below Equipoise.
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SYNTHESIZING THE EVIDENCE FOR CAUSATION 193

in a posterior resembling Figure 8-7, then the scientific community should 

categorize the evidence as Against causation. 

Comparison of the Committee’s Proposed and Previous Frameworks

The Committee’s proposed framework departs from that used by previous IOM committees in assessing Agent Orange (Table 8-1) in at least 

three respects. First, as noted, previous IOM committees evaluating Agent 

Orange (IOM, 1994, 1996, 1999, 2001, 2003b, 2005b) relied primarily on 

epidemiologic studies to classify strength of evidence for association and 

did not systematically incorporate evidence from animal toxicology and 

mechanistic studies. 

Second, the Agent Orange categorization differentiated between levels 

of evidence for association instead of causation (IOM, 1994, 1996, 1999, 

2001, 2003b, 2005b). As we have proposed in the previous chapter, the 

claims at issue related to compensation of veterans are causal claims, not 

associational claims. Association, especially association adjusted for potential confounders, is evidence for the causal claim, but it is not identical to

the causal claim. In fact, making a presumptive decision to compensate 

on the basis of “limited/suggestive” evidence of an association presents 

the possibility that there is no causal link at all, and all of those receiving 

compensation because of such a presumption could be false positives. A 

causal category was added by previous IOM committees on Gulf War and 

Health, but the categories below “Sufficient evidence of a causal relationship” retain the language of association (IOM 2000, 2003, 2004, 2005a, 

2006b, 2007). This Committee recommends, therefore, a categorization 

Posterior

Over β

Posterior

Mass Over

an Effect

0 Size of the Causal Effect β

P(β)

8­7

redrawn

FIGURE 8-7 Example posterior for Against.
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194 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

that makes explicit the evidential role of association, but that keeps the 

clear and explicit overall goal of assessing causation. 

Third, we created the category of Equipoise and Above to capture 

the spirit of presumption: the tie goes to the veteran, and to stay true and 

scientifically consistent to the evidential standard suggested by Congress in 

the Agent Orange Act of 1991 (Public Law Number 102-4, 102d Cong., 

1st Sess.), which gave the VA Secretary authority to prescribe regulations 

providing for a presumption “[w]henever the Secretary determines, on the 

basis of sound medical and scientific evidence, that a positive association 

exists between” herbicide exposure and a disease. Section (4)(b)(3) states 

the following:

An association between the occurrence of a disease in humans and exposure to an herbicide agent shall be considered to be positive for the purposes of this section if the credible evidence for the association is equal to 

or outweighs the credible evidence against the association.

In our categorization, Equipoise and Above represents a state in which 

there is credible evidence, and the credible evidence for causation is equal to 

or greater than the credible evidence against causation. We also intend this 

categorization to be flexible over time. We expect that, as the evidence base 

grows, evaluations about the state of evidence for a causal claim may be 

upgraded or downgraded over time. The descriptive categorization language 

used by previous IOM Agent Orange committees for “limited/suggestive” 

evidence of an association implies that a single high-quality epidemiologic 

study can in some circumstances be sufficient for the “limited/suggestive” 

category: 

Evidence is suggestive of an association between herbicides and the outcome but is limited because chance, bias, and confounding could not be 

ruled out with confidence. For example, at least one high-quality study 

shows a positive association, but the results of other studies are inconsistent. (IOM, 1994, p. 97; IOM, 1996, 1999, 2001, 2003b, 2005b)

If a scientific committee’s conclusion were based on a single study and 

later studies were to show more definitive evidence of an association, a 

subsequent committee could upgrade the “limited/suggestive” classification 

of this association to Sufficient. On the other hand, if definitive studies were 

reported that supported an overall weight of the evidence of below “limited/

suggestive,” a subsequent committee could downgrade the classification. 

Under the current approach, however, it is unclear if any reclassifications 

of evidence may lead to a change in a presumptive decision that VA has 

established based upon the classification of “limited/suggestive” evidence 

of an association.
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SYNTHESIZING THE EVIDENCE FOR CAUSATION 195

SUMMARY

Combining human evidence with meta-analysis is very useful when 

several reasonably exchangeable studies are to be combined. However, the 

technique cannot be used to combine the full range of evidence relevant to 

classifying the level of evidence for causation. A very general technique for 

combining diverse evidence into a single, quantitative description of belief 

about the causal claim at stake is the Bayesian approach, but its usefulness 

in a presumptive disability decision-making context may be limited. As 

a result, other organizations such as IARC have resorted to a qualitative 

categorization of the strength of evidence for causation. These agencies 

base the overall categorization on separate judgments about the strength of 

evidence from epidemiologic studies, animal studies, or other mechanistic, 

toxicological, or biological sources.

For the presumptive disability decision-making process, this Committee 

recommends categorizing the level of overall evidence for a causal relationship 

between exposure and health outcome in one of the following categories:

1. Sufficient: The evidence is sufficient to conclude that a causal relationship exists.

2. Equipoise and Above: The evidence is sufficient to conclude that a 

causal relationship is at least as likely as not, but not sufficient to conclude 

that a causal relationship exists. 

3. Below Equipoise: The evidence is not sufficient to conclude that a 

causal relationship is at least as likely as not, or is not sufficient to make a 

scientifically informed judgment.

4. Against: The evidence suggests the lack of a causal relationship.

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198

9

Applying Population-Based 

Results to Individuals: 

From Observational Studies to 

Personal Compensation

The previous chapters address problems of inferring causation from 

observational studies in the context set by other types of evidence. We also 

provide a classification scheme for the level of evidence in support of causation in general. Having determined that the level of evidence is sufficient 

to infer causation, two additional matters are of interest: (1) What is the 

burden of disease among those exposed that is caused by the exposure? 

and (2) What is the likelihood that the disease was caused by exposure in a 

particular individual? Information pertinent to the first question is relevant 

to forecasting the administrative and financial implications of the causal 

determination. Information relevant to the second question may be of value 

in handling individual cases. 

In the present chapter we address these topics, beginning with the 

simplifying assumption that a causal association has been established in 

the population, and that we have an accurate estimate of relative risk (RR) 

among exposed people. We turn to an epidemiologic measure, the attributable fraction (AF), to answer these questions. This chapter also addresses 

the complexities of using the AF in devising compensation approaches. It 

provides a conceptual foundation that should prove useful in the further 

elaboration of the Committee’s framework and its implementation.
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 199

ATTRIBUTABLE FRACTION

Definitions and Assumptions

The attributable fraction (AF) is used several ways in the literature 

(Rothman and Greenland, 1998). We use the term in a way most relevant 

to compensation by the Department of Veterans Affairs (VA), namely as 

the proportion of disease in an exposed group that can be attributed to 

the exposure. This report uses the terminology service-attributable fraction

(SAF) when the exposed group is a military population. We begin with two 

simplifying assumptions: (1) exposure produces new cases of the disease 

that would not have occurred otherwise, and (2) the additional RR from 

exposure is stable over age and across subgroups within the population of 

exposed veterans. Later we discuss complications that might occur when 

these assumptions do not hold. Under these two assumptions, the AF is 

interpreted as the probability that among the exposed people with the disease, their disease has actually been caused by the exposure. 

Crucial Properties of the AF

In applying the AF, there are two key properties. First, it is not a statement about whether the exposure is able to cause the disease. In calculating 

the AF, we take as given that the exposure does, in fact, cause the disease. 

However, even among exposed persons, the exposure does not necessarily 

cause all cases of the disease—most diseases have many possible causes. 

When an exposed person gets the disease, the chance that the disease is 

caused by the exposure is almost certainly less than one. The AF represents 

this probability. 

The second important aspect of the AF is that it cannot specifically tell 

us which exposed people have their disease because of the exposure. All 

the AF can provide is an estimate of the average probability for all exposed 

persons. We can refine this estimate in various ways (e.g., by age or levels of 

exposure), but even with perfect information it is seldom, if ever, possible 

with current methods to identify which particular cases of a disease with 

multiple causes were caused by the exposure and which were not.

Estimating the AF

An AF is based on an estimation of RR, which is the ratio of disease 

risk among exposed persons compared to the risk among otherwise similar, 

but unexposed persons. RR is the most common expression of disease risk 

in epidemiologic studies. As discussed in Chapter 7, odds ratios from casecontrol studies approximate the RR.
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200 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

The AF is calculated by the following formula:

AF Risk (exposed) Risk (unexposed)

Risk (e = [ − ]xposed)

This may also be expressed as: AF = (RR – 1)/RR.

Consider the example of smoking and lung cancer. The RR for lung 

cancer among smokers is around 20. Applying the formula above, a RR 

of 20 yields an attributable risk of 95 percent, AR = (20 – 1)/20. In other 

words, 95 percent of all lung cancers among smokers can be attributed to 

their smoking, possibly acting in combination with other factors, while the 

remaining 5 percent of the lung cancers of smokers come from other causes. 

For another example, smoking and cardiovascular disease, the RR is close 

to 2. Thus, only half of the cases of cardiovascular disease among smokers, 

50 percent = (2 – 1)/2, can be attributed to smoking. The lower the RR, 

the less likely it is that the disease in an exposed person is caused by the 

exposure, and the more likely that other factors are the cause. 

Factors That Can Distort the AF

Broadly speaking, there are two problems that can bias an estimate of 

disease burden due to an exposure when using the AF. One is portability—

that is, the degree to which the RR estimated from one population can be 

properly applied to another population. The second problem is error in the 

measurement of exposure. We consider each of these limitations below. 

Problems in Portability 

Chapter 7 discusses the biases and confounding that can distort estimates of RR. Even if these problems have been carefully handled in the 

original estimation of RR, the application of a valid RR to a new group 

introduces a fresh set of opportunities for distortions. This problem goes 

under the general rubric of portability, that is, the ability of a valid RR in 

one population to be applied to a new population. The portability of RRs 

and hence of AFs is often uncertain because of differing characteristics of 

the population in which the AF was estimated compared to those in which 

it is to be applied.

A simple example of a problem with portability is effect modification 

by gender. Suppose that, at a given level of exposure, the RR of disease 

differs by gender of the exposed person (a common observation). If the 

distribution of men and women in the study group is different from the 

exposure group to which the RR is being applied, and gender is ignored, 
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the resulting AF will be incorrect. This particular problem can be handled 

by applying gender-specific RRs to gender strata of the exposed population. 

However, more complicated scenarios of confounding or effect modification 

can be readily anticipated; methods to handle these have been proposed by 

Bruzzi et al. (1985) and Benichou (2001). Although such methods work in 

principle, they may require detailed data for subgroup-specific RRs that are 

difficult to obtain. 

A similar problem can arise when the RR is estimated in a population 

with high exposure (as in an occupational setting) and then applied to a 

population with lower levels of exposure. The RR will tend to overestimate 

the AF for the lower-exposed population. With enough information from 

epidemiologic studies on exposure-specific risk and information on levels 

of exposure in the population of interest, the appropriate adjustments of 

the AF can be made to account for exposure. 

In summary, problems of portability do not call into question the validity of the original RR, but rather its generalizability—that is, the validity 

of its application to a new population and the estimate of the AF. Even 

when the causal association is certain (as we assume here), the problems 

of portability raise questions about the strength of the disease risk in the 

population of interest—and thus the size of the AF.

Problems in Exposure Classification

The second distortion that can occur with the AF is when the RR is 

applied to a population in which some persons classified as exposed were 

not in fact exposed. (This problem is especially relevant in the context of 

the charge of this Committee, in that VA is frequently unable to establish 

actual exposure during military service, and therefore must infer it—with 

inevitable error.) Usually the decision is to err in the direction of assuming 

people are exposed when they may not be exposed. 

When an “exposed” group includes some people who are not actually 

exposed, the AF for the whole “exposed” group would be 

AF

P RR

P RR

“exp”

exp exp

exp exp

= ( ) × − ( )

× − ( ) 

  +

1

1 1

,

where AF“exp” = the AF for an “exposed” group containing some unexposed 

people, Pexp = the proportion of the supposedly “exposed” group who are 

truly exposed, and RRexp = the RR for the truly exposed group.

Typically, we do not know what proportion of those reported as exposed 

were actually exposed. However, we can make reasonable assumptions and 
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202 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

see how much difference such errors might make. In our previous smoking 

example, if only half of the “exposed” group had truly been exposed, 

then the true AF for the “exposed” group would be 90 percent instead of 

95 percent. Thus, exposure misclassification introduces a trivial difference 

between the true AF and the calculated AF when the RR is high. 

This is not true when the RR is lower (as is often the case). Taking the 

example of RR = 2 (for smoking and cardiovascular disease), the true AF is 

50 percent when every person in the “exposed” group was truly exposed, 

but only 33 percent, if half of the “exposed” group had actually been 

unexposed. Thus, when the RR is low, misclassification of exposure results 

in an estimated AF that is an overestimate of the true AF. 

Reconsidering the Assumptions of the AF and Alternatives

A basic assumption in calculating the AF is that the RR is known. In 

the real world, RRs are only estimates and typically include some measure 

of the statistical imprecision of that estimate. The implications of such 

uncertainty can be explored by calculating a range of AFs under different 

assumptions for the RR. 

What if other assumptions about the AF are untrue? For example, 

what if the exposure accelerates disease among persons who were going to 

get the disease anyway, instead of causing disease in persons who would 

not otherwise have gotten the disease? In this more complex scenario, the 

AF may not adequately capture the total burden of disease caused by the 

exposure. Alternatives to the AF that attempt to capture the total impact 

of exposure on disease include “years of life lost” (YLL) (Robins and 

Greenland, 1989a; Steenland and Armstrong, 2006) and “years of life lived 

with disability” (YLD). 

Methods for the calculation of YLL, YLD, and disability-adjusted life 

years (DALYs) have been recently reviewed (Steenland and Armstrong, 

2006). YLL is the total number of deaths caused by the disease of interest 

multiplied by the average number of years of survival expected beyond 

the age of death from that disease. YLD is the product of the number of 

incident cases, a disability weight, and mean duration of disease; in the 

absence of incidence data an estimate can be based on mortality data 

and case-­fatality rates. The total burden of disease can be estimated as 

the sum of YLL and YLD and is known as disability-adjusted life years, 

or DALYs. YLL, YLD, and DALYs caused specifically by military service 

exposure can be calculated by multiplying them by the AF (Steenland and 

Armstrong, 2006). In the case of military service, we refer to this as the 

service-­attributable fraction (SAF). Because the AF is a fundamental element 

of these alternatives to the AF, they are subject to the same caveats about 

portability and misclassification of exposure as the AF itself. In the section 
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“Promoting the Use of AFs in Determining Compensation for Veterans” we 

return to this discussion with regard to the AF and the SAF. 

Further Refinements of the AF

Once we have estimated the total disease burden caused by the exposure using the AF, it may be possible to refine this estimate further by considering characteristics of persons, including features of their exposure, that 

make their individual risk of disease higher or lower than in the exposed 

population as a whole. In other words, we can move from an estimate of 

overall AF, applied equally to all, to estimates for subgroups or even individuals, based on additional information regarding their risk factors. This 

refined expression of the AF as estimated for individuals has usually been 

designated as the probability of causation, or PC, although in actuality it is 

simply the AF estimated for subgroups of those exposed.

PROBABILITY OF CAUSATION FOR AN INDIVIDUAL

The AF attempts to apportion the disease burden in a population 

between the exposure and other factors causing the disease. In contrast, the 

PC attempts to address the question of whether the exposure could have 

caused a particular disease in an individual, given that individual’s particular characteristics of genetic makeup, lifestyle, and personal history—that 

is, the characteristics that determine individual susceptibility. For the past 

two decades, estimates of the PC have been available to guide the compensation of atomic veterans and others exposed to ionizing radiation (DHHS, 

2002; NIH, 1985; Thomas, 2000). These estimates have been possible 

because of the extensive information on cancer risk in relation to radiation 

exposure.

PC Definition

A precise definition of PC will help illustrate the challenges in estimating it. Following the National Institutes of Health (NIH) Working Group 

(1985), the PCi is the probability that individual i’s disease was caused by the 

exposure, given i’s unique set of characteristics (call them Xi). Sym­bolically, 

PCi, is defined using two terms—the probability that the individual would 

have developed the disease given no exposure, ( ) E P( ) D E Xi 

  , , , and the 

probability that the individual developed the disease given the exposure,

P D E Xi  ( ) , :  


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204 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

PC

P D E X P D E X

P D E X i

i i

i

= ( ) − ( ) 

 

( )

, ,

,

PCi = probability of causation for an individual

P = probability

D = disease

E = exposure

E = no exposure

Xi = an individual’s unique set of characteristics

Notice the equation represents an allocation of the probability of disease between the exposed and unexposed. The probability that the background caused the disease in individual i is simply 1 – PCi

. If everyone in 

the population is identical in susceptibility to the disease and in the extent 

of exposure, and if the exposure-induced cases are completely independent of other cases (i.e., cases that were caused by something else), then 

the PC for every individual in the population is given by the population 

AF. Implications of not meeting these assumptions are discussed below in 

“Promoting the Use of AFs in Determining Compensation for Veterans.” 

Still, additional information on the levels of exposure, age at exposure, time 

since exposure, mechanism of disease causation, and other factors can be 

used to define subgroups within populations, and then to estimate AFs for 

these subgroups. As described below, these subgroup measures provide the 

basis for better estimates of PCs for individuals within these classes. 

Because individuals may vary in susceptibility to a particular exposure 

because of genetics, lifestyle, and other factors, estimates of PCs are not 

necessarily expected to resemble the true probability that an individual’s 

disease was caused by the exposure. The term assigned share (AS) has 

been used in place of PC, especially as it pertains to issues of compensation (Lagakos and Mosteller, 1986). The NIH Ad Hoc Working Group to 

Develop Radioepidemiological Tables (NIH, 1985) (for use in compensating cancer victims exposed to ionizing radiation) found itself constrained 

by legislative mandate to use the term probability of causation rather than 

assigned share. Reflecting on the history of the use of the terms, a more 

recent National Research Council (NRC) committee decided to use the 

terms synonymously (NRC, 2000). 
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 205

Refining Estimates by Differences in Exposure Levels

Exposures to any given chemical or other disease-causing factor would 

be expected to vary substantially among veterans in any theater of war or 

duty, with corresponding large differences in individual risk and hence PCs. 

Also, the pattern of exposure can be important. For the same cumulative 

dose, the dose rate, timing, and duration may play a significant role in 

determining those who get the disease and those who do not. Route and 

exposure pathways are also to be considered. Although obtaining accurate 

estimates of exposure among veterans will typically be challenging, in some 

cases exposures may differ by orders of magnitude, and it may be possible 

to develop at least crude exposure estimates. 

If exposure can be quantified and the relationship between risk and 

exposure is understood, the AF can be expressed as a function of exposure. 

For example, dose-response relationships can be derived from occupational 

epidemiologic data for various carcinogens. As the example below shows, 

it can be important to stratify by the degree of exposure if this information 

is available, because the AF can vary substantially with exposure level.

Consider the following simple relationship between the lifetime probability of cancer P, or risk, and the air concentration, D, and the duration 

of exposure t, P(D) = 1 – exp(– a – bDt), which at P less than 10 percent is 

closely approximated by a simple linear relationship P(D) = a + bDt, where 

a, the intercept, is the risk in the absence of exposure, and b, the slope, 

describes the incremental increase in risk with increasing air concentration 

and time. Here RR is given by

RR

a bDt

a

bD

a = ( ) +

= +1 ,

and the AF is given by

AF

RR

RR = ( ) −1 ,

which, substituting in the above, reduces to

AF

bD

a

bDt

a

bDt

a bDt =





 





+ 



 





=

( ) + 1

.
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206 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

P = lifetime probability (or risk) of cancer 

D = air concentration

t = duration of exposure

a = risk in the absence of exposure

b = incremental increase in risk with increasing air concentration 

and time

RR = relative risk

AF = attributable fraction

Benzene provides an example of how very different AFs can result from 

differently exposed subgroups. We show how when exposure is taken into 

account PC estimates can be made for individuals with different levels of 

exposure. Benzene is an established cause of acute myelogenous leukemia 

(AML) in humans (Austin et al., 1988). Benzene exposures are ubiquitous; 

for example, benzene is a constituent of gasoline and also cigarette smoke. 

The general population in the United States is exposed to levels averaging 

from 1 to 5 ppb in indoor and outdoor air, and it would be anticipated 

that Service members would be similarly exposed. In addition, some in 

the service may have duties that result in exposures to considerably higher 

levels of benzene (e.g., those servicing airplanes or working in garage facilities). We might assume that some service jobs result in exposures as high 

as 10 ppm. 

AML is relatively uncommon, with a lifetime risk of diagnosis (an 

estimate for parameter a in the equation above) of about 0.3 percent. A 

lifetime exposure to 1 ppm causes AML in roughly 5 percent of those 

so exposed, corresponding to an estimate of b in the above equation of 

0.00062/ppm-years (= 0.05/ppm/78 years). Applying these parameter estimates, AFs can be derived, while acknowledging the caveats and limitations 

noted above, including the issue of portability since the b was estimated 

from occupational cohorts in China and the United States (OEHHA, 

2001). Service members who contract AML after being exposed during 

a tour of duty of 3 years to general background levels (e.g., 5 ppb) have 

a 0.2 percent chance that their leukemia arose because of their military 

exposure (AF = [0.00062 × 0.005 × 3]/[0.003 + 0.00062 × 0.005 × 3]). 

Thus, any case of AML among the exposed Service members would be 

highly unlikely to have resulted from military exposure. The AF associated 

with military service lasting 30 years is higher, at 3 percent. In contrast, 

Service members with a 3-year tour of duty who were exposed to 10 ppm 

during work hours, or a daily average of approximately 5 ppm, have an 
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AF of 76 percent: AF = (0.00062 × 5 × 3)/(0.003 + 0.00062 × 5 × 3). This 

simple example illustrates the importance of segregating groups in terms 

of the magnitude and duration of exposure when those data are available. 

It also illustrates the importance of identifying those most heavily exposed 

in determining whether disease caused by an exposure to a given factor 

deserves compensation. 

As illustrated below, it is occasionally possible to classify or otherwise 

identify individuals or groups of individuals in terms of their exposure 

duration, age at exposure, exposure intensity, as well as other factors to 

derive exposure group-specific AFs and hence more refined estimates of 

PCs for individuals. 

Refining Estimates in the Presence of Multiple Known Causes of Disease

Many illnesses considered for compensation have multiple causes. For 

example, lung cancer has many known causes in addition to smoking, 

including asbestos, arsenic, radiation, and environmental tobacco smoke 

(NCI, 2006). Some lung cancers occur in individuals without significant 

exposures to any known cause. The proportion of disease that is attributable to military service exposure can be estimated when there are valid RR 

estimates for (1) the military service-related exposure in the absence of the 

other known causes (RRE), (2) other known causes that individuals in the 

group were subjected to (such as smoking—RRS), and (3) the joint exposure 

of both military service and other specific known causes (RRboth). 

As an illustration, the proportion of disease attributable to military 

exposure and smoking, separately and jointly, is estimated for the hypothetical case described in Chapter 7. This is derived for two cases below, 

with smoking and military exposure interacting either additively or multiplicatively. In the additive model, smoking adds a constant RR over background (RRS – 1) regardless of whether there is military exposure. Thus, in 

the presence of both exposures, the RR is RRboth = RRE + RRS – 1. In the 

multiplicative model, RRboth = RRE × RRS. 

We introduce new terminology to aid in the derivation of AFs for the 

joint and separate effects of these multiple known causal exposures. The 

population attributable fraction (PAF) is the proportion of disease in the 

entire population attributable to an exposure or any other factor. (The relation of the PAF to the AF will be discussed below.) 

Assume that all disease in the population is attributed either to the 

background or to the two identified causes. PAF0 is the proportion of disease attributable to background factors unrelated to smoking or military 

exposure. PAFboth is the proportion of disease attributable to smoking and 

military exposures. The two sum to unity 1 = PAF0 + PAFboth. Analogous 

to the AF, the PAFboth is given by 
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208 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

PAF

RR

RR both

both

both

= ( ) −1 .

Thus PAF0 is given by

PAF PAF

RR

RR both

both

both

0 1 1

1 = − = − ( ) − ,

which reduces to

PAF

RRboth

0

1 = .

PAFE, the proportion attributable to military exposure alone, is simply the 

proportion of disease attributable to background factors multiplied by the 

excess RR above the background (RRE − 1):

PAF RR PAF E E = − ( ) 1 × 0,

which reduces to 

PAF

RR

RR E

E

both

= ( ) −1 .

Similarly PAFS, the proportion attributable to smoking acting alone, is

PAF

RR

RR S

S

both

= ( ) −1 .

The additional proportion attributable to the two factors acting in combination (i.e., interacting), PAFInt is

PAF

RR RR RR

RR Int

both E S

both

= ( − − +1).
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 209

PAF0 = proportion of disease attributable to background 

factors unrelated to smoking or military exposure

PAFboth = proportion of disease attributable to smoking and 

military exposures

PAFE = proportion of disease attributable to military exposure 

alone

PAFS = proportion of disease attributable to smoking acting 

alone

PAFInt = the additional proportion of disease attributable to the 

two factors acting in combination

RRE = RR estimates for military service-related exposure in 

the absence of the other known causes

RRS = RR estimate for other known causes that individuals 

in the group were subjected to (e.g., smoking)

RRboth = RR for the joint exposure of both military service and 

other specific known causes

Table 9-1 provides the parameter values for the hypothetical case 

described in Chapter 7 for the two different cases—when smoking and military exposure interact multiplicatively and when they interact additively. 

The calculations of AFs to the separate and joint exposures for this 

hypothetical example are laid out in Table 9-2. For the multiplicative example, one might be tempted to conclude that the contribution of military 

exposure was very small, since in the absence of the smoking interaction, 

the AF is only 6.7 percent. However, due to its interaction with smoking, 

the total contribution of military exposure is 66.7 percent (Table 9-2). 

(Note that this is the same PAFE as for nonsmokers, [3 – 1]/3 = 67 percent 

[Table 9-1], revealing that under a multiplicative model, the total PAFE

TABLE 9-1 Hypothetical Example of Risks from Multiple Causal 

Exposures

Military 

Exposure

Smoking 

Habit

Number 

at Risk Cancer Cases Relative Risk

No Never 1,000 10 1

No Current 1,000 100 10

Yes Never 1,000 30 3

Yes Current 1,000 Multiplicative 300 30

Additive 120 12
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TABLE 9-2 Hypothetical PAFs Due to Smoking and Military Exposure

PAF Due to Multiplicative Model Additive Model

Background only, PAF0 1/30 = 3.3% 1/12 = 8.3%

Military exposure only, PAFE 2/30 = 6.7% 2/12 = 16.7%

Smoking only, PAFS 9/30 = 30% 9/12 = 75%

Military exposure and smoking 

interaction, PAFInt

(30 − 3 − 10 + 1)/30 = 60% (12 – 3 – 10 + 1)/12 = 0%

Total: PAF0 + PAFE + PAFS + 

PAFInt

3.3 + 6.7 + 30 + 60 = 100% 8.3 + 16.7 + 75 = 100%

SAF: Disease preventable by 

eliminating military exposure, 

PAFE + PAFInt

6.7 + 60 = 66.7% 16.7 + 0 = 16.7%

does not depend upon smoking.) Of course, the same calculation applied 

to smoking would yield an estimate of 90 percent for the total fraction 

attributable to that factor. If one were naively to add these two figures, it 

would appear that more than 100 percent of the risk would be accounted 

for, but of course, this is simply because the interaction contribution has 

been counted twice. In terms of prevention, 66.7 percent of the cancer cases 

in this group could have been prevented had the military exposure not 

occurred (or 90 percent [30 percent + 60 percent] if they had not smoked 

or 96.7 percent [30 percent + 60 percent + 6.7 percent] if both causes were 

eliminated [Table 9-2]).

Under a purely additive model, there is no interaction, no proportion of 

disease is attributable to the interaction, and the term PAFInt becomes zero 

(Table 9-2). Among smokers, then, the proportion attributable to military 

exposure is 16.7 percent, considerably lower than in the multiplicative case. 

Among nonsmokers, however, military exposure accounts for 67 percent of 

the cases (PAFE = [3 – 1]/3 = 67 percent [Table 9-1]), revealing that under 

an additive model (or any less-than-multiplicative model), the PAFE will 

be larger for nonsmokers than for smokers. This holds even if the relative 

effect of smoking is much larger than exposure.

Chapter 7 also considered a scenario where one of the two factors was 

an intermediate variable on a causal pathway from exposure to disease (the 

example was smoking resulting from an amputation and leading to lung 

cancer). In this case, one would not want to partition the AF in this manner, 

because the direct effect of smoking on lung cancer was itself a consequence 
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 211

of the exposure (battle trauma) and is therefore part of the total lung cancer 

burden attributable to that trauma. 

Turning to the concept of the AF that was introduced at the beginning 

of this chapter, as the fraction of disease in the population that would not 

have occurred had the exposure not occurred, the AF can be derived from 

PAFs computed in this manner. It is simply 

AF PAF PAF E Int = + .

As before, the AF can be refined to provide estimates for individuals 

in specific subgroups, with the same caveats and cautions discussed earlier. 

For the multiplicative case in the hypothetical illustration above, the SAF is 

thus estimated to be 66.7 percent (Table 9-2). The elimination of exposure 

would have eliminated the excess cases due to exposure acting alone and 

those due to its joint action with smoking. Hence, both components are 

counted in deriving the SAF. For the additive case, with the interaction term 

(PAFInt) equal to zero, the SAF estimate is 16.7 percent. This underscores 

the importance of understanding the potential for interaction among multiple causal factors when evaluating the SAF for specific subgroups to be 

applied to individuals.

Using Data on Susceptibility and Exposure to Refine an AF Estimate

People differ in their susceptibility to disease and predispositions 

toward certain disabilities. Some of these differences are within an individual’s control (e.g., food choices and eating habits), while other differences (e.g., genetics, age, and gender) are not. Differences in susceptibility 

remain to a great extent unquantifiable for most diseases, and thus are a 

source of uncertainty that in turn cannot be quantified in estimating the PC 

for individuals. When the background risk (in the absence of the exposure 

in question) varies substantially among individuals in the group, or there 

are strong interactions between background factors and exposure, the PCs 

among individuals can vary substantially, even for the same exposure level, 

and these will be misestimated by the AFs calculated for specific subgroups 

that cannot incorporate information on background risk. 

Epidemiologic data may provide the basis for refining estimates of the 

AF for subgroups to be applied to individuals. As illustrated above, data 

on smoking or other causes of a disease not related to military service may 

allow refinement of the SAF. A variety of susceptibility and other factors 

have been used to refine estimates of the AF for radiation-induced cancers. 

In 1985, a set of radioepidemiological tables was released that provided 

probability of causation estimates for radiation exposures in terms of a 
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212 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

person’s gender, age at exposure, age of cancer diagnosis, dose, and other 

factors (DHHS, 2002; NIH, 1985) (see the case study on radiation in 

Appendix I for details). These tables have since been updated using mathematical models of risk incorporating the characteristics of the individual 

claimant. In addition to gender, age at exposure and diagnosis, and smoking 

status, the dose, type, and energy intensity of the radiation are addressed. 

These estimates can now be obtained using an interactive computer program. The program also explicitly accounts for uncertainty in model inputs 

to “help minimize the possibility of denying compensation to claimants 

under the Energy Employees Occupational Illness Compensation Program 

(EEOICPA) for those employees with cancers likely to have been caused by 

occupational radiation exposures” (NIOSH, 2007, p. 3). Few if any other 

exposures lend themselves to such precise adjustments of risk.

Other Complexities of the AF

Most of the above discussion treats RR of exposure as fixed. A typical 

assumption for cancers is that, following a latency period after exposure, d, 

there is an age-specific incidence p(t,d) that is a fixed multiplicative factor 

above the nonexposed

p t( ) ,d R= R d( ) × p t( ) ,0 .

In other words, there is a constant RR at any age t. An alternative assumption—constant excess risk—is that a given exposure d increases the absolute 

risk in the exposed by a fixed amount g(d), so that p(t,d) = g(d) + p(t,0). 

Because background incidence of every type of cancer changes with age, the 

constant excess risk model is incompatible with the assumption of constant 

RR. Another aspect of this problem is that for some diseases there are ages 

at which an individual is more susceptible to certain diseases. For radiation carcinogenesis there are considerable data for evaluating dose-response 

relationships that account for exposure level and duration, and age at 

exposure, and still uncertainty remains regarding how best to model these 

relationships for the purpose of calculating AFs for individuals (DHHS, 

2002). For other cancer causes and other diseases there is usually much 

greater uncertainty about these relationships. 

AF AND COMPENSATION

Earlier in this chapter, the concepts of the AF and the SAF were further 

developed after being initially introduced in Chapter 6. The extension of 

these concepts to attempt to estimate refined AFs that could be applied to 
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 213

individuals was then introduced and discussed. We now bring these concepts to bear on the issue of compensation. 

Considerations in Assessing Alternative Compensation Schemes

Exposure-Based Schemes 

Compensation can theoretically be based on any number of considerations, not all of which make use of the notion of causation. For example, 

compensation could simply be based on a determination that certain types 

of exposure are so hazardous or extreme that they merit compensation 

regardless of whether they cause a disease. The Prisoner of War (POW) 

experience could reasonably be a candidate for an experience worthy of 

compensation on the basis of exposure alone, regardless of whether any 

illnesses resulted from this “exposure,” and with perhaps some consideration of the severity of the experience. Similarly, when an exposure 

strongly increases the risk of a specific disease or condition, compensation 

could be granted regardless of whether the disease actually occurs. This 

approach was considered by the Presidential Commission on Catastrophic 

Nuclear Accidents and discarded (Presidential Commission, 1990). These 

approaches to compensation will not be considered further here, as they 

are matters of policy. We restrict our discussion to the compensation of 

persons whose exposure was causally linked to a health outcome and who 

were actually diagnosed with the outcome of interest.

A Traditional Approach Using the PC 

For most questions of compensation, the decision rests on whether a 

specific exposure has been established as the cause of a disease or condition. 

It is usually not possible to establish the fact of causation for indi­viduals 

(also referred to as causation in fact or individual causation) because the 

exposed cases caused by the exposure cannot be distinguished from the 

exposed cases caused by something else (Presidential Commission, 1990, 

pp. 107, 110). Furthermore, it is often difficult, if not impossible, to reconstruct the past doses, or even the exposures, when the latency period is very 

long. One approach to establishing the fact of causation in these circumstances has been to use an estimate of the probability of causation (PC) to 

determine whether compensation should be provided (OSTP, 1988). This 

estimate of PC (which is itself sometimes also referred to as PC), as discussed above, is the AF refined to be applicable to subgroups of indi­viduals 

and is used to assign group risk to exposed individuals with the condition. 

A minimum threshold value of this estimated PC is then selected to determine whether one is eligible for compensation. This PC can also then be 
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214 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

used to determine, in those below this threshold, what lesser degrees of 

compensation might be provided. 

The Presidential Commission on Catastrophic Nuclear Accidents used 

this approach when it recommended, in the context of radiation exposure, 

that someone for whom PC was determined to be more likely than not (i.e., 

PC > 0.50) would merit full compensation (Presidential Commission, 1990). 

At the other end of the spectrum, those in which it was determined that “it 

is extremely unlikely that an illness results from” an exposure would receive 

no compensation. For those who fell in between those two extremes, a 

“proportional recovery” approach was recommended in which compensation was awarded in relation to the PC (Presidential Compensation, 1990, 

p. 10). This approach, then, uses PC at a threshold of 0.5 to determine full 

compensability, with PC being determined by estimated exposure dose. 

Information on dose is then again brought to bear in determining the 

amount of compensation for those who do not meet the threshold PC, but 

who have received a dose that could possibly have caused the disease. Some 

of these issues are developed in more detail below (see “Possible Applications of the AF in Determining Individual Compensation”).

A cogent critique has been developed that argues against the use of PC 

for the purpose of determining compensation (Cox, 1984, 1987; Greenland, 

1999; Greenland and Robins, 1988, 2000; Robins, 2004; Robins and 

Greenland, 1989a,b, 1991). This critique has important implications as to 

whether the AF itself should be used in compensation. We later summarize 

the relevant aspects of this critique in the context of promoting use of AFs 

for this purpose as it relates to veterans (see “Promoting the Use of AFs in 

Determining Compensation for Veterans”).

Use of YLL, YLD, and DALYs in Compensation 

As an alternative to the use of PC or AF, Greenland and Robins proposed 

an approach to compensation based on expected years of life lost (YLL) 

(Greenland and Robins, 2000) (see above, “Reconsidering the Assumptions 

of the AF and Alternatives,” where YLL, YLD, and DALYs are defined). 

Compensation would then be based on some reasonably assessed amount 

per year of life lost. An important feature of such a scheme is that it takes 

into account when an exposure caused death rather than merely whether it 

caused death. A compensation scheme based on YLL, it is argued, is economically rational because the total compensation payable under such a scheme 

corresponds to the total health burden caused by an exposure (at least as 

reflected by mortality), a quantity that can be estimated from epidemiologic 

data. However, because YLL cannot be estimated for any individual from 

epidemiologic data, it is not possible to determine the correct apportionment of the total YLL among those exposed (Robins and Greenland, 1991). 
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 215

Apportioning compensation among exposed individuals would still require 

a policy decision based on unverifiable, but—one hopes—realistic, assumptions. Because mortality is not as relevant for veterans’ compensation as 

illness and disability, the above scenario can use YLD and DALYs instead. 

Applying Concepts of Sensitivity and Specificity to Compensation Schemes

Criteria for determining compensation make both explicit and implicit 

assumptions. One set of assumptions involves sensitivity and specificity 

(see Chapter 6). Sensitivity in this context is the probability that someone 

whose condition (or disease) was caused by a specific exposure is identified 

as such. Specificity is the probability that someone whose condition (or disease) was caused by something other than the specific exposure is identified 

as such. Typically when one improves sensitivity, specificity deteriorates, 

and vice versa. By trying to provide compensation for everyone whose 

condition was caused by the exposure, we typically increase the likelihood 

of mistakenly compensating some whose condition was not caused by the 

exposure. Conversely, in trying to exclude from compensation those who 

do not warrant it, we increase the chance of excluding those whose disease 

was in fact caused by exposure. 

 It is difficult to maximize both sensitivity and specificity. Optimizing 

one or the other means making some kind of mistake: either we optimize 

sensitivity by compensating some whose disease was not caused by exposure or we optimize specificity by failing to compensate some whose disease 

was caused by exposure. 

The closely related concepts of true positive (TP) and false positive 

(FP), and true negative (TN) and false negative (FN), describe making the 

right and the wrong decisions (Table 9-3). True positives are those correctly 

identified by some criteria. False positives are those mistakenly identified 

by the criteria. False negatives are those not identified by the criteria, but 

who should have been. True negatives are those who were correctly not 

identified by the criteria. 

Sensitivity is TP/(TP + FN)—the proportion of those whose condition 

was in fact caused by the exposure (TP + FN) who are correctly identified 

TABLE 9-3 True and False Positive and Negative Rates

Disease Caused by Exposure

Yes No

Compensation 

criteria

Met TP FP

Not met FN TN
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216 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

as such (TP). Specificity is TN/(TN + FP)—the proportion of those whose 

condition was in fact not caused by the exposure (TN + FP) who are correctly identified as such (TN). 

The positive predictive value (PPV) and negative predictive value (NPV) 

are important related concepts that are also defined from Table 9-3. The 

PPV is the proportion of those who meet the criteria whose condition was 

caused by the exposure, namely, PPV = TP/(TP + FP). The NPV is the 

proportion of those who do not meet the criteria whose condition was not 

caused by the exposure, namely, NPV = TN/(TN + FN). 

A hypothetical example using two alternative criteria for compensation 

will be used to help clarify these concepts. Consider a disease, D, caused 

by an exposure, E, and service in a theater, T, the only theater in which 

exposure to E was known to have occurred. First, criteria that would provide compensation to all veterans who are eventually diagnosed with D and 

who served in T, and who would therefore have potentially been exposed 

to E, are very sensitive criteria (Criteria A in Table 9-4). No veteran whose 

disease D was caused by exposure to E would be missed by using these 

criteria (i.e., sensitivity is excellent). However, because we have elected to 

make sure that all veterans whose disease D was caused by exposure to E

are compensated, we likely mistakenly also compensate those individuals 

whose disease D had another cause (i.e., specificity is poor). The use of 

criteria in this case to make certain that everyone in whom the disease was 

caused by exposure to E is compensated results in compensating many with 

the disease in whom it was not caused by E. 

In contrast, criteria that would provide compensation only to veterans 

with the disease D who, for example, also had documented exposure to E

for a specified period of time and of a specified intensity, and who also were 

diagnosed with D within a specified number of years of their first exposure, would be very “specific” criteria (Criteria B in Table 9-4). One can be 

more certain that if any group of veterans got D from exposure to E, those 

who were provided compensation by these criteria would be most likely to 

TABLE 9-4 Comparing Sensitivity and Specificity of Two Hypothetical 

Sets of Compensation Criteria

Specificity

excellent good some poor

Sensitivity

excellent Criteria A

good

some Criteria B

poor
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 217

belong to that group (i.e., specificity is excellent). However, these specific 

criteria could potentially result in not providing compensation to some of 

those in whom D was in fact caused by E (i.e., sensitivity is compromised). 

The use of specific criteria increases the likelihood of denying compensation 

to some whose disease was in fact caused by E.

Sensitivity and specificity are not affected by the AF (the proportion 

of those with the condition whose condition was caused by the exposure). 

However, PPV and NPV are strongly influenced by the AF. Because the 

PPV indicates what fraction (or percentage) of veterans compensated for 

a condition actually had their disease caused by the exposure, varying the 

AF will change the likelihood that those compensated will have had their 

disease caused by the exposure. The following tables illustrate how this 

works. It is assumed that the compensation criteria have fixed excellent 

sensitivity (0.90) and relatively poor specificity (0.20)—a realistic scenario. 

What happens when the AF is allowed to vary? In Table 9-5, we begin 

with a hypothetical scenario in which half of the veterans with the disease 

will have gotten it as a result of the exposure (AF = 0.50). Here the PPV 

is 9,000/17,000 = 0.53, or 53 percent of those who are compensated will 

have had the disease caused by the exposure. 

In Table 9-6, a lower and in some instances a more realistic AF of 0.09 

is assumed, produced here by decreasing the number of those whose disease 

was caused by the exposure 10-fold. Here the PPV is 900/8,900 = 0.10, 

which means only 10 percent of those compensated will have it caused 

TABLE 9-5 Hypothetical Scenario 1: PPV When AF = 50 Percent

Disease Caused by Exposure

Yes No Total

Compensation 

criteria

Met 9,000 8,000 17,000

Not met 1,000 2,000 3,000

Total 10,000 10,000 20,000

TABLE 9-6 Hypothetical Scenario 2: PPV When AF = 9 Percent

Disease Caused by Exposure

Yes No Total

Compensation 

criteria

Met 900 8,000 8,900

Not met 100 2,000 2,100

Total 1,000 10,000 11,000
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218 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

by the exposure, but 90 percent will have been compensated without the 

exposure having played a role. If the AF is even lower, say 0.02 (2 percent), 

then PPV falls to 0.02 and only 2 percent of those compensated will actually 

have had it caused by exposure while 98 percent will have been compensated without the exposure having contributed (Table 9-7).

The definition of exposure as used in these calculations plays a large 

role in determining whether the AF is large or small. For example, if exposure is defined precisely based on documented exposure to a specific agent, 

then a larger AF may be realistic. However, if a nonspecific exposure is 

used, such as presence in a given theater where relevant exposure to the 

agent is relatively uncommon, then the AF might be expected to be very 

small, meaning that the proportion of disease caused merely by being in a 

given theater would often most likely be small. As discussed above, while 

the AF can clearly vary depending on level of exposure, in this case, it is 

the definition of exposure that strongly influences the AF.

The Receiver Operator Characteristics Curve

A more flexible and informative way of displaying these concepts is by 

the use of the receiver operator characteristics (ROC) curve (Obuchowski, 

2003). An ROC curve (Figure 9-1) can display similar features as Table 9-4, 

but allows sensitivity (the proportion of true positives) and specificity (in 

this case reflected by the proportion of false positives [1 – specificity]) to 

be expressed on a continuous scale. The straight line of identity indicates 

combinations of sensitivity and specificity for criteria that do no better than 

chance in distinguishing those with disease caused by the exposure from 

those with disease not caused by exposure; the ability of criteria along this 

line to distinguish the two is no greater than that of tossing a coin. 

Points on curved lines that are displaced upwards and to the left of 

the line of identity indicate combinations of sensitivity and specificity corresponding to specific criteria (cut points) that perform better than chance. 

Points on a line are generated using different criteria and produce an 

empirical ROC curve. The resulting curve illustrates how sensitivity and the 

TABLE 9-7 Hypothetical Scenario 3: PPV When AF = 2 Percent

Disease Caused by Exposure

Yes No Total

Compensation 

criteria

Met 180 8,000 8,180

Not met 20 2,000 2,020

Total 200 10,000 10,200
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 219

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

1-Specificity

S

e

n

sitivity

Uninformative

Good

Excellent

FIGURE 9-1

A

B

C

D

FIGURE 9-1 Example of ROC curves. 

NOTE: Example of ROC curves. Different individual compensation criteria (A and B, 

and C and D) are displayed for different sets of criteria (dashed and dotted lines).

specificity vary together for different criteria. Each curved line corresponds 

to a different set of criteria for which varying the criteria within each set 

corresponds to different points along the line. Those curves displaced further upwards to the left than curves with lesser degrees of displacement 

generally perform better in distinguishing those with disease caused by 

exposure from those in which it was not caused by exposure. The point 

at the extreme upper left corner indicates largely unachievable criteria in 

which there is both perfect sensitivity and specificity—all those whose disease was caused by exposure receive compensation and none of those whose 

disease was not caused by the exposure receive compensation. The relevant 

advantages of an ROC curve over the table presented above are that the 

ROC curve (1) displays all possible criteria, (2) displays the relationship 

between sensitivity and specificity for different criteria, and (3) allows the 

performance of different sets of criteria (curves) to be directly compared. 

The hypothetical example of disease D and exposure E can also serve 

to attempt to make ROC curve concepts clearer. A set of criteria were 

presented above in which compensation was provided only to veterans 

who developed D with documented exposure to E for a specified period 
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220 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

of time and of a specified intensity, and who also were diagnosed with D

within a specified number of years of their first exposure. Using this set of 

criteria, alternative specific criteria can be considered. Criteria that favor 

specificity (A, Figure 9-1) might require cumulative exposure to E of at 

least 3 months of direct dermal or inhalational exposure and diagnosis of D

within 10 years of first exposure (i.e., a latency of diagnosis of less than 10 

years). Alternative criteria (B) that favored sensitivity might only require 1 

week of direct dermal or inhalational exposure to E, with the same latency 

requirement. Each of these criteria would correspond to a specific point on 

an ROC curve, with corresponding sensitivity and specificity. 

Another set of criteria could be considered that only uses information 

on exposure E, for example, but did not incorporate information on latency 

of diagnosis of D; this set of criteria would generate a new curve, with 

points corresponding only to different criteria for exposure. Another curve 

could be generated that only used information on time in theater T, for 

example 6 months (C) or 3 months (D), without any attempt to incorporate 

information either on exposure E or on latency. These criteria would be less 

specific, but probably more sensitive, than criteria A or B. 

A feature shared by the ROC curve, and sensitivity and specificity, since 

the ROC curve simply displays sensitivity and specificity, is that there is no 

allowance for graded decisions. Compensation does not necessarily need 

to be an either-or decision, but instead could incorporate a mechanism (see 

below) that allows degrees of compensation. Sensitivity and specificity, and 

therefore the ROC curve, cannot accommodate such decisions. 

 In the earlier discussion pertaining to the AF and compensation (“A 

Traditional Approach Using the PC” in which PC terminology was used 

in place of AF terminology) it was noted that the level of the AF can be 

used to determine compensation. Note that selection of a specific AF for 

this purpose necessarily implies some sensitivity and specificity. Selection 

of a large AF would be less sensitive but more specific (i.e., with the more 

stringent criteria entailed by a larger AF, more people whose disease was 

caused by the exposure would not be compensated, but those compensated 

would be less likely to have had their disease caused by something besides 

the exposure), while a small AF would be more sensitive, but less specific. 

Valuing Sensitivity or Specificity

Another feature of ROC curves, as was also noted above in discussing 

sensitivity and specificity, is that they are not affected by the proportion of 

a disease caused by the exposure (i.e., the AF) and therefore do not directly 

incorporate information on PPV and NPV. However, consideration of the 

AF can inform deliberations as to which criteria along an ROC curve are 

better than others. Specifically, the ROC curve does not tell us whether 
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we should place more value on improving sensitivity at the expense of 

specificity, or vice versa. The AF, by identifying the proportion of those 

with the disease that is caused by the exposure and thereby allowing us to 

calculate PPV, provides information that allows us to quantify the mistakes 

entailed in using different criteria. 

The value (or cost) placed on these mistakes will play an important 

part in determining which mistake is least (or more) tolerable, and therefore 

whether it is better to optimize sensitivity or specificity. One could argue, 

using an analogy from the battlefield, that it is intolerable to think of leaving any wounded behind on the battlefield. In the compensation context, 

this sentiment might translate into optimizing sensitivity to make sure that 

no one whose disease was in fact caused by the exposure was denied compensation, even at the expense of mistakenly providing compensation to 

many whose disease was not caused by the exposure. Alternatively, if economic concerns were paramount (for example, if there were severe budgetary constraints on the total amount of money available to a compensation 

program), then it might be better to optimize specificity, making sure that 

only those whose disease was caused by exposure received compensation, 

even at the expense of mistakenly not providing compensation to some 

whose disease was in fact caused by the exposure.

Options for compensation criteria lie on the spectrum that ranges 

from complete sensitivity (top right corner of the ROC curve) to complete 

specificity (bottom left corner). Obviously, there is no universally correct 

choice from among the options along this spectrum. However, whether this 

is done explicitly, or whether this is merely implicit in the decisions (which 

is normally the case), a compensation policy chooses some combination 

of sensitivity and specificity. Typically such decisions favor one over the 

other. In the case of a common disease or illness, if there is a fixed budget 

available for compensation, then use of very sensitive criteria, such as 

motivated by the battlefield analogy, might result in many receiving only 

a small amount of compensation. If the budget is not fixed, use of very 

sensitive criteria would result in the total amount of compensation paid 

out becoming exceedingly large. These issues are further developed in the 

following section.

Developing a Basis for Compensation Based on AF

In earlier sections of this chapter, we discussed the properties of the AF, 

its underlying assumptions, and its inherent limitations. Here we discuss a 

critique of AF as a tool for determining compensation and propose justifications for its continued use in the context of veterans’ compensation. We 

also explore options for the application of AF for this purpose.
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222 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Promoting the Use of AFs in Determining Compensation for Veterans

In the 1980s, Cox published an important critique of using epidemiologic data based on groups (and therefore the AF that is derived from these 

data) to draw conclusions about individuals, as is done in compensation 

settings (Cox, 1984, 1987). This theme was extended in a series of papers 

published from 1988 to 2004 by Robins and Greenland in which they 

developed their own critique of using probability of causation, and by 

implication, AF, as a basis for compensation or liability (Greenland, 1999; 

Greenland and Robins, 1988, 2000; Robins, 2004; Robins and Greenland, 

1989a,b, 1991). There are at least three points in their critique that are 

relevant to the issue of AF and compensation. 

First, compensation schemes based on AF alone allow consideration 

only of whether a disease occurs, not when the disease occurs. Although 

RRs, and the AFs derived from them, can vary by time in the sense that 

they can be estimated for different ages and for varying times since exposure, they do not reflect time lost due to disability or death. Those who live 

with a disease for a longer period of time, or had their life shortened by a 

longer period of time, presumably deserve more compensation. Approaches 

that use YLD or YLL (or DALYs) reflect when disease occurs and therefore provide an attractive alternative. (It should be recalled that the AF is 

a component of any calculation of YLD or YLL that tries to estimate the 

portion due to exposure [Steenland and Armstrong, 2006], and so any limitations inherent to the estimation of the AF itself will also apply to these 

extensions of the AF.) 

Second, with an RR we cannot distinguish a situation where an exposure causes new disease in a few that would otherwise not have occurred 

from the extreme case where an exposure accelerates the onset of disease 

that would have occurred anyway in all of the exposed (Robins, 2004). 

In fact any RR, no matter how little elevated above a no-effect RR of 

1.0, is as consistent with the exposure accelerating the onset of disease in 

all exposed as it is with the exposure causing the disease in the fraction 

of the exposed represented by the AF. One important implication is that 

an RR of 2.0 (and hence an AF of 0.5) does not equate to a 50 percent 

probability that exposure contributed to the disease in either the population or in an individual. That is, an RR of 2.0 does not make it as likely 

as not that the exposure caused the disease. It is important to understand 

that the distinction between accelerating the onset of a disease and causing disease that would not have occurred without the exposure is a blurry 

one. For example, because most men have latent prostate cancer by age 80 

(Oh et al., 2003), it is often assumed that all men, if they were to live long 

enough, will get prostate cancer. Yet we have no hesitation in referring to 

exposures as potential causes of prostate cancer even though any exposure 
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would in reality have accelerated the onset in all who got it as a result of 

the exposure. 

Third, when there is heterogeneity in baseline disease risks (i.e., when 

the risk of disease in the absence of exposure is different for different 

people, which is the usual situation), the AF does not necessarily equal 

the average of the probabilities that exposure caused the disease in each 

individual. This follows from the general principle that a nonlinear function (in this case a ratio) of averages does not in general equal the average 

of individual nonlinear functions (i.e., individual ratios). In the case here, 

the ratio of averages is the AF, and the average of ratios is the average of 

individual probabilities that exposure caused the disease. The greater the 

individual differences in the baseline probabilities, the greater the disparity 

between the AF and the average of individual probabilities. 

In light of these compelling arguments, why would the AF continue to 

be recommended in compensation plans? Part of the answer relates to the 

features of a given compensation plan. A compensation plan that pays a 

lump sum to a veteran (or spouse/survivor) in direct proportion to the AF 

would be open to the criticisms of Robins and Greenland. VA compensation does not work in this way. VA compensation has many features of a 

compensation plan based on YLD or YLL. For diseases associated with 

disability only (which is common), monthly VA disability benefits begin 

when a case is approved for compensation and continue until death. VA 

compensation therefore accounts for the period of time a veteran lives with 

a disability. 

Further, the amount of each monthly payment is intended to reflect the 

amount of disability, another feature incorporated in YLD (Steenland and 

Armstrong, 2006). Even though VA compensation does not directly account 

for YLL, spouse/survivor benefits for diseases that result in early mortality 

continue for the lifetime of the spouse/survivor. Thus, if the spouse/survivor 

outlives the veteran by many years because the veteran’s life was shortened 

by many years due to the disease, the total payment would reflect this 

degree of life shortening. Although this might not be true in any individual 

case (if the spouse/survivor also dies early, for example) VA compensation 

nonetheless accounts for YLL at least indirectly. 

Although we acknowledge the limitations, we also recognize the simplicity and transparency of the AF as a measure of disease burden. As 

others have deliberated similar issues of AF and assigned shares (NRC, 

2000), we accept the utility of the AF as an input to compensation. In the 

following section we explore ways in which the AF might be applied for 

VA compensation. 
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224 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Possible Applications of the AF in Determining Individual Compensation

There are several possible criteria for choosing among compensation 

plans. We focus here on two: economic rationality and fairness. 

An economically rational basis for compensation is one in which the 

total compensation provided to the population is equal to the total burden 

of disease caused by exposure in the exposed group (as defined by the AF). 

Thus, the total compensation given to the exposed group is determined by 

the total disease burden caused by their exposure. For example, if the AF 

is 50 percent (and we make the simplifying assumption that half of the 

cases of disease among the exposed are due to the exposure), then the total 

economically rational compensation is the amount needed to compensate 

half of the afflicted persons. Unless the AF were 100 percent (a rare occurrence), the total economically rational compensation is always less than full 

compensation to every person with the disease. 

One problem with the economically rational approach is that it says 

nothing about how to divide the total fairly among the eligible persons. 

The “correct” way would be to compensate each person according to his or 

her particular burden of disease caused by the exposure. We have discussed 

ways in which better information on exposure or individual susceptibility 

might improve estimates of individual PC. Ultimately, however, it is almost 

always impossible to determine which person’s disease was caused by military exposure. This is because most disabilities and diseases have multiple 

causes, and each exposed person is also exposed to other causes of the 

condition. Even with perfect research, it is not usually possible to determine 

which case of the disease was caused by the military exposure and which 

was not. This is a central feature and problem of compensation for military 

exposure.

Given this problem, one approach would be to spread the total compensation evenly among all exposed persons who have the disease. For 

example, if half of the disease cases among the exposed were caused by 

the exposure (AF = 50 percent), then half compensation could be given 

to everyone. More generally, under this plan every exposed person with 

the disease would get a percent of compensation equal to the AF for their 

disease. This plan is illustrated in Figure 9-2. This approach has been used 

in class-action suits, but to our knowledge has not been used for military 

compensation.

A criticism of this approach is that even if we cannot identify them, we 

know there are probably some people whose disease was actually caused by 

their military exposure. Such people get only partial compensation, which 

can be construed as unfair. The only way to guarantee this never happens is 

to compensate everyone 100 percent, regardless of the likelihood that their 

disease was caused by their exposure (Figure 9-3). Such an approach achieves 
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 225

0

20

40

60

80

100

10 20 30 40 50 60 70 80 90 100

Attributable Fraction (%)

Compensation for Exposed Persons

with Disease (%)

 FIGURE 9-2

0

20

40

60

80

100

10 20 30 40 50 60 70 80 90 100

Attributable Fraction (%)

Compensation for Exposed Persons

with Disease (%)

FIGURE 9-3

FIGURE 9-3 Complete compensation (100 percent) for all exposed persons with 

disease, regardless of attributable fraction.

FIGURE 9-2 “Economically rational” compensation plan, based on the attributable fraction.
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226 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

extremely high sensitivity, but at high cost. This plan is not economically 

rational, in that it provides more compensation to the exposed population 

(in some cases, far more compensation) than the total disease burden would 

justify. It is worth noting that other criteria may legitimately be regarded by 

policy makers as more important than economic rationality.

The two plans described in Figures 9-2 and 9-3 define the boundaries of 

practical plans for compensation. The economically rational model provides 

the minimum rational compensation (Figure 9-2) and the compensation-toall model provides the maximum possible compensation (Figure 9-3). All 

remaining plans discussed here fall somewhere between. 

One in-between approach would be to establish a level of AF necessary 

for 100 percent compensation. The usual criterion is 50 percent—that is, 

the chance that the disease in an exposed person was caused by their exposure is at least 50:50. This approach is shown in Figure 9-4. 

A criticism of the “50 percent criterion” is its all-or-none property. 

Because of uncertainty in the estimate of RR, there is little real difference 

between an RR of 2.1 and 1.8 (producing AFs of 52 percent and 44 percent), and yet a disease with the first AF might get 100 percent compensation, and a disease with the other might get none. By the criterion of 

economic rationality, the plan in Figure 9-4 undercompensates persons 

when the AF is less than 50 percent, and overcompensates them when it is 

50 percent or greater.

0

20

40

60

80

100

10 20 30 40 50 60 70 80 90 100

Attributable Fraction (%)

Compensation for Exposed Persons

with Disease (%)

FIGURE 9-4

FIGURE 9-4 Complete compensation for all exposed persons only when attributable fraction is 50 percent or more.
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 227

This problem of all or none has been addressed in an alternative compensation scheme. The 1984 NRC Oversight Committee (NRC, 1984) suggested that when the AF was 50 percent or greater, compensation should be 

100 percent, and when it is less than 50 percent, it should be linearly scaled 

down to 10 percent. This is shown in Figure 9-5.

A graded strategy of compensation (such as Figure 9-5), is more fair 

than an arbitrary cutoff of 50 percent and comes closer to achieving economic rationality—although at any given AF, it still provides total payouts 

much larger than the total burden of disease. 

In the past, there has been a policy not to compensate individuals at 

levels less than 10 percent. Such a threshold would be relevant if any these 

models generated estimated compensations under 10 percent.

INTEGRATIVE SYNTHESIS: ROLES FOR PRESUMPTIONS

In this chapter the factors that can serve as information inputs to the 

decision-making process underlying the determination of veterans’ compensation have been identified and discussed. These factors and the point(s) 

in the process at which they come into play are displayed in Figure 9-6. 

Additional inputs to the compensation process that are not strictly informational in nature are also displayed. These consist of ethical, political, and 

economic considerations that in practice can be critical determinants of the 

0

20

40

60

80

100

10 20 30 40 50 60 70 80 90 100

Attributable Fraction (%)

Compensation for Exposed Persons

with Disease (%)

FIGURE 9-5

FIGURE 9-5 Complete compensation for an AF of 50 percent or more, plus graduated compensation below 50 percent.
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228 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

FIGURE 9-6

Compensation 

criteria

Values

(financial,

moral,

political)

Compensation 

(and/or

medical care)

Resources

Biomedical knowledge 

(observational and 

toxicological studies) 

Exposure effect 

estimates 

(and uncertainties) 

Service-attributable 

fraction(s) (SAFs) 

(strata specific) 

Other

risk factors

Unified exposurerisk factor 

disease model 

Individual

disease risk

profile

Individual

exposure

(amount, 

timing)

Individual

disease

(diagnosis,

timing, 

age)

SAF for the 

individual

FIGURE 9-6 A rational process for determining veterans’ compensation.
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 229

outcome of the process, but do not lend themselves to the type of exploration that has been undertaken in this chapter. 

A Rational Compensation Determination Process

The compensation determination process for veterans displayed in 

Figure 9-6 is, we argue, a scientifically based and rational scheme, albeit 

necessarily somewhat idealized for most situations. Scientific findings here 

form the foundation for compensation. These scientific findings are more 

typically observational in nature, although toxicological or other experimental findings, depending on the specific exposure or disease, can either 

complement the observational findings or occasionally comprise the bulk 

of the findings. However, to be useful in this scheme, science must provide 

estimates of exposure effect that can be used to derive estimated AFs, and 

such effect estimates are best derived from observational data. Measures 

of uncertainty in the effect estimates could potentially play a role in some 

compensation schemes, although we have not here presented applications 

of how this might work. Toxicological findings, or the lack of them, could 

be reflected in the measures of uncertainty. 

The size of effect estimates are affected by the extent of exposure and, 

by definition, effect modifiers. These, then, also affect the SAFs. Moreover, as we have seen, the SAF can be affected by how other risk factors 

interact with the exposure in causing disease, being affected not at all if 

they interact multiplicatively, but potentially dramatically if they interact 

additively (see Table 9-2 and corresponding discussion). To make use of 

these influences on the AF in the compensation process, science must not 

only provide information on how exposure and effect modifiers influence 

effect estimates, but also provide information on the form of interactive 

effects of other disease risk factors. 

 Armed with a host of exposure SAFs that correspond to levels (strata) 

of exposure, to states (strata) of the modifying factors, and to states of 

other risk factors if their interactions with the exposure are other than 

additive, individual SAFs can be estimated. Assuming that this information 

on exposure and these factors are also available for a given veteran seeking 

compensation, a corresponding SAF can be assigned to the veteran in lieu 

of our ability to know any individual’s PC. 

A compensation scheme for a specific exposure-disease combination that is economically rational (i.e., one that provides a total award 

reflecting the total disease burden of the exposed group) is formulated. 

A compensation scheme can potentially incorporate features relating to 

the certainty of the scientific information that is used in estimating the 

SAF, although we have not provided examples as to how this might be 

done. Criteria that define who is eligible for some form of compensation 
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230 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

implicitly assume some sensitivity and specificity, and for the population 

of concern, corresponding false positive and false negative rates. The AF, 

as shown above (Tables 9-5 to 9-7), has a great impact on both of these 

rates for a fixed sensitivity and specificity, and therefore could influence 

the selection of compensation criteria apart from its role in determining 

the individual SAF. Because of the trade-offs involved in choosing one 

set of criteria over another, the choice will always entail invoking values 

of some sort, for example, ethical, political, or financial (i.e., resource) 

values. 

 For many cases, including those involving veterans, this version of a 

compensation process may seem farfetched. It is unlikely that any single 

instance involving determination of compensation for veterans has features that look exactly like this. Nevertheless, it is instructive to consider 

how individual processes differ from this version. First, by identifying how 

actual cases differ from this framework, insight can be gained into some 

not so obvious assumptions that have been made in these cases. Second, 

this framework might help pinpoint or clarify the critical influences on any 

given compensation process. Finally, this framework can serve to identify 

information needs that, if met, would improve the specific presumptive disability decision-making process. 

One way of viewing presumptions is as compromises necessitated by 

either poor or absent information on one or several of the inputs to the 

veterans’ compensation determination process. For example, absent information on exposures of Service members in a specific theater, a presumption 

could be used to make the determination that any Service member who 

served in that theater was exposed. As another example, epidemiologic 

and other evidence about the association between a specific exposure and 

disease may be inadequate for estimating the AF. A presumption could be 

used to determine that any veteran with the disease who had been exposed 

most likely had the disease caused by the exposure. Or, there may be no 

information on how risk factors other than the exposure of interest influence the risk of disease, or how timing of disease occurrence influences the 

likelihood that the exposure was relevant. Even if this information existed, 

there may be no reliable way of obtaining this information for a veteran. A 

presumption might be used to determine that all exposed veterans, regardless of gender, age, the time since exposure, or exposure to other suspected 

disease risk factors, have the same AF. 

Some Case Studies Revisited

It is instructive to again examine some of the case studies in light of 

this view of presumptions, and to assess characteristics of presumptions 

pertaining to sensitivity and specificity, and positive and negative predictive 
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 231

value. The contrasting cases of Agent Orange and type 2 diabetes and of 

radiation and lung cancer will be used for this purpose. 

With Agent Orange and type 2 diabetes, much of the information 

needed to apply our proposed process is unavailable or of poor quality 

(see Agent Orange and type 2 diabetes case study in Appendix I). First, 

scientific information that can be used to estimate an SAF indicates that the 

SAF is small, at best, and uncertain. Consequently, it is difficult based on 

this information to provide meaningful SAFs that correspond to different 

levels of exposure, or SAFs that correspond to different strata of possible 

modifying factors. There is information on the effect of several diabetes 

risk factors, but none is available on how any of these interact with Agent 

Orange exposure to influence diabetes risk. 

Assuming that meaningful SAFs could be estimated, information about 

the veteran to make use of the SAFs is needed. First, information on 

exposure to Agent Orange is needed, including first and foremost whether 

exposure occurred, and the intensity and duration of exposure. Although 

there has been little attempt to make use of possible sources of exposure 

information for Agent Orange in Vietnam veterans for the purpose of 

compensation, attempting to characterize exposure based on current information will nevertheless be difficult. Information on the time of onset of 

diabetes, the certainty of diagnosis, and diabetes risk factors, while not 

perfect, is comparatively good. 

Compensation schemes for Agent Orange and type 2 diabetes could 

take several forms, any of which might require some type of presumptions. 

We assume that the scientific findings indicate that exposure to constituents 

of Agent Orange causes type 2 diabetes, with some degree of certainty. With 

the SAF being small, even among those with well-documented exposure, 

the total disease burden is relatively small. This is true whether total disease burden is estimated directly from the SAF or using the SAF to modify 

a YLD or DALY. For compensation to be economically rational, the total 

compensation award to the veterans affected would then also be relatively 

small. Alternatively, if the overall cost of compensation for Agent Orange 

and type 2 diabetes is not relevant, then economic rationality is also not 

pertinent. With a small SAF, it is also likely that the proportion of those 

who would receive compensation under any scheme whose diabetes was 

actually caused by Agent Orange exposure would also be small (i.e., the 

false positive rate would be high). With crude measures of exposure that 

would include large numbers of veterans without the degree of exposure 

needed to cause disease, the SAF would be smaller still, with a correspondingly high proportion mistakenly compensated. 

Any available information on the above inputs to the compensation 

process could restrict the scope of presumptions needed for Agent Orange 

and type 2 diabetes. Clearly the use of some information on exposure to 
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232 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Agent Orange would reduce the effect on reduction of the SAF caused by 

including unexposed veterans. In the absence of better scientific information 

on Agent Orange exposure and type 2 diabetes, it will not be possible to 

utilize veteran information on potential modifying factors such as age of 

exposure, age of disease onset, or latency period to provide strata of SAF, 

although assumptions might have a role. For example, a hypothetical case 

could be made to limit the number of years allowable between exposure 

to Agent Orange and onset of diabetes. Regarding the presence of other 

diabetes risk factors that modify baseline risk, in the absence of good information on the form of interactions with Agent Orange, an assumption of 

additivity of risks might be made that could make it possible to provide 

stratified SAFs. A later age of diabetes onset in this case, for example, would 

increase baseline risk and reduce the SAF. 

The current presumption for Agent Orange and type 2 diabetes has 

implicit assumptions as to sensitivity and specificity. With a presumption 

that requires service in Vietnam and diagnosed type 2 diabetes, sensitivity, 

TP/(TP + FN), is nearly 1.0 as there are essentially no FNs. That is, any 

Vietnam veteran who got diabetes from Agent Orange exposure will receive 

compensation. On the other hand, specificity, TN/(TN + FP), is 0 since there 

are no TNs. That is, no Vietnam veterans whose diabetes was caused by 

something other than Agent Orange will not be compensated. The positive 

predictive value of compensation, TP/(TP + FP) is very small because FP 

is exceedingly large due to the small SAF. That is, only a small fraction 

of those who receive compensation will actually have had their diabetes 

caused by exposure. The negative predictive value, TN/(TN + FN), is almost 

meaningless because both TN and FN are essentially nonexistent. These 

characteristics of this particular presumption are therefore quite extreme. 

The case of radiation and lung cancer presents distinct contrasts to 

that of Agent Orange and type 2 diabetes. As detailed earlier (see radiation 

case study in Appendix I), here the case for causation is strong, uncertainty is relatively well estimated, and there is extensive information on 

dose-response relationships. Information on the effects of other factors, 

principally smoking and age, is also relatively extensive. However, even 

in this case there are deficiencies in the state of the information that invite 

presumptions. These deficiencies include (1) poor individual person-dose 

estimation; and (2) inadequate information on the form of the radiation 

interaction model for other risk factors, again principally smoking. 

Based on the above information it is clear that the estimated SAF is 

relatively large for radiation and lung cancer and has less associated uncertainty than most exposures. As noted before, the radioepidemiological 

tables (NIH, 1985) provide estimated PCs for radiation in lung cancer by 

exposure dose, age at exposure and at cancer diagnosis, latency, and cigarette smoking history. However, there is little agreement on the form of the 
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APPLYING POPULATION-BASED RESULTS TO INDIVIDUALS 233

radiation-smoking interaction in lung cancer, with initial evidence favoring 

additive effects and more recent interpretations favoring multiplicative (or 

submultiplicative) effects (see radiation case study in Appendix I). Because 

the form of the interaction has a large impact on estimation of the SAF, 

uncertainty about the form complicates use of an SAF even for lung cancer 

(see discussion on effects on the positive predictive value below).

The current presumption for radiation and lung cancer also has implicit 

assumptions as to sensitivity and specificity. Sensitivity, TP/(TP + FN), is 

good as there will only be a few FNs. That is, most radiation-exposed 

veterans who get lung cancer from radiation exposure will receive compensation, at least when based on a presumption of exposure. Specificity, 

TN/(TN + FP) is also good because those with low radiation risk, such as 

those with low estimated exposure, are less likely to receive compensation, 

although because of inaccuracies in the estimated exposure, some will (these 

will be FPs). The positive predictive value of compensation, TP/(TP + FP), 

is very good because FPs are relatively uncommon because of the large AF. 

That is, a large fraction of those who receive compensation will actually 

have had their lung cancer caused by exposure. The negative predictive 

value, TN/(TN + FN), is also very good because FNs are relatively uncommon. These characteristics of this particular presumption therefore seem 

to be reasonable. 

However, even for the case of radiation and lung cancer, the above 

assessment of these characteristics is dependent on the way other disease 

risk factors, for example smoking, are determined to interact with the effect 

of radiation. For nonsmokers the above assessment is reasonable and does 

not depend on the form of the interaction. For smokers the assessment 

varies depending on whether smoking is determined to interact additively or 

multiplicatively with radiation exposure. With a multiplicative interaction, 

exposure RR and therefore AF is the same regardless of smoking status. 

In the additive case, the RR and the AF can vary dramatically by smoking 

status (see Tables 9-1 and 9-2, above). This will have no effect on sensitivity 

or specificity, as these are unaffected by the AF. However, positive and negative predictive values will be affected as both change as a function of the 

AF. Because the AF is substantially smaller in smokers than nonsmokers 

under an additive model, the positive predictive value is likewise smaller, 

indicating that for smokers a substantial percentage of those receiving 

compensation will not have gotten lung cancer as a result of exposure to 

radiation. The AF (and the PC derived from it) in the radioepidemiological 

tables is therefore critically dependent on the form of the interaction that 

is determined to be the case. Therefore, even with better scientific information than is available for any other military exposure, there is still room for 

presumptions. However, the better the information, the more focused and 

limited in scope the presumptions can be. 
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234 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Science and Compensation Presumptions

The inability to identify the disease role of specific military exposures 

in any individual veteran partly motivates the need for compensation presumptions. The scope of a presumption is, in turn, partly determined by 

the available scientific information and corresponding information on any 

given veteran. The more scientific information available on the causal relationship between a service exposure and disease, and the more information 

available on an individual veteran’s exposure and disease risk, the more 

narrow in scope the presumption needs be. The contrasting cases of Agent 

Orange and type 2 diabetes, and radiation and lung cancer, discussed above 

serve to make these points. 

It is likely that there will be substantial advances in our ability to 

quantify exposure and other disease risks in individual veterans, perhaps 

through the use of specific biomarkers of exposure or disease for example, 

and by exploiting findings from toxicogenetics and toxicogenomics. These 

advances could possibly refine the scope of presumptions or conceivably do 

away with the need for some presumptions. 

Earlier chapters laid out a framework for determining when a compensation presumption may be considered based on the state of scientific 

information. The intent in this chapter has been to identify concepts and 

tools that can be utilized in making decisions as to the form and content 

of a compensation presumption. These include (1) a set of SAFs that is as 

refined as the science permits; (2) features of alternative presumptions, such 

as sensitivity, specificity, and positive predictive value, that characterize and 

quantify the relative strengths and unavoidable mistakes (and therefore 

costs) implicit in each presumption; and (3) an appreciation of the relationship between the SAFs and some of these features, namely the positive and 

negative predictive values. 

It has not been the intent here to determine whether a specific presumption and its form are justified or sensible or to identify better alternatives. 

These are issues on which VA and Congress deliberate. It is hoped, however, 

that the framework outlined can be used in these deliberations to allow 

for more rational, science-based decisions about the content of specific 

presumptions than may have been the case in the past. 

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Benichou, J. 2001. A review of adjusted estimators of attributable risk. Statistical Methods in 

Medical Research 10:195-216.
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Bruzzi, P., S. B. Green, D. P. Byar, L. A. Brinton, and C. Schairer. 1985. Estimating the population attributable risk for multiple risk factors using case-control data. American Journal 

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DHHS (Department of Health and Human Services). 2002. 42 CFR Parts 81 and 82. Guidelines for determining the probability of causation and methods for radiation dose reconstruction under the Employees Occupational Illness Compensation Program Act of 2000; 

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Greenland, S. 1999. Relation of probability of causation to relative risk and doubling dose: 

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Lagakos, S. W., and F. Mosteller. 1986. Assigned shares in compensation for radiation-related 

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cdc.gov.mill1.sjlibrary.org/niosh/ocas/pdfs/irep/irepug0607.pdf (accessed July 28, 2007).

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NRC. 2000. A review of the draft report of the NCI-CDC Working Group to Revise the 1985

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Obuchowski, N. A. 2003. Receiver operating characteristic curves and their use in radiology. 

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Robins, J. M., and S. Greenland. 1989a. Estimability and estimation of excess and etiologic 

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154(6):718-719.
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237

10

Health and Exposure 

Data Infrastructure to Improve the 

Scientific Basis of Presumptions

INTRODUCTION

This chapter addresses the implementation of a system of data collection to support surveillance and research, as well as to track the exposures of individual military personnel. The long-term goal is a system that 

would improve or complete many of the evidence gaps that now lead to 

presumptions. Information on exposure is needed to conduct studies that 

will provide data for calculating attributable fractions and for determining 

exposure groups of particular individuals.

Once a causal relationship has been established or presumed between 

a specific disease and a type of exposure, it becomes crucial to establish 

whether the Service member was exposed during military service. When 

data are not sufficient to describe a specific Service member’s serviceexposure history, presumptions are needed to give guidance about what 

to assume as exposure magnitude is considered. One clear path toward 

reducing the need for presumptions in decision making is to accurately 

document and provide Service member-specific exposure and health data 

to those making decisions regarding that Service member’s case. Thus 

individuals determined by an adequate exposure surveillance system not to 

be exposed to an agent of concern would not be at risk for the particular 

health outcome(s) caused by that specific exposure. The availability of 

exposure data would provide evidence to support a veteran’s claim that the 

exposure occurred while in military service. The availability of exposure 

data will allow more informative epidemiological studies to be performed 

and a more accurate determination of service-attributable fraction (SAF). 
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238 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

The need for having better exposure data has been recognized repeatedly in 

numerous external reviews of Department of Defense (DoD) and Department of Veterans Affairs (VA) activities regarding Service member health 

protection and veteran health care and disability determination (GAO, 

1999, 2000a,b, 2005a,b, 2006; IOM, 1996a, 1999b, 2000c).

Detailed health status data collected throughout a Service member’s 

active duty and veteran experience, coupled with individual exposure data 

collected during that period, would provide the data needed to make better 

decisions about an individual’s likelihood of service-related disease causation and thus minimize the need for presumptions. As the Institute of 

Medicine (IOM) noted in 1996, 

The DoD, the branches of the armed services, and the DVA should continue to work together to develop, fund, and staff medical information systems that include a single, uniform, continuous, and retrievable electronic 

medical record for each [S]ervice member. The uniform record should 

include each relevant health item (including baseline personal risk factors, 

every inpatient and outpatient medical contact, and all health-related 

interventions), allow linkage to exposure and other data sets, and have 

the capability to incorporate relevant medical data from beyond DoD and 

DVA institutions (e.g., U.S. Public Health Service facilities, civilian medical 

providers, and other health-care institutions). . . . (IOM, 1996a, p. 10)

DoD and VA have been working together since 1998 to improve sharing of medical information for active-duty military personnel and veterans. 

The agencies have developed a short-term plan to improve their existing 

health information systems and a long-term plan to create a modern health 

information system based on computable data. However, as GAO points 

out, DoD and VA lack a detailed project management plan to guide their 

efforts (GAO, 2007).

In 1997, President Clinton issued a directive to DoD and VA “to create 

a new Force Health Protection Program. Every soldier, sailor, airman, and 

Marine will have a comprehensive, life-long medical record of all illnesses 

and injuries they suffer, the care and inoculations they receive, and their 

exposure to different hazards. These records will help us prevent illness and 

identify and cure those that occur” (DoD, 2006a, p. 2).

Also in 1997, coincident with the presidential directive described above, 

DoD issued an instruction describing the “Implementation and Application 

of Joint Medical Surveillance for Deployments.” This document defined 

initial expectations for more detailed medical surveillance and exposure 

assessment data collection systems for both deployment and in-garrison or 

nondeployment settings. This plan laid the groundwork for systems that 

would “eventually be capable of linking deployment and nondeployment 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 239

environmental and occupational exposure and data to health hazard and/or 

health risk assessments to individual medical records and medical outcome 

databases” (DoD, 1997, p. 5).

The vision for a more comprehensive and continuous surveillance system was articulated in DoD Directive 6490.2 issued in 2004. It proposed 

that 

Health surveillance systems shall be continuously in effect throughout each 

[Service member]’s career, capturing data about individual health status; 

instances of disease and injury; medical interventions such as immunizations, treatments, and preventive medications; and exposures to potential 

and actual health hazards associated with occupation, deployment, and 

lifestyle. (DoD, 2004, p. 3)

 It also dictated policy that “[s]urveillance data collected on individual 

[Service member]s during their careers shall be provided to VA upon their 

separation or retirement from the military” (DoD, 2004, p. 4). 

Defining and developing the mechanisms and systems to implement 

these goals has been an iterative process that has taken years—largely due to 

the magnitude and complexity of the issues being addressed. Those efforts 

are now bringing action as a series of systems and expectations are being 

implemented. DoD Instruction 6490.03 of 2006, which replaced the 1997 

DoD Instruction 6490.3, sets clear expectations that deployment exposure 

assessment and monitoring data be submitted to individual health records 

and to a DoD-wide database (DOEHRS—the Defense Occupational and 

Environmental Health Readiness System) (DoD, 2006c, p. 21).

The remainder of this chapter reviews the current state and future plans 

for DoD and VA collection and use of health and exposure data throughout 

a Service member’s span of service. The availability of such data would 

enable studies to better understand potential linkages between serviceconnected exposures and future health status and would reduce reliance on 

presumptions in decision making.

DOD Health and Exposure Assessment Data Collection

DoD Health Assessment and Medical Surveillance

Overview 

Opportunities for health assessments of Service members on active duty 

occur at obvious service milestones throughout the Service member’s span 

of service. These milestones include the initial medical evaluation at accession, or entry into the service, and subsequent periodic health assessments 
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240 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

that continue until separation or retirement from the service. These milestones are displayed in Figure 10-1. Additional surveillance may precede 

or follow specific deployments with assessments tailored to the particular 

hazards of a deployment.

Routine Health Assessments Throughout the Span of Service

Elements of the health data collected for each of the assessments performed over the span of a Service member’s service are found in Table 10-1. 

They may include responses to a health history questionnaire, physical 

examination findings, and laboratory test results. The degree of detail and 

areas of emphasis in each assessment vary based on the specific point in the 

span of service or on the purpose of each individual assessment. Generally, 

a self-completed questionnaire contains a core set of questions regarding 

physical and mental health, and history of environmental and occupational 

exposures and stressors. This is intended to follow the recommendations of 

the U.S. Preventive Health Services Task Force’s Guide to Clinical Preventive Services (AHRQ, 2006). Data are collected in a combination of written 

and electronic formats. 

All new recruits and enlisted Service members undergo an initial evaluation at the time of accession. This is the most comprehensive of the assessments and provides the baseline set of data that is updated at the time of 

each future assessment. As in all assessments, the nature of the responses 

and test results partly determine what additional evaluation or screening is 

performed. At this time, data from this evaluation are generally saved only 

in a hard copy format. The Health Assessment Review Tool (HART) is an 

electronic and standardized implementation of the self-reporting questionnaire that is currently being pilot tested at Ft. Jackson (Army) and San 

Diego (United States Marine Corps); the HART-A (the accession version) 

is expected to be more generally available in the next few months (Personal 

communication, Col. K. Cox and C. Postlewaite, Department of Defense, 

November 1, 2006). 

The periodic health assessments (PHAs) are episodic (generally annual) 

follow-up evaluations primarily employing self-completed questionnaires. 

Positive responses on this questionnaire, or additions to previously collected information, trigger a more detailed assessment. In following the 

U.S. Preventive Health Services Task Force recommendations, the PHAs are 

ideally targeted based on gender, age, disease risk factors, medical history, 

and exposure history (DoD, 2006d). The PHA is currently being instituted 

by the Army, but it has been established in the Navy and Air Force for 

several years. 

The separation, retirement, or deactivation assessment is the final routine evaluation that all Service members undergo. Whereas previously a 
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241

Service 

Initial medical

evaluation

Health

assessment

before entering

service

Pre-deployment

health

assessment

Post-deployment

health

assessment

Post-deployment

health

reassessment

Separation/

retirement health

assessment

Annual Periodic

Health

Assessments

(PHA)

Training 

Predeployment 

Deployment 

Postdeployment 

Separation/

retirement 

Exposure data from

post-deployment health

assessment and

reassessment

Medical Surveillance Data Exposure Data Accession Daily location tracking and exposure monitoring (occupational and environmental) Occupational and

Environmental Health

Site Assessment

Routine industrial hygiene and environmental exposure assessments by operation and/or job/task

FIGURE 10-1

reduced to final size to show type size in book

Landscape view

FIGURE 10-1 Timeline for medical surveillance and exposure data collection.
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242TABLE 10-1 Timeline for Medical Surveillance and Exposure Data Collection

In Service

Accession

After Training Before Service

Throughout Service

PreDeployment Deployment Post- Deployment

PostDeployment Reassessment

Separation/Retirement

Routine Medical Surveillance DataaSelf-Administered QuestionnaireFamily history of chronic 

diseases

X X

Personal habits XPast medical history XMedications X X X XAllergies XGeneral health status X X X XSignificant events since last 

periodic health assessment

X X

On a profile, light duty, or 

undergoing a medical board

X

Medical or dental problems X XPregnancy XCounseling or care for mental 

health in past year

X

Questions or concerns about 

health

X

Health changes during 

deployment

X X

In sick call during deployment X XNights spent as a patient in a 

hospital during deployment

X X X

Vaccinations XS

d

l

d 

X X
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243

Health changes during 

deployment

X

X

In sick call during deployment

X

X

Nights spent as a patient in a 

hospital during deployment

X

X

X

Vaccinations

X

Symptoms now or developed 

anytime during this deploymentb

X

X

See anyone wounded, killed, or 

dead during this deployment

X

Engaged in direct combat 

where discharged weapon

X

During deployment, feel like in 

great danger of being killed

X

Interested in receiving help for 

a stress, emotional, alcohol, or family problem

X

X

X

Little interest or pleasure in 

doing things 

X

X

Feeling down, depressed, or 

hopeless

X

X

Thoughts that you would be 

better off dead or hurting yourself in some way

X

Nightmares due to an 

experience so frightening, horrible, or upsetting

X

X

Constantly on guard, watchful, 

or easily startled 

X

X

Numb or detached from 

others, activities, or your surroundings

X

X

continued
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244 In Service

Accession

After Training Before Service

Throughout Service

PreDeployment Deployment Post- Deployment

PostDeployment Reassessment

Separation/Retirement

Self-Administered Questionnaire (continued)Concerns of serious conflicts 

with spouse, family members, or close friends

X X

Concerns of hurting or lose 

control with someone

X

Having problems if wounded, 

injured, or assaulted during deployment

X

Alcohol use XDifficulty working, taking care 

of things at home, or getting along with other people

X X

Illnesses or injuries that caused 

you to miss duty for longer than 3 days

X

Treated by a healthcare 

provider, admitted to a hospital, or had surgery

X

Injuries or illnesses while on 

active duty for which you did not seek medical care

X

Other questions or concerns 

about your health

X

Intend to seek Department of 

Veterans Affairs disability

X

L

b

T

TABLE 10-1 Continued
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245

active duty for which you did not seek medical care

Other questions or concerns 

about your health

X

Intend to seek Department of 

Veterans Affairs disability

X

Laboratory TestsUrinalysis (albumin, sugar, 

HCG)

X

X

X

H/H

X

X

X

Blood type

X

X

X

Drugs and alcohol

X

X

X

Serum sample

X

X

X

X

HIV testing

X

X

CBC

X

Hemoglobin

X

Hematocrit

X

Vaccination status

X

Clinical Screening and MeasurementsHeight

X

X

X

Weight

X

X

X

Temperature

X

X

X

Pulse

X

X

X

Blood pressure

X

X

X

Distant vision, near vision

X

X

X

Refraction by autorefraction or 

manifest

X

X

X

Heterophoria

X

X

X

Color vision

X

X

X

Depth perception, field of 

vision, night vision

X

X

X

continued
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246

In Service

Accession

After Training Before Service

Throughout Service

PreDeployment Deployment Post- Deployment

PostDeployment Reassessment

Separation/Retirement

Clinical Screening and Measurements (continued)Intraocular tension X X XAudiometer X X XPap smear X X XAllergies XTobacco use XAlcohol abuse and stress 

management

X

Chronic illnesses XMedications XCholesterol XBreast exam, mammogram XFecal occult blood XSigmoid XColonscopy XImmunizations XClinical EvaluationsHead, face, neck, and scalp X X XNose, sinuses X X XMouth and throat X X XHeart X X XLungs and chest, vascular 

system

X X X

Anus and rectum X X XAbdomen and viscera X X X

TABLE 10-1 Continued
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247

Nose, sinuses

X

X

X

Mouth and throat

X

X

X

Heart

X

X

X

Lungs and chest, vascular 

system

X

X

X

Anus and rectum

X

X

X

Abdomen and viscera

X

X

X

External genitalia

X

X

X

Upper and lower extremities

X

X

X

Spine, musculoskeletal system

X

X

X

Body marks, scars, tattoos

X

X

X

Skin

X

X

X

Neurologic and psychiatric 

disorders

X

X

X

Pelvis

X

X

X

Endocrine system

X

X

X

Routine Exposure DataaIndustrial Hygiene Exposure Assessment of Operations, Jobs/Tasks

X

Qualitative Exposure 

Judgments

X

Occupational Exposure 

Monitoring

X

Routine Environmental Health Programs 

X

continued
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248

In Service

Accession

After Training Before Service

Throughout Service

PreDeployment Deployment Post- Deployment

PostDeployment Reassessment

Separation/Retirement

Environmental Health Site Assessment (EHSA)cCurrent use of site, adjoining 

properties, and surrounding area

X

Past use of site, adjoining 

properties, and surrounding area

X

Geologic, hydrogeologic, 

hydrologic, meteorologic, and topographic conditions

X

General description of 

structures

X

Roads XPotable water supply XSewage disposal system XHazardous materials in 

connection with identified use

X

Storage tanks XOdors XPools of liquid XDrums XHazardous materials and 

petroleum products containers

X

TABLE 10-1 Continued
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249

Pools of liquid

X

Drums

X

Hazardous materials and 

petroleum products containers

X

Unidentified substance 

containers

X

Heating and cooling

X

Stains or corrosion

X

Drains and sumps

X

Pits, ponds, and lagoons

X

Stained soil or pavement

X

Stressed vegetation

X

Solid waste

X

Waste water

X

Well

X

Septic systems

X

Daily Location Tracking

X

OEHS Site Assessments

X

Environmental Monitoring

X

Exposure Incident Response

X

Self-Administered QuestionnaireDEET insect repellant applied 

to skin

X

X

Pesticide-treated uniforms

X

X

continued
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250

In Service

Accession

After Training Before Service

Throughout Service

PreDeployment Deployment Post- Deployment

PostDeployment Reassessment

Separation/Retirement

Self-Administered Questionnaire (continued)Environmental pesticides (like 

area fogging)

X X

Flea or tick collars X XPesticide strips X XSmoke from oil fire or burning 

trash or feces

X X

Vehicle or truck exhaust fumes X XTent heater smoke X XJP8 or other fuels X XFog oils (smoke screen) X XSolvents X XPaints X XIonizing radiation X XRadar/microwaves X XLasers X XLoud noises X XExcessive vibration X XIndustrial pollution X XSand/dust X XDepleted uranium X XDays wear MOPPS over 

garments

X

Times put on gas mask because 

of alerts and not because of exercises

X

E

t

l

l

i

t 

X

TABLE 10-1

Continued
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251

Sand/dust X XDepleted uranium X XDays wear MOPPS over 

garments

X

Times put on gas mask because 

of alerts and not because of exercises

X

Ever enter or closely inspect 

any destroyed military vehicles

X

Exposed to chemical, 

biological, or radiological warfare agents during deployment

X

a Non-routine medical surveillance and exposure data are event driven.b Includes chronic cough, runny nose, fever, weakness, headaches, swollen, stiff or painful joints, back pain, muscle aches, numbness or tingling in hands or feet, skin diseases or rashes, redness of eyes with tearing, dimming of vision, chest pain or pressfainting, lightheadedness, difficulty breathing, still feeling tired after sleeping, difficulty remembering, diarrhea, frequent indigestion, vomiting, ringing of the ears.c This information is used to develop a conceptual site model and may be summarized into a preliminary hazard assessment; SOURCE: ASTM, 2003.SOURCE: For medical surveillance data: Personal communication, Col. K. Cox and C. Postlewaite, Department of Defense, November 1, 2006; DoD Form 2808 “Report of Medical Examination”; DoD Form 2795 “Predeployment Health Assessment Form”; DoD Form 2796 “Post-­Deployment Health Assessment Form”; DoD Form 2900 “Post Deployment Health Reassessment Form”; DoD Form 2697 “Separation and Retirement Medical Assessment.” For exposure data: ASTM, 2003; DoD Form 2796 “Post Deployment Health Assessment Form”; DoD Form 2900 “Post Deployment Health Reassessment Form.”
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252 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

retirement evaluation of a career Service member was optional, this has 

become mandatory since 2005 (Personal communication, Col. K. Cox 

and C. Postlewaite, Department of Defense, November 1, 2006). The final 

assessment is performed to document any history of a “limiting” condition. This is determined by a medical evaluation board and may describe 

the need for “alternative duty” in subsequent employment because of a 

disability suffered while in the service. The determination of this board 

addresses the service connectedness of a condition that a Service member 

may have and thus that Service member’s eligibility for VA services. 

Nonroutine Health Assessments

Event-driven assessments Health evaluations are also performed in the 

event of acute health problems or worsening of preexisting conditions. 

These are focused evaluations that address the specific concern at hand.

Deployment-specific health assessments The predeployment assessment 

occurs within 60 days of deployment and builds on the PHA. This brief 

evaluation focuses on interval changes since the most recent PHA, highlighting medications used and any limited duty or short-term disability 

given. A serum sample is archived and any theater-specific or occupationspecific testing is performed. An HIV test is required if none has been done 

in the previous 12 months. For deployments lasting less than 30 days, the 

predeployment assessment is optional as determined by the deployment 

health authority. Combatant command determines whether additional specific tests will be required, such as cholinesterase levels if deployed into pest 

management activities or zones, or G6PD enzyme levels. Although not all 

Service members undergo this assessment, at least 90 percent do (Personal 

communication, Col. K. Cox and C. Postlewaite, Department of Defense, 

November 1, 2006).

During deployment there are no generic health assessments. Evaluations are triggered by specific exposures or events, and there may be 

theater-specific assessments. Also, follow-up may be indicated when environmental sampling suggests a hazard, such as poor water quality. Patientencounter data are often in electronic format and are captured by the 

Armed Forces Health Longitudinal Technology Application (AHLTA); sites 

that are currently not using an electronic data record are planned to have 

their data entered in the future. Depending on the circumstance, exposures 

to documented excursions of ambient air, water, or soil concentrations, are 

also theoretically entered into individual records. Under a new requirement, environmental summaries for all permanent and semi-permanent 

base camps will be generated according to time and location (Personal 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 253

communication, Col. K. Cox and C. Postlewaite, Department of Defense, 

November 1, 2006).

Postdeployment evaluations must occur within 30 days of reployment, although most take place before actually leaving the deployment 

arena, or while in transit from theater. This evaluation uses a self-reported 

questionnaire, but also includes a personal interview with a care provider 

who determines the need for further follow-up. A serum sample is typically 

obtained when a Service member is at “home.” There is documentation of 

environmental and occupational exposures. Rosters of specific exposure- or 

event-defined cohorts are assembled based on professional judgment; these 

are used for purposes of health follow-up or risk communication. Examples 

include lung function testing following sulfur dioxide exposures or followup of those exposed to depleted uranium (Personal communication, Col. 

K. Cox and C. Postlewaite, Department of Defense, November 1, 2006). 

Though the impact of combat related stressors on mental health may be significant, structured assessments on symptoms related to emotional stressors, 

depression, anxiety, posttraumatic stress disorder, and interpersonal difficulties, including hurting someone or losing control, are brief and only 

assessed at postdeployment period.

HEALTH DATABASES

The above-described assessments generate data that are stored in 

several databases or formats, thus requiring record linkage, and data entry, 

for analysis. One primary database is the Defense Medical Surveillance 

System (DMSS). The DMSS is a relational database that currently contains 

up-to-date Service member data for all in- and out-patient in-garrison 

health encounters including acute health events and exposures. It currently 

has some in-theater encounters provided by AHLTA, but not all. As noted 

above, HART-A is only now being implemented, so much of the accession 

evaluation is only present in hard copy form. Also, while standardization 

is the goal, data collection is not completely standardized across the service 

branches. AHLTA is the new DoD automated medical records system and 

clinical data repository; this includes all laboratory data and electronic 

PHAs. Integration of medical records is clearly a goal in DoD. This is 

manifested in the current process of establishing an Armed Forces Health 

Surveillance Center to integrate DMSS, AHLTA, and personnel data (from 

the Defense Manpower Data Center). Although much of the surveillance 

health data present in the DMSS are relevant to AHLTA (for example, 

reportable medical conditions), there is no need for complete overlap (Personal communication, Col. K. Cox and C. Postlewaite, Department of 

Defense, November 1, 2006). 
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254 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Troop Tracking and Linking of Individual Exposure and Health Data

Improvements in tracking of troop location are underway, reflecting in part an awareness of the need to perform troop tracking to allow 

reconstruction of exposure scenarios. A new tracking software, the Defense 

Theater Accountability Software, which is in limited use, currently requires 

data entry by hand at the unit level. The Defense Manpower Data Center 

can currently query records in the DMSS. There is no capability to resolve 

location within a 24-hour period, as only one 24-hour entry is currently 

used (Personal communication, Col. K. Cox and C. Postlewaite, Department of Defense, November 1, 2006). 

The need to link exposure data with health outcomes is appreciated, 

but this capability is currently not fully developed. The current situation 

is driving efforts to construct environmental monitoring summaries for 

various theaters and locales, and to assign surveillance exposure data to 

individual health records.

DOD EXPOSURE ASSESSMENT

Overview

Occupational and environmental exposures occur throughout the span 

of a Service member’s service career. In summarizing the exposure assessments needed to cover that experience, we can use the same milestones 

as were used to describe health assessments. They begin with exposure 

opportunities in the first months of service immediately following service 

entry and also proceed in a longitudinal manner through routine garrison 

experiences through multiple deployments and on through separation or 

retirement (see Figure 10-1). 

Exposure Assessments Throughout the Span of Service

Exposure assessment elements collected for each milestone of the Service 

member’s span of service are summarized in Table 10-1 and may include 

qualitative exposure judgments, occupational exposure monitoring, and 

environmental monitoring results. As in the case of health assessments, the 

degree of detail and areas of emphasis vary based on the specific point in the 

span of service or a specialized reason for the assessment. Data are collected 

in a combination of written and electronic formats, but there is significant 

activity moving DoD toward fully integrated electronic records.

Exposure assessments are made so that appropriate exposure controls 

can be planned and implemented. In the case of routine operations or 

low-risk combat scenarios the implementation of these controls is straight-
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 255

forward. Under high-risk combat scenarios, however, it may be difficult 

or impossible to consistently implement controls for environmental agents 

as the risks posed by implementing those controls under severe combat 

conditions may be higher than those posed by the exposures. In each case, 

however, there is a need to characterize and document exposures to agents 

from occupational and environmental sources.

Nondeployment Military Bases

The individual services within DoD have had traditional industrial 

hygiene and environmental health programs in place for many years in 

military base or installation settings. These programs conduct occupational 

and environmental exposure risk assessments for routine and nonroutine 

operations and document results in a variety of service-specific paper and 

electronic data repositories. 

Predeployment

In support of deployment occupational environmental health and safety 

(OEHS) measures for information/intelligence preparation of the environment, a phase I deployment OEHS assessment is produced for military 

location(s) of interest that assesses known and/or potential deployment 

OEH hazards and threats ranging from industrial chemicals, historical 

contamination, radiation, infectious disease, entomological risks, weapons 

of mass destruction, and specified intelligence based threats. These assessments are quantitative and also identify any preventive medicine measures 

and counter-measures and deployment OEH surveillance activities to ensure 

force health protection measures for deployments. For deployments less 

than 30 days, some of these activities are performed at the discretion of the 

operational commander as it is recognized that for special operations and 

very short deployments they may not all be feasible (DoD, 2006c).

Deployment

OEHS site assessments, exposure assessments, environmental monitoring, exposure incident response (and reports), and daily individual troop 

locations as determined by global positioning system (GPS) or other means 

are performed during deployment (see Figure 10-2) (DoD, 2006c). The 

content and detail included in these assessments vary depending on the 

length of deployment, the location of deployment, the intensity of combat 

operations, the number of deployed personnel, and the training of deployed 

personnel (DoDI 6490.03 2006 [DoD, 2006c]).
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256 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Baseline

Environmental

Risk Assessment

Routine and

Incident-specific

Occ/Environ

Monitoring

Pre-deployment

Health Assessment

Medical

Surveillance

DNBI*

Post-deployment

Health

Assessments

Pre-deployment

Readiness

Indicators

Preventive Medicine/

Health & Wellness

Programs

Post-deployment

Health Clinical

Practice Guidelines

Follow-up and

Routine Medical

Care/Med

Surveillance

During

Deployments

In Garrison 

Accession 

Separation/

Retirement 

FIGURE 10-2

Arrows redrawn

figure reduced to final size

FIGURE 10-2 DoD’s deployment health surveillance elements.

*DNBI (disease and nonbattle injury).

SOURCE: Adapted from Postlewaite, 2006.

Postdeployment

Postdeployment assessment activities primarily involve data and report 

cleanup and submission for central documentation—including documentation of health and exposure data and incidents in individual health 

records.

EXPOSURE DATABASES

Service Specific

The Army and Navy maintain collected exposure data at their respective occupational health and preventive medicine headquarters, the U.S. 

Army Center for Health Promotion and Preventive Medicine and the Navy 

Environmental Health Center respectively. The Air Force retains its data at 

each individual Air Force base (Table 10-2). Although the Army and Navy 

have a central headquarters database maintenance system, they also have 

individual activity databases for exposure data. These individual activity 

databases are rolled into the headquarters system but are also maintained at 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 257

TABLE 10-2 Service-Specific Databases for Exposure 

Service Database

Data 

Maintenance

Health 

Hazard 

Inventory 

Database

Quantitative 

Exposure 

Data

Deployment 

Exposure 

Data

In-Garrison 

Data

Army HHIM CHPPM HHIM Yes No Yes

Army DESS USACHPPM DESS Yes Yes No

Navy IHIMS NEHC NOED Yes Yes Yes

Air Force CCS AF Bases AF-EMIS/

HMMS

Yes No* Yes

NOTE: Table conveys the service-specific databases available and where the data are stored. 

ABBREVIATIONS: AF-EMIS = Air Force Environmental Management Information System; 

CCS = Command Core System; CHPPM = U.S. Army Center for Health Promotion and 

Preventive Medicine; DESS = Deployment Environmental Surveillance System; HHIM = 

Health Hazard Information Module; HMMS = Hazardous Material Management System; 

IHIMS = Industrial Hygiene Information Management System; NEHC = Navy Environmental 

Health Center; NOED = Navy Occupational Exposure Database. 

*Some deployment exposure data are currently stored in the Air Force’s Global Expeditionary 

Medical System (GEMS).

SOURCE: Adapted from DoD, 2006a.

the respective individual activities. All data will eventually be consolidated 

into the DOEHRS program, but individual activity data are also retained at 

the respective individual sites. Services have indicated that they will retain 

some of their legacy systems after inclusion of data into DOEHRS. Industrial hygiene exposure data consolidation into DOEHRS is expected to be 

completed by 2010 with all exposure data entry completed by 2013. 

DOEHRS—DEFENSE OCCUPATIONAL AND ENVIRONMENTAL 

HEALTH READINESS SYSTEM

Overview

DOEHRS is an automated information system designed to replace existing service-specific database collection and storage systems. It supports reduction in redundant data entry between worksites and occupational health 

clinics. DOEHRS also eliminates redundant exposure data collection through 

interfaces with clinical, environmental, safety, and personnel automated information systems. The DOEHRS structure is outlined in Figure 10-3. 
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258 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

FIGURE 10-3

• DOEHRS – IH

 Industrial Hygiene

 (Garrison)

• DOEHRS – Theater

 • IH/Occupational Health

 • Environmental Health

 • Surveys

 • Sampling

 • Personnel

 • DOEHRS Data Library

• Hearing Conservation

DOEHRS 

DOEHRS – IH

(OH Garrison)

DOEHRS – T

(Theater)

DOEHRS – OH (Occ Health)

(DOEHRS – IH Garrison)

DOEHRS – EH (Envir Health)

DOEHRS Data Library

Hearing Conservation

FIGURE 10-3 National Defense Occupational and Environmental Health Readiness System (DOEHRS).

SOURCE: Adapted from Heller, 2006. 

According to the DOEHRS student guide,

The Industrial Hygiene module of DOEHRS, DOEHRS [sic] is a key 

enabling technology within the presidentially mandated FHP and is further supported by Public Law 105-85. DOEHRS is a comprehensive, 

automated information system for assembling, comparing, using, evaluating, and storing occupational personnel exposure information, workplace 

environmental monitoring data, personal protective equipment usage data, 

observa­tion of work practices data, and employee health hazard educational data. DOEHRS provides information needed by occupational health 

staff and command surgeons for reporting options to commanders regarding the reduction of health threats. (DoD, 2006b, ch. 1, p. 2)

DOEHRS supports the prevention of illness and injury in DoD military 

members and civilian employees from exposure to chemical, biological, or 

physical hazards. Exposures can occur throughout the continuum of military operations, such as industrial maintenance facilities, administrative 

offices, hospitals, aboard ship, while operating weapon systems in training 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 259

exercises, and while deployed in war fighting or other military operations. 

DOEHRS prevents illness by identifying potential health hazards; providing and documenting exposures and provides recommendations to commanders, supervisors, and personnel to minimize adverse health effects; 

and monitoring effectiveness of procedures followed. Interface with other 

DOEHRS occupational health programs provides medical surveillance for 

early identification of exposure, treatment, rehabilitation, and follow-up to 

ensure that no repeated illnesses occur. (DoD, 2006b, ch. 1, p. 3)

DOEHRS maintains longitudinal exposure records for individual workers 

in DoD. Longitudinal exposure records contain a history of predeployment, 

deployment, and postdeployment exposure. These records provide a baseline to facilitate postdeployment follow-up. (DoD, 2006b, ch. 1, p. 2) 

DOEHRS is scheduled to interface with each service’s hazardous material tracking system and laboratory information management systems. 

DOEHRS is the occupational medicine answer for DoD’s medical records 

system (AHLTA). . . . DOEHRS will be deployed on a Defense Information 

Systems Agency (DISA) platform in the DISA Defense Enterprise Computing Center Detachment in San Antonio, Texas to support the Army, Navy, 

Coast Guard, and other agencies. (DoD, 2006b, ch. 1, p. 3)

Initial implementation of this system includes the DOEHRS industrial hygiene module, which supports the DoD industrial hygiene exposure 

assessment model based on the American Industrial Hygiene Association’s 

“Strategy for Assessing and Managing Occupational Exposures,” a stateof-the-art approach developed through consensus of government, industry, 

and academic industrial hygienists (DoD, 2006b). The approach is applicable to assessing and managing occupational and environmental exposures 

associated with routine and nonroutine operations that may be encountered 

in-garrison and during deployment. Core to the approach is the appropriate 

grouping of individuals into similar exposure groups and the characterization, assessment, and control of exposures common to individuals in those 

groups (DoD, 2006b).

DOEHRS Implementation and Continuous Improvement

DODI 6490.3 (DoD, 1997, p. 9) set the original intent to integrate 

exposure records with medical records. DODI 6490.03 (DoD, 2006c, p. 28) 

directed that exposure data records will be integrated into individual medical records and commits DoD to accomplish the integration. DoD personnel 

acknowledge that this integration will be a continuous improvement effort 

as functionalities of DOEHRS are developed (Personal communication, 

C. Postlewaite et al., Department of Defense, November 21, 2006). 
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260 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

The current version of DOEHRS, version 1.0.5.0, includes the first 

iterations of the industrial hygiene and theater-focused environmental 

health sample management capabilities. Many additional requirements 

were addressed in the DoD planning and programming budget for fiscal 

year (FY) 2013 (POM 2008-2013). 

Because DOEHRS is a platform information system for all services, DODI 

6490.03 specified how integration would occur and provided standardized 

definitions and exclusions for compliance. Recording exposures occurring 

during deployment is a crucial part of the database with deployment defined 

here as “[t]he relocation of forces and materiel to desired operational areas. 

Deployment encompasses all activities from origin or home station through 

destination, specifically including intracontinental United States, intertheater, 

and intratheater movement legs, staging, and holding areas” (DoD, 2006c, 

p. 2). This definition allows for home station (in-­garrison) delineation of 

exposure data distinct from deployment data. The use of the term deployment for the Navy has different connotations and consequently this instruction addresses that issue: “[s]hipboard operations that are not anticipated to 

involve operations ashore are exempt from the requirements of this instruction except for recording individual daily deployment locations or when 

potential health threats indicate actions necessary beyond the scope of shipboard occupational health programs or per the decision of the commander 

exercising operational control” (DoD, 2006c, p. 2). 

DOEHRS Current Functionality

DOEHRS is being implemented step-by-step, phasing in each of its 

functional elements. The hearing conservation portion of DOEHRS has 

been functional since 1997, as directed by the DoD Instruction 6490.3. 

(DoD, 1997). Some industrial hygiene exposure data have been collected 

and entered into the system through the DoD Industrial Hygiene Exposure Assessment Model released in January 2000 (DoD Industrial Hygiene 

Working Group, 2000). The Navy and Air Force plan to fully implement 

the industrial hygiene (in-garrison) function by the end of FY 2008. This 

implementation includes the downloading of currently stored exposure data 

as applicable. The use of the DOEHRS industrial hygiene functionality for 

currently collected exposure data will be deployed to all Army installations by March 2007. While deployment data are currently being collected 

and archived, the deployment exposure data function has not been fully 

developed or implemented. The Army serves as the DoD lead for deployment occupational and environmental health surveillance data archives 

(DODI 6490.03, 2006; CJCS Memorandum MCM-0006-02, 2002, under 

revision). This deployment data with DOEHRS is expected to be fully completed and online in FY 2010 (POM 2008-2013). 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 261

As set out in the DoD POM 2008-2013 for DOEHRS, all anticipated requirements and functionalities for the project have been addressed. 

Funding support is anticipated on a fiscal year basis with new functionalities being developed and implemented on the same fiscal year basis. If 

fully funded as anticipated, all DOEHRS functionalities will be completed 

and online by the end of FY 2013. As presented by DoD representatives 

(Postlewaite, 2006; Personal communication, C. Postlewaite et al., Department of Defense, and reiterated during the teleconference on November 21, 

2006), DOEHRS has full funding support by DoD, and DoD is fully committed to DOEHRS full implementation and triservice functioning by the 

end of FY 2013.

DOEHRS Effectiveness

As proposed and defined, DOEHRS will be a highly effective system for 

coordinating collected exposure data from both home station (in-garrison) 

and deployment locales. Combining the Service member’s medical records 

with the consolidated environmental monitoring and personal exposure 

data in DOEHRS is key to enabling VA to provide necessary health care 

to these future veterans. A major problem encountered in the current VA 

health-care provision system is a lack of exposure data. The DOEHRS 

program has the potential to alleviate this lack of data. However, the data 

must be provided to VA to be of any use. Currently, there is no avenue to 

transfer these data from DoD to VA. This avenue of data transference must 

be developed and supported by both DoD and VA for DOEHRS to fully 

benefit the veteran. An agency-to-agency coordinating board between DoD 

and VA would be a starting point. VA is at a distinct disadvantage if it must 

consistently request the data from DoD. 

One barrier to implementation of this system of shared exposure data 

is the concern that sharing some of these data may compromise the secrecy 

of troop locations or other combat-specific or national security issues. 

Although DoD classification for security purposes must be considered, 

there remains a need to work through this challenge for the benefit of the 

veteran. Although secrecy is a necessary requirement for the protection of 

Service members during conflict, a rapid declassification of the collected 

exposure data is also necessary to provide health care to Service members 

when needed. Furthermore, if exposure studies are conducted involving 

secrecy classification, VA must make their health-care providers aware of 

the possible adverse health effects so that presenting veterans can be properly treated. 

DOEHRS, as envisioned, is a project that can greatly benefit DoD and 

VA when used effectively and competently by both agencies. Full funding 

to complete development and implementation of DOEHRS is necessary to 
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262 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

provide and deliver to VA the exposure data needed for the provision of 

health care for our nation’s veterans.

USE OF HEALTH AND EXPOSURE DATA BY VA

Veteran Care and Disability Support

Overview

The Veterans Health Administration (VHA) is the largest of the three 

operational administrations of VA and comprises more than 200,000 

employees who provide medical, surgical, and rehabilitative care via a 

system of over 150 hospitals and 1,000 outpatient clinics nationwide. Close 

to 8 million veterans were enrolled in the VA hospital system in 2005; of 

those, more than 5.3 million sought and received care (VA, 2006a, pp. 2, 

3, 6).

The vast majority of care provided by VHA is through its network of 

outpatient clinics, which registered more than 57 million visits in 2005. 

Close to 600,000 inpatients were also treated in hospitals (VA, 2006a, 

p. 2).

Eligibility 

Eligibility for VHA care has been codified into an elaborate hierarchy 

of eight levels with the first level being the highest priority for care. In this 

level are veterans with service-connected disabilities rated 50 per­cent or 

more or veterans determined by VA to be unemployable due to serviceconnected conditions (VA, 2007a, p. 2). Lower priority levels of eligibility 

for VHA care are a function of degree of service-connected disability and 

income. Importantly, by FY 2005, it was estimated that close to 80 percent 

of all disabled and low-income veterans had enrolled with VHA for care, 

and 65 percent sought care and were treated (VA, 2006a, pp. 2-3).

It is also important to note that while incurring a disability during 

military service is one pathway to eligibility for VA care, the care provided 

is not limited to that required for the qualifying disability, but rather, that 

needed for the total care the veteran requires. Following entry into the 

VA health-care system, a veteran may request an appointment with a primary care physician who can conduct a comprehensive assessment of the 

veteran’s health-care needs.. For veterans in the first level of eligibility, the 

wait time for this initial appointment is supposed to be less than 30 days 

(VA, 2007d).
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 263

Military Service and Special Eligibility for VA Health Care

On the application form for health benefits required for entry into 

the VA health-care system, veterans record their service branch, dates of 

service, and type of discharge. Veterans are also queried about history of 

injury (Purple Heart awarded), presence of a service-connected disability, 

percentage of impairment, and a host of questions on specialized exposure 

opportunities including Agent Orange, radiation, and presence of illness 

from Gulf War service or spinal cord injury (VA, 2005b).

Seamless Transition

There has been an increased effort on the part of VA to publicize to 

Service members who are preparing for discharge their eligibility for VA 

benefits and health care (VA, 2007b). This is true for both those who have 

not incurred a service-related disability and those who have. A network 

of field-based VA employees has been sent to the larger military transfer 

facilities to act as onsite liaisons and offer counseling on benefit eligibility 

to Service members. Currently, under the seamless transition effort, VA 

has employees staffed at Landstuhl, Germany, and major military transfer 

facilities, such as Walter Reed and Eisenhower medical centers. These VA 

employees assist with disability claims and Service members’ transfer to 

enrollment in the VA system. The VA Secretary also notifies every new 

veteran by mail of his or her potential eligibility. There is also an attempt, 

again in the field, when large groups of Service members are separating, 

to have onsite VA counselors on hand to help with the transition. However, the “seamless transition” appears to be more about communicating 

eligibility for care and benefits than about the transfer of medical and 

exposure records. With the exception of Service members who are being 

discharged from a military transfer facility to a local VA facility with significant residuals of traumatic injuries, the likelihood that a Service member’s 

medical record, much less an exposure record (if one existed), seamlessly 

passes from DoD to the VA health-care system is remote at best. 

Seamless Transfer of DoD Data to VA

The medical records system of the DoD (AHLTA) does not interface 

easily with VA’s (VISTA) systems. Some transfer to VA of both physical 

and electronic records takes place, but this is generally on a case-by-case 

basis.

The reports from medical evaluation boards dealing with a Service 

member’s health conditions that render him or her unfit for regular duty 

or requiring restricted duty (e.g., asthma, insulin-dependent diabetes) are 
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264 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

currently relatively crude, impairing their usefulness for decision making 

regarding service connectedness for VA care. This directly affects the ability 

of VA to determine care and benefit eligibility assessments and disability 

evaluations. A postdeployment electronic form—the Health Assessment 

Form—is under development and uses the Federal Health Information 

Exchange to transfer information in one direction, between DoD and VA. 

The plan is to use the Federal Health Information Exchange (FHIE) to 

allow two-way data transfer (Do, 2006), though currently it provides only 

for unidirectional flow of information from DoD to VA. The plan is for the 

FHIE to evolve into the Clinical Health Data Repository (CHDR).

EPIDEMIOLOGIC STUDIES OF VETERANS

Introduction

Epidemiologic studies on the adverse health effects of military service 

in veterans have covered exposures that have occurred in essentially every 

war in which U.S. Service members have been deployed, beginning with 

World War I. Although the largest group of these studies has been carried 

out in some fashion through VA, some have been supported through the 

National Institutes of Health (NIH), the Centers for Disease Control and 

Prevention (CDC), and other funding organizations. In this section, we 

review the breadth of these studies with a view to understanding the sources 

of data and the sources of funding. In this way, it is hoped that insights can 

be gained that might recommend preferred, or even alternative, approaches 

to carrying out epidemiologic studies on the health of veterans to inform the 

compensation and disability decision-making process. It is not the primary 

purpose of this chapter to review these studies with a view to assessing the 

validity of their findings. 

VA has carried out and been involved in many epidemiologic studies 

addressing the health of veterans. Here we provide an overview of studies 

that specifically deal with veterans’ health in relation to actual or suspected 

exposures that occurred while they were serving in the U.S. military. 

Department of Veterans Affairs Epidemiologic Studies

Veterans Health Administration (VHA) Studies

The VHA funds research studies through its Office of Research and 

Development. A broad range of health-related studies is supported, including clinical, basic science, and epidemiologic studies. Epidemiologic studies 

include those on the effects of wartime exposures on veterans’ health, 

including studies on recently returning Service members. For example, in 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 265

2005 the Office of Research and Development announced an invitation for 

research proposals on combat casualty neurotrauma (VA, 2005a), and in 

2006 it announced an invitation for research proposals on health studies of 

veterans returning from Afghanistan and Iraq (VA, 2006b). Other research 

surveillance activities sponsored by VA include the establishment of several 

registries. In 2003, the Office of Research and Development created a 

national registry of veterans with amyotrophic lateral sclerosis to track the 

health status of veterans with the disease and help recruit research participants (VA, 2003). Strategic planning for VHA-funded research is carried 

out by the Field Research Advisory Committee. 

Two centers for the study of war-related illnesses were established in 

VA medical centers in 2001, one in Washington, D.C., and one in East 

Orange, New Jersey. Initially known as the Centers for the Study of WarRelated Illnesses, these were subsequently renamed the War-Related Illness 

and Injury Study Centers (WRIISC). Both have clinical and research responsibilities (VA, 2006c). 

The largest and undoubtedly the most substantial body of research 

on health effects of returned veterans has been carried out by Dr. Han K. 

Kang and his colleagues at the Environmental Epidemiology Service at the 

VHA in Washington, D.C., which is now part of the Washington, D.C., 

WRIISC. Dr. Kang has carried out studies of veterans in the following 

broad areas: mustard gas exposure, prisoners of war, radiation exposure, 

Vietnam veterans, Gulf War veterans, and women veterans. A bibliography 

of Dr. Kang’s epidemiologic studies is included in Appendix K-1, organized 

by these subject areas.

Twin Registry Studies 

In 1958, the Medical Follow-Up Agency, with funding by NIH and VA, 

began a project to identify white male twin pairs who had been in military 

service during World War II (The National Academy of Sciences [NAS]/

National Research Council [NRC] Twin Registry of WWII Military Veteran 

Twins [SOURCE: http://www.iom.edu/CMS/3795/4907.aspx]). Using state 

birth records, searches were made by hand against VA files to determine 

veteran status. Eventually, nearly 16,000 twin pairs were identified. Baseline 

data were abstracted from VA and military records and a baseline questionnaire was mailed to the twin pairs. Anthropometric and fingerprint data 

were used to determine zygosity (IOM, 2004b).

A bibliography of research studies based on this NAS/NRC twin 

registry can be found at http://www.iom.edu/CMS/3795/4907/17038.aspx. 

A total of 308 published research studies and 7 research reports are based 

on this registry.
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266 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

The Vietnam Era Twin (VET) Registry The VET registry was created by 

VA in the mid-1980s in response to concerns regarding the health effects 

specifically of exposure to Agent Orange (Goldberg et al., 2002). The registry was built using DoD computerized records and consists of 7,369 malemale twin pairs born between 1939 and 1957, who served from 1965 to 

1975 (VA, 2007e). It is now housed in the Seattle Epidemiological Research 

and Information Center, a joint venture of the Department of Epidemiology 

at the University of Washington’s School of Public Health and Community 

Medicine and VA (VA, 2007c). Approximately half of the twins are monozygotic, and half are dizygotic (Henderson et al., 1990). Table 10-3 details 

the research studies that have been completed using the VET registry, or 

are currently underway.

National Academies’ Monographs on Veterans’ Health by Theater or 

Exposure

The National Academies has produced a large number of monographs 

on veterans’ health dealing with exposures during military service dating 

back to WWI (Table 10-4). These provide useful summaries, assessments, 

and updates of scientific findings based on studies completed before the 

publication of each monograph. It is evident that the more recent the exposure, the larger the number of monographs devoted to it.

Non-VA Epidemiologic Studies of Veterans’ Health

The Millennium Cohort Study

The Millennium Cohort Study is the largest prospective study of military personnel ever conducted. Sponsored by DoD, and recommended by 

the IOM Committee on Measuring the Health of Gulf War Veterans (IOM, 

1999a, p. 6), the study was initiated in 2001 to evaluate the long-term health 

effects of military service, particularly operational deployment. More than 

110,000 people are enrolled currently, and a total of 140,000 are expected 

to be enrolled by the end of study recruitment in 2007. Study participants 

will complete a paper or Web-based questionnaire assessing demographics, 

medical conditions and symptoms, and health-related behaviors once every 

3 years until 2022. Survey data will be linked with data from other military 

databases on deployment, occupation, vaccinations, health-care utilization, 

and disability. It is hoped that the cohort data will serve as a foundation 

upon which additional epidemiologic studies of military personnel might 

develop, in addition to revealing trends in veterans’ health over time (Gray 

et al., 2002; The Millennium Cohort Study, 2007). 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 267

TABLE 10-3 Summary of VET Registry Projects

Study Name

Method of 

Recruitment

Recruitment 

Period

Number of 

Participants

Twin 

Pairs

Registry construction

Military Records Record abstracts 1983-1986 14,750 7,375

Studies of the full registry

Survey of Health Mail/telephone 

follow-up

1987 10,979 4,774

NHLBI VET Study of 

Cardiovascular Disease

Mail/telephone

follow-up

1990 8,169 3,698

Harvard Twin Study of Drug 

Abuse and Dependence

Telephone 1991-1993 10,979 3,698

Male Health Survey Mail 1999 5,349 1,615

Studies of selected twins

Impulsivity and aggression Mail/telephone

follow-up

1992 796 314

Consequences of drug abuse In-person 1995-1996 254 127

Alcohol and health services use Telephone 1995 2,936

Biologic markers for 

posttraumatic stress disorder 

(PTSD)

In-person

Telephone

1995-1998

1995-1996

322

2,003

161

322

Alcohol vulnerability In-person 1997-1999 760 380

PTSD Sleep study In-person

Telephone

Ongoing 11/22

207/248

9

248

Twin-family study of health 

behaviors

Telephone and

mail

Ongoing 533 214

PTSD MRI study 1 In-person Ongoing 48 45

PTSD MRI study 2 In-person Ongoing 52

New studies of selected

twins pathological gambling

Spirituality and PTSD Mail Newly

funded 

2006

510 255

Cardiovascular disease and 

depression

Mail Newly

funded 

2006

320 160

Twins as parents Telephone and 

mail

Newly

funded 

2006

1,060 530

SOURCE: Adapted from VA, 2007c.
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268 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 10-4 National Academies’ and VA Medical Monographs on 

Veterans’ Health by Theater or Exposure

Mustard gas 

exposure

IOM. 1993. Veterans at risk: The health effects of mustard gas and 

lewisite.

Prisoners of 

war

VA Medical Monographs. 1954. A follow-up study of World War II 

prisoners of war (Cohen and Cooper, 1954).

IOM. 1992. The health of former prisoners of war: Results from the 

Medical Examination Survey of Former POWs of World War II and the 

Korean Conflict.

Other WWII VA Medical Monographs. 1955. Tuberculosis in the Army of the United 

States in World War II. (Long and Jablon, 1955).

VA Medical Monographs. 1961. A follow-up study of head wounds in 

World War II (Walker and Jablon, 1961).

Radiation 

exposure

NRC. 1985. Studies of participants in nuclear tests (Robinette et al., 1985).

IOM. 1995a. Adverse reproductive outcomes in families of atomic 

veterans: The feasibility of epidemiologic studies.

IOM. 1996b. Mortality of veteran participants in the CROSSROADS 

nuclear test.

Vietnam 

veterans

IOM. 1994. Veterans and Agent Orange: Health effects of herbicides used 

in Vietnam.

IOM. 1996b. Mortality of veteran participants in the CROSSROADS 

nuclear test.

IOM. 1997. Characterizing exposure of veterans to Agent Orange and 

other herbicides used in Vietnam: Scientific considerations regarding a 

request for proposals for research.

IOM. 1999c. Veterans and Agent Orange: Update 1998.

IOM. 2000d. Veterans and Agent Orange: Herbicide/dioxin exposure and 

type 2 diabetes. 

IOM. 2001b. Veterans and Agent Orange: Update 2000.

IOM. 2002. Veterans and Agent Orange: Herbicide/dioxin exposure and 

acute myelogenous leukemia in the children of Vietnam veterans.

IOM. 2003a. Characterizing exposure of veterans to Agent Orange and 

other herbicides used in Vietnam: Interim findings and recommendations.

IOM. 2003b. Characterizing exposure of veterans to Agent Orange and 

other herbicides used in Vietnam: Final report.

IOM. 2003d. Veterans and Agent Orange: Update 2002.

IOM. 2004c. Veterans and Agent Orange: Length of presumptive period 

for association between exposure and respiratory cancer. 

IOM. 2005b. Veterans and Agent Orange: Update 2004.
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 269

Gulf War 

veterans

IOM. 1995b. Health consequences of service during the Persian Gulf War: 

Initial findings and recommendations for immediate action.

IOM. 1996a. Health consequences of service during the Persian Gulf War: 

Recommendations for research and information systems.

IOM. 1998a. Adequacy of the VA Persian Gulf Registry and Uniform Case 

Assessment Protocol. 

IOM. 1998b. Measuring the health of Persian Gulf veterans: Workshop 

summary.

IOM. 1999a. Gulf War veterans: Measuring health.

IOM. 2000a. The five series study: Mortality of military participants in 

U.S. nuclear weapons tests.

IOM. 2000b. Gulf War and health, volume 1: Depleted uranium, 

pyridostigmine bromide, sarin, vaccines. 

IOM. 2001a. Gulf War veterans: Treating symptoms and syndromes.

IOM. 2003c. Gulf War and health, volume 2: Insecticide and solvents.

IOM. 2004a. Gulf War and health: Updated literature review of sarin.

IOM. 2005a. Gulf War and health, volume 3: Fuels, combustion products, 

and propellants. 

IOM. 2006. Gulf War and health, volume 4: Health effects of serving in 

the Gulf War.

IOM. 2007. Gulf War and health, volume 5: Infectious diseases.

TABLE 10-4 Continued

CDC-Funded Studies

The CDC and its National Center for Environmental Health has supported studies on veterans of Vietnam (SOURCE: http://www.cdc.gov/

nceh/veterans/default1.htm) and the Gulf War (SOURCE: http://www.cdc.

gov/nceh/veterans/default2.htm). Relating to Vietnam, CDC supported the 

following studies:

• Vietnam Experience Study 

• Postservice Mortality Among Vietnam Veterans Study 

• Agent Orange Validation Study 

• Selected Cancers Study

On the Gulf War, CDC funded the following studies: 

• Health Effects of Exposure to Smoke from Oil Well Fires

• Birth Defects 

• Air Force Study 

• Health Assessment of Gulf War Veterans from Iowa 

• Iowa Asthma Follow-Up Study

• Cognitive Function and Symptom Patterns in Gulf War Veterans 
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270 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

• Defining Gulf War Illness

• Epidemiologic Study of the Occurrence of Amyotrophic Lateral 

Sclerosis (ALS) among Gulf War Veterans 

• Deployment to the Gulf War and Subsequent Development of 

Cancer 

Of these CDC-funded studies, the Vietnam Experience Study was arguably the most influential. A random sample of 7,924 men who enlisted in 

the period from 1965 to 1971 and who served in Vietnam, and 7,364 nonVietnam veterans, were interviewed by telephone. Vietnam veterans reported 

more health problems than non-Vietnam veterans, including less fertility and 

more health problems in their children. An in-person, comprehensive health 

evaluation was done on a random subsample of 2,490 Vietnam veterans and 

1,972 non-Vietnam veterans. Although the vast majority of comparisons 

showed no differences, results of this examination showed more hearing 

loss, lower sperm concentrations, and more depression, anxiety, and PTSD 

in Vietnam veterans. Offspring of Vietnam veterans did not show increased 

birth defects (see Appendix K-3) (CDC VES, 1989).

NIH-Funded, Individual Investigator Studies 

The NIH has funded a large number of health studies involving veterans 

through its several research funding mechanisms, and has also collaborated 

with VHA and CDC in providing funding for research on veterans. Relatively few NIH studies focus on investigating the role of military exposures 

in disease. Many use a population sample of veterans to gain mechanistic 

insight into diseases affecting the general population. Others evaluate effectiveness of disease treatment. NIH-funded studies that are relevant to the 

assessment of military exposure effects are listed in Appendix K-4 by title 

and year funding was begun.

Observations and Recommendations on Epidemiologic Studies of Veterans

Clearly a large number of epidemiologic studies on health effects of 

military exposure in veterans have been completed over the years. Many 

continue to be performed, reflecting the ongoing military engagements in 

Iraq and Afghanistan. There has been a near-exponential increase in the 

number of completed health studies and IOM reports in relation to the 

proximity in time of the specific engagement. 

Although the scientific information on military exposures and subsequent health status is extensive, some exposures of concern remain 

inadequately studied or the relevant studies on these exposures have yielded 

findings that are inconclusive. It is acknowledged that there may be obsta-
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 271

cles to performing rigorous observational studies on the veteran population. 

Nevertheless, there are at least three other potential reasons for some of 

the inadequacy in the scientific information: (1) there has been no effective 

organized approach to setting research priorities; (2) exposure information 

and exposure metrics are relatively crude for most exposure-disease combinations of interest; and (3) there is no standardized, comprehensive, universal, and accessible source of information on veteran’s health outcomes. 

Two complementary options for improving the utility of this health 

research in strengthening the scientific foundations for veterans’ compensation are (1) establishing a body that is responsible for strategically managing 

the research agenda on veterans and military exposures, and (2) developing 

and maintaining a repository of research on veterans’ health to allow an 

overview of research supported by various funding agencies. Suggestions 

to facilitate carrying out these studies and to allow more rigorous study of 

exposure health effects center on exploiting the exposure and health information systems described above. This would require more centralized data 

storage and improved data access. 

VA REGISTRIES

Another public health surveillance tool that can be used to collect and 

organize health status data of a specific population is a registry. “A registry is an organized system for the collection, storage, retrieval, analysis, 

and dissemination of information on individual persons who have either 

a particular disease, a condition (e.g., a risk factor) that predisposes to 

the occurrence of a health-related event, or prior exposure to substances 

(or circumstances) known or suspected to cause adverse health effects” 

(SOURCE: From FAQ on Public Health Registries: www.ncvhs.hhs.gov/

9701138b.htm). 

Registry data offer a number of valuable uses in public health and 

medicine, “including estimating the magnitude of a problem,” “determining 

the incidence of disease,” “examining trends of disease over time,” “identifying groups at high-risk,” estimating health service needs, and “conducting research” (SOURCE: www.ncvhs.hhs.gov/9701138b.htm). For some 

groups of veterans, surveillance could be extended to intermediate markers, 

such as indicators of physiological functioning, so that adverse effects of 

exposures could be detected before the level of impairment became sufficient to produce a diagnosed disease. For example, in personnel exposed 

to respiratory hazards, lung function could be tracked over time to detect 

a rate of loss beyond that expected on the basis of aging alone.

Registries collect data on individuals who share certain characteristics, 

typically a specific disease or condition. This information includes demographic and medical information. Registries often seek validation of the 
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272 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

data by collecting detailed test results (such as a pathology report from a 

biopsy or a specific blood test result).

More recently, the registry concept has been applied to follow groups of 

people who do not share a common disease, but rather, a common exposure 

history. Examples here would include the National Exposure Registry operated by the Agency for Toxic Substances and Disease Registry (ATSDR), 

part of CDC. This registry identifies and enrolls persons likely to have been 

exposed to hazardous environmental toxicants, usually due to the location 

of the person’s residence near a contaminated Superfund site. The registry 

establishes a pool of persons, potentially at increased risk of health harm, 

and allows tracking of this group. This tracking enables subsequent contact of the registered persons by health authorities, who may offer health 

information, opportunities for study participation, or care recommendations. The course of the registrant’s health may also be followed over time 

through periodic surveys performed by the registry (ATSDR, 2003).

VA has used the public health registry concept to identify and track 

several different groups of veterans. It operates registries that are both 

disease based, such as the multiple sclerosis (MS) and amyotrophic lateral 

sclerosis (ALS) registries, and those that are exposure based, such as the 

Agent Orange and Gulf War registries (see Table 10-5). 

Summary of Important Findings and Recommendations

DoD and VA are clearly intent on improving the breadth, depth, and 

availability of health and exposure data. In addition, there are numerous 

examples of those data being used to better understand Service member 

and veteran health and its relationship to exposures. Suggestions follow 

for ensuring that the data improvements are fully realized and the data 

fully utilized in Service member–veteran disease prevention and treatment 

in well-conceived and coordinated surveillance and research efforts and 

in compensation adjudication and presumptive decision-making. Many of 

these recommendations are also found in the Committee’s overall recommendations in Chapter 13. The Committee presents these suggestions here 

to tie back into the specific lessons learned from an assessment of the military personnel’s and veterans’ health and exposure data infrastructure.

1. Ensure that DOEHRS is implemented as planned.

DOEHRS is a major undertaking that has potential for dramatically 

increasing the availability of exposure data. However, DoD has many 

important priorities and short-term funding pressures have the potential to 

delay implementation activities. Due to the importance of these efforts for 

both DoD and VA, we recommend that additional steps be taken to ensure 

that DOEHRS is fully implemented as planned. In addition, due to the 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 273

importance of adequately trained individuals to the success of DOEHRS, 

we further recommend that these steps specifically include detail on the 

training of individuals needed to make the accurate professional judgments 

and generate appropriate exposure data critical to DOEHRS. These additional steps are as follows:

1. Include a specific DoD budget line item for DOEHRS that includes 

funding for system development and enhancement, system implementation, 

and training of personnel.

2. Develop clear metrics for tracking the effective deployment and 

utiliza­tion of DOEHRS throughout DoD.

3. Require an annual status report to Congress on DOEHRS development and implementation progress and related training activities.

2. Improve the interface between the electronic health record data systems used by DoD and VA—including capabilities for handling indi­vidual 

exposure information that is included as part of a Service member’s 

health record.

While there are efforts underway to electronically transfer Service member health records from DoD to VA, these efforts are moving slowly and 

the timeline for completion of a seamless interface is unclear. DoD and VA 

should increase attention to this effort with a clear integration plan, timetable for implementation, metrics for tracking implementation progress, 

and annual reporting of metric results.

To date, there has been little discussion regarding the electronic transfer of Service member exposure information to VA. As the inclusion of 

exposure data in employee health records is a key DoD strategy for ensuring that exposure information is available for individual Service members, 

this seems a major disconnect. DoD and VA should explicitly include the 

integration of these individual exposure data into the health record transfer 

integration plan, implementation timetable, metrics, and annual reporting. 

Reports on progress of these plans should be included in the annual report 

to Congress on DOEHRS progress.

3. Develop an interface that allows the VA to access the electronic exposure 

data systems used by DoD.

DoD is investing heavily in DOEHRS and other improved exposure 

data systems that are standardized across the various armed services. In 

our interviews with people responsible for development and deployment 

of these systems we did not encounter anyone with knowledge of activities by DoD or VA to develop a VA interface with these systems that will 

allow use of the Service member-specific and longitudinal exposure data 

by VA.
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274 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 10-5 VA Health Registries 

Registry

Management

Purpose

Number of 

Veterans

Basis for 

Enrollment Source of Data

Type of 

Data Data Colle

Agent Orange 

Registrya

(Started in 1978)

Managed by the 

Environmental 

Agents Service 

To identify 

medical problems 

associated with 

Agent Orange 

exposure

408,811

400,849 men 

7,962 women

Service in 

Vietnam, 

Korea, or 

otherwise 

exposed

Dates, areas of 

service, possible 

Agent Orange 

exposure, birth 

defect data

Purely 

voluntary; 

data from 

Agent 

Orange 

Registry 

exams; 

veterans 

are well 

informed of 

the existence 

of registry 

exams

Demograp

Race/ethn

current mi

service in 

of last two 

Vietnam o

including 

occupation

alcohol, an

possible to

Medical h

Assessmen

examinati

are asked 

chest X ra

necessary)

comprehen

chemistrie

hepatitis C 

Exposure:

Exposure 

yes, not su

or sprayin

sprayed bu

exposed to 

Orange; d

Orange; a

been spray
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 275

of 

Data Collected Selected Publications from Registry

y 

tary; 

rom 

 

ge 

try 

s; 

ans 

ell 

med of 

xistence 

istry 

s

Demographics:

Race/ethnicity; martial status; gender; 

current military status; branch of service; 

service in either/or Vietnam or Korea; dates 

of last two periods of service if other than 

Vietnam or Korea; full medical history, 

including information about the family, 

occupation, social history noting tobacco, 

alcohol, and drug use; civilian exposure to 

possible toxic agents; psychosocial history 

Medical history:

Assessment of own health; date of registry 

examination; complaints/symptoms (coders 

are asked to enter ICD-9 codes on form); 

chest X ray (if determined to be medically 

necessary); complete blood count; 

comprehensive metabolic panel or blood 

chemistries and enzyme studies; urinalysis; 

hepatitis C screening

Exposure:

Exposure to Agent Orange (definitely 

yes, not sure, definitely no); handling 

or spraying Agent Orange; not directly 

sprayed but in a recently sprayed area; 

exposed to herbicides other than Agent 

Orange; directly sprayed with Agent 

Orange; ate food/drink that could have 

been sprayed with Agent Orange

Bullman TA, Kang HK. 1994. Posttraumatic 

stress disorder and the risk of traumatic 

deaths among Vietnam veterans. Journal of 

Nervous and Mental Disorder 182:604-610.

Bullman TA, Watanabe KK, Kang HK. 

1994. Risk of testicular cancer associated 

with surrogate measures of Agent Orange 

exposure among Vietnam veterans on 

the Agent Orange Registry. Annals of 

Epidemiology 4:11-16.

Bullman TA, Kang HK, Thomas TL. 

1991. Posttraumatic stress disorder among 

Vietnam veterans on the Agent Orange 

Registry: A case control analysis. Annals of 

Epidemiology 1:505-512.

continued
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276 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 10-5 Continued

Registry

Management

Purpose

Number of 

Veterans

Basis for 

Enrollment Source of Data

Type of 

Data Data Colle

Gulf War Registryb

(Started in 1992)

Managed by the 

Environmental 

Agents Service 

To identify 

medical problems 

associated with 

exposures in the 

Persian Gulf

97,002

87,074 men

9,928 women

Service in SW 

Asia (1990 to 

present)

Operation 

Enduring 

Freedom 

(OEF) 

veterans not 

included 

because 

they are in 

Afghanistan

Exposures 

of concern, 

combat 

experiences, 

birth defect 

data

Purely 

voluntary; 

data from 

Gulf War 

Registry 

exams

Demograp

Race/ethn

occupation

of service; 

area; date

of service

Medical h

Family his

history inc

use; civilia

toxic agen

service in 

military oc

last two p

Medical h

Psychosoc

complaint

to include 

of onset o

intensity; 

details of 

blood cou

tests; urin

sperm cou

medically 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 277

of 

Data Collected Selected Publications from Registry

y 

tary; 

rom 

War 

try 

s

Demographics:

Race/ethnicity; marital status; gender; 

occupation; current military status; branch 

of service; military service in Persian Gulf 

area; dates and MOS of last two periods 

of service

Medical history:

Family history; occupational history; social 

history including tobacco, alcohol, drug 

use; civilian exposure(s) history to possible 

toxic agent; psychosocial history; military 

service in Persian Gulf area; dates and 

military occupational specialty (MOS) of 

last two periods of service

Medical history:

Psychosocial conditions; review of systems; 

complaints and symptoms (coders asked 

to include ICD-9 codes on form); time 

of onset of the symptoms or conditions; 

intensity; degree of physical incapacitation; 

details of any treatment received; complete 

blood count; blood and serum screening 

tests; urinalysis; pulmonary function, 

sperm counts, or other diagnostic studies if 

medically indicated 

Miller R, Costigan, Young H, Kang H, 

Salager N, Crawford H, Page W, Thaul S. 

2006. Patterns of health care seeking of 

Persian Gulf War Registry members prior to 

deployment. Military Medicine 171:370-375.

Gray GC, Gackstetter GD, Kang HK, 

Graham JT, Scott KC. 2004. After more 

than 10 years of Gulf War veteran medical 

evaluation, what have we learned? American 

Journal of Preventive Medicine 26:443-452.

Hallman WK, Kipen HM, Diefenbach M, 

Boyd K, Kang H, Leventhal H, Wartenber 

D. 2003. American Journal of Public Health 

93:624-629.

Smith TC, Smith B, Ryan MA, Gray GC, 

Hooper TI, Heller JM, Dalager NA, Kang 

HK, Gackstetter GD. 2002. Ten years and 

100,000 participants later: Occupational 

and other factors influencing participation 

in US Gulf War health registries. Journal of 

Occupational and Environmental Medicine 

44:758-768.

Murphy FM, Kang HK, Dalager NA. 1999. 

The health status of Gulf War veterans: 

Lessons learned from the Department of 

Veterans Affairs health registry. Military Military

Medicine 164:327-331.

Kipen HM, Hallman W, Kang HK, et al. 

1999. Prevalence of chronic fatigue and Prevalence of chronic fatigue and 

chemical sensitivities in Gulf Registry 

veterans. Archives of Environmental Health 

54:313-318.

continued
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278 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 10-5 Continued

Registry

Management

Purpose

Number of 

Veterans

Basis for 

Enrollment Source of Data

Type of 

Data Data Colle

Gulf War Registry

(continued)

Exposure:

Exposure 

(smoking 

cigarettes, 

per day, ye

Gulf expo

fumes from 

(passive fr

petrochem

feces; skin 

agent-resis

solvent an

depleted u

pesticide u

agent

Ionizing Radiation 

Registryc

(Started in 1986)

Managed by the 

Environmental 

Agents Service 

To identify 

medical problems 

associated with 

ionizing radiation 

exposure

23,624

23,472 men

152 women

Set up for 

WWII and 

Cold War 

veterans

Service in 

Hiroshima 

and Nagasaki, 

gaseous 

diffusion 

plants, and 

area K25 

in United 

States; nuclear 

weapons 

testing

Receipt of 

nasopharyngeal 

treatment, 

birth defect 

data, diagnoses 

if possible 

radiogenicrelated diseases, 

disability claims

Purely 

voluntary; 

data from 

Ionizing 

Radiation 

Registry 

exams

Demograp

Family; oc

drug use

Medical H

Psychosoc

of the vete

intensity o

degree of 

of any trea

ray (if med

blood cou

and comp

equivalent 

studies; ur

ALS Registry

Managed by the 

Epidemiologic 

Research and 

Information Center 

in Durham, NC 

To identify and 

characterize 

veterans with ALS

1,602 Diagnoses of 

ALS within 

VA health-care 

system and 

self-referrals

Health-care 

utilization, 

ALS Functional 

Rating Scale 

every 6 months

Data from 

existing 

VA files 

and selfreferrals; a 

consecutive 

registry
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 279

of 

Data Collected Selected Publications from Registry

Exposure:

Exposure to environmental factors 

(smoking cigarettes, years of smoking 

cigarettes, number of packs smoked 

per day, years smoked); while in the 

Gulf exposure to smoke from oil fires, 

fumes from tent heaters, cigarette smoke 

(passive from others), diesel and/or other 

petrochemical fumes, and burning trash/

feces; skin exposure to diesel; chemical 

agent-resistant compounds; other paint or 

solvent and/or petrochemical substances; 

depleted uranium; microwaves; personal 

pesticide use; nerve gas or other nerve 

agent

Gray GC, Hawksworth AW, Smith TC, 

Kang HK, et al. 1998. Gulf War veterans’ 

health registries. Who is most likely to 

seek evaluation? American Journal of 

Epidemiology 148:343-349.

Blanck RR, Hiatt J, Hyams KC, Kang HK, 

et al. 1995. Unexplained illnesses among 

Desert Storm Veterans: A search for causes, 

treatment, and cooperation. Archives of 

Internal Medicine 155:262-268.

y 

tary; 

rom 

ng 

tion 

try 

s

Demographics:

Family; occupation; tobacco, alcohol, and 

drug use

Medical History: 

Psychosocial conditions; time of the onset 

of the veteran’s symptoms or conditions; 

intensity of symptoms or conditions; 

degree of physical incapacitation; details 

of any treatment received; chest X 

ray (if medically necessary), complete 

blood count; basic metabolic panel 

and comprehensive metabolic panel or 

equivalent blood chemistries and enzyme 

studies; urinalysis

from 

ng 

es 

elf

als; a 

cutive 

ry

Kasarkis EJ, Dominic K, Oddone EZ. 2004. 

The National Registry of Veterans with 

Amyotrophic Lateral Sclerosis: Department of 

Veterans Affairs Cooperative Studies Program 

(CSP). Amyotrophic Lateral Sclerosis & 

Other Motor Neuron Disorders 5(Supplement 

1):129-132. 

continued
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280 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 10-5 Continued

Registry

Management

Purpose

Number of 

Veterans

Basis for 

Enrollment Source of Data

Type of 

Data Data Colle

MS Registry

(Started in 1998)

Managed by the 

MS Center of 

Excellence East in 

Baltimore, MD, 

and the MS Center 

of Excellence 

West in Portland, 

OR, and Seattle, 

WA, to identify 

and characterize 

veterans with MS

31,946 Diagnoses of 

MS within the 

VA health-care 

system

Health-care 

utilization, 

health economic 

data

Data from 

existing 

VA files; a 

consecutive 

registry

Cancer Registry

(Started in 1995)

Managed by the 

Program Office 

for Oncology in 

Washington, DC 

To identify and 

characterize 

veterans with 

cancer, analysis of 

specific therapies 

and outcomes, and 

resource allocation

356,174 Diagnoses of 

cancer within 

the VA healthcare system

Possible 

cancer risk 

factors, cancer 

identification, 

prognosis 

factors, 

treatment data, 

follow-up, and 

recurrence

Compilation 

of cancer 

registries 

at each VA 

facility; a 

consecutive 

registry
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 281

of 

Data Collected Selected Publications from Registry

from 

ng 

es; a 

cutive 

ry

Culpepper WJ, Mhrmantraut M, Wallin MT, 

Flannery K, Bradham DD. 2006. Veteran 

Health Administration multiple sclerosis 

surveillance registry: The problem of casefinding from administrative databases. 

Journal of Rehabilitation Research and 

Development 43(1):17-24.

pilation 

ncer 

ries 

h VA 

y; a 

cutive 

ry

continued
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282 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 10-5 Continued

Registry

Management

Purpose

Number of 

Veterans

Basis for 

Enrollment Source of Data

Type of 

Data Data Colle

HIV Registry

(Started in 1983)

Managed by the 

Center for Quality 

Management in 

Public Health in 

Palo Alto, CA 

To track overall 

trends in HIVrelated outcomes, 

health-care 

utilization 

planning, quality 

improvement of 

care

54,000 Diagnoses of 

HIV within 

the VA healthcare system

Possible 

risk factors, 

lab results, 

pharmacy use

Data from 

existing 

VA files; a 

consecutive 

registry

Hepatitis C 

Registry

(Started in 1996)

Managed by the 

Center for Quality 

Management in 

Public Health in 

Palo Alto, CA 

To track overall 

trends in hepatitis 

C-related 

outcomes, healthcare utilization 

planning, quality 

improvement of 

care

253,160 Diagnoses of 

hepatitis C 

within the VA 

health-care 

system

Liver biopsy 

data, lab results, 

pharmacy use

Data from 

existing 

VA files; a 

consecutive 

registry
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 283

of 

Data Collected Selected Publications from Registry

from 

ng 

es; a 

cutive 

ry

from 

ng 

es; a 

cutive 

ry

continued
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284 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

TABLE 10-5 Continued

Registry

Management

Purpose

Number of 

Veterans

Basis for 

Enrollment Source of Data

Type of 

Data Data Colle

Depression 

Registry

(Started in 2001)d

Managed by the 

Serious Mental 

Illness Treatment, 

Research, and 

Evaluation Center 

in Ann Arbor, MI 

To identify and 

characterize 

veterans with 

depression; 

monitor and 

evaluate care

690,867 

(in FY 2005)

Diagnoses of 

depression 

within the VA 

health-care 

system

Health-care 

utilization, 

Global 

Assessment 

Functioning 

Scores, 

medication use, 

health-care 

costs

Data from 

existing 

VA files; 

an annual 

registry

Demograp

Age, gend

VISN anal

patient cla

medical ca

Medical H

Inpatient a

medication 

costs; prim

psychiatric 

alone or d

disorder o

substance 

other com

comorbidi

chronic ob

diseases of 

disease, ge

injury and 

of Functio

Psychoses Registrye

(Started in 1988)

Managed by the 

Serious Mental 

Illness Treatment, 

Research, and 

Evaluation Center 

in Ann Arbor, MI 

To identify and 

characterize 

veterans with 

psychoses; monitor 

and evaluate care

239,304 

(in FY 2005)

Diagnoses 

of psychoses 

within the VA 

health-care 

system

Healthcare 

utilization, 

Global 

Assessment 

Functioning 

Scores, 

medication use, 

health-care 

costs

Data from 

existing 

VA files; a 

consecutive 

registry

Demograp

Age, gend

Medical H

Pharmacy 

cost; diagn

bipolar, ot

VERA pat

connection

psychiatric 

inpatient d

nursing ho

a More information can be found at http://www1.va.gov/vhapublications/ViewPublication.

asp?pub_ID=77.

b More information can be found at http://www.vethealth.cio.med.va.gov/Pubs/ 

1303.2GWHB-05.pdf.

c

 More information can be found at http://www1.va.gov/irad/docs/IRADHANDBOOK012006.

PDF.
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 285

of 

Data Collected Selected Publications from Registry

from 

ng 

es; 

nual 

ry

Demographics:

Age, gender; race/ethnicity; marital status; 

VISN analyses; service connection; VERA 

patient class, homelessness, access to 

medical care 

Medical History:

Inpatient and outpatient services uses; 

medication and services use; health-care 

costs; primary care treatment; mortality; 

psychiatric comorbidities (depression 

alone or depression with an anxiety 

disorder other than PTSD); depression and 

substance abuse; depression and PTSD; 

other complicated depression; medical 

comorbidities (peripheral vascular disease, 

chronic obstructive pulmonary disease, 

diseases of the digestive system, liver 

disease, genitourinary symptoms, arthritis, 

injury and poisoning); Global Assessment 

of Functioning (GAF) 

from 

ng 

es; a 

cutive 

ry

Demographics:

Age, gender, race; martial status 

Medical History:

Pharmacy and medical services use; 

cost; diagnoses (total, schizophrenia, 

bipolar, other); GAF scores; mortality; 

VERA patient class; homelessness; service 

connection; access to health care; inpatient 

psychiatric care; inpatient rehabilitation; 

inpatient domiciliary care; inpatient 

nursing home care; outpatient care 

ublication.

.gov/Pubs/ 

OK012006.

d More information can be found at http://www.hsrd.ann-arbor.med.va.gov/documents/

2002NARDEP.pdf.

e More information can be found at http://www.hsrd.ann-arbor.med.va.gov/documents/

3rdAnnual_psychosisVHA.pdf.

SOURCE: Derived from a DoD/VHA, 2000; b DoD/VHA, 2005; c DoD/VHA, 2006; Kang, 

2006; d SMITREC, 2002; e SMITREC, 2001.
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286 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

VA should move quickly to develop plans for interfaces to these new 

DoD exposure data systems. This should not require massive new data 

systems within VA but instead consist of appropriate interfaces and views 

to the data within DoD systems that are accessible by the VA. The first 

step would be a VA team embedded with DoD implementation team at the 

Army’s CHPPM where they can examine the system capabilities and data 

structures so that appropriate interfaces can be defined and developed to 

meet the needs of VA. 

Recommendation: Conduct a critical evaluation of Gulf War troop 

tracking and environmental exposure monitoring data so that improvements can be made in this key DoD strategy for characterizing exposures during deployment.

Characterizing exposures during intense combat deployment scenarios 

is the most challenging aspect of DoD’s efforts to characterize Service 

member exposures throughout their military service. An important part of 

the current strategy is a combination of troop tracking and environmental 

monitoring such that overlaying of troop location with the location of 

environmental monitoring results will enable the characterization of troop 

exposures. The success of this approach depends directly on the detail of 

both the troop tracking and the environmental monitoring. More frequent 

measurement and recording of troop location coupled with more frequent 

(e.g., time and location) environmental exposure monitoring will allow 

more accurate characterization of individual exposures. The current goal is 

to record troop location at least once every 24 hours. Minimal environmental monitoring requirements are less clear. In particular, monitoring during 

shorter deployments (less than 30 days) may be sporadic as requirements 

vary depending on the predeployment risk assessment, the availability of 

appropriate medical personnel, and the commander’s discretion (DOD 

Instruction 6490.03 [DoD, 2006c]).

DoD should undertake a detailed review of this strategy using data 

from the Gulf War and subsequent deployments in Afghanistan and Iraq 

to determine limitations to the current approach and identify opportunities 

for improvement. The review should consist of the formation of exposure 

matrices for a group of randomly selected Service members who served in 

that theater using data available on troop location, environmental measurements, and exposure data in individual health records. Gaps in those 

exposure matrices should then be examined to identify data limitations so 

that strategies can be developed for future approaches that minimize those 

limitations. 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 287

4. Develop DoD policy to ensure that classification/declassification (secrecy) 

issues are managed appropriately for both DoD and the veteran.

There are clearly times when national security or mission success 

depends on maintaining secrecy regarding certain aspects of a Service 

member’s military experience. However, every effort should be made to 

find mechanisms for characterizing Service member exposure and health 

histories in manners that do not interfere with the broader issues of 

national security or mission success. DoD should develop procedures that 

ensure full or partial declassification of sensitive information for the timely 

provision of that Service member’s or veteran’s health care. When such 

declassification is not possible, DoD should establish procedures whereby 

blinded data relevant to the Service member’s health and exposure history 

are provided.

In some instances where national security and secrecy issues cannot be 

resolved, DoD and VA may need to establish mechanisms involving experts 

with appropriate security clearances to monitor affected registry cohorts 

for potential health outcomes and define surveillance or research activities 

that may need to be conducted within appropriate secrecy clearances. An 

interagency agreement could be developed between DoD and VA addressing the secrecy issue. Since both agencies have used the classification system 

in the past this agreement would address the policy development process 

and the exchange of classified information between the two agencies. The 

process would include establishment of a joint DoD-VA board comprised of 

individuals who have sufficient security clearance to discuss classified data. 

The access to classified information process would be contained in a written 

document outlining a mechanism to identify, monitor, track, and medically 

treat individuals who were part of research activities involving human subjects and whose research design and results have been classified.

Recommendation: Establish registries of Service members and veterans 

based on exposure, deployment, and disease histories.

Recommendation: DoD and VA should establish and implement 

mechanisms to identify, monitor, track, and medically treat individuals 

involved in research and other activities that have been classified and 

are secret.

5. Strengthen the assessment of psychological stressors and symptoms.

Psychological and combat-related stressors may detrimentally impact 

the long-term mental and emotional well-being of military personnel and 

should be thoroughly assessed at key points during the military career of 

men and women. Currently, basic clinical evaluations for neurological and 

psychiatric disorders are made at accession, after training, and throughout 
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288 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

the service career. Very brief structured assessments for some psychiatric 

symptoms occur during the post-deployment periods only.

Assessment of exposure to combat and of psychological stress during 

deployment is a particularly challenging element of the Committee’s proposed approach to tracking factors influencing the health of veterans. Scales 

have been developed to assess exposures during combat and the validity and 

reliability of these instruments has been assessed (Friedman et al., 1986; 

Janes et al., 1991; Keane et al., 1989; Laufer et al., 1984; Lund et al., 1984; 

Wessely et al., 2003). These instruments have been used in investigations of 

Vietnam veterans (Buydens-Branch et al., 1990; Frueh et al., 2005; Green 

et al., 1989; Yehuda et al., 1992) and more recently for personnel deployed 

in Iraq and Afghanistan (Hoge et al., 2004). A 2004 study carried out by 

military investigators addressed mental health problems and combat duty 

in personnel deployed to Iraq and Afghanistan (Hoge et al., 2004). This 

study demonstrates the feasibility of investigations directed at troops in 

relation to combat deployment. A follow-up study of Vietnam veterans, the 

National Vietnam Veterans Readjustment Study, incorporated an exposure 

measure based on military records (Dohrenwend et al., 2006). Onset of 

posttraumatic stress disorder (PTSD) was associated with combat exposure, 

with evidence for a positive close-response relationship.

These studies show that combat exposure and related stress can be 

measured. They also show the feasibility of informative research on neuropsychiatric disorders among veterans. Further development will be needed 

to achieve the type of surveillance proposed by the Committee.

Psychiatric disorders, particularly PTSD, depression, and alcohol abuse 

and dependence are common. More data systematically collected using 

validated and structured instruments pre- and post-deployment will aid 

DoD and the VA to better identify stressors that may predispose individuals 

to develop these disorders, identify Service members to whom early intervention should be provided, and track individuals exposed to emotional 

trauma and with psychiatric symptoms in specialized registries.

A number of brief validated instruments are available for PTSD, major 

depression, and alcohol abuse and dependence—three common psychiatric 

disorders experienced by veterans. A dedicated, face-to-face interview by an 

experienced clinician, recognized to be the most valid method of assessing 

PTSD, is likely not feasible in the post-deployment or separation/retirement 

medical evaluations. While a host of instruments are available for assessing 

PTSD, realistically the only feasible instruments that might be useful in this 

context would be one of several available screening questionnaires. These 

include (1) the 4-question Primary Care PTSD Screen (Prins et al., 2003), 

(2) a 7-question scale keyed to the DSM-IV criteria for PTSD (Breslau et al., 

1999), (3) the 17-question PTSD Symptom Scale Self-Report (Coffey et al., 

1998), (4) the Screen for Posttraumatic Stress Symptoms (Carlson, 2001), 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 289

and (5) the PTSD subscale of the large Psychiatric Diagnostic Screening 

Questionnaire (Zimmerman and Mattia, 2001). Only the first of these, the 

Primary Care PTSD Screen, has been validated on combat veterans. Also, 

while these screening instruments may be useful in identifying veterans who 

may have PTSD, they are not adequate for diagnosing PTSD. 

There are also a host of screening instruments for major depression 

including the 2 item Prime-MD, the 9 item Patient Health Questionnaire, 

and the 20 item Centers for Epidemiological Studies Depression (CES-D) 

scale, among others. Alcohol abuse and dependence can be screened with a 

number of instruments including the RAPS-QF, the AUDIT, and the CAGE, 

among others. These instruments vary in length and sensitivity and specificity in different populations.

Studies that employ these screening instruments for prospective research 

will need to account for some degree of misclassification of the health outcome. In spite of these shortcomings, data from a screening instrument 

on an unselected population of veterans obtained in a systematic manner 

would be very valuable for the type of prospective studies envisioned in this 

report to better understand service-related morbidity.

6. Establish registries of Service members and veterans based on exposure, 

deployment, and disease histories.

The Committee recommends that VA and Congress consider the initiation and prospective follow-up of specific veteran populations who may 

share a common exposure history as a viable surveillance tool. Creating a 

registry that may include initial demographic, exposure, and health information is a reasonable interim response to veterans with unexplained or 

underexplained health complaints that are temporally but not scientifically 

related to military service.

A registry would allow the formation of a pool of veterans who are 

linked by some shared attribute of military service, such as combat campaign, theater location, or catastrophic event (e.g., Khamisiyah, Iraq), to be 

identified and actively followed forward through regular follow-up contacts 

from the registry staff. Trends in health of the registrants could be followed 

forward, and communication with registrants about new health information 

or treatment recommendations could be facilitated. As well, the registrants 

could be invited to participate in scientific studies to elucidate the cause or 

proposed mechanism of health harm they may have experienced. Such a 

model is being used to follow the World Trade Center responders, workers, 

and neighborhood population. This model differs somewhat from existing 

VA registries (e.g., Gulf War or Agent Orange) in that these tend to be crosssectional assessments, with little regular follow-up or interaction with staff.

Although registry costs can be high, so are the costs of presumptions. 

Enrollment in a registry may offer the veteran access to some of the medi-
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290 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

cal services a presumption provides, but under a different mechanism that 

could allow time for the clinical and epidemiologic evidence to accumulate 

so as to make a more evidence-based decision about a presumption.

Recommendation: Develop a plan for an overall integrated surveillance 

strategy for the health of Service members and veterans. 

It is critical that DoD and VA work together to define a common strategy for integrated health surveillance of Service members and veterans.

Fully leveraging the Service member-veteran exposure and health data is 

critical to the full understanding of disease etiology and causation, the 

establishment of relative risk, the adjudication of disability claims, and the 

treatment of disease. It is also critical to appropriate deliberations regarding 

presumptions in disability decision making.

The need for surveillance can be identified at any point in a Service 

member’s or veteran’s experience history. Surveillance studies begun during a Service member’s service career may need to extend into his or her 

post-service experience. Data needs for the specific surveillance activity 

may have been generated during either the Service member experience or 

the veteran experience or both. Therefore this activity must be jointly well 

managed by DoD and VA. A strong central organization, staffed jointly by 

DoD and VA with external expert advisors, should be given responsibility 

for the ongoing evaluation of health and exposure data quality, the regular 

review of registry and surveillance activities, the definition of surveillance 

and research strategies, and the coordination of surveillance and research 

projects. This joint DoD-VA Service member and veteran exposure and 

health surveillance organization would have broad responsibility for oversight of all DoD and VA surveillance and research activities whether they 

are conducted internally or externally by those organizations.

Recommendation: Improve the data linkage between the electronic 

health record data systems used by DoD and VA—including capabilities for handling individual Service member exposure information that 

is included as part of the individual’s health record.

Although there are efforts underway to electronically transfer Service 

member health records from DoD to VA, these efforts are moving slowly 

and the timeline for completion of a seamless interface is unclear. DoD and 

VA should increase attention to this effort with a clear integration plan, 

timetable for implementation, metrics for tracking implementation progress, and annual reporting of metric results.

To date there has been little discussion regarding electronic transfer of 

Service members’ exposure information in their health records to VA. As the 
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HEALTH AND EXPOSURE DATA INFRASTRUCTURE 291

inclusion of exposure data in employee health records is a key DoD strategy 

for ensuring that exposure information is available for individual Service 

members, this appears to be a major weakness in the system. DoD and VA 

should explicitly include the integration of these individual exposure data 

into the health record transfer integration plan, implementation timetable, 

metrics, and annual reporting. Reports on progress of these plans should be 

included in the annual report to Congress on DOEHRS progress.

Recommendation: Ensure implementation of the DoD strategy for 

improved exposure assessment and exposure data collection.

The DOEHRS program is a major undertaking that has potential for 

dramatically increasing the availability of exposure data. However, DoD 

has many important priorities, and short-term funding pressures have the 

potential to delay implementation activities. Because of the importance 

of these efforts, not only to DoD but to VA as well, we recommend that 

additional steps be taken to ensure that DOEHRS is fully implemented as 

planned. In addition, because of the importance of adequately trained individuals to the success of DOEHRS, we further recommend that these steps 

specifically include detail on the training of individuals needed to make the 

accurate professional judgments and generate appropriate exposure data 

critical to DOEHRS. These additional steps are as follows:

1. Include a specific DoD budget line item for DOEHRS that includes 

funding for system development and enhancement, system implementation, 

and training of personnel.

2. Develop clear metrics for tracking the effective deployment and utilization of DOEHRS throughout DoD.

3. Require an annual status report to Congress on DOEHRS development and implementation progress and related training activities.

Recommendation: Develop a data interface that allows VA to access 

the electronic exposure data systems used by DoD.

DoD is investing heavily in DOEHRS and other improved exposure 

data systems that are standardized across the various armed services. In 

the Committee’s interviews with people responsible for development and 

deployment of these systems, we did not encounter anyone with knowledge 

of activities by DoD or VA to develop a VA interface with these systems 

that will allow use of the Service member-specific and longitudinal exposure 

data by VA.

VA should move quickly to develop plans for interfaces to these new 

DoD exposure data systems. This should not require massive new data 
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292 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

systems within VA but instead consist of appropriate interfaces and views 

to the data within DoD systems that are accessible by VA. The first step 

would be a VA team embedded within the DoD implementation team at the 

Army’s Center for Health Promotion and Preventive Medicine where the VA 

team can examine the system capabilities and data structures so that appropriate interfaces can be defined and developed to meet the needs of VA. 

Recommendation: Consider interim interventions for affected veterans 

while data are collected or more thoroughly analyzed to resolve scientific uncertainty.

It can take significant time to collect and analyze data needed to adequately resolve scientific uncertainty in establishing causal relationships 

between exposure and disease. VA should consider interim interventions 

in instances where veterans are severely affected during the time it takes to 

conduct the needed research. These measures might consist of provisional 

health care for affected veterans during the interim period.

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Walker, A. E., and S. Jablon. 1961. A follow-up study of head wounds in World War II. VA 

Medical Monograph. Washington, DC: U.S. Government Printing Office.

Wessely, S., C. Unwin, M. Hotopf, L. Hull, K. Ismail, V. Nicolaou, and A. David. 2003. 

Stability of recall of military hazards over time. Evidence from the Persian Gulf War of 

1991. British Journal of Psychiatry 183:314-322.

Yehuda, R., S. M. Southwick, and E. L. Giller, Jr. 1992. Exposure to atrocities and severity 

of chronic posttraumatic stress disorder in Vietnam combat veterans. American Journal 

of Psychiatry 149:333-336.

Zimmerman, M., and J. I. Mattia. 2001. The Psychiatric Diagnostic Screening Questionnaire: 

Development, reliability, and validity. Comprehensive Psychiatry 42(3):175-189.
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298

11

Governmental Classification and Secrecy

BACKGROUND

Secrecy surrounds many facets of homeland security issues and, in general, is of concern to national security. Many scientific studies conducted 

during the two world wars through the Cold War were classified, and many 

are still not declassified. Studies dealing with warfare gases and radiation 

were classified during the time of the studies and remain classified today. 

This classification makes appropriately informed treatment of the involved 

veterans with adverse health effects difficult, if not impossible, and impedes 

research on the consequences of exposures. The recent declassification 

of mustard gas and lewisite studies conducted during World War II and 

numerous radiation studies documented that classification greatly deterred 

treatment of health effects affecting the volunteers who played key roles 

during these studies. To many citizens, the idea of secrecy in government 

is linked with “national security secrets” or “classified information.” The 

system of classification occupies a special place in governmental secrecy. 

Classified information is accessible only to those who have been “cleared” 

following investigation and who agree to abide by the rules regarding access 

to this information; violation of these rules can result in severe criminal 

penalties. These rules can greatly hinder medical treatment of individuals 

who have been exposed during classified activities. 

The authority to classify information derives from legislation and from 

Presidential executive order. In 1917, Congress passed the Espionage Act to 

address wartime spying (SOURCE: http://www.firstworldwar.com/source/espionageact1918.htm; Gathering, Transmitting or Losing Defense Informa-
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GOVERNMENTAL CLASSIFICATION AND SECRECY 299

tion. 2007. 18 U.S.C. § 793; Gathering, or Delivering Defense Information 

to Aid Foreign Government. 2007. 18 U.S.C. § 794), and further legislation 

providing for military secrets was enacted in 1938 (Photographing and 

Sketching Defense Installations. 2007. 18 U.S.C. § 795; Use of Aircraft for 

Photographing Defense Installations. 2007. 18 U.S.C. § 796; Publication 

and Sale of Photographs of Defense. 2007. 18 U.S.C. § 797; Quist, 2002). 

In 1940 President Franklin D. Roosevelt issued the first executive order on 

classification, which was based on the authorization of the 1938 law enacted 

to protect military installations and equipment (Truman, 1950). The regulations that interpreted the World War I law declared that secrets could be kept 

not only for national security reasons but also for other reasons. In 1936, for 

example, the Army issued rules that provided for Secret, Confidential, and 

Restricted information. The definition of Confidential provided that

A document will be classified and marked “Confidential” when the 

informa­tion it contains is of such nature that its disclosure, although not 

endangering our national security, might be prejudicial to the interests 

or prestige of the Nation, an individual, or any governmental activity, 

or be of advantage to a foreign nation. (Classification, 1936; emphasis 

added) 

Similarly, data could be classified Secret if release “might endanger 

the national security or cause serious injury to the interests or prestige 

of the Nation, an individual, or any government activity”(Classification, 

1936).

The use of classification and secrecy by the government is detailed 

exquisitely by the history of the formation of the Atomic Energy Commission and the development of the atomic bomb during World War II. The 

Advisory Committee on Human Radiation Experiments (ACHRE) Report 

(ACHRE, 1995) provides an extremely detailed chronology of the development of the classification scheme and the use of secrecy by the government 

as it relates to any aspect of radiation work. The history of use of the 

secrecy classification for radiation studies is outlined in Appendix L-1.

Especially during times of national crisis the general public and the 

government take security seriously. The concern about national security 

has evolved considerably over the evolutionary period of classification. 

During World War II and the development of the atomic bomb under the 

Manhattan Project, considerable emphasis was placed on wartime secrecy. 

Secrecy and the oath of secrecy were extended not only to the actual participating scientists and staff but to families of these individuals. Appendix L-1 

provides an overview of the secrecy concerns surrounding these projects. 

During this developmental time period, considerable emphasis was placed 

on secrecy surrounding the use of human volunteers, and that empha-
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300 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

sis remains today. Some materials still remain classified today under the 

umbrella of national security. 

The historical development of the classification systems used during the 

atomic bomb era revealed that more than national security was a concern 

for classifying some material as secret. Concerns revolving around prestige, 

public relations, and governmental embarrassment were also used to invoke 

the secrecy umbrella. In public, some officials stated that national security 

was the paramount concern, while in private they endorsed the concerns 

involving prestige, public relations, and embarrassment (ACHRE, 1995). 

Declassification of materials has been slow, and many documents are still 

being withheld because of these expressed concerns. 

Although Appendix L-1 addresses the history of classification in relationship to the birth of the Atomic Energy Commission (AEC), the recent 

declassification of some of the World War II mustard gas and lewisite 

studies reveals that radiation studies were not the only studies classified 

for national security concerns (IOM, 1993). A more current example of 

this classification usage is the recent declassification of some of the SHAD 

(Shipboard Hazard and Defense) Project data, studies that were conducted 

and classified in the 1960s (SOURCE: http://www.deploymentlink.osd.

mil/shad/factSheets.jsp). In view of these two chemical examples, concern 

arises as to how many other studies were classified secret and have not yet 

been declassified, leading potentially to the withholding of needed medical 

care from human participants in the studies.

Although the written history addresses the experiences of the AEC (see 

Appendix L-1), the issues of secrecy and classification obviously could be 

extrapolated to other areas of research that would involve human subjects. 

Pertinent areas of concern in this regard would involve the use of chemical 

warfare agents for both prevention of injuries and possible use in tactical 

defense. The use of mustard agents and lewisite in studies addressing protective measures during and following World War II is a prime example 

of human subject use that was classified and remains partially classified 

today. Results from some of these studies were not declassified until the 

early 1990s at the insistence of an Institute of Medicine (IOM) study (IOM, 

1993), and some studies remain classified today. 

The use of chemical warfare agents and simulants in the 1960s is a 

further example of retaining human studies under the umbrella of secret 

classification. In a series of tests under the project list of SHAD, Navy ships 

were exposed to chemical or biological agents or simulants to establish 

protective measures and decontamination efficiency for machinery and 

personnel (SOURCE: http://www.deploymentlink.osd.mil/shad/index.jsp; 

http://www1.va.gov/shad/; Brown, 2003). The numerous tests were classified as secret and have only been recently partially declassified, again at the 

insistence of an IOM study (IOM, 1993). In this example, the Department 
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GOVERNMENTAL CLASSIFICATION AND SECRECY 301

of Defense (DoD) allowed IOM and the Department of Veterans Affairs 

(VA) personnel who possessed sufficient security clearance levels to review 

the documents and release selected pieces of information. It must be noted, 

however, that not all of the classified SHAD data have been declassified; 

only those parts that identify personnel involved, for which records were 

kept by DoD, and the agents or simulants they were potentially or actually exposed to have been declassified. These examples then bring to the 

forefront: How many other human use studies have been, or are being, 

conducted and are classified secret? In an August 2006 information letter 

released by the Veterans Health Administration (VHA) (VHA, 2006, p. 2), 

more than 250 chemicals were identified as chemicals of potential concern 

related to human use studies.

DoD classification authority derives primarily from Presidential order. 

Currently the DoD Information Security Program (DoD, 1997) is the 

program used for classification and is based on Executive Order 12958 

(Clinton, 1995) and its subsequent amendment Executive Order 13292 

(Bush, 2003) addressing classified national security information. The current national security classification system is “designed primarily to protect 

the confidentiality of military, foreign policy, and intelligence information. It deals with only a small slice of the government information that 

requires protection although it drives the government’s security apparatus 

and most of its costs . . . the classification system, largely unchanged since 

the Eisenhower administration, has grown out of control. More information is being classified and for extended periods of time. Security rules 

have proliferated, becoming more complex yet remaining unrelated to the 

threat” (Pike, 2002). 

Today’s classification system “starts with three levels of classification 

(Confidential, Secret, and Top Secret), often referred to collectively as collateral national security information. Layered on top of these three levels 

are at least nine additional protection categories. These include DoD Special 

Access Programs, Department of Energy (DOE) Special Access Programs, 

Director of Central Intelligence Sensitive Compartmented Information Programs, and other material controlled by special access or bigot lists such 

as the war plans of the Joint Chiefs of Staff and the operational files and 

source information of the CIA Operations Directorate. Further complicating the system are restrictive markings and dissemination controls such 

as ORCON (originator controlled dissemination and extraction of information), WNINTEL (warning notice, intelligence sources and methods), 

NOFORN (not releasable to foreign nationals), and NOCONTRACT (not 

releasable to contractors)” (Pike, 2002). 
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302 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

LEVELS OF CLASSIFICATION

Policies governing DoD’s classification program are implemented 

through the Information Security Program (DoD, 1997). This regulation 

implements Executive Order 12958 (Clinton, 1995), “Classified National 

Security Information,” and has been codified at 32 CFR Part 159 (DoD 

Information Security Program. 2001. 32 C.F.R. § 159). “A security clearance is a determination that a person is eligible for access to classified 

information. ‘Need to know’ is a determination made by a possessor of 

classified information that a prospective recipient, in the interest of national 

security, has a requirement for access to, or knowledge, or possession of 

the classified information in order to accomplish lawful and authorized 

government purposes” (Pike, 2002). Current levels of classification are 

broadly contained under the headings of Unclassified, Limited, Confidential, Secret, Top Secret, Limited Dissemination (LIMDIS), Special Access 

Program (SAP), and Sensitive Compartmented Information (SCI) (Pike, 

2002). Appendix L-2 provides a discussion of each of the categories of 

unclassified and classified information control. 

No person may have access to classified information unless that person 

has been determined to be trustworthy and unless access is essential to 

the accomplishment of lawful and authorized government purposes, that 

is, the person has the appropriate security clearance and a need to know. 

Further, cleared personnel may not have access until they have been given 

an initial security briefing. Procedures are established by the head of each 

DoD component to prevent unnecessary access to classified information. 

(Pike, 2002)

There must be a demonstrable need for access to classified information 

before a request for a personnel security clearance can be initiated. The 

number of people cleared and granted access to classified information is 

maintained at the minimum number that is consistent with operational 

requirements and needs. No one has a right to have access to classified 

information solely by virtue of rank or position. The final responsibility 

for determining whether an individual’s official duties require possession 

of or access to any element or item of classified information, and whether 

the individual has been granted the appropriate security clearance by 

proper authority, rests upon the individual who has authorized possession, 

knowledge, or control of the information and not upon the prospective 

recipient. (Pike, 2002) 

SECRECY AND MEDICAL RESEARCH

Numerous aspects of medical research have been classified on the basis 

of national security and have only recently been brought to public light. The 
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GOVERNMENTAL CLASSIFICATION AND SECRECY 303

ACHRE Report (ACHRE, 1995) enumerated numerous radiation studies 

conducted during and after World War II which were classified, and some 

still have not been declassified. Although the Espionage Act of 1918 really 

began the era of national security classification, more and more documents 

have been classified with each new Presidential administration (ACHRE, 

1995; Quist, 2002). Today the system is complicated and burdensome to 

use as discussed above. Medical research is still conducted and classified 

under the aegis of national security. This secrecy classification can establish 

hindrances in the medical care provided to the participants in these studies. 

All institutions that participate in medical research have some degree of 

classification for their projects, depending upon funding sponsor, subject, 

and agents used. Much of the current research on modern nerve agents, 

for example, is classified at the secret and above levels, even though there 

are many unclassified documents on nerve agents available to the public 

(IOM, 1993). And while DoD participates extensively in classified medical 

research studies, VA has not been excluded from such activities. Chapter 13 

of the ACHRE Report outlined VA participation in maintenance of “confidential” files regarding radiation studies:

VA, similarly, was able to provide fragments of information that show that 

“confidential” files were kept in anticipation of potential radiation liability 

claims. However, neither the VA, nor the DOE and DoD (who evidently 

were parties to this secret record keeping), have been able to determine 

exactly what secret records were kept and what rules governed their collection and availability. (ACHRE, 1995, ch. 13) 

(As explained in Chapter 10 of the ACHRE Report, VA concluded that 

a “confidential” division contemplated in relation to secret record keeping 

was not activated.)

VA publications did contain lists of several thousand (nonclassified) human 

experiments conducted at VA facilities; however, the information was quite 

fragmentary, and further information could not be readily retrieved (if it 

still exists) on the vast majority of these experiments. Thus, in looking for 

answers to questions about the secrecy of data on human experiments and 

intentional releases, we find record-keeping practices that leave questions 

about both what secrets were kept and what rules governed the keeping 

of secrets. (ACHRE, 1995, ch. 13)

Medical research involving human subjects must follow certain ethical 

and standard practice guidelines such as those established by the Nuremberg 

Code of 1947 (Trials of War Criminals Before the Nuremberg Military 

Tribunals, 1949). The 10 key elements of the Nuremberg Code are outlined 

in Appendix L-3.
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304 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Some medical research studies conducted prior to the Nuremburg Code 

implementation might not have followed the precepts of the code. Congressional inquiries during 1975 and 1976 requested that the Army Inspector 

General review the use of human volunteers in chemical agent research 

(IOM, 1993). An excerpted summary of this review (Taylor and Johnson, 

1975) is presented in Appendix L-4. While this report concentrated on 

psychochemical testing conducted during the period 1950-1975, it also 

addressed the history of chemical warfare testing using human volunteers 

and the degree of compliance with the Nuremberg Code (IOM, 1993). 

The overriding conclusion from this report was that the secrecy applied 

to research using human volunteers “left ample room for misinterpretation, lack of knowledge about [guidelines governing human volunteers] 

and outright disregard for established policies and guidelines” (Taylor and 

Johnson, 1975, as referenced in IOM, 1993, p. 379). Concern regarding 

these conclusions remains today.

The issue of secrecy hindering medical treatment for veterans is amply 

exhibited in the IOM report Veterans at Risk: The Health Effects of Mustard 

Gas and Lewisite (IOM, 1993). Serious concerns were enumerated in the 

report over the secrecy issue demonstrated by DoD. These expanded concerns are presented in Appendix L-5. 

CONCLUSIONS AND RECOMMENDATIONS FROM 

IOM’S VETERANS AT RISK REPORT

In Veterans at Risk (IOM, 1993), emphasis was placed on (1) the lack 

of exposure data, (2) the continuing dependence and reliance on secrecy by 

DoD, (3) serious ethical questions regarding the use of human volunteers, 

(4) total absence of long-term medical surveillance of participants, and 

(5) in some cases inadequate short-term follow-up even though medical 

knowledge was available as early as 1933 that exposure to mustard gas or 

lewisite could produce adverse health problems. 

The oath of secrecy taken by participants, and enforced by potential 

punishment protocols if broken, resulted in continual and escalating cases 

of health impairment among the human volunteers in these chemical agent 

studies. The Taylor and Johnson report contains specific statements addressing the issue of secrecy and the participants who took the secrecy oath. An 

overarching conclusion stated in the report addressed future DoD research 

with human subjects. These future studies must be conducted following a 

set of ethical principles that mirror those that non-DoD researchers must 

follow. The 1975 Army Inspector General report (Taylor and Johnson, 

1975) concludes that the mantle of secrecy gives implicit permission to 

researchers to stretch the boundaries of ethical guidelines in DoD human 

research under the guise of national security. 
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GOVERNMENTAL CLASSIFICATION AND SECRECY 305

VA acknowledges that it must, at times, request exposure data from 

DoD in order to make a compensation decision. These exposure data may 

or may not be classified by DoD, and DoD has the option of releasing the 

data to VA. If the data are classified, DoD may not release them to VA 

citing national security issues (as stated during Do, 2006, and Freeman, 

2006). This failure to release exposure data hinders medical treatment to 

the veteran. The potential for negative impact on the veteran population 

is demonstrated in the August 2006 VHA information letter released to 

health-care providers and the public (VHA, 2006). In this letter, VHA indicated that there may be in excess of 250 additional chemical agents that 

were used or tested in the chemical warfare arena. The Committee does not 

know if there are data available on each of these chemicals or if the data are 

unclassified. DoD is the only organization that can provide those answers. 

DoD has acknowledged that some 250 additional chemicals might fall 

under this concern (VHA, 2006). If chemical studies have been classified, 

DoD is not obligated to inform VA about the studies under the umbrella of 

national security concerns. As discussed above in the levels of classification, 

there are many levels under which exposure data could be classified. And, 

if DoD were to impose the restriction on VA that they must identify which 

data and under which level of classification the data fall before they release 

the data to VA, this would hinder access to important information useful 

for the care of veterans. Not withstanding national security issues, VA must 

have access to all exposure data to fully provide health care to veterans. 

A high level of cooperation between both agencies is necessary to provide 

maximum support to the veteran population.

SUMMARY

In view of the history of human subject use in various DoD and other 

agency studies, a mechanism is needed to protect the health of our veterans 

and their families. A joint effort between DoD and VA must be initiated 

to develop a mechanism to monitor human studies and provide healthprotection measures to those individuals involved. Foremost would be 

the identification of all Service members involved in the studies. Secondly, 

the chemical, biological, infectious, and radiological agents used during 

the studies must be identified so that potential adverse health effects and 

treatments can be determined. Thirdly, accurate exposure assessment data 

must be collected and made available to appropriate scientists to be used 

in determining treatment regimens. As is the case in issues of this concern, 

the “dose makes the poison.” Fourthly, national security concerns must be 

maintained while providing the necessary health support to veterans and 

their families. 

These areas of concern should be addressed by the formation of, and 
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306 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

effective and intelligent use of, a joint DoD-VA board to develop and 

implement policy areas surrounding national security and human subject 

research. Paramount to the effectiveness of the board, would be membership of individuals with sufficient security clearance to address national 

security, DoD weapons and tactical areas, and medical concerns, including 

exposure assessment. The major undertakings of this board would be the 

following: 

• Identifying any human-use study

• Developing a registry of Service members involved in the studies

• Developing a tracking mechanism to maintain contact with the 

Service members involved in the studies

• Providing periodic medical evaluations or surveillance of Service 

members involved in the studies

• Determining appropriate medical treatment if an adverse health 

effect is detected

• Developing a mechanism to make information public as necessary

• Keeping the veteran, and family as applicable, fully informed 

regarding potential health effects of the materials that were used in the 

studies

Recommendation

DoD and VA should establish and implement mechanisms to identify, 

monitor, track, and medically treat individuals involved in research and 

other activities that have been classified and are secret.

There are clearly times when national security or mission success 

depends on maintaining secrecy regarding certain aspects of a Service 

member’s military experience. However, every effort should be made to 

find mechanisms for characterizing Service member exposure and health 

histories in manners that do not interfere with the broader issues of 

national security or mission success. DoD should develop procedures that 

ensure full or partial declassification of sensitive information for the timely 

provision of that Service member’s or veteran’s health care. When such 

declassification is not possible, DoD should establish procedures whereby 

blinded data relevant to the Service member’s health and exposure history 

are provided.

In some instances where national security and secrecy issues cannot be 

resolved, DoD and VA may need to establish mechanisms involving experts 

with appropriate security clearances to monitor affected registry cohorts 

for potential health outcomes and define surveillance or research activities 

that may need to be conducted within appropriate secrecy clearances. An 
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GOVERNMENTAL CLASSIFICATION AND SECRECY 307

interagency agreement could be developed between DoD and VA addressing 

the secrecy issue. As both agencies have used the classification system in the 

past, this agreement would address the policy development process and the 

exchange of classified information between the two agencies. The process 

would include establishment of a joint DoD-VA board composed of individuals who have sufficient security clearance to discuss classified data. The 

access to the classified information process would be contained in a written 

document outlining a mechanism to identify, monitor, track, and medically 

treat individuals who were part of research activities involving human subjects and whose research design and results have been classified.

REFERENCES

ACHRE (Advisory Committee on Human Radiation Experiments). 1995. Final report. 

Washington, DC: Government Printing Office. http://hss.energy.gov/healthsafety/ohre/roadmap/achre/report.html (accessed March 7, 2007).

Brown, M. 2003. VA charge to the IOM Oversight Committee on the Study of the Health 

of Participants in Project SHAD (Shipboard Hazard and Defense). Washington, DC: 

Department of Veterans Affairs. http://www1.va.gov/shad/docs/VA_Charge_IOM_on_

the_Health_Study_of_SHAD.pdf (accessed March 7, 2007). 

Bush, G. W. 2003. Executive order 13292: Further amendment to executive order 12958, as 

amended, classified national security information. Federal Register 68(60):15315-15334. 

http://a257.g.akamaitech.net/7/257/2422/14mar20010800/edocket.access.gpo.gov/2003/

pdf/03-7736.pdf (accessed March 7, 2007).

Classification. 1936. Dictionary of Unites States Army terms: Army regulation 320-5. Attachment 2. Washington, DC: Government Printing Office. http://www.gwu.edu/~nsarchiv/

radiation/dir/mstreet/commeet/meet14/brief14/tab_d/br14d1b.txt (accessed March 7, 

2007).

Clinton, W. J. 1995. Executive order 12958: Classified national security information. 

Federal Register 60(76):19825-19843. http://frwebgate.access.gpo.gov/cgi-bin/getdoc.

cgi?dbname=1995_register&docid=fr20ap95-135.pdf (accessed March 7, 2007).

Do, N. 2006. DoD and Veterans Affairs: Health information sharing. Paper presented at the 

third meeting of the IOM’s Committee on the Evaluation of the Presumptive Disability 

Decision-Making Process for Veterans, San Antonio, TX. 

DoD (Department of Defense). 1997. Information Security Program. DoD 5200.1-R. Washington, DC: Office of the Assistant Secretary of Defense/Command, Control, Communications, and Intelligence. http://www.fas.org/irp/doddir/dod/5200-1r/ (accessed March 7, 

2007).

Freeman, C. 2006. Department of Veterans Affairs/Department of Defense: Health data 

systems interoperability. A presentation to the Institute of Medicine Committee on the 

Evaluation of the Presumptive Disability Decision-Making Process for Veterans, San 

Antonio, TX.

IOM (Institute of Medicine). 1993. Veterans at risk: The health effects of mustard gas and 

lewisite. Washington, DC: National Academy Press. 

Pike, J. 2002. Security and classification. Gloucester, MA: Granite Island Group, Technical Surveillance Counter Measures. http://www.tscm.com/classification.html (accessed 

April 10, 2007).
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Quist, A. S. 2002. Introduction, history, and adverse impacts. Vol. 1. Oak Ridge, TN: Oak 

Ridge Classification Associates, LLC. http://www.fas.org/sgp/library/quist/index.html 

(accessed March 7, 2007). 

Taylor, J. R., and W. N. Johnson. 1975. Research report concerning the use of volunteers in 

chemical agent research. DAIG-IN 21-75. Washington, DC: Department of the Army, 

Office of the Inspector General and Auditor General.

Trials of war criminals before the Nuremberg military tribunals. 1949. Control Council 

Law 10(2):181-182. http://www.copernicusgroup.com/irbForms/NurembergCode.pdf 

(accessed March 7, 2007). 

Truman, H. S. 1950. Executive order 10104: Defining certain vital military and naval installations and equipment as required protection against the general dissemination of 

information relative thereto. http://www.presidency.ucsb.edu/ws/index.php?pid=59321 

(accessed April 10, 2007).

VHA (Veterans Health Administration). 2006. Under Secretary for Health Information Letter:

Potential health effects among veterans involved in military chemical warfare agent 

experiments conducted from 1955 to 1975. Information letter 10-2006-010. Washington, DC: Department of Veterans Affairs. http://www1.va.gov/environagents/docs/USHInfoLetterIL10-2006-010.pdf (accessed March 7, 2007).
Copyright © National Academy of Sciences. All rights reserved.

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309

12

The Way Forward

INTRODUCTION

In previous chapters of this report, the Committee examined and 

described Congress’ and the Department of Veterans Affairs’ (VA’s) past 

and present approaches to establishing presumptions. The case studies 

illustrate the application of the current approach, as well as approaches 

taken previously, and point to multiple points in the process of establishing presumptions that, in the Committee’s view, should be modified by its 

participants (Chapter 5). The Committee set out principles related to evidence evaluation and causal inference as a foundation for setting in place 

an approach that is as firmly grounded as possible in the relevant base of 

scientific evidence for particular exposures and health outcomes (Chapters 6-9). The Committee also addressed the task of more comprehensively 

tracking the exposures of those serving in the military and prospectively 

monitoring military personnel and veterans for disease occurrence so that 

the risks of exposures can be assessed more systematically (Chapter 10) and 

so that exposures subject to secrecy can be considered (Chapter 11). 

Based on the case studies and other information that was gathered, the 

Committee has concluded that there is a basis for making changes to the 

present approach. Building on the conceptual foundation developed in these 

earlier chapters, the Committee addresses the second part of its charge in 

this chapter and recommends a framework for establishing presumptions 

in the future.

The Committee suggests that its recommended framework be considered as a model to guide the evolution from the current approach toward 
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310 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

that proposed by the Committee. The Committee recognizes that specific 

elements of its proposal (e.g., the call for carrying out exposure assessments 

and making exposure estimates) are not fully practicable for all relevant 

exposures at present and would take time to develop and implement. 

However, feasibility of specific elements of its proposal should be enhanced 

with future methodologic developments. The Committee believes that its 

approach can be applied to the full range of factors (e.g., chemical, biological, infectious, physical, and psychological) that may adversely affect the 

health of military personnel and veterans. The Committee does not intend 

that its approach be applied retrospectively to existing presumptions. The 

Committee is aware that policy or other concerns could lead Congress or 

VA to modify or even reject some of the Committee’s recommendations. 

Congress and VA may find alternative processes to achieve the overall objective of the Committee’s recommendations: an evidence-based approach to 

making presumptive disability decisions. However, the Committee suggests 

that its proposal will prove feasible and practical over time, that many of 

the elements in its proposal can and should be implemented without delay, 

and that the Committee’s proposal would significantly improve the presumptive disability decision-making process for veterans. 

Out of necessity, the Committee also makes some recommendations 

related to the implementation of its proposed approach. The Committee 

makes specific recommendations with regard to proposed advisory and 

review committees that will likely require congressional authorization, and 

the Committee recommends that VA would need to make adjustments in 

its overall approach to the presumptive disability decision-making process 

in order to follow the Committee’s recommendations. 

The Committee’s recommended approach (Figure 12-1) has multiple 

new elements: a process for proposing exposures and illnesses for review; 

a systematic evidence review process incorporating a new evidence classification scheme and quantification of the extent of disease attributable to 

an exposure; a transparent decision-making process by VA; and an organizational structure to support the process. In using the term “exposure,” 

the Committee defines exposure in a broad manner to include chemical, 

biological, infectious, physical and psychological stressors. We also call 

for a comprehensive approach to tracking exposures of military personnel 

and monitoring their health while in service and subsequent to service. The 

tracking should cover the full spectrum of exposures relevant to future 

risk for disease, including chemical, biological, infectious, physical and 

psychological stressors. The Committee’s recommendations are based in a 

framework that sets out this evidence-based process (Figure 12-1). 

The proposed process includes the engagement of two panels: An 

Advisory Committee and a Science Review Board. The Advisory Committee would be advisory to VA and would consider proposals for the review 
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THE WAY FORWARD 311

Research/

Surveillance a

Stakeholder

Nominations b

Science Review

Boardd

VA Compensation

Decision Process

Advisory Committeec

Decisione

VA Secretary

VA Secretary

Report 

Charge 

Recommendations 

Initiates presumption 

consideration process 

FIGURE 12-1

Vertical arrows have been shortened.

There is now a little over an inch of extra 

space at the bottom of 6 x 9 page

If more space is needed the figure will be

reduced in size in the page layout process

FIGURE 12-1 Proposed framework for future presumptive disability decisionmaking process for veterans.

a Includes research for classified or secret activities, exposures, etc. 

b Includes veterans, veterans service organizations, federal agencies, scientists, 

general public, etc.

c This committee screens stakeholders’ proposals and research in support of evaluating evidence for presumptions and makes recommendations to the VA Secretary 

when full evidence review or additional research is appropriate. 

d The board conducts a two-step evidence review process (see report text for further 

detail).

e Final presumptive disability compensation decisions are made by the Secretary, 

Department of Veterans Affairs, unless legislated by Congress.
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312 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

of exposures and illnesses that might be the basis for presumptions and 

recommend to the VA Secretary exposures and illnesses needing further 

consideration. The Science Review Board, which would be independent 

from VA, would conduct a comprehensive evaluation of the evidence for 

causation and, if warranted by the level of evidence in support of causation, 

estimate the service-attributable fraction of disease. 

The Committee calls for the implementation of a health and exposure 

surveillance system such that veterans’ health would be seamlessly tracked 

from entry into the service through retirement or separation and on to 

death. The resulting evidence on service-caused risks to health would be one 

critical component of the foundation of evidence for decision making, along 

with other sources of evidence, including studies of other populations, 

toxicologic studies, and other research. The accumulating evidence would 

undergo periodic review in a transparent and uniform fashion to gauge the 

strength of evidence in support of general causation and for determination 

of individual causation, drawing on the exposure data and perhaps other 

information. This review, carried out by the Science Review Board, would 

classify the strength of evidence for general causation in a standardized 

classification scheme as input into a compensation process by VA. VA, 

also deliberating in a transparent fashion based on established principles, 

would render a decision by the VA Secretary with regard to a presumption. 

The process includes a mechanism for stakeholders to propose exposures 

and illnesses for potential presumptions. These would be considered by the 

Advisory Committee. 

GENERAL FRAMEWORK: THE ADVISORY COMMITTEE AND 

THE SCIENCE REVIEW BOARD

In the Committee’s view, a change in the processes for the entities 

involved in the presumptive disability decision-making process is needed. 

In its recommendations for Congress, the Committee proposes the creation 

of an Advisory Committee and a Science Review Board.

The Advisory Committee would serve as an advisory committee to VA 

and consider the wide range of exposures and illnesses that might be a basis 

for presumptions. It would also consider research needs and assist VA in 

strategic research planning. The Science Review Board (independent from 

VA) would evaluate the evidence for causation and, if warranted, estimate 

the attributable fraction of disease in veterans due to exposure. 

The role of the Advisory Committee would be to gather suggestions 

from all stakeholders (i.e., veterans service organizations, veterans, scientists, policy makers, and others) regarding specific exposures and illnesses 

that might be considered for comprehensive evaluation as potential presumptions, and to recommend to the VA Secretary those exposures and 
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THE WAY FORWARD 313

illnesses worthy of further consideration. This committee would also advise 

on research to be carried out by various entities.

The role of the Science Review Board would be to weigh the evidence on 

general causation of disease (including data from a wide range of sources) 

and to provide recommendations to the VA Secretary regarding presumptions. One critical element in the deliberations of the Science Review Board 

would be evidence from monitoring the veterans themselves. The health of 

military personnel should be seamlessly tracked from entry into the service through retirement or separation and on to death. This accumulating 

evidence would undergo periodic review by the Science Review Board in a 

transparent and consistent manner. The Science Review Board would also 

consider evidence from studies of nonveteran populations, toxicological 

studies, and basic science research. The Science Review Board would provide VA with input for its presumptive decisions, including a summary 

report of the available scientific evidence in a standardized classification 

scheme. VA would then render its decision with regard to a presumption 

through a transparent process of deliberation for potential compensation. 

PRINCIPLES FOR THE PRESUMPTIVE DISABILITY 

DECISION-MAKING PROCESS FOR VETERANS

This section describes the principles that should be incorporated into 

this process at every level. VA’s decision to make a presumption may involve 

weighing difficult and incomplete scientific evidence, in the context of veterans’ concerns and society’s obligations to the affected veterans as well as 

potential costs. Although the potential complexity of the presumptive disability decision-making process may make a complete codification difficult, 

the underlying principles can be clearly expressed. 

Our country has long recognized that veterans make great sacrifices 

through their service, including being willing to risk their lives in combat. 

Historically, presumptions established by Congress and VA have acknowledged the special responsibilities of the government to injured veterans. 

Recent military conflicts have brought new concerns that extend beyond 

combat injury and that reflect the potential for delayed adverse consequences of complex combat exposures from chemical, biological, infectious, 

physical, and psychological stressors. The principles underlying presumptive disability decision making are critical for its success, and consequently

the Committee calls for Congress and VA to affirm certain principles that 

underlie decision making around presumptions. The Committee recommends the following six principles as such a foundation: 

1. Stakeholder inclusiveness

2. Evidence-based decisions
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314 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

3. Transparency

4. Flexibility

5. Consistency

6. Causation, not just association, as the target for decision making

Each of these principles is discussed in detail below.

 Stakeholder Inclusiveness

The Committee was impressed with the number of groups who 

expressed intense interest in the Committee’s deliberations and in this 

report. The Committee’s meetings were attended by representatives of veterans service organizations and by individual veterans. Optimal decision 

making has to include input from such stakeholders who will be affected 

by the process. Veterans and their families already have some input to VA 

through the political process. However, the Committee sees a need for more 

active solicitation of stakeholder input, not just into decisions on specific 

presumptions but more generally with regard to VA’s overall process for 

making presumptions. It is with this principle in mind that the Committee 

recommends the creation of the Advisory Committee, separate from but 

advisory to VA, to consider exposures and diseases for which comprehensive scientific evaluation and possible presumptions may be warranted. 

Among others, this entity should consult with: representatives of veterans 

service organizations; veterans; veterans’ families; medical personnel at VA 

who are engaged in the research, diagnosis, and treatment of conditions at 

issue; and personnel at the Department of Defense (DoD) who are knowledgeable about pertinent exposures and exposure data. 

Evidence-Based Decisions

Over the last several decades, there has been a strong movement to 

ground clinical medicine and public health in an evidence-based framework 

for decision making. The systematic and consistent capture and analysis of 

all relevant evidence is central in this approach. Many previous IOM committees addressing scientific issues that would later be used by Congress 

or VA in establishing presumptions have followed structured approaches, 

typically evaluating all relevant observational studies on particular hazards 

faced by veterans and interpreting the findings in a broad biomedically 

grounded framework. However, while some of these reviews evaluated 

additional available toxicological or mechanistic evidence, they did not 

incorporate this evidence when reaching conclusions about the available 

scientific evidence for the relationship. The Committee recommends giving 

more consideration to toxicological investigation in general and to mecha-
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THE WAY FORWARD 315

nisms of action in particular. The overall presumptive disability decisionmaking process needs to be grounded in the full extent of the scientific 

evidence available. 

Although previous IOM committees have appropriately considered all 

available epidemiologic evidence on veterans, both domestic and foreign, 

as well as relevant studies from civilian populations, the available studies 

may be limited for many agents. In spite of efforts over the years by VA, 

the Medical Follow-Up Agency at IOM, and other federal and non-federal 

organizations to address critical health matters for veterans, the array of 

studies and findings is lacking as a basis for establishing well-grounded 

scientific presumptive disability decisions for many health outcomes. With 

the principle of evidence-based decisions in mind, this Committee also recommends that veterans be more effectively monitored, both in their military 

exposures and in relevant health outcomes throughout their lifetimes. 

Transparency

Transparency in decision making is critical to the perception of fairness. The Committee strongly recommends that more emphasis be put on 

assuring transparency at every stage of the presumptive disability decisionmaking process. There are multiple stakeholders concerned with every 

specific presumption, including veterans who are already ill, those potentially at risk of illness, veterans service organizations, and the general 

public. Transparency means that each step of decision making should have 

a clear and known basis; stakeholders should be able to fully understand 

how decisions about presumptions are made, and the basis for those decisions, with reference to documented details of the presumptive disability 

decision-making process. VA has expressed concern that transparency could 

compromise internal discussion and affect decision-making deliberations; 

any unanticipated, adverse consequences of transparency should be noted 

and implications considered.

Flexibility

Scientific evidence is not static, and it often is less than certain. Given 

that the scientific basis for presumptive decisions will change over time, the 

Committee recommends that VA should be able to adjust future decisions 

when such change is scientifically justified. This does not mean that the 

Committee recommends that benefits previously granted should be terminated. The Committee is aware that disabled veterans and their families 

are often dependent on such payments and that it could create a hardship 

to remove them, a matter that VA disability policy recognizes in other 

situations. There should be a process of ongoing data collection so that 
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316 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

relevant new findings are recognized and taken into account as quickly as 

possible. Differing approaches to assisting affected veterans might be used 

as evidence is accumulating. For example, when causation is very uncertain, 

a decision might be made by VA to award medical care to the veterans possibly harmed, leaving open the possibility of future financial compensation 

if the evidence strengthens over time. 

Another aspect of flexibility is ongoing improvement of the decisionmaking process. At present, the Committee found little indication that VA 

assesses the performance of its own presumptive disability decision-­making 

process or seeks to improve it. Even if VA were to adopt the decisionmaking structure recommended by the Committee (see Figure 12-1), it 

would also be necessary to set up mechanisms for evaluating VA’s internal 

process over time. The Committee recommends that VA establish ongoing monitoring and evaluation to allow the decision-making process to be 

refined and improved. An information-gathering process would be needed 

for this purpose; consideration might also be given to appointment of an 

external committee to provide independent guidance on quality improvement, or the Advisory Committee could provide this function. 

For the short term, as a new approach is implemented, careful review 

and evaluation may be particularly critical. Consequently, Congress may 

choose to be involved in the assessment and change the process as well, 

particularly as there is a transition from the current approach to a new 

process. 

Consistency

One lesson from the case studies is that there is no firm consistency in 

the basis for presumptive decisions, possibly contributing to a perception 

by some of arbitrariness in the presumptive disability decision-making 

process. VA has offered a description of its internal processes as they have 

evolved over the last 15 years with regard to the receipt and consideration 

of IOM’s Agent Orange and Gulf War reports. The materials from VA do 

not describe a standard protocol by which various internal groups respond 

to an IOM report. Although the Committee lacks full information on VA’s 

processes, the Committee was left with the impression that better structure 

and documentation of its approach are needed. The Committee recommends that VA take steps to ensure that the bases for its internal decision 

making are explicit and applied consistently from case to case. To achieve 

consistency, consideration should be given to procedures for each element 

of the process within VA: evidence review, decision making, and implementation. For some elements of the process, models are already available, as in 

the instance of previous IOM Agent Orange and Gulf War committees. 
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THE WAY FORWARD 317

Causation, Not Just Association

One of the most critical matters, in the Committee’s view, is clarifying 

the basis for making a decision to compensate veterans for service-related 

disability. The Committee recommends that causation, not just association, 

should be the basis of presumptive compensation. The justification for this 

recommendation is provided below. 

Presumptive disability decisions are based on two judgments: (1) that a 

group of veterans was exposed to a potentially harmful agent or condition 

during service, and (2) that the agent or condition is able to cause disease 

leading to disability. The second proposition states a causal association, and 

not merely an association for which causation has not been established. An 

association between an exposure and outcome can be good evidence for a 

causal claim, but it is not the same as a causal claim. 

The history of presumptions for Agent Orange illustrates the need to 

be clear on this point. The Veterans’ Dioxin and Radiation Exposure Compensation Standards Act of 1984 (Public Law 98-542. 98th Cong., 2d Sess.) 

used language of both association and causation in describing the evidence 

required for presumptions. Initially, VA interpreted the law as requiring a 

certain threshold of evidence for causation, and as a result denied presumptions between Agent Orange and all diseases except chloracne. Veterans 

interpreted the intent of the law differently, and a district court sided with 

the veterans finding the Act ambiguous and interpreting congressional 

intent as establishing a threshold of evidence for an association (Nehmer 

v. United States Veterans’ Administration, 1989. Henderson, T. E. United 

States District Court for the Northern District of California Case Number 

C86-6160 TEH). 

The Agent Orange Act of 1991 (Public Law 102-4. 102d Cong., 1st 

Sess.) led the VA to provide the following charge to IOM in making scientific determinations:

• whether a statistical association with herbicide exposure exists, taking 

into account the strength of the scientific evidence and the appropriateness of the statistical and epidemiologic methods used to detect the 

association;

• the increased risk of the disease among those exposed to herbicides 

during service in the Republic of Vietnam during the Vietnam era; 

and 

• whether there exists a plausible biological mechanism or other evidence 

of a causal relationship between herbicide exposure and the disease.

VA contracted with IOM to provide a biennial review of the scientific 

evidence, and VA provided each of the IOM Agent Orange committees 

(IOM, 1994, 1996, 1999, 2001, 2003b, 2005b) the 3-point charge con-
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318 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

tained in the Agent Orange Act. IOM reports on Agent Orange (IOM, 1994, 

1996, 1999, 2001, 2003b, 2005b) generally stated that the committees were 

unable to address the second point of their charge and did not use evidence 

from the third point of their charge to incorporate into the overall strength 

of evidence decision on association. The first IOM Agent Orange committee 

(IOM, 1994) established categories for the strength of evidence based on 

an association (sufficient, limited/suggestive, inadequate/­insufficient, and no 

association) that have been used by subsequent IOM Agent Orange committees (IOM, 1996, 1999, 2000b, 2001, 2003b, 2005b).

Based in part upon IOM’s categorization of limited/suggested evidence 

of an association between exposure to Agent Orange and a specific health 

outcome—without scientific research on increased risk in exposed veterans 

(second point of charge), or robust evidence for a plausible biological 

mechanism (third point of charge), VA has presumptively service-connected 

several health outcomes to Agent Orange since 1994. In the example of 

type 2 diabetes, the scientific basis for the presumption was not evidence 

of a causal connection, but far more limited evidence of an association. Of 

course, the Committee recognizes that Congress and VA may choose to 

presumptively service-connect health outcomes for which the evidence for 

causation is weak; however, the basis for making such a decision should 

be made explicit.

In recommending a shift from association to causation as the underlying basis for compensation decisions, the Committee notes that such a 

shift would not necessarily raise the bar for establishing a presumption. It 

should be noted here that previous IOM committees reviewing mustard gas 

and lewisite (IOM, 1993) and the Gulf War (IOM, 2000a, 2003a, 2005a, 

2006, 2007) each used a causal categorization in their reports. A more 

thorough consideration of mechanistic evidence of causation could actually 

reduce the need for evidence of an association. For example, in Gulf War 

and Health (IOM, 2003a, p. 330) IOM found that “there is inadequate/insufficient evidence to determine whether an association exists between 

chronic exposure to benzene and myelodysplastic syndromes” in veterans 

even though many toxicologists and hematologists view the overall evidence 

as strongly supportive of a causal relationship in rodents. 

The Committee recommends a scheme for the classification of evidence 

for causation in the following section.

STRUCTURE AND ACTIVITIES OF THE PRESUMPTIVE 

DISABILITY DECISION-MAKING PROCESS

The Committee proposes a transparent, public process through which 

diseases or health conditions potentially caused or aggravated by military 

service and the putative causal agents (e.g., chemical, biological, infectious, 
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THE WAY FORWARD 319

physical, and psychological stressors) would be nominated for review and, 

given sufficient information and numbers of veterans affected, formally 

evaluated to determine if the evidence for causality supports consideration 

of presumptive service connection by VA. The process would be fully 

transparent and the outcomes of the evaluation made available in a timely 

manner. 

The Committee recommends that Congress create an Advisory Committee to VA. This Advisory Committee would be composed of scientific 

experts and veterans’ representatives who would identify and recommend 

to the VA Secretary health conditions and agents (i.e., chemical, biological, 

infectious, physical, and psychological stressors) for referral to and comprehensive evaluation by the independent Science Review Board. In turn, 

the Science Review Board’s findings and report would be provided to the 

VA Secretary for consideration in establishing presumptive compensation 

decisions.

The Advisory Committee

An Advisory Committee, chartered by Congress, is needed to identify 

potential exposures during military service, and related disabilities caused 

by these exposures, and to refer these topics for comprehensive review to 

the Science Review Board. This permanent committee would receive proposals for review, screen the available scientific information and research, 

and give priority to proposals based on the nature and extent of evidence 

supporting the relationship. The Advisory Committee would be composed 

of veterans’ representatives and recognized and credible experts in relevant 

fields, for example epidemiology, industrial hygiene, toxicology, occupational medicine, public health, military surveillance and databases, and 

exposure assessment. The Advisory Committee would be supported by VA 

and other federal staff with appropriate backgrounds and expertise to assist 

the committee. The Advisory Committee would review the initial assessment, give priorities, and make recommendations for proceeding with the 

full, comprehensive scientific review to the VA Secretary. The VA Secretary 

would have the authority to select conditions and agents for comprehensive 

scientific review by the Science Review Board. 

Open Proposal Process

Health conditions and causative agents or circumstances would be proposed for review based on evidence of a connection between the condition 

and military service, and evidence that a sizable or well-defined group of 

veterans is likely to be affected. Concerns as to the need for a presumption might arise from the health surveillance of veterans or active military 
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320 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

personnel, laboratory research discoveries, or findings from occupational 

studies of exposures and health effects (e.g., by the International Agency for 

Research on Cancer [see Chapter 8]). Proposals from any source on behalf 

of affected veterans (e.g., veterans, veterans’ families, veterans service organizations, VA, DoD, other governmental bodies, researchers, or the general 

public) would be accepted. Proposals along with supporting information 

would be tracked and evaluated on a scheduled basis. 

Screening of Proposals 

An initial review of the evidence would be performed by professional 

VA staff in support of the Advisory Committee. The purpose of the screen 

would be to determine whether there is a minimum amount of evidence suggesting that the condition could have been caused or aggravated by military 

service, or of military exposure to the putative causal agent, and also to 

gauge the extent and nature of the evidence supporting the proposal. The 

process of proposal review would be structured to be responsive to stakeholders of varying expertise and capabilities, and include the gathering of 

additional evidence beyond that submitted with the proposal. 

Prioritization 

Those exposures found to, at a minimum, have some positive evidence 

of a relationship to health conditions and adequate data to initiate review 

would be candidates for full evaluation. Higher priority would be given 

to the conditions and causative agents or circumstances with the strongest 

evidence, affecting the largest numbers of veterans, and leading to the most 

severe health consequences. 

Advisory Committee Review 

The Advisory Committee would review materials assembled by the VA 

staff and other input from stakeholders and the general public to make recommendations to the VA Secretary for full, comprehensive scientific review 

by the Science Review Board. The process used by the Advisory Com­mittee, 

which would be subject to the Federal Advisory Committee Act, and the 

rationale for recommendations would be documented and transparent. The 

process would also provide opportunities for input by stakeholders during 

the Advisory Committee’s review of proposals. To assist the Advisory Committee in developing recommendations, it is important that VA improve 

its data collection processes to track claims filed by veterans for benefits 

so that environmental exposure issues connected with new claims can be 

identified quickly.
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THE WAY FORWARD 321

The VA Secretary

Ultimately, the decision regarding which topics deserve full, comprehensive scientific evaluation resides with VA. VA would take the Advisory 

Committee recommendations under advisement, and consider the nature 

and extent of evidence, number of veterans potentially affected, severity of 

the conditions, public comment, and potentially other factors to decide the 

topics that would proceed to the Science Review Board for full, comprehensive scientific evaluation. Transparency at this stage by VA is critical. The 

VA Secretary would be required to respond to the Advisory Committee’s 

recommendations, providing an explanation for his or her decisions, a copy 

of which would be filed with Congress on an annual basis. 

In the Committee’s proposed presumptive disability decision-making 

process, VA would receive the full, comprehensive scientific evaluation, 

as described below, from the Science Review Board. We recommend that 

VA establish a uniform and transparent process for making decisions with 

regard to presumptions following receipt of such evidence reviews. The 

process should incorporate the principles embodied in this Committee’s 

proposed approach. VA procedures should be established with input from 

the many concerned stakeholders. Its protocols should acknowledge who 

would be accountable for considering the reports of the Science Review 

Board and a description of how the reports would be used. A clear and 

comprehensive evidence-based rationale should be offered for all decisions 

and made public.

Science Review Board

For the process of comprehensive scientific review of the evidence to be 

successful, it must be regarded as credible by veterans, the general public, 

and the scientific community. It is essential that the process be objective, 

transparent, and of the highest scientific quality, reflecting scientific consensus 

among acknowledged experts at the time of the review. The Science Review 

Board is envisioned as following a transparently operated, adequately funded 

and staffed process in which outside experts, with various disciplinary backgrounds serving as needed, would conduct the full, comprehensive scientific 

evaluation. Rereview of cases would be conducted as new evidence would 

emerge, and further research would be encouraged when important hypotheses are unresolved by the available scientific evidence. 

An independent Science Review Board would be authorized by Congress 

and funded by VA. The group would have expertise in the key disciplines 

needed to weigh the causal evidence and determine the service-attributable 

fraction. Ad hoc members could be added when specialized expertise was 

needed or issues of secrecy would need to be addressed. Members of the 
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322 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Science Review Board would serve as independent experts, and without 

conflicts of interest. The Science Review Board would be housed in an 

organization or institution that would ensure its credibility, its sustained 

growth, and consistent efforts and products.

A staff of professionals with expertise in relevant disciplines would 

be needed to support the Science Review Board. Staff would seek out and 

compile relevant information, solicit input from outside organizations, and 

assist in report writing and in developing and finalizing recommendations 

from the Science Review Board. 

Public and Other Requests for Relevant Data 

VA would publicly announce in the Federal Register the health conditions and putative causal agents that would undergo full, comprehensive 

scientific review by the Science Review Board. In the initial preparations 

for the evidence review, a request for information on the evidence for and 

against causal relationship for the particular condition and agent or circumstance would be announced, for example in the Federal Register and on 

VA’s website. Relevant data may also be requested from DoD, organizations 

within VA, or other knowledgeable organizations, by project staff or the 

Science Review Board.

Two-Step Process of Evidence Utilization 

The Committee recommends a two-step process for evaluation of scientific evidence by the Science Review Board. Step one would involve a 

systematic review of relevant data to determine the strength of evidence for 

causation, using one of four categories as presented in Chapter 8:

1. Sufficient: The evidence is sufficient to conclude that a causal relationship exists.

2. Equipoise and Above: The evidence is sufficient to conclude that a 

causal relationship is at least as likely as not, but not sufficient to conclude 

that a causal relationship exists. 

3. Below Equipoise: The evidence is not sufficient to conclude that a 

causal relationship is at least as likely as not, or is not sufficient to make a 

scientifically informed judgment.

4. Against: The evidence suggests the lack of a causal relationship.

The scientific review would include all relevant evidence using existing systematic review models. The Science Review Board would develop 

standard operating procedures, which would be reviewed and updated 

on a regular basis, and outline the protocol by which evidence would be 
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reviewed and categorized. The evidence gathered and reviewed would be 

similar in nature to that supporting cancer or reproductive toxicity evaluations by the National Toxicology Program’s Center for the Evaluation of 

Risks to Human Reproduction, the National Toxicology Program’s Report 

on Carcinogens, the International Agency for Research on Cancer, and the 

U.S. Environmental Protection Agency. The public and stakeholders would 

be encouraged to provide input into the scientific review process. 

If the evidence for causation were categorized as Sufficient or at Equipoise and Above, then we anticipate that VA would consider a presumptive service connection based upon causal evidence categorization and the 

service-attributable fraction if available (to be estimated in the second step 

of the process, described below). As is current VA policy, if the evidence is 

at Equipoise, the benefit of the doubt would be given to the veteran, and a 

presumptive service connection would be considered. If the evidence were 

categorized as Against, then we anticipate that VA would not consider a presumptive service connection. If, however, the evidence were categorized as 

Below Equipoise, then we anticipate that VA would, after carefully considering the prospects and recommendations for future research, decide on an 

appropriate time frame for the subsequent scientific review of the evidence, 

with the expectation that the evidence would then be sufficient to resolve 

matters either for or against the causal claim at that time. Such information 

would be considered by the Advisory Committee serving in its capacity as 

overseer of the overall process and advisor to the VA Secretary. 

If the VA Secretary were to decide that a presumption would not be 

established for evidence categorized as Below Equipoise or, for other reasons, for evidence categorized as Equipoise and Above, then during the 

period of further evidence development and gathering and prior to the 

subsequent scientific review of the evidence, VA should consider providing 

some support to potentially affected veterans, such as providing provisional 

access to medical care. 

As evidence accumulates, the balance might move to strengthen or 

to weaken the case for causality. Importantly, the Science Review Board 

should be free to upgrade the level of evidence, to downgrade the level of 

evidence, or to leave it as the same categorization. For evidence that has 

reached the classification of Sufficient, we would not anticipate a potential 

lowering of the classification, if the original determination was correctly 

made and based on sound scientific evidence. 

If the strength of the evidence reaches Sufficient or Equipoise and 

Above, then the evaluation would move to step two, the calculation of 

the service-attributable fraction of disease when required information and 

data are available. This calculation is independent of the classification of 

the strength of evidence for causation, and the magnitude of the serviceattributable fraction is not considered in the application of the four-level 
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324 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

schema for categorizing evidence. Rather, the service-attributable fraction 

would be of value for decision making, giving an understanding of the 

scope of the population to be covered by a presumption. 

In step two, the Science Review Board would consider the extent of 

exposure among veterans and subgroups of veterans, as well as doseresponse relationships. When such information is available, the board 

would estimate the service-attributable fraction and its related uncertainty. 

The purpose of step two is to convey the impact of the exposure on veterans as a whole for the purpose of decision making and planning, but 

not to serve inappropriately as an estimate of probability of causation for 

individuals. Some exposures may contribute greatly to the disease burden 

of veterans, while other exposures (even with a known causal effect) may 

have a small impact overall. This additional information would be useful 

to VA in its decision making as to whether a presumption should be made 

for the veteran population in general, for subgroups, or not at all. When 

service-attributable fraction data are not available, the VA may consider 

presumptions on the information contained in step one.

Periodic Reevaluation of Evidence 

All but the most conclusive evaluations would be subject to rereview 

and updating. Rereviews could follow a fixed cycle, for example every 

5, 7, or 10 years. Rereview and updating could also be triggered by new 

compelling scientific information, in which case outside parties could make 

nominations to the Advisory Committee for reconsideration by the Science 

Review Board. 

EXAMPLE OF APPLICATION IN CURRENT CONFLICTS

The Committee’s framework is intended for prospective application 

during peace- and wartime and for in-garrison exposures as well as those 

experienced in wartime theatres. The potential utility of the recommended 

approach might be considered by applying it retrospectively to the case 

studies or prospectively to the current conflicts in Iraq and Afghanistan. For 

the purposes of this hypothetical illustration we use the current conflicts, 

although in establishing the framework we drew on lessons learned from 

the case studies regarding such matters as secrecy (e.g., mustard gas and 

lewisite), lack of ongoing epidemiological surveillance (e.g., cardiovascular 

disease in amputees), and insufficient exposure information (e.g., Agent 

Orange and Gulf War in 1990).

With regard to the current military actions in Iraq and Afghanistan, 

the conflicts have been marked by the hostility of the environments with 

ubiquitous threats to military personnel and widespread use of improvised 
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THE WAY FORWARD 325

explosive devices (IEDs) bringing risk of maiming and death. The level of 

psychological stress has increased risk for posttraumatic stress disorder 

(PTSD) and the IEDs have led to high rates of limb loss and traumatic 

brain injury (TBI). Additionally, many of the deployed personnel are in 

the National Guard and Reserves and have faced unexpected disruption 

of their civilian lives from one or several deployments during the course of 

the current conflicts.

How might a full implementation of the Committee’s proposed framework prove useful for the purpose of presumptive disability decision making for veterans of the current conflicts in Iraq and Afghanistan? We call 

for systematic and ongoing exposure assessment that would extend beyond 

chemical, biological, and physical stressors to psychological stress; with 

suitable instruments, exposures to stress would be estimated among samples 

of various at-risk groups of individuals, as the basis for future observation 

for onset of PTSD or other disorders in relation to exposure. For chemical 

exposures, industrial hygiene approaches could also be used for exposed 

groups of individuals, again as the basis for assigning exposures to various groups. Stored blood samples from pre- and post-deployment examinations could also be used to indicate and assess exposures to chemical 

agents, to assess immune responses to infectious agents, or to measure other 

biomarkers of exposure or of injury. For all deployed personnel, geographic 

location and duties could serve as the basis for assigning potential exposures to groups of individuals.

Information on future disease risks in relation to exposure could be 

obtained through follow-up via health status and exposure data records 

linkage to VA, DoD, and other data systems, including the National Health 

Index for mortality. Special cohorts (e.g., registries) could be constructed 

to identify and track particular exposed groups with greater intensity and 

focused outcome assessment. Service members with TBI should be identified and tracked, for example, for level of functioning and quality of life. 

Risk for PTSD might be monitored in groups with greater and lesser levels 

of stress.

A general consequence of the Committee’s approach would be continuous monitoring of health outcomes among those who had been deployed 

to the zones of current conflict in Iraq and Afghanistan. Comparison of 

disease risks in those deployed to those not deployed in these areas could 

signal any potential increased risk and lead to more focused assessment and 

review of exposure and health outcomes concerns, including review by the 

Advisory Committee.

In the event that the Advisory Committee determined that an evidence evaluation was needed, the Science Review Board would be able 

to use the findings of the exposure and health tracking system. Evidence 

would be available directly from the tracking of veterans that would be 
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326 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

included in the review along with other relevant information. If indicated 

by the classification of strength of evidence, the service-attributable fraction should be estimable. The size of the exposed, and hence eligible, pool 

of veterans would be known with some degree of certainty. The evidence 

review conducted by the Science Review Board would be reported back to 

VA, so that the VA Secretary could make a determination as to whether 

a s­ervice-­connection presumption would be established. These activities 

would follow the transparent process laid out by the Committee, possibly 

increasing confidence in the decisions made. 

SECRECY AND THE PRESUMPTIVE DISABILITY 

DECISION-MAKING PROCESS

Research involving individuals exposed to chemical, biological, or 

radiological agents is often classified for security reasons, and information 

related to clandestine missions is also classified. This classification can be 

detrimental to the long-term health status of our veterans, who maintain the 

oath of secrecy. So long as information remains classified—which can be for 

a long period of time—these veterans cannot openly investigate or inquire 

about the relationships between their disease or health condition and the 

exposures they received. Although secrecy must be applied and maintained 

for obvious homeland security and national defense reasons, this designation must not be used to deny or forestall necessary medical treatment 

for afflicted individuals. As made clear by the case study of mustard gas 

and lewisite (see Appendix I), veterans may be harmed by exposures from 

classified activities. It is absolutely necessary for DoD and VA to develop, 

implement, and maintain a policy program that addresses the issues of 

health maintenance and national security for our veterans. The case study 

of mustard gas and lewisite illustrates the opportunity for harm to occur in 

research volunteers because of secrecy (see Appendix I).

Regarding the processes for science review proposed here, review would 

be particularly challenging when classified or secret information is involved. 

Nonetheless, the Committee recommends that DoD and VA develop a process for ensuring that exposures sustained in the course of classified or secret 

activities are not excluded from the presumptive disability decision-making 

process. Our Committee can make only general comments on this matter. 

For some issues involving classified and secret information, consultants with 

appropriate expertise and security clearance might be added to the Advisory 

Committee and Science Review Board. They could review the classified or 

secret information and provide information or recommendations for the 

decision process in a format that would not violate the government’s need 

for secrecy. This variation in process would be clearly and openly described. 
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THE WAY FORWARD 327

Perhaps in some circumstances, no element of the relationship between 

military exposure and the condition could be divulged. This circumstance 

would call for a separate special process to protect government secrecy as 

well as provide fair treatment for affected veterans.

ADDITIONAL DATA FOR DECISION MAKING

To make the best possible decisions regarding compensation for veterans, it is necessary to go beyond the published literature. In this section 

we will consider several sources of data that would greatly enhance the 

presumptive disability decision-making process for veterans.

At present, research on the health of veterans is conducted in a variety 

of venues. Examples include the following:

• Intramural research of the War-Related Illness and Injury Study 

Center assesses the health consequences of deployment to a combat 

theater. 

• The Medical Follow-Up Agency of IOM’s Board on Military and 

Veterans Health carries out targeted epidemiologic research on health of 

military personnel. 

• Extramural research related to the health of veterans may be funded 

by VA through its extramural research program or by the National Institutes of Health. 

Although investigators at the War-Related Illness and Injury Study 

Center have a track record of productivity, the Committee anticipates that 

substantial additional capacity for multidisciplinary research will be needed 

as better surveillance methods are put into place and new hypotheses are 

generated.

The approach to research should be driven by a sustained and iterative 

planning process that strategically identifies and addresses emerging questions. Issues needing investigation might be identified through surveillance 

findings, stakeholder input, or findings emerging in research conducted 

beyond VA. VA needs a process that strategically addresses research needs 

to ensure that presumptions are evidence-based to the best extent possible. 

In the Committee’s recommendations, we call for an Advisory Committee that would provide guidance to VA in developing and maintaining a 

targeted and strategic research planning process. The reviews carried out 

by the Science Review Board would also highlight gaps that need to be 

addressed through research.
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328 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

REFERENCES

IOM (Institution of Medicine). 1993. Veterans at risk: The health effects of mustard gas and 

lewisite. Washington, DC: National Academy Press.

IOM. 1994. Veterans and Agent Orange: Health effects of herbicides used in Vietnam. Washington, DC: National Academy Press. 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy 

Press. 

IOM. 1999. Veterans and Agent Orange: Update 1998. Washington, DC: National Academy 

Press. 

IOM. 2000a. Gulf War and health, volume 1: Depleted uranium, pyridostigmine bromide, 

sarin, vaccines. Washington, DC: National Academy Press. 

IOM. 2000b. Veterans and Agent Orange: Herbicide/dioxin exposure and type 2 diabetes. 

Washington, DC: National Academy Press. 

IOM. 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy 

Press. 

IOM. 2003a. Gulf War and health, volume 2: Insecticides and solvents. Washington, DC: The 

National Academies Press.

IOM. 2003b. Veterans and Agent Orange: Update 2002. Washington, DC: The National 

Academies Press. 

IOM. 2005a. Gulf War and health, volume 3: Fuels, combustion products, and propellants. 

Washington, DC: The National Academies Press. 

IOM. 2005b. Veterans and Agent Orange: Update 2004. Washington, DC: The National 

Academies Press.

IOM. 2006. Gulf War and health, volume 4: Health effects of serving in the Gulf War. Washington, DC: The National Academies Press. 

IOM. 2007. Gulf War and health, volume 5: Infectious diseases. Washington, DC: The 

National Academies Press. 
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329

13

Recommendations

In meeting its charge, the Committee has heard presentations and 

received information from past and present congressional staff members 

as well as representatives of the Department of Veterans Affairs (VA), the 

Department of Defense (DoD), the Institute of Medicine (IOM), various 

stakeholder groups (e.g., veterans service organizations [VSOs]), individual 

veterans and the general public. The Committee has reviewed an extensive 

amount of information including (but not limited to): documents provided 

by the Veterans’ Disability Benefits Commission, public laws and their supporting House and Senate committee reports, Federal Register notices, VA 

documents (i.e., cost estimates), DoD documents, and IOM reports that 

have been commissioned by VA and DoD. The Committee has completed 

case studies that analyze a wide variety of circumstances in which presumptions have been established by Congress and VA. Additionally, the Committee has considered how to use scientific evidence in guiding the process for 

making decisions that impact the compensation of veterans. It has covered 

the evaluation of evidence for inferring association and causation as well 

as the quantification of the contribution of an agent to disease causation in 

populations and the extension of this quantification to individuals. 

Based on its extensive evaluation of the current process for establishing presumptive disability decisions and its consideration of alternative approaches, the Committee has a series of recommendations for an 

approach that is both more strongly grounded in scientific evidence and 

more responsive and open to veterans. Chapter 12 describes that process. We propose a transformation of the current presumptive disability 

decision-making process for veterans. We recognize that considerable time 
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330 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

will be needed to implement some of these recommendations and will 

require investment in tracking the exposures and health of current military 

service men and women as well as veterans. Progress depends on greater 

research capacity and changes in the evaluation and use of scientific evidence in making compensation decisions. The Committee finds that there 

are sufficient remediable shortcomings within the current process to warrant immediate action as Congress and VA move toward implementation 

of a new approach. The Committee concluded that improvements are 

needed throughout the presumptive disability decision-making process. 

The recommendations that follow are based on the Committee’s proposed 

framework for making presumptive decisions (see Chapter 12). We list the 

recommendations in relation to the appropriate body. In recommending the 

organizational structure below, the Committee recognizes that Congress 

and VA might pursue alternative structures to achieve the Committee’s 

overall goal of having an evidence-based presumptive disability decisionmaking process. However, the Committee believes that its proposal is feasible and practical over time, many of the elements in its proposal can and 

should be implemented without delay and that the Committee’s proposal 

would significantly improve the presumptive disability decision-making 

process for veterans.

CONGRESS

Recommendation 1. Congress should create a formal advisory committee (Advisory Committee) to VA to consider and advise the VA Secretary on disability-related questions requiring scientific research and 

review to assist in the consideration of possible presumptions.

The investigation and evaluation of the relationships of exposures during military service and subsequent disabilities experienced by veterans have 

not been sufficiently prompt and comprehensive. To assure that research 

and review are timely and on target, the Committee recommends creation 

of an Advisory Committee to VA composed of veterans and recognized 

experts in disciplines such as epidemiology, toxicology, exposure assessment and biostatistics to identify and assess issues for referral to the VA 

Secretary and then to the Science Review Board, which would carry out 

the subsequent full, comprehensive scientific evaluation of the evidence (see 

Recommendation 2).

In the Committee’s recommended approach, the Advisory Committee 

has two key roles: screening exposures and illnesses proposed for review 

for possible presumptive compensation, and providing guidance to VA on 

research needs and planning. The multidisciplinary Advisory Committee 
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RECOMMENDATIONS 331

should include stakeholder representatives and have a permanent staff to 

support its function. 

The Advisory Committee would also receive the proposals for exposures and illnesses of concern made by stakeholders and other groups. With 

staff, the Advisory Committee would evaluate the candidates for potential presumptions and make recommendations to the VA Secretary as to 

whether a full, comprehensive scientific review by the Science Review Board 

should be carried out. Recommendations made to the VA Secretary and 

his or her responses thereto should be reported to Congress on an annual 

basis. To assist the Advisory Committee, a VA tracking system should be 

developed to identify filed disability claims that suggest the need for further 

investigation of the relationship linking exposures to health conditions during service. Additionally, claims filed and decided following the creation of 

a presumption should be tracked to validate previous estimates of case load 

and to project future claims arising secondarily from the primary condition 

for service connection.

Recommendation 2. Congress should authorize a permanent independent review body (Science Review Board) operating with a well-defined 

process that will use evaluation criteria as outlined in this Committee’s 

recommendations to evaluate scientific evidence for VA’s use in considering future service-connected presumptions.

Current statutory authority for independent evaluation of scientific evidence for potential service-connected presumptions has too often resulted 

from ad hoc responses to the pressing questions of the moment. Absent a 

permanent committee and staff to consider and evaluate the evidence relevant to particular potential presumptions, approaches to evaluation have 

not been uniform and have not always provided VA with evidence syntheses 

that fully used the available evidence. The implementation of the Science 

Review Board, or a comparable entity, is central to the Committee’s recommended changes to the presumptive disability decision-making process.

The Science Review Board would implement a well-defined, consistent, 

and transparent evidence-based approach as described in this report. It 

should be housed within an organization or institution that can assure the 

highest level of credibility for its process and reports. The existence of a 

permanently staffed body would also allow it to be proactive rather than 

reactive to veterans’ concerns. 

Recognizing that the development of sufficient scientific evidence to 

warrant a positive presumptive decision does not always occur quickly, 

Congress should also consider granting VA discretionary authority to provide provisional medical treatment to veterans while research findings are 

pending.
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332 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

DEPARTMENT OF VETERANS AFFAIRS

Recommendation 3. VA should develop and publish a formal process 

for consideration of disability presumptions that is uniform and transparent and clearly sets forth all evidence considered and the reasons 

for the decisions reached.

Pursuant to statute, VA is directed to make decisions concerning the 

establishment of service-connected presumptions for Agent Orange determined on the basis of sound medical and scientific evidence. In making such 

decisions, VA is required to consider pertinent reports from the National 

Academy of Sciences and “all other sound medical and scientific information and analyses available” (Agent Orange Act of 1991. Public Law 102-4. 

102d Cong., 1st Sess.).

The Committee found that VA (1) has no formal published rules governing this process, (2) does not thoroughly disclose and discuss what 

“other” medical and scientific information it considered, and (3) publishes 

abbreviated and insufficiently informative explanations of why a presumption was or was not granted. 

The closed nature of VA practices does not foster public understanding 

of the reasoning behind the VA’s decisions; the Committee believes that a 

move by VA to a more transparent process would better meet the expectations of the nation’s veterans and of the public at large. The Committee 

recommends that VA promulgate, without delay, a more formal procedure 

for establishing presumptive disability decisions. The procedure needs to 

be transparent and consistent with the practices of federal regulatory agencies. The word “uniform” in the recommendation refers to a process that 

works in a consistent fashion with regards to its procedures and outcomes; 

in other words, given a similar body of evidence for different diseases, the 

end result of the process should be similar. Members of internal working 

groups should be disclosed; all evidence considered should be disclosed; and 

a thorough discussion of the weight attached to the evidence considered 

should be published so that veterans and the public have a clear understanding of the basis for the decision reached.

SCIENCE REVIEW BOARD

The recommendations that follow are directed toward the proposed, 

future Science Review Board, the entity to be established in the Committee’s 

proposed approach.

Recommendation 4. The Committee recommends that the goal of the 

presumptive disability decision-making process be to ensure compen-
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RECOMMENDATIONS 333

sation for veterans whose diseases are caused by military service and 

that this goal must serve as the foundation for the work of the Science 

Review Board. The Committee recommends that the Science Review 

Board implement its proposed two-step process.

Previous IOM Agent Orange committees have focused on strength of 

evidence for an association when causal language has also been included 

in their charge (IOM, 1994, 1996, 1999, 2000b, 2001, 2003b, 2005b). 

Agent Orange legislation calls for establishing the presence of an “association” between exposure and disease; however, the enabling legislation 

also called for consideration of study bias and biologic mechanisms, which 

address the underlying question of causation (Agent Orange Act of 1991. 

Public Law 102-4. 102d Cong., 1st Sess.). IOM Gulf War committees have 

established evidence categorizations based upon both causation and association (IOM, 2000a, 2003a, 2005a, 2006, 2007). The enabling legislation 

for Gulf War actions did not specify the strength of evidence to be used in 

scientific reviews (Veterans’ Benefits Improvements Act of 1994. Public Law 

103-446. 103rd Cong., 2d Sess., codified as Compensation for Disabilities 

Occurring in Persian Gulf War Veterans. 2006. 38 U.S.C. § 1117; Omnibus 

Consolidated and Emergency Supplemental Appropriations Act of 1998 

(Part II). Public Law 105-277. 105th Cong., 2d Sess.). The IOM committee 

that evaluated mustard gas and lewisite based its evidence categorization 

solely upon causation (IOM, 1993). The Committee therefore recommends 

that the focus be shifted to the question most fundamental to presumptions, 

namely whether a military exposure is able to cause a disease. 

Recommendation 5. The Committee recommends that the Science 

Review Board use the proposed four-level classification scheme, as 

follows, in the first step of its evaluation. The Committee recommends 

that a standard be adopted for “causal effect” such that if there is at 

least as much evidence in favor of the exposure having a causal effect 

on the frequency or severity of disease as there is evidence against, then 

a service-connected presumption will be considered.

The Committee recognizes that gathering and synthesizing the evidence 

necessary to prove a causal effect can be daunting, but expert groups have 

repeatedly done so using replicable approaches and standard classification 

schemes. The Science Review Board should adopt a written protocol for evidence review and apply the Committee’s recommended four-level scheme: 

1. Sufficient: The evidence is sufficient to conclude that a causal relationship exists.

2. Equipoise and Above: The evidence is sufficient to conclude that a 
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334 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

causal relationship is at least as likely as not, but not sufficient to conclude 

that a causal relationship exists. 

3. Below Equipoise: The evidence is not sufficient to conclude that a 

causal relationship is at least as likely as not, or is not sufficient to make a 

scientifically informed judgment.

4. Against: The evidence suggests the lack of a causal relationship.

Using this scheme, the Committee recommends that the presumption of 

a causal effect be considered when an expert scientific evaluation finds the 

evidence considered in support of a causal effect to be at least as strong as 

the evidence against. We express this criterion as “Equipoise and Above.” 

Recommendation 6. The Committee recommends that a broad spectrum of evidence, including epidemiologic, animal, and mechanistic 

data, be considered when evaluating causation. 

Past decisions on presumptions have sometimes been based largely on 

epidemiologic evidence. The Committee recommends that evidence to evaluate causation be derived not only from epidemiologic studies of veterans 

and other exposed groups, but also from toxicological studies of animals or 

tissue, mechanistic studies of biological mechanisms related to the exposure 

or the disease process, and any other relevant scientific evidence. There 

are a number of existing approaches used by other organizations that the 

Science Review Board should consider.

Recommendation 7. When the causal evidence is at Equipoise and 

Above or Sufficient, the Committee recommends that an estimate also 

be made of the size of the causal effect among those exposed. 

In past evaluations, the primary question has been whether there is 

an association between an exposure and disease. The Committee recommends that future evaluations should, in addition, provide an estimate of 

the strength of this association. In the crudest setting, this may be a simple 

ratio of the risk among the exposed compared with the risk among the 

unexposed (the relative risk). More sophisticated estimates may also be 

made, for example when there are dose-response data that can be applied 

to levels of military exposure. 

Recommendation 8. The Committee recommends that, as the second 

part of the two-step evaluation, the relative risk and exposure prevalence be used to estimate an attributable fraction for the disease in the 

military setting (i.e., service-attributable fraction).
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RECOMMENDATIONS 335

The relative risk can be used to make a rough estimate of the fraction of 

diseased persons exposed in the military setting whose disease was actually 

caused by their military exposure. Although this number is only roughly 

approximate, it does provide an estimate of the burden of disease caused 

by the military exposure and could be useful for projecting future costs. 

This estimate may be useful to VA in its decision-making process and to the 

veterans themselves in assessing the need for a presumption. 

DEPARTMENT OF DEFENSE AND THE 

DEPARTMENT OF VETERANS AFFAIRS

The following recommendations are intended to improve the evidence 

on exposures and health status of veterans:

Recommendation 9. Inventory research related to the health of veterans, including research funded by DoD and VA, and research funded 

by the National Institutes of Health and other organizations.

Recommendation 10. Develop a strategic plan for research on the 

health of veterans, particularly those returning from conflicts in the 

Gulf and Afghanistan.

Models are available for planning major long-term research agendas 

that are intended to identify critical gaps in the availability of evidence. For 

example, a National Research Council committee provided a national agenda 

for research on airborne particles (NRC, 1998) that was used by the Environmental Protection Agency to initiate and track a major research program. 

Recommendation 11. Develop a plan for augmenting research capability 

within DoD and VA to more systematically generate evidence on the 

health of veterans.

Recommendation 12. Assess the potential for enhancing research 

through record linkage using DoD and VA administrative and health 

record databases.

Recommendation 13. Conduct a critical evaluation of Gulf War troop 

tracking and environmental exposure monitoring data so that improvements can be made in this key DoD strategy for characterizing exposures during deployment.

Characterizing personnel exposures during deployment depends extensively on a system of troop location tracking and environmental monitoring 
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336 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

that can be coordinated to characterize Service members’ exposures. This 

approach is relatively new and, while promising, faces some key limitations as currently implemented that may significantly affect the degree to 

which the approach can adequately characterize individual Service member 

exposures. Experience acquired during the Gulf War, and subsequent uses 

of tracking systems in Afghanistan and Iraq, offer important opportunities 

to evaluate effectiveness so that refinements can be implemented.

Recommendation 14. Establish registries of Service members and veterans based on exposure, deployment, and disease histories.

Creating registries of Service members based on common groupings 

that may be important for future health surveillance or research is most 

easily performed at the time the Service members are together in those 

groupings. Making lists years after the common experience can lead to 

inaccuracies from lost records and recall bias. Groupings for registries can 

be based on many characteristics, including common exposures, common 

jobs, common deployment experiences, or common illnesses.

Recommendation 15. Develop a plan for an overall integrated surveillance strategy for the health of Service members and veterans. 

DoD and VA need to work together to define a common strategy for 

integrated health surveillance of Service members and veterans. The need 

for surveillance can be identified at many points along a veteran’s service 

to post-service experience. Surveillance studies that are initiated during a 

Service member’s service career may need to extend beyond the period of 

military service. Data requirements for the specific surveillance activity 

may have been generated during military service, after military service, or 

both.

Recommendation 16. Improve the data linkage between the electronic 

health record data systems used by DoD and VA—including capabilities 

for handling individual Service member exposure information that is 

included as part of the individual’s health record.

There is immediate benefit to be gained by a robust electronic sharing of military health records, including exposure information, by DoD 

with VA. DoD has mandated inclusion of service exposure records into its 

health records. Military health records are a routine part of VA’s approach 

to assessing veteran health and disability. The final link in the chain is the 

complete transfer of those exposure and health records from DoD to VA.
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RECOMMENDATIONS 337

Recommendation 17. Ensure implementation of the DoD strategy for 

improved exposure assessment and exposure data collection.

DoD has an ambitious and robust plan for improving the breadth 

and depth of its exposure evaluations and in consolidating records and 

approaches. These data would be especially useful for the longitudinal 

characterization of Service member exposures. Given the importance 

of the success of this initiative to the future understanding of servicerelated exposures, it is critical that the plan be fully implemented. The 

Committee recommends that the Veterans’ Disability Benefits Commission work through Congress to establish a specific DoD budget line for 

the Defense Occupational and Environ­mental Health Readiness System 

(DOEHRS) implementation, including the appropriate training of personnel in exposure assessment and in use of the system, and that Congress 

receive annual reports from DoD on the status of DOEHRS development 

and implementation.

Recommendation 18. Develop a data interface that allows VA to access 

the electronic exposure data systems used by DoD.

DoD continues to invest heavily in electronic systems for documenting 

exposures experienced by Service members during their military service. 

These data are critical to VA’s ability to manage veteran health and disabilities and to the presumptive disability decision-making process, yet 

VA has direct access to little of DoD’s data. DoD and VA should begin to 

work together immediately to assess the available systems and to define and 

construct appropriate interfaces for these systems. The Committee recommends that the Veterans’ Disability Benefits Commission work through 

Congress to establish specific DoD and VA budget lines to enable the development and implementation of a data interface that allows electronic access 

between DoD and VA records, and that Congress receive annual reports 

from DoD and VA on the development and implementation efforts.

Recommendation 19. DoD and VA should establish and implement 

mechanisms to identify, monitor, track, and medically treat individuals 

involved in research and other activities that have been classified and 

are secret.

The major requirements for interaction between DoD and VA regarding 

classified activities would be the following: 

• Prospectively identify classified studies and activities involving 

humans.
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338 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

• Develop a registry of Service members involved in the studies and 

activities.

• Develop a tracking mechanism to maintain contact with the Service 

members involved.

• Provide periodic medical evaluations and surveillance of Service 

members involved.

• Determine appropriate medical treatment if an adverse health effect 

is detected.

• Develop a mechanism to make information public as necessary.

• Keep the veterans, and families as applicable, fully informed regarding potential health effects of the materials that were used in the studies and 

activities. 

The Advisory Committee, mentioned previously, could be assigned to 

oversee these functions.

REFERENCES

IOM. 1993. Veterans at risk: The health effects of mustard gas and lewisite. Washington, DC: 

National Academy Press. 

IOM. 1994. Veterans and Agent Orange: Health effects of herbicides used in Vietnam. Washington, DC: National Academy Press. 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy 

Press. 

IOM. 1999. Veterans and Agent Orange: Update 1998. Washington, DC: National Academy 

Press. 

IOM. 2000a. Gulf War and health, volume 1: Depleted uranium, pyridostigmine bromide, 

sarin, vaccines. Washington, DC: National Academy Press. 

IOM. 2000b. Veterans and Agent Orange: Herbicide/dioxin exposure and type 2 diabetes. 

Washington, DC: National Academy Press. 

IOM. 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy 

Press. 

IOM. 2003a. Gulf War and health, volume 2: Insecticides and solvents. Washington, DC: The 

National Academies Press. 

IOM. 2003b. Veterans and Agent Orange: Update 2002. Washington, DC: The National 

Academies Press. 

IOM. 2005a. Gulf War and health, volume 3: Fuels, combustion products, and propellants. 

Washington, DC: The National Academies Press. 

IOM. 2005b. Veterans and Agent Orange: Update 2004. Washington, DC: The National 

Academies Press. 

IOM. 2006. Gulf War and health, volume 4: Health effects of serving in the Gulf War. Washington, DC: The National Academies Press. 

IOM. 2007. Gulf War and health, volume 5: Infectious diseases. Washington, DC: The 

National Academies Press. 

NRC (National Research Council). 1998. Research priorities for airborne particulate matter: 

I. Immediate priorities and a long-range research portfolio. Washington, DC: National 

Academy Press.
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339

Appendix A

Statement of the Veterans’ Disability 

Benefits Commission to the 

Institute of Medicine’s Committee on the 

Presumptive Disability Decision-Making 

Process, May 31, 2006

The Veterans’ Disability Benefits Commission created by Public Law 

108-136 is charged with studying the benefits provided to compensate and 

assist veterans for disabilities attributable to military service. The Commission was mandated to consult with the Institute of Medicine (IOM) 

of the National Academy of Sciences with respect to the medical aspects 

of contemporary disability compensation policies. The Commission will 

evaluate and assess:

• The appropriateness of benefits

• The appropriateness of the level of those benefits

• The appropriate standard(s) for determining whether the disability 

should be compensated

In order to meet the three goals above, the Commission produced a 

list of 31 research questions to be answered during its investigation. IOM 

has established four committees that will address some of these questions 

in whole or in part. Your Committee will research and report on presumptions. Another committee, the Committee on Medical Evaluation of 

Veterans for Disability Compensation, was created to research and report 

on several aspects of compensation policies. IOM also established two 

committees to deal with various aspects of PTSD including diagnosis, treatment, and compensation. The Commission encourages your Committee to 

collaborate with the other three committees since there are many areas of 

overlapping and complementary interests.
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340 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

The Commission consists of 13 members who were appointed by the 

President and the leaders of Congress. Twelve of the Commissions have 

served in the military. Nine members have combat experience. Combined, 

the members have over 260 years of military experience. The establishing 

statute requires that seven members have received combat decorations such 

as the Silver Star or higher. The Commission is charged to submit its report 

by October 1, 2007, to the President and Congress.

The Commission is looking forward to receiving expert advice from 

your Committee regarding the process by which presumptions of service 

connections are established. The Commission asks that you evaluate the 

current model used to determine diseases that qualify for service connection on a presumptive basis, and if appropriate, propose improvements in 

the model.

The Commission requests that your Committee assess the overall process used to establish a presumption. Currently, in determining if a herbicide 

disease should have a presumption established, the Secretary must determine that the results upon which the presumption is based are statistically 

significant, are capable of replication, and withstand peer review.

The Commission previously provided IOM an analysis of the history of 

presumptions completed by the VA Office of General Counsel in 1993. The 

Commission also provided an analysis completed this year by Mr. Donald 

Zeglin, legal consultant to the Commission, which summarized the General 

Counsel analysis and analyzed decisions on presumptions that occurred 

since the completion of the General Counsel analysis.

A presumptive condition is an injury or illness in which VA presumes 

a relationship exists between service and the conditions being claimed. A 

recurring theme within the compensation program has been the expansion of the definition of service connection, mainly under the presumption 

basis.

In general terms, presumptions shift the burden of proof from the veteran to the Government. Among the earliest presumptions, not dealing with 

service connection, are the presumption of sound condition upon entry on 

active military duty, the presumption relating to aggravation of pre-existing 

conditions during service, and the presumption of death after an absence 

of seven years.

In many instances, presumptions of service connection have been created when the manifestation of disability is remote from the veteran’s service. This could be because medical science could not determine the origin 

or cause of some disabilities such as multiple sclerosis or how long the time 

period should be between exposure to the origin and initial diagnosis. In 

some cases, delayed onset is recognized as a feature of a disability such as 

posttraumatic stress disorder. In other cases, evidence supporting the need 

for a presumption can only be obtained through epidemiological studies 
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APPENDIX A 341

of the frequency of disease among groups of people and research into the 

effects of various exposures on health.

Some presumptions were mandated by statute and some of those were 

based more on a political decision than a scientific decision. Often, the basis 

for presumption consisted of a combination of expert opinion, advocacy 

from organizations and individuals, and Congress’ sense of justice, rather 

than scientific evidence.

The Commission would like you to thoroughly assess the processes used 

in the past and at the current time to make decisions on presumptions. In 

some cases, you may find that the processes are ad hoc in nature, varying from 

time to time and depending on the political and management philosophies of 

those involved. An understanding of past processes will be very instructive in 

deciding what the most appropriate process should be in the future.

The Commission is aware, as is the Institute of Medicine, that several 

presumptions were approved because it was not possible to document exposure to biological, chemical, radiological, or other environmental agents by 

accurate information on the exact locations to which military service members were assigned during precise periods of time. This lack of information 

prevented definitive studies. Your Committee may be able to provide substantive advice concerning how to ensure that this situation is not repeated 

in the future. Currently everyone who served in Vietnam is presumed to 

have been exposed to dioxin from Agent Orange. Do we have a better way 

of making these determinations?

A review of the history of the process for some presumption determinations indicates that many years can elapse between the onset of the 

disease and the establishment of the presumption. Examples of this include 

diseases associated with herbicide exposure during Vietnam service and 

experi­mental exposure to mustard gas during WWII service. Such long 

periods of time without compensation have no doubt resulted in significant 

hardship for many veterans and their families. What are the factors that 

contribute to these long periods of elapsed time? What can be done about 

these factors to improve the result?

Agent Orange, Radiation, and Gulf War Syndrome have resulted in a 

rapidly growing area of environmental presumptions that have prompted 

some to raise questions about the disability compensation program. War 

often affects men and women in profound ways that are not easily explainable or treatable. Many veterans experience problems/diseases that they 

attribute to chemical or radiation exposure. Leaving aside questions of the 

possible effect of psychic injuries inflicted by war on these questions, it 

seems that science cannot easily or quickly resolve these issues particularly 

where (1) chemical/radiation exposure levels are often unknowable or difficult to ascertain and (2) the effect of exposure on diseases experienced is 

scientifically unsettled.
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342 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Notwithstanding this uncertainty, the intense emotions surrounding 

those genuinely suffering and the perceived unfairness of forcing veterans 

to “prove” the environments or places where they served related to their 

possible exposure has led Congress and the Executive Branch to create 

presumptions. Certain studies (not even necessarily involving veterans), for 

example, showing that those exposed to dioxin have slightly higher rates of 

diabetes or prostate cancer, have resulted in an inexorable push to compensate all veterans with diabetes/prostate cancer even if it is likely that dioxin 

exposure is a determinative factor in only a small percentage of cases. Since 

it is impossible to know what role dioxin played in any particular case, all 

Vietnam veterans with diabetes and prostate cancer have been and are being 

granted presumptive service connection. Is this presumption fully supported 

by medical evidence? What amount of increase in occurrence rate is enough 

to warrant compensation? What approaches could be considered to alleviate this costly result?

Your Committee should consider if a different methodology should 

be used in determining causal relationships other than the environmental 

aspect used for the current method. Should the Committee on Presumptions 

review the Gulf War Illness presumptions? Should there be a defined process 

in place at VA to review and establish presumptions? Should the same or a 

different process be used periodically to review existing presumptions?

The Commission also requests that your Committee provide advice, 

from an epidemiological and statistical standpoint, on what strength of 

evidence would be the appropriate requirement when the Secretary of Veterans Affairs considers whether to establish a presumption. Currently, in 

determining if a herbicide disease should have a presumption established, 

the Secretary must determine that the results upon which the presumption 

is based are statistically significant, are capable of replication, and withstand peer review. And, an association is considered positive if the credible 

evidence for the association is equal to or outweighs the credible evidence 

against the association. Should the standards for inferential statistical evidence in finding an association between causative factors and disabilities change? From whom should VA accept sound medical and scientific 

information to analyze and to consider whether a condition be added as a 

presumption?

Are medical advancements occurring so rapidly and new medical findings becoming available so quickly that a formal regulatory process for 

presumption impedes decision making? How could a regulatory process 

react in a timely manner to the accelerating changes in medical science? Is 

a significant change in the methodology used to establish a presumption 

something to be considered?

During your Committee’s review, the Commission would ask you to 

analyze all key documents and literature regarding presumptions to include 
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APPENDIX A 343

all legislative and committee reports. We also encourage you to review 

published research on and medical studies of disease exposure and the 

subsequent development of those diseases.

Requesting your Committee to study these issues underlining the 

research question should not be taken as directing any disposition or finding with respect to the research question. Rather the Commission is asking 

that particular attention be focused on the issue.

SUMMARY

The Commission recognizes the challenges that the Committee on 

Presumptive Disability Decision Making Process faces in dealing with this 

issue. Your Committee has been asked to help ensure that future veterans 

are granted service connection under a presumption basis based on the 

best scientific evidence available. Your advice is crucial. The Commission 

anticipates that you will provide suggestions that will improve the processes 

that establish future presumptions. Presumptions are intended to protect a 

service member from being denied service connection for a disease or injury 

because he/she is unable to confirm the incurrence of the injury during 

combat or exposure to the disease through no fault of his or her own. To 

the extent possible, suggestions that will avoid the necessity for many future 

presumptions by ensuring that exposure of service members is documented 

and scientific evidence is made available would be important.

Having a method of granting service connection quickly and fairly 

based on a presumption is of critical importance to our disabled veterans 

and their surviving spouses. A through review of the present processes is 

needed. The presumptions must also be understandable to raters to allow 

for uniform and equitable application to veterans’ claims regardless of 

where the rating is prepared. Ensuring that future presumption processes 

reflect the then current medical knowledge about the causal relationship 

would benefit entire veteran community.

Your suggestions will be considered by the Commission in determining 

the appropriateness of benefits, the appropriateness of the level of such benefits, and the appropriate standard or standards for determining whether a 

disability or death of a veteran should be compensated.

The Commission will consider the Committee’s findings and suggestions 

in framing its response to the charge from Congress and the President.

We look forward to hearing the results of your Committee’s deliberations in the coming months.
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344

Appendix B

Committee on Evaluation of the 

Presumptive Disability Decision-Making 

Process for Veterans Open Session 

Meeting Agendas

Committee Meeting #1 

May 31, 2006

Keck Center of the National Academies

Washington, D.C.

Agenda

Wednesday, May 31 Room 201

8:30 a.m. Closed Session (Committee Members and IOM Staff Only) 

10:30 a.m. Open Session Begins 

10:30 a.m. Welcome and Introductory Remarks, Introduction of 

Committee Member and Attendees

Jonathan Samet, M.D., M.S., Committee Chair

10:40 a.m. Expectations of the Study Sponsor

Commissioner John Grady (Member, Veterans’ Disability 

Benefits Commission)

11:00 a.m. An Overview of the Disability Benefits Program and 

Presumptions Affecting Veterans’ Benefits

Thomas Pamperin, M.B.A. (Assistant Director for Policy, 

Compensation and Pension Service, Department of Veterans 

Affairs)

11:45 a.m. Legislative and Regulatory History of Presumptions 

David Barrans, J.D. (Deputy Assistant General Counsel, 

Office of General Counsel, Department of Veterans Affairs)
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APPENDIX B 345

12:15 p.m. Lunch

1:15 p.m. The Role of Science in Establishing VA Disability 

Compensation Policies

Mark Brown, Ph.D. (Director, VA’s Environmental Agents 

Service, Office of Public Health and Environmental Hazards, 

Department of Veterans Affairs)

1:45 p.m. Presumptions in VA’s Disability Program—The Effect

Thomas Pamperin, M.B.A. (Assistant Director for Policy, 

Compensation and Pension Service, Department of Veterans 

Affairs)

2:05 p.m. PANEL Q&A—VA Presenters and Committee Members 

2:45 p.m. Break

3:00 p.m. An Examiner’s Use of the Clinician’s Guide and 

How Examiners Are Selected and Trained by VHA

Patrick Joyce, M.D., J.D., M.P.H. (Chief Physician, 

Compensation and Pension Program, VA Medical Center, 

Washington, D.C.)

3:45 p.m. Making Decisions Based on Medical Evidence

Bradley Flohr (Chief of Advisory Review Staff, 

Compensation and Pension Service)

4:15 p.m. Public Comments (Attendees will be given the opportunity to 

make brief remarks to the Committee Members) 

5:15 p.m. Open Session Ends 

5:15 p.m. Closed Session (Committee Members and IOM Staff Only) 

6:15 p.m. Adjourn 

Committee Meeting #2 

July 27, 2006 

Keck Center of the National Academies

Washington, D.C.

Agenda

Thursday, July 27 Room 101

8:30 a.m. Closed Session (Committee Members and IOM Staff Only) 

9:00 a.m. Open Session Begins 

9:00 a.m. Welcome and Introductory Remarks, Introduction of 

Committee Members and Attendees

Jonathan Samet, M.D., M.S., Committee Chair
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346 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

9:10 a.m. Summary of Recent IOM Studies Conducted for VA

Rose Marie Martinez, Sc.D. (Director, Board on Population 

Health and Public Health Practice, Institute of Medicine)

9:45 a.m. VA Health Care Utilization Among Operation Iraqi Freedom/

Operation Enduring Freedom Veterans

Han K. Kang, Dr.P.H. (Director, Environmental 

Epidemiology Service, Department of Veterans Affairs)

10:15 a.m. Overview of VA Registries

Han K. Kang, Dr.P.H. (Director, Environmental 

Epidemiology Service, Department of Veterans Affairs)

10:45 a.m. Break 

11:00 a.m. Assessing Environmental and Occupational Exposures—

VA Disability and Compensation Policies

Lawrence R. Deyton, M.S.P.H., M.D. (Chief Officer, Public 

Health and Environmental Hazards, Department of Veterans 

Affairs)

12:00 p.m. Lunch 

1:00 p.m. Overview of DoD Deployment and Installation-Based 

Occupational and Environmental Health Programs

R. Craig Postlewaite, D.V.M., M.P.H. (Senior Analyst, 

Environmental Health Surveillance, DoD Deployment Health 

Support Directorate)

1:20 p.m. Deployment Health Surveillance: Past, Current, and Future 

Operations

Jack M. Heller, Ph.D. (Director, Health Risk Management, 

U.S. Army Center for Health Promotion and Preventive 

Medicine)

2:05 p.m. DoD Occupational Health Exposure Assessment Processes

John Seibert, C.I.H., C.S.P. (Assistant for Safety, Health and 

Fire Protection, Office of the Deputy Under Secretary of 

Defense for Installations and Environment)

2:50 p.m. Break 

3:00 p.m. Panel Discussion with DoD Representatives 

4:00 p.m. Public Comments from Veterans Service Organizations 

The American Legion

Cathy Wiblemo, M.H.A. (Deputy Director, Veterans 

Affairs and Rehabilitation Division) 

AMVETS

Jim Doran (National Service Director)

United Spinal Association

Leonard Selfon, Esq. (National Service Director)
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APPENDIX B 347

Veterans of Foreign Wars of the United States

Quentin Kinderman (Deputy Director, National 

Legislative Service)

Vietnam Veterans of America

Rick Weidman (Executive Director for Policy and 

Government Affairs) 

4:30 p.m. Public Comments from Attendees

(Attendees will also be given the opportunity to make brief 

remarks to the Committee Members)

5:00 p.m. Open Session Ends

5:15 p.m. Closed Session (Committee Members and IOM Staff Only)

6:00 p.m. Adjourn

Committee Meeting #3 

October 4, 2006

Emily Morgan Hotel

705 East Houston Street

San Antonio, Texas

Agenda

Wednesday, October 4 Emily Morgan Hotel (Room 2)

7:30 a.m. Closed Session (Committee Members and IOM Staff Only) 

8:00 a.m. Open Session Begins

8:00 a.m. Welcome and Introductory Remarks, Introduction of 

Committee Members and Attendees

Jonathan M. Samet, M.D., M.S., (Chair, Committee on 

Evaluation of the Presumptive Disability Decision-Making 

Process for Veterans) 

8:10 a.m. Presentations from Past Congressional Staffers

Laura Petrou

Patrick Ryan, J.D.

Edward Scott, J.D.

Chris Yoder

9:10 a.m. Panel Q&A—Panel Presenters and Committee Members 

9:50 a.m. Break

10:00 a.m. DoD and Veterans Affairs: Health Information Sharing

Nhan Do, M.D., M.S., F.A.C.P. (Information Manager, 

Medical Informatics, TricareManagement Activity)

Cliff Freeman, M.A., M.S. (Director, VA/DoD Health IT 

Sharing Program)
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348 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

10:30 a.m. Panel Q&A—Health IT Presenters and Committee Members 

11:00 a.m. Public Comments from Veterans Service Organizations 

Public Comments from Attendees

(Attendees will also be given the opportunity to make brief 

remarks to the Committee Members)

Comments from LTG James Terry Scott, U.S. Army (Ret.) 

(Chairman, Veterans Disability Benefits Commission)

Closing Comments from Jonathan M. Samet, M.D., M.S. 

(Chair, Committee on Evaluation of the Presumptive 

Disability Decision-Making Process for Veterans) 

12:00 p.m. Open Session Ends 

1:00 p.m. Closed Session (Committee Members and IOM Staff Only) 

6:00 p.m. Adjourn 
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349

Appendix C

Glossary

a priori—Proceeding from a known or assumed cause to a necessarily 

related effect; based on a hypothesis or theory rather than on experiment or experience; made before or without examination and not supported by factual study.

Accession—Entry into the service.

Acidosis—A pathologic state characterized by an increase in the concentration of hydrogen ions in the arterial blood above the normal level, 

40 nmol/L, or pH 7.4; may be caused by an accumulation of carbon 

dioxide or acidic products of metabolism, or by a decrease in the concentration of alkaline compounds. (Stedman’s medical dictionary 28th 

ed., 2005)

Acneiform (or acneform) lesions—Lesions resembling acne. (Stedman’s 

medical dictionary 28th ed., 2005)

Active duty—(A) Full-time duty in the Armed Forces, other than active duty 

for training; (B) Full-time duty (other than for training purposes) as a 

commissioned officer of the Regular or Reserve Corps of the Public 

Health Service (i) on or after July 29, 1945, or (ii) before that date 

under circumstances affording entitlement to “full military benefits” or 

(iii) at any time, for the purposes of chapter 13 of this title (38 U.S.C.S. 

§ 1301 et seq.); (C) Full-time duty as a commissioned officer of the 

National Oceanic and Atmospheric Administration or its predecessor 

organization the Coast and Geodetic Survey (i) on or after July 29, 

1945, or (ii) before that date (I) while on transfer to one of the Armed 

Forces, or (II) while, in time of war or national emergency declared by 

the President, assigned to duty on a project for one of the Armed Forces 
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350 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

in an area determined by the Secretary of Defense to be of immediate 

military hazard, or (III) in the Philippine Islands on December 7, 1941, 

and continuously in such islands thereafter, or (iii) at any time, for the 

purposes of chapter 13 of this title (38 U.S.C.S. § 1301 et seq.); (D) Service as a cadet at the United States Military, Air Force, or Coast Guard 

Academy, or as a midshipman at the United States Naval Academy; 

and (E) Authorized travel to or from such duty or service. (Definitions. 

2006. 38 U.S.C. § 101.)

Active duty for training—(A) Full-time duty in the Armed Forces performed 

by Reserves for training purposes; (B) Full-time duty for training purposes performed as a commissioned officer of the Reserve Corps of the 

Public Health Service (i) on or after July 29, 1945, or (ii) before that 

date under circumstances affording entitlement to “full military benefits,” or (iii) at any time, for the purposes of chapter 13 of this title 

(38 U.S.C.S. § 1301 et seq.); (C) In the case of members of the National 

Guard or Air National Guard of any State, full-time duty under section 316, 502, 503, 504, or 505 of title 32 (32 U.S.C.S. § 316, 502, 

503, 504, or 505), or the prior corresponding provisions of law; and 

(D) Duty performed by a member of a Senior Reserve Officers’ Training 

Corps program when ordered to such duty for the purpose of training 

or a practice cruise under chapter 103 of title 10 (10 U.S.C.S. § 2101 

et seq.) for a period of not less than four weeks and which must be 

completed by the member before the member is commissioned; and 

(E) Authorized travel to or from such duty. The term does not include 

duty performed as a temporary member of the Coast Guard Reserve. 

(Definitions. 2006. 38 U.S.C. § 101.)

Active military, naval, or air service—(A) Active duty; (B) any period of 

active duty for training during which the individual concerned was 

disabled or died from a disease or injury incurred or aggravated in line 

of duty; and (C) Any period of inactive duty training during which 

the individual concerned was disabled or died—(i) from an injury 

incurred or aggravated in line of duty; or (ii) from an acute myocardial 

infarction, a cardiac arrest, or a cerebrovascular accident occurring 

during such training. (Definitions. 2006. 38 U.S.C. § 101.)

Acute myelogenous leukemia (AML)—A form of leukemia characterized 

by an uncontrolled proliferation of myelopoietic cells in the bone marrow and in extramedullary sites, and the presence of large numbers 

of immature and mature granulocytic forms in various tissues (and 

organs) and in the circulating blood.

Acute nonlymphocytic leukemia (ANLL)—Any of several forms of myelogenous leukemia marked by an abnormal increase in the number of 

immature white blood cells; risk of disease is increased among people 

who have been exposed to massive doses of radiation.
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APPENDIX C 351

Addison’s anemia (also known as primary anemia, pernicious anemia)—A 

chronic progressive anemia of older adults (occurring more frequently 

during the fifth and later decades, rarely before 30 years of age), due to 

the failure of absorption of vitamin B12, usually resulting from a defect 

of the stomach accompanied by mucosal atrophy and associated with 

lack of secretion of “intrinsic” factor; characterized by numbness and 

tingling, weakness, and a sore smooth tongue, as well as dyspnea after 

slight exertion, faintness, pallor of the skin and mucous membranes, 

anorexia, diarrhea, loss of weight, and fever; laboratory studies usually 

reveal greatly decreased red blood cell counts, low levels of hemoglobin, numerous characteristically oval shaped macrocytic erythrocytes 

(color index greater than normal, but not truly hyperchromic), and 

hypo- or achlorhydria, in association with a predominant number of 

megaloblasts and relatively few normoblasts in the bone marrow; the 

leukocyte count in peripheral blood may be less than normal, with 

relative lymphocytosis and hypersegmented neutrophils; a low level 

of vitamin B12 is found in peripheral red blood cells; administration 

of vitamin B12 results in a characteristic reticulocyte response, relief 

from symptoms, and an increase in erythrocytes, provided that pernicious anemia is not complicated by another disease; the condition is 

not actually “pernicious,” as it was prior to the availability of therapy 

with vitamin B12. At least two autosomal recessive forms are known. 

In one there is a defect of intrinsic factor and in the other a defective 

absorption of vitamin B12 from the intestine. (Stedman’s medical dictionary 28th ed., 2005)

Additive model—A model in which the combined effect of several factors is the sum of the effects that would be produced by each of the 

factors in the absence of the others. For example, if factor X adds 

x percent to risk in the absence of Y, and if factor Y adds y percent 

to risk in the absence of X, an additive model states that the two 

factors together will add (x + y) percent to risk. (Last, 2001)

Adult fibrosarcoma—A sarcoma of relatively low malignancy consisting 

chiefly of spindle-shaped cells that tend to form collagenous fibrils.

Agent Orange—An herbicide and defoliant consisting of 2,4,5-trichlorophenoxyacetic acid, 2,4-dichlorophenoxyacetic acid, and dioxin, that 

was widely used during the Vietnam War; it has been shown to produce 

residual postexposure carcinogenic and teratogenic effects in humans. 

(Stedman’s medical dictionary 28th ed., 2005)

Alveolar (alveolus)—A small cell, cavity, or socket. (1) Syn: pulmonary 

alveolus. (2) One of the terminal secretory portions of an alveolar 

or racemose gland. (3) One of the honeycomb pits in the wall of the 

stomach. (4) Syn: tooth socket. (Stedman’s medical dictionary 28th 

ed., 2005)
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352 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Ambient air—The surrounding or encompassing air; pertaining to the environment in which an organism or apparatus functions.

Amebiasis—Infection with the protozoon Entamoeba histolytica. (Stedman’s 

medical dictionary 28th ed., 2005)

Amebic dysentery—An inflammation of the intestine caused by infestation 

with Entamoeba histolytica. Marked by dysentery, abdominal pain, 

and erosion of the intestinal wall.

Amputation—The cutting off of a limb or part of a limb, the breast, or 

other projecting part.

Amyloidosis—A disease characterized by extracellular accumulation of 

amyloid in various organs and tissues of the body; may be primary or 

secondary.

Amyotrophic lateral sclerosis (ALS)—A rare fatal progressive degenerative disease that affects pyramidal motor neurons, usually begins in 

middle age, and is characterized especially by increasing and spreading 

muscular weakness. Also known as Lou Gehrig’s disease. (Stedman’s 

medical dictionary 28th ed., 2005)

Anemia—Any condition in which the number of red blood cells/mm3, 

the amount of hemoglobin in 100 ml of blood, and/or the volume of 

packed red blood cells/100 ml of blood is less than normal; clinically, 

generally pertaining to the concentration of oxygen-transporting material in a designated volume of blood, in contrast to total quantities as 

in oligocythemia, oligochromemia, and oligemia. Anemia is frequently 

manifested by pallor of the skin and mucous membranes, shortness of 

breath, palpitations of the heart, soft systolic murmurs, lethargy, and 

tendency to fatigue. (Stedman’s medical dictionary 28th ed., 2005)

Angioendotheliomatosis—Proliferation of endothelial cells within blood 

vessels. (Stedman’s medical dictionary 28th ed., 2005)

Angiosarcoma—A rare malignant neoplasm occurring most often in soft 

tissues; believed to originate from the endothelial cells of blood vessels; 

microscopically composed of spindle-shaped cells, some of which line 

small spaces resembling vascular clefts. (Stedman’s medical dictionary 

28th ed., 2005)

Anthrax—Infection by the bacterium Bacillus anthracis, which in humans is 

caused by infected animals or animal products, and ingestion or inhalation of spores of the bacterium. The most common naturally occurring 

form of human anthrax is the cutaneous, and both the inhalational and 

the gastrointestinal forms are quite rare. Anthrax in animals occurs 

throughout the world, primarily in herbovores, especially cattle, horses, 

goats, and sheep. (Stedman’s medical dictionary 28th ed., 2005)

Anxiety neurosis—Apprehension of danger and dread accompanied by 

restlessness, tension, tachycardia, and dyspnea unattached to a clearly 

identifiable stimulus. 
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APPENDIX C 353

Aplastic anemia—Anemia characterized by a greatly decreased formation 

of erythrocytes and hemoglobin, usually associated with pronounced 

granulocytopenia and thrombocytopenia, as a result of hypoplasticity 

or aplasticity of bone marrow. (Stedman’s medical dictionary 28th ed., 

2005) 

Appendectomy—Surgical removal of the appendix. (Stedman’s medical 

dictionary 28th ed., 2005)

Armed Forces—The United States Army, Navy, Marine Corps, Air Force, 

and Coast Guard, including the reserve components thereof. (Definitions. 2006. 38 U.S.C. § 101.)

Arrhythmia—Loss or abnormality of rhythm; denoting especially an irregularity of the heartbeat. (Stedman’s medical dictionary 28th ed., 2005)

Arteriosclerosis—Hardening of the arteries; types generally recognized are: 

atherosclerosis, Mönckeberg arteriosclerosis, and arteriolosclerosis. 

(Stedman’s medical dictionary 28th ed., 2005)

Arthritis—Inflammation of a joint or a state characterized by inflammation 

of joints. (Stedman’s medical dictionary 28th ed., 2005)

Asbestosis—Pneumoconiosis due to inhalation of asbestos fibers suspended 

in the ambient air; sometimes complicated by pleural mesothelioma or 

bronchogenic carcinoma; ferruginous bodies are the histologic hallmark 

of exposure to asbestos. (Stedman’s medical dictionary 28th ed., 2005)

Assay—(1) The quantitative or qualitative evaluation of a substance for 

impurities, toxicity, etc.; the results of such an evaluation. (2) To examine; to subject to analysis. (3) Test of purity; trial. (Stedman’s medical 

dictionary 28th ed., 2005)

Assigned share—For two groups of people that are alike, except that one 

group is exposed and the other is not exposed, the excess number of 

cases in the exposed group expressed as a fraction of the total number 

of cases in the exposed group.

Association—Statistical dependence between two or more events, characteristics, or other variables. An association is present if the probability of 

occurrence of an event or characteristic, or the quantity of a variable, 

is related to the occurrence of one or more other events, the presence of 

one or more other characteristics, or the quantity of one or more other 

variables. The association between two variables is described as positive when higher values of a variable are associated with higher values 

of another variable. In a negative association, the occurrence of higher 

values of one variable is associated with lower values of the other variable. An association may be fortuitous or may be produced by various 

other circumstances; the presence of an association does not necessarily 

imply a causal relationship. If the use of the term association is confined to situations in which the relationship between two variables is 

statistically significant, the terms statistical association and statistically 
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354 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

significant association become tautological. However, ordinary usage 

is seldom so precise at this. The terms association and relationship are 

often used interchangeably. Associations can be broadly grouped under 

two headings, noncausal and causal. (Adapted from Last, 2001)

Asthma—An inflammatory disease of the lungs characterized by reversible 

(in most cases) airway obstruction. Originally, a term used to mean 

“difficult breathing”; now used to denote bronchial asthma. (Stedman’s 

medical dictionary 28th ed., 2005)

Atherosclerosis—Arteriosclerosis characterized by irregularly distributed 

lipid deposits in the intima of large and medium sized arteries, causing narrowing of arterial lumens and proceeding eventually to fibrosis 

and calcification. Lesions are usually focal and progress slowly and 

intermittently. Limitation of blood flow accounts for most clinical 

manifestations, which vary with the distribution and severity of lesions. 

(Stedman’s medical dictionary 28th ed., 2005)

Atrophy—A wasting of tissues, organs, or the entire body, as from death 

and reabsorption of cells, diminished cellular proliferation, decreased 

cellular volume, pressure, ischemia, malnutrition, lessened function, or 

hormonal changes. (Stedman’s medical dictionary 28th ed., 2005)

Attributable fraction (AF)—Fraction of disease in the population that 

would not have occurred had the exposure not occurred. A term 

sometimes used to refer to the attributable fraction in the population, 

and sometimes to the attributable fraction among the exposed (Last, 

2001). The AF may be best understood by seeing how it is calculated: 

AF = (R1 – R0) / R1, where R1 is the rate of a disease (typically incidence 

rate) in an exposed population and R0 is the rate in that same population if unexposed. AF, then, is the fraction of the rate of disease in the 

exposed that is due to exposure. Dividing numerator and denominator 

by R0, since R1/R0 is the relative risk (RR), produces the more familiar 

expression, AF = (RR – 1) / RR. See Population attributable fraction.

Avitaminosis—Properly, hypovitaminosis. (Stedman’s medical dictionary 

28th ed., 2005)

Bacillary dysentery (also known as shigellosis)—Infection with Shigella 

dysenteriae, Shingella flexneri, or other organisms. (Stedman’s medical 

dictionary 28th ed., 2005)

Bancroft[ian] filariasis—Filariasis caused by Wuchereria bancrofti. (Stedman’s 

medical dictionary 28th ed., 2005)

Bari Harbor Disaster—On December 2, 1943, German Junkers Ju 88 

bombers attacked the port of Bari, a key supply center for Allied 

forces fighting their way up the Italian peninsula. Several Allied ships 

were sunk in the overcrowded harbor, including John Harvey, which 

was carry­ing mustard gas, intended for use if German forces initiated 

chemical warfare. The presence of the gas was highly classified, and 
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APPENDIX C 355

authorities ashore had no knowledge of it. This increased the number 

of fatalities, since physicians—who had no idea that they were dealing 

with the effects of mustard gas—prescribed treatment proper for those 

suffering from exposure and immersion, which proved fatal in many 

cases.

Basophil—(1) A cell with granules that stain specifically with basic dyes. 

(2) Syn: basophilic. (3) A phagocytic leukocyte of the blood characterized by numerous basophilic granules containing heparin and histamine 

and leukotrines; except for its segmented nucleus, it is morphologically 

and physiologically similar to the mast cell though they originate from 

different stem cells in the bone marrow. (Stedman’s medical dictionary 

28th ed., 2005)

Bayes’ Theorem—A theorem for probability first derived and described by 

Thomas Bayes (1702-1761), an English clergy­man and mathematician, 

in his Essay Towards Solving a Problem in the Doctrine of Chances 

(1763, published posthumously). In epidemiology, the theorem is often 

used to obtain the probability of disease in a group of people with 

some characteristic on the basis of the overall rate of that disease (the 

prior probability of disease) and the likelihoods of that characteristic 

in healthy and diseased individuals. The most familiar application is in 

clinical decision analysis, where it is used for estimating the probability 

of a particular diagnosis given the appearance of some symptoms or 

test results. A simplified version of the theorem is

P D S

P S D P D

P S D P D P S D P D ( ) = ( ) ( )

( ) ( ) + ( ) ( )

where D = disease, S = symptom, and D = no disease. The probability 

of disease given the symptom is the posterior probability. The probability of disease before knowing of the presence or absence of the 

symptom is the prior probability. The formula emphasizes what clinical 

intuition often overlooks, namely, that the probability of disease given

the symptom depends not only on how characteristic that symptom is 

of the disease but also on how frequent the disease is among the population being served.

 The theorem can also be used for estimating exposure-specific 

rates from case-control studies if there is added information about the 

overall rate of disease in that population. 

 The theorem is sometimes presented in terms of the odds of disease before knowing the symptom (prior odds) and after knowing the 

symptom (posterior odds). (Adapted from Last, 2001) 
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356 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Bayesian approach—A method of statistical inference that begins with the 

state of knowledge, i.e., the facts, prior to an exposure or an intervention, and augments this with the study data to yield the state of knowledge posterior to the study.

Benzene—The basic six-carbon ring structure in most aromatic compounds; 

a highly toxic hydrocarbon from light coal tar oil; used as a solvent. 

(Stedman’s medical dictionary 28th ed., 2005)

Beriberi—A specific nutritional deficiency syndrome occurring in endemic 

form in eastern and southern Asia, sporadically in other parts of 

the world without reference to climate, and sometimes in alcoholic 

patients, resulting mainly from a dietary deficiency of thiamin; the 

“dry” form is characterized by painful polyneuropathy that involves 

both large and small somatic nerve fibers, as well as autonomic 

nerve fibers, the initial symptom is burning feet, and later symptoms 

consist of painful parathesias in the distal upper limbs as well, weakness and atrophy of the feet and hands, and distal atrophic skin and 

hair loss; the “wet” form is characterized by edema resulting from 

a high-output form of heart failure, but usually there is evidence of 

a coexisting poly­neuropathy as well. (Stedman’s medical dictionary 

28th ed., 2005)

Beryllium disease—Various conditions resulting from exposure to beryllium 

and its compounds or alloys.

Bias—Deviation of results or inference from the truth, or process leading 

to such deviation; any trend in the collection, analysis, interpretation, 

publication, or review of data that can lead to conclusions that are 

systematically different from the truth. Among the ways in which deviation from the truth can occur, are the following: 

1. Systematic (one-sided) variation of measurements from the true 

values (syn: systematc error)

2. Variation of statistical summary measures (means, rates, measurements of association, etc.) from their true values as result of systematic variation of measurements, other flaws in data collection, 

or flaws in study design or analysis

3. Deviation of inferences from the truth as a result of flaws in study 

design, data collection, or the analysis or interpretation of results

4. A tendency of procedures (in study design, data collection, analysis, 

interpretation, review, or publication) to yield results or conclusions that depart from the truth 

5. Prejudice leading to the conscious or unconscious selection of study 

procedures that departs from the truth in a particular direction or 

to one-sidedness in the interpretation of results
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APPENDIX C 357

 The term bias does not necessarily carry an imputation of prejudice or other subjective factor, such as the experimenter’s desire for a 

particular outcome.This differs from conventional usage, in which bias 

refers to a partisan point of view. (Adapted from Last, 2001)

Biological plausibility—The criterion that an observed, presumably or putatively causal association is coherent with previously existing biological 

or medical knowledge. This judgment should be used cautiously since it 

could impede development of new knowledge that does not fit existing 

ideas. (Last, 2001)

Bipolar disorder—An affective disorder characterized by the occurrence 

of alternating manic, hypomanic, or mixed episodes and with major 

depressive episodes. The DSM specifies the commonly observed patterns of bipolar I and bipolar II disease and cyclothymia. (Stedman’s 

medical dictionary 28th ed., 2005)

Black lung—A form of pneumoconiosis, common in coal miners, characterized by deposits of carbon particles in the lung. (Stedman’s medical 

dictionary 28th ed., 2005)

Black water fever—Hemoglobinuria resulting from severe hemolysis occurring in falciparum malaria. (Stedman’s medical dictionary 28th ed., 

2005)

Bonus Expeditionary Forces—About 20,000 WWI veterans, their families, 

and other affiliated groups who demonstrated in Washington, D.C., 

during the spring and summer of 1932 seeking immediate payment of 

a “bonus” granted by the Adjusted Service Certificate Law of 1924 for 

payment in 1945.

Bradford Hill criteria—Heuristic criteria for interpreting when evidence 

supports moving beyond observed association to causation. The criteria 

include strength of association, consistency, specificity, temporality, 

dose-response, plausibility, coherence, experimental evidence, and 

analogy. Named after Sir Austin Bradford Hill.

Bradley Commission—Formed in 1987 in response to concerns regarding the 

quality and quantity of the history taught in American classrooms.

Brain hemorrhage (cerebral hemorrhage)—Hemorrhage into the substance 

of the cerebrum, usually in the region of the internal capsule by the 

rupture of the lenticulostriate. (Stedman’s medical dictionary 28th ed., 

2005)

Brain thrombosis (cerebral thrombosis)—Clotting of the blood in a cerebral 

vessel. (Stedman’s medical dictionary 28th ed., 2005)

Bronchiectasis—Chronic dilation of bronchi or bronchioles as a sequel 

of inflammatory disease or obstruction often associated with heavy 

sputum production.

Bronchiolo-alveolar carcinoma—A relatively uncommon lung cancer which 

is a type of non-small cell lung cancer.
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358 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Bronchitis—Inflammation of the mucous membranes of the bronchi. 

(Stedman’s medical dictionary 28th ed., 2005) 

Buccal cavity—That part of the mouth bounded anteriorally and laterally 

by the lips and the cheeks, posteriorly and medially by the teeth and/or 

gums, and above and below by the reflection of the mucosa from the 

lips and cheeks to the gums. (Stedman’s medical dictionary 28th ed., 

2005)

Buerger’s disease—Thromboangiitis (thromboangiitis—an inflammation of 

the blood vessels associated with thrombosis) of the small arteries and 

veins of the extremities and especially the feet resulting in occlusion, 

ischemia, and gangrene. 

Bulbar—(1) Relating to a bulb. (2) Relating to the rhombencephalon (hindbrain). (3) Bulb-shaped; resembling a bulb. (Stedman’s medical dictionary 28th ed., 2005)

Burden of persuasion—The duty upon a party in a legal proceeding to persuade the fact-finder to decide for that party on an assertion of fact.

Burden of proof—The duty of proving a disputed assertion or charge.

Butadiene—A flammable gaseous open-chain hydrocarbon used in making 

synthetic rubbers.

Cacodylic acid—Arsenical contact herbicide that defoliates or desiccates a 

wide variety of plant species. (Stedman’s medical dictionary 28th ed., 

2005)

Calculi (Calculus)—A concretion formed in any part of the body, most 

commonly in the passages of the biliary and urinary tracts; usually 

composed of salts of inorganic or organic acids, or of other material 

such as cholesterol. (Stedman’s medical dictionary 28th ed., 2005)

Cancer—General term frequently used to indicate any of various types of 

malignant neoplasms, most of which invade surrounding tissues, may 

metastasize to several sites, and are likely to recur after attempted 

removal and to cause death of the patient unless adequately treated; 

especially, any such carcinoma or sarcoma, but, in ordinary usage, especially the former. (Stedman’s medical dictionary 28th ed., 2005)

Cannikin—A nuclear device detonated beneath Amchitka Island, Alaska, 

in 1971. 

Carcinogen—Any cancer-producing substance or organism, such as polycyclic aromatic hydrocarbons, or agents such as in certain types of 

irradiation. (Stedman’s medical dictionary 28th ed., 2005)

Carcinoma—Any of various types of malignant neoplasm derived from 

epithelial cells, chiefly glandular (adenocarcinoma) or squamous 

(squamous cell carcinoma); the most commonly occurring kind of 

cancer. (Stedman’s medical dictionary 28th ed., 2005)

Cardiovascular disease—Any abnormal condition characterized by dysfunction of the heart and blood vessels.
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APPENDIX C 359

Case-control study—An epidemiologic study design in which a population 

sample is defined on the basis of whether (cases) or not (controls) a 

disease (or other endpoint) is present; cases and controls are then compared with respect to disease risk factors, typically exposure. 

Cataracts (posterior subcapsulary)—Complete or partial opacity of the 

ocular lens. (Stedman’s medical dictionary 28th ed., 2005)

Causal association—An association between two events or characteristics 

that arises because one causes the other. 

Causal inference—Examining the structure and results of many investigations in an attempt to assess and, if possible, eliminate all possible 

noncausal reasons for observed associations.

Causal pathway—A sequence mechanism, possibly involving several intermediate factors, by which one factor causes another. 

Causation—The relating of causes to the effects they produce. A relationship 

between events (specific, or individual causation) or between variables 

(general, or population level causation) in which an outside intervention to change the cause would result in a change in the effect.

Child—Except for purposes of chapter 19 of this title (38 U.S.C.S. § 1901 et 

seq.) (other than with respect to a child who is an insurable dependent 

under section 1965[10][B] of such chapter [38 U.S.C.S. § 1965(10)(B)] 

and section 8502[b] of this title [38 U.S.C.S. § 8502(b)]) a person who 

is unmarried and—(i) who is under the age of eighteen years; (ii) who, 

before attaining the age of eighteen years, became permanently incapable of self-support; or (iii) who, after attaining the age of eighteen years 

and until completion of education or training (but not after attaining 

the age of twenty-three years), is pursuing a course of instruction at 

an approved educational institution; and who is a legitimate child, 

a legally adopted child, a stepchild who is a member of a veteran’s 

household or was a member at the time of the veteran’s death, or an 

illegitimate child but, as to the alleged father, only if acknowledged 

in writing signed by him, or if he has been judicially ordered to contribute to the child’s support or has been, before his death, judicially 

decreed to be the father of such child, or if he is otherwise shown by 

evidence satisfactory to the Secretary to be the father of such child. A 

person shall be deemed, as of the date of death of a veteran, to be the 

legally adopted child of such veteran if such person was at the time of 

the veteran’s death living in the veteran’s household and was legally 

adopted by the veteran’s surviving spouse before August 26, 1961, or 

within two years after the veteran’s death; however, this sentence shall 

not apply if at the time of the veteran’s death, such person was receiving 

regular contributions toward the person’s support from some individual 

other than the veteran or the veteran’s spouse, or from any public or 

private welfare organization which furnishes services or assistance for 
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360 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

children. A person with respect to whom an interlocutory decree of 

adoption has been issued by an appropriate adoption authority shall 

be recognized thereafter as a legally adopted child, unless and until that 

decree is rescinded, if the child remains in the custody of the adopting parent or parents during the interlocutory period. A person who 

has been placed for adoption under an agreement entered into by the 

adopting parent or parents with any agency authorized under law to so 

act shall be recognized thereafter as a legally adopted child, unless and 

until such agreement is terminated, if the child remains in the custody 

of the adopting parent or parents during the period of placement for 

adoption under such agreement. A person described in clause (ii) of the 

first sentence of this subparagraph who was a member of a veteran’s 

household at the time the person became 18 years of age and who is 

adopted by the veteran shall be recognized as a legally adopted child of 

the veteran regardless of the age of such person at the time of adoption. 

(B) For the purposes of subparagraph (A) of this paragraph, in the case 

of an adoption under the laws of any jurisdiction other than a State (as 

defined in section 101[20] of this title [para. (20) of this section] and 

including the Commonwealth of the Northern Mariana Islands)—(i) a 

person residing outside any of the States shall not be considered to be 

a legally adopted child of a veteran during the lifetime of such veteran 

(including the purposes of this subparagraph a Commonwealth Army 

veteran or new Philippine Scout, as defined in section 3566 of this title 

(38 U.S.C.S. § 3566) unless such person—(I) was less than eighteen 

years of age at the time of adoption; (II) is receiving one-half or more 

of such person’s annual support from such veteran; (III) is not in the 

custody of such person’s natural parent, unless such natural parent is 

such veteran’s spouse; and (IV) is residing with such veteran (or in the 

case of divorce following adoption, with the divorced spouse who is 

also an adoptive or natural parent) except for periods during which 

such person is residing apart from such veteran (or such divorced 

spouse) for purposes of full-time attendance at an educational institution or during which such person or such veteran (or such divorced 

spouse) is confined in a hospital, nursing home, other health-care facility, or other institution; and (ii) a person shall not be considered to 

have been a legally adopted child of a veteran as of the date of such 

veteran’s death and thereafter unless—(I) at any time within the oneyear period immediately preceding such veteran’s death, such veteran 

was entitled to and was receiving a dependent’s allowance or similar 

monetary benefit under this title for such person; or (II) for a period 

of at least one year prior to such veteran’s death, such person met the 

requirements of clause (i) of this subparagraph. (Definitions. 2006. 38 

U.S.C. § 101.)
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APPENDIX C 361

Chloracne—An acnelike eruption due to occupational contact, by inhalation or ingestion or through the skin, with certain chlorinated compounds (naphthalenes and diphenyls) used as insulators, insecticides, 

fungicides, and herbicides, including Agent Orange; keratinous plugs 

(comedones) form in the pilosebaceous orifices, and various sized small 

papules (2 to 4 mm) develop. (Stedman’s medical dictionary 28th ed., 

2005) 

Chlorophenols—Several substitution products obtained by the action of 

chlorine on phenol; used as antiseptics. (Stedman’s medical dictionary 

28th ed., 2005)

Cholecystitis—Inflammation of the gallbladder. (Stedman’s medical dictionary 28th ed., 2005)

Cholera—An acute epidemic infectious disease caused by the bacterium 

Vibrio cholerae. A soluble toxin elaborated in the intestinal tract by 

the bacterium activates the adenylate cylase of the mucosa, causing 

active secretion of an isotonic fluid resulting in profuse watery diarrhea, 

extreme loss of fluid and electrolytes, and dehydration and collapse, 

but no gross morphologic change in the intestinal mucosa. (Stedman’s 

medical dictionary 28th ed., 2005)

Chondrosarcoma—A malignant neoplasm derived from cartilage cells, 

occurring most frequently in pelvic bones or near the ends of long 

bones, in middle-aged and older people; most chondrosarcomas arise 

de novo, but some may develop in a preexisting benign cartilaginous 

lesion. (Stedman’s medical dictionary 28th ed., 2005)

Chronic fatigue syndrome—A disorder of uncertain cause that is characterized by persistent profound fatigue usually accompanied by impairment 

in short-term memory or concentration, sore throat, tender lymph 

nodes, muscle or joint pain, and headache unrelated to any preexisting 

medical condition.

Chronic multisymptom illness—Chronic illness characterized by a complex 

of multiple symptoms. More common in deployed Gulf War I (1991) 

veterans than in non-deployed veterans.

Chronic obstructive pulmonary disease—Comprised of two related diseases 

(chronic bronchitis and emphysema); chronic obstruction of the flow 

of air through the airways and out of the lungs, and the obstruction 

generally is permanent and progressive over time. 

Cirrhosis of the liver—A chronic degenerative disease of the liver in which 

the lobes are covered with fibrous tissue, the parenchyma degenerates, and the lobules are infiltrated with fat. Caused by any of various 

chronic progressive conditions affecting the liver.

Class Action—A legal action undertaken by one or more plaintiffs on behalf 

of themselves and all other persons having an identical interest in the 

alleged wrong.
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362 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Classification—Assignment to predesignated classes on the basis of perceived common characteristics (e.g., exposure). A means of giving order 

to a group of disconnected facts.

Clofibrate—An antilipemic agent that reduces plasma levels of cholesterol, 

triglycerides, and uric acid; used in the treatment of hypercholesterolemia and atherosclerosis.

Coccidioidomycosis—A variable, benign, severe, or sometimes fatal systemic 

mycosis due to inhalation of arthroconidia of Coccidioides immitis. 

In benign forms of the infection, the lesions are limited to the upper 

respiratory tract, lungs, and near lymph nodes; in a low percentage 

of cases, the disease disseminates to other visceral organs, meninges, 

bones, joints, and skin and subcutaneous tissues. (Stedman’s medical 

dictionary 28th ed., 2005)

Cohort study—An epidemiologic study design in which a population sample of persons is defined on the basis of some characteristic, typically 

exposure, and then observed for occurrence of disease events, e.g., 

death. Comparisons are made between those with varying degrees of 

exposure or other characteristics. 

Compensation—A monthly payment made by the Secretary to a veteran 

because of service-connected disability, or to a surviving spouse, child, 

or parent of a veteran because of the service-connected death of the 

veteran occurring before January 1, 1957. (Definitions. 2006. 38 U.S.C. 

§ 101.)

Confidence interval (CI)—The computed interval with given probability—

e.g., 95%—that the true value of a variable such as a mean, proportion, 

or rate is contained within the interval. (Last, 2001) 

Confounder—A variable that can cause or prevent the outcome of interest, 

is not in the causal pathway between the exposure and the disease on a 

causal pathway from the cause to the effect, and is associated with the 

factor under investigation (e.g., exposure). Confounders can create associations between two variables that are not themselves causally related; 

these associations are often referred to as spurious associations. 

Conjunctivitis—Inflammation of the conjunctiva. (Stedman’s medical dictionary 28th ed., 2005)

Corneal opacities—Dense, thick white areas in the cornea, through which 

one cannot see. 

Corpuscular—Relating to a corpuscle. (1) A small mass or body. (2) A 

blood cell. (Stedman’s medical dictionary 28th ed., 2005)

Cortisol—The principal glucocorticoid produced by the zona fasciculata of 

the adrena cortex. It promotes gluconeogenisis and lipolysis, suppresses 

protein synthesis, inhibits inflammatory and immune responses, and 

has mild mineralocorticoid (e.g., hypernatremic, kaliuretic, anti­diuretic) 

effects. Most plasma cortisol is bound to transcortin and albumin. Syn-
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APPENDIX C 363

thetic cortisol administered as a drug is usually known by the alternative 

name hydrocortisone. (Stedman’s medical dictionary 28th ed., 2005) 

Counterfactual—A measure in which at least one of the two circumstances 

in the definition of variables must be contrary to fact. An example is 

a hypothetical control group that represents what the distribution of 

exposure would have been if past events had been different from what 

they actually were. In a case-specular study design, the counterfactual 

control group comprises (imaginary) dwellings on the opposite side of 

the street from the dwellings occupied by the cases. The purpose is to 

asses what the exposure would have been in these hypothetical dwellings. The counterfactual difference in past exposure must be defined 

precisely to facilitate unambiguous calculating of variables in the hypothetical control group. (Adapted from Last, 2001)

Covariate—A possible confounder that is to be adjusted in a statistical 

analysis—a variable that is considered to be possibly associated with 

the outcome under study and may or may not be of direct interest to 

the study. A covariate may be a confounding variable, an effect modifier, or unrelated to the outcome or the exposure.

Crossover study—A method of comparing two or more treatments or 

interventions in which the subjects or patients, upon completion of the 

course of one treatment, are switched to another. In the case of two 

randomly allocated treatments, A and B, half the subjects are randomly 

allocated to receive these in the order of A, B, and half to receive them 

in the order of B, A.

CROSSROADS (Operation)—An atmospheric nuclear weapons test series 

conducted in the summer of 1946 in the Marshall Islands. 

Cross-sectional study—An epidemiologic study design in which the relationship between diseases (or other health endpoints) and health-related 

characteristics is examined as they exist in a defined population at one 

particular time. The interpretation of associations in cross-sectional 

studies is limited by the fact that the time order cannot be determined. 

Thus, an association between A and B may be because A caused B, or 

B caused A. 

Defoliate—To cause the leaves of a plant, tree, or forest to fall off, especially by the use of chemicals. 

Dehydroepiandrosterone (DHEA)—A steroid secreted chiefly by the adrenal 

cortex, but also by the testis; it is the principal precursor of urinary 

17-ketosteroids. Weakly androgenic itself, it is metabolized to delta-5 

androstenediol, a hormone with both androgenic and estrogenic effects, 

and is one of the precursors of testosterone. Serum levels are elevated in 

adrenal virilism. It may function as a neurotransmitter. DHEA secretion 

begins during fetal life, reaches a peak in the 3rd decade, and declines 

steadily thereafter; the level at age 80 is only 10-20 percent of the peak 
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364 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

level. This decline has been speculatively associated with the changes 

of aging. Commercial formulations of DHEA are marketed as dietary 

supplements, although this substance is neither a nutrient nor a component of the human food chain. Available from health food stores in 

10-, 25-, and 50-mg capsules, DHEA has been promoted for the prevention of degenerative diseases including atherosclerosis, Alzheimer’s 

dementia, and parkinsonism, and other effects of aging. None of the 

alleged benefits have been demonstrated in large, randomized clinical trials. Long-term administration to postmenopausal women has 

been associated with insulin resistance, hypertension, and reduction 

of LDL cholesterol. An analysis of 16 preparations of DHEA by highperformance liquid chromatography showed a variation in content 

from 0 to 150 percent of the labeled strength; only 7 products fell 

between the expected 90-110 percent of labeled strength. (Stedman’s 

medical dictionary 28th ed., 2005)

Department—Department of Veterans Affairs. (Definitions. 2006. 38 U.S.C. 

§ 101.)

Dependency and indemnity compensation—A monthly payment made by 

the Secretary to a surviving spouse, child, or parent (A) because of a 

service-connected death occurring after December 31, 1956, or (B) pursuant to the election of a surviving spouse, child, or parent, in the case 

of such a death occurring before January 1, 1957. (Definitions. 2006. 

38 U.S.C. § 101.)

Depleted uranium—A modestly radioactive heavy metal used in projectiles 

and armament.

Depressive neurosis—A mental state or chronic mental disorder characterized by feelings of sadness, loneliness, despair, low self-esteem, and 

self-reproach; accompanying signs include psychomotor retardation or 

less frequently agitation, withdrawal from social contact, and vegetative states such as loss of appetite and insomnia. (Stedman’s medical 

dictionary 28th ed., 2005)

Dermatitis—Inflammation of the skin. (Stedman’s medical dictionary 28th 

ed., 2005)

Dermatofibrosarcoma protuberans—A relatively slowly growing dermal 

neoplasm consisting of one or several firm nodules that are usually 

covered by dark red-blue skin, which tends to be fixed to the palpable 

masses; histologically, the neoplasm resembles a cellular dermatofibroma with a pronounced storiform pattern; metastases are unusual, 

but the incidence of recurrence is fairly high. (Stedman’s medical dictionary 28th ed., 2005)

Diabetes insipidus—Chronic excretion of very large amounts of pale urine 

of low specific gravity, causing dehydration and extreme thirst; ordinarily results from inadequate output of pituitary antidiuretic hormone; 
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APPENDIX C 365

the urine abnormalities may be mimicked as a result of excessive fluid 

intake, as in psychogenic polydipsia. Several types exist: central, neurohypophyseal, and nephrogenic. Autosomal dominant, X-linked, and 

even autosomal recessive forms have been described. (Stedman’s medical dictionary 28th ed., 2005)

Diabetes mellitus—A chronic metabolic disorder in which utilization of 

carbohydrate is impaired and that of lipid and protein enhanced; it is 

caused by an absolute or relative deficiency of insulin and is characterized, in more severe cases, by chronic hyperglycemia, glycosuria, water 

and electrolyte loss, ketoacidosis, and coma; long-term complications 

include neuropathy, retinopathy, nephropathy, generalized degenerative 

changes in large and small blood vessels, and increased susceptibility to 

infection. (Stedman’s medical dictionary 28th ed., 2005)

Diabetes Type 1—A condition characterized by high blood glucose levels 

caused by a total lack of insulin. Occurs when the body’s immune 

system attacks the insulin-producing beta cells in the pancreas and 

destroys them. The pancreas then produces little or no insulin. Type 1 

diabetes develops most often in young people but can appear in adults. 

(Stedman’s medical dictionary 28th ed., 2005)

Diabetes Type 2—A condition characterized by high blood glucose levels 

caused by either a lack of insulin or the body’s inability to use insulin 

efficiently. Type 2 diabetes develops most often in middle-aged and 

older adults but can appear in young people. (Stedman’s medical dictionary 28th ed., 2005)

2,4-Dichlorophenoxyacetic acid—An herbicide, more toxic to broad-level 

dicotyledonous plants (weeds) than to monocotyledonous ones (grains 

and grass), used with 2,4,5-trichlorophenoxyacetic acid as a constituent 

of Agent Orange. 

Dioxin—A contaminant in the herbicide 2,4,5-T; it is potentially toxic, 

teratogenic, and carcinogenic. 

Direct causation—There are no intervening causes between an act and the 

resulting harm.

Disability Compensation—A benefit paid to a veteran because of injuries 

or diseases that happened while on active duty, or were made worse 

by active military service; also paid to certain veterans disabled from 

VA health care. 

Discharge or release—(A) Retirement from the active military, naval, or 

air service, and (B) The satisfactory completion of the period of active 

military, naval, or air service for which a person was obligated at the 

time of entry into such service in the case of a person who, due to 

enlistment or reenlistment, was not awarded a discharge or release 

from such period of service at the time of such completion thereof and 

who, at such time, would otherwise have been eligible for the award 
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366 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

of a discharge or release under conditions other than dishonorable. 

(Definitions. 2006. 38 U.S.C. § 101.)

Disfigure—To impair (as in physicality) by deep and persistent injuries.

Distal amputation—An amputation situated away from the center of the 

body, or from the point of origin. 

Dizygotic twins—Relating to twins derived from two separate zygotes, i.e., 

bearing the same genetic relationship as full sibs but sharing a common intrauterine environment. (Stedman’s medical dictionary 28th ed., 

2005)

Dose-response—The relationship of risk for observed outcomes (responses) 

in a population with varying levels of an agent or characteristic, often 

an exposure. 

Dosimeter—A device for measuring doses of radiations (as X-rays).

Double blind design—A procedure of assignment to study (or treatment) 

and control (or placebo) groups in which neither the investigator nor 

the study subject has knowledge of the group to which the subject was 

assigned.

Doubling dose—The dose of a causal factor required to increase the risk 

of disease twofold. 

Dracontiasis (also known as Dracunculosis)—Infection with Dracunculus 

medinensis. (Stedman’s medical dictionary 28th ed., 2005)

Dysentery—A disease marked by frequent watery stools, often with blood 

and mucus, and characterized clinically by pain, tenesmus, fever, and 

dehydration. (Stedman’s medical dictionary 28th ed., 2005)

Dysthymic disorder—(1) A chronic disturbance of mood characterized 

by mild depression or loss of interest in usual activities. (2) A DSM 

diagnosis is established when the specified criteria are met. (Stedman’s 

medical dictionary 28th ed., 2005)

Ectomesenchymoma—A rare tumor that may arise in the brain or soft 

tissue.

Edema—(1) An accumulation of an excessive amount of watery fluid in 

cells or intercellular tissues. (2) At the gross level, used to describe the 

physical sign commonly likened to swelling or increased girth that often 

accompanies the accumulation of fluid in a body part, most often a 

limb. (Stedman’s medical dictionary 28th ed., 2005)

Effect modifier—A factor that modifies the effect on a health outcome of a 

putative causal factor under study. For example, age is an effect modifier for many conditions, and immunization status is an effect modifier 

for the consequences of exposure to pathogenic organisms. (Adapted 

from Last, 2001)

Electrocardiogram—Graphic record of the heart’s integrated action currents 

obtained with the electrocardiograph displayed as voltage changes over 

time. (Stedman’s medical dictionary 28th ed., 2005)
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APPENDIX C 367

Emphysema—(1) Presence of air in the interstices of the connective tissue of 

a part. (2) A condition of the lung characterized by increase beyond the 

normal in the size of air spaces distal to the terminal bronchiole (those 

parts containing alveoli), with destructive changes in their walls and 

reduction in their number. Clinical manifestation is breathlessness on 

exertion, due to the combined effect (in varying degrees) of reduction of 

alveolar surface for gas exchange and collapse of smaller airways with 

trapping of alveolar gas in expiration; this causes the chest to be held in 

the position of inspiration (“barrel chest”), with prolonged expiration 

and increased residual volume. Symptoms of chronic bronchitis often, 

but not necessarily, coexist. Two structural varieties are panlobular 

(panacina) emphysema and centrilobular (centriacinar) emphysema; 

paracicatricial, paraseptal, and bullous emphysema are also common. 

(Stedman’s medical dictionary 28th ed., 2005)

Encephalitis—Inflammation of the brain. (Stedman’s medical dictionary 

28th ed., 2005)

Encephalitis lethargica residuals—Any diffuse inflammation of the brain 

occurring in epidemic form.

Endocarditis—Inflammation of the endocardium. (Stedman’s medical dictionary 28th ed., 2005)

Endocrinopathy—A disorder in the function of an endocrine gland and the 

consequences thereof. (Stedman’s medical dictionary 28th ed., 2005)

Entitlement—A right to benefits specified especially by law or contract; 

a government program providing benefits to members of a specified 

group and funds supporting or distributed by such a program; belief 

that one is deserving of certain privileges.

Eosinophil—A polymorphonuclear leukocyte characterized by many large 

or prominent, refractile, cytoplasmic granules that are fairly uniform 

in size and bright yellow-red or orange when treated with Wright or 

similar stains; the nuclei are usually larger than those of neutrophils, do 

not stain as deeply, and characteristically have two lobes (a third lobe 

is sometimes interposed on the connecting strand of chromatin); these 

leukocytes are motile phagocytes with distinctive antiparasitic functions; they also phagocytose antigen-antibody complexes. (Stedman’s 

medical dictionary 28th ed., 2005)

Epidemiology—The study of the distribution and determinants of illnesses 

or diseases in specified populations, and the application of this study 

to control of health problems. “Study” includes surveillance, observation, hypothesis testing, analytic research, and population experiments. 

“Distribution” refers to analysis by time, place, and classes of persons 

affected. (Adapted from Last, 2001)

Epilepsies—Any of various disorders marked by abnormal electrical discharges in the brain and typically manifested by sudden brief episodes 
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368 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

of altered or diminished consciousness, involuntary movements, or 

convulsions.

Epithelioid leiomyosarcoma—An uncommon neoplasm of smooth muscle 

in which the cells are polygonal in shape. It usually develops in the 

stomach.

Epithelioid sarcoma—Malignant mesenchymal tumor showing nodular 

granulomalike growth of eosinophilic epithelioid and spindle cells 

palisading around the centrally located necrotic areas. Two subtypes 

are recognized: a classic distal and fibromalike form. Tumors typically 

occur in the subcutaneous tissue along the tendons and the fascia. 

(Stedman’s medical dictionary 28th ed., 2005)

Equipoise—A state of uncertainty about the benefit or harm that may result 

from a suspected causal factor, in which evidence for and against the 

causal association is equally balanced.

Erythrocyte—A mature red blood cell. (Stedman’s medical dictionary 28th 

ed., 2005)

Escherichia coli—A species that occurs normally in the intestines of man 

and other vertebrates, is widely distributed in nature, and is a frequent 

cause of infections of the urogenital tract and of diarrhea in infants. 

Enteropathogenic strains (serovars) of Escherichia coli cause diarrhea 

due to enterotoxin, the production of which seems to be associated 

with a transferable episome; the type species of the genus. (Stedman’s 

medical dictionary 28th ed., 2005)

Etiology—Literally, the science of causes, causality; in common usage, 

cause. See also Causality; Pathogenesis. (Last, 2001)

Ewing’s tumor—A malignant neoplasm that occurs usually before the age of 

20 years, about twice as frequently in males, and in about 75 percent of 

patients involves bones of the extremities, including the shoulder girdle, 

with a predilection for the metaphysis; histologically, there are conspicuous foci of necrosis in association with irregular masses of small, regular, 

rounded, or ovoid cells (2–3 times the diameter of erythrocytes), with 

very scanty cytoplasm. (Stedman’s medical dictionary 28th ed., 2005)

Exanthema—A skin eruption occurring as a symptom of an acute viral or 

coccal disease, as in scarlet fever or measles. (Stedman’s medical dictionary 28th ed., 2005)

False negative error—The mistake made in accepting a null hypothesis in 

the presence of a causal association (type I error, alpha error). In the 

context of diagnostic tests or criteria (or compensation), the number (or 

percentage) diagnosed not to have the condition who in fact had it.

False positive error—The mistake made in rejecting a null hypothesis in the 

absence of a causal association (type II error, beta error). In the context 

of diagnostic tests or criteria (or compensation), the number (or percentage) diagnosed with the condition who in fact did not have it.
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APPENDIX C 369

Fasting blood glucose—Measures the amount of glucose in your blood after 

you have not eaten for at least eight hours. It is often done to check 

for diabetes. 

Fibromyalgia—A common syndrome of chronic widespread soft-tissue pain 

accompanied by weakness, fatigue, and sleep disturbances; the cause is 

unknown. (Stedman’s medical dictionary 28th ed., 2005)

Fibrosarcoma—A malignant neoplasm derived from deep fibrous tissue, 

characterized by bundles of immature proliferating fibroblasts arranged 

in a distinctive herringbone pattern with variable collagen formation, 

which tends to invade locally and metastasize by the bloodstream. 

(Stedman’s medical dictionary 28th ed., 2005)

Fibrous histocytoma—A cutaneous nodule that is painless, round, firm, 

gray or red, elevated, and commonly found on the extremities.

Filariasis—Presence of filariae in the tissues of the body or in blood (microfilaremia) or tissue fluids (microfilariasis), occurring in tropical and 

subtropical regions; living worms cause minimal tissue reaction, which 

may be asymptomatic, but death of the adult worms leads to granulomatous inflammation and permanent fibrosis causing obstruction of 

the lymphatic channels from dense hyalinized scars in the subcutaneous 

tissues; the most serious consequence is elephantiasis or pachyderma. 

(Stedman’s medical dictionary 28th ed., 2005)

Five Series Study—Included Operations GREENHOUSE, UPSHOT-KNOTHOLE, CASTLE, REDWING, and PLUMBBOB; these were chosen for 

a study of atomic veterans to represent tests at both the Nevada Test 

Site and the Pacific Proving Grounds.

Flat-rate pension—A uniform pension or one based on years of service.

Follicle-stimulating hormone—An acidic glycoprotein hormone of the anterior pituitary that stimulates the graafian follicles of the ovary and assists 

subsequently in follicular maturation and the secretion of estradiol; in 

the male, it stimulates the epithelium of the seminiferous tubules and is 

partially responsible for inducing spermatogenesis. (Stedman’s medical 

dictionary 28th ed., 2005)

Formaldehyde—A pungent gas, HCHO; used as an antiseptic, disinfectant, 

and histologic fixative, usually in an aqueous solution. (Stedman’s 

medical dictionary 28th ed., 2005)

Former prisoner of war—A person who, while serving in the active military, naval or air service, was forcibly detained or interned in line of 

duty—(A) By an enemy government or its agents, or a hostile force, 

during a period of war; or (B) By a foreign government or its agents, or 

a hostile force, under circumstances which the Secretary finds to have 

been comparable to the circumstances under which persons have generally been forcibly detained or interned by enemy governments during 

periods of war. (Definitions. 2006. 38 U.S.C. § 101.)
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370 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Frostbite—Local tissue destruction resulting from exposure to extreme 

cold; in mild cases, it results in superficial, reversible freezing followed 

by erythema and slight pain (frostnip); in severe cases, it can be painless 

or paresthetic and result in blistering, persistent edema, and gangrene. 

Frostbite is currently treated by rapid rewarming. (Stedman’s medical 

dictionary 28th ed., 2005)

Gallstone—A concretion in the gallbladder or a bile duct, composed chiefly 

of a mixture of cholesterol, calcium bilirubinate, and calcium carbonate, 

occasionally as a pure stone composed of just one of these substances. 

(Stedman’s medical dictionary 28th ed., 2005)

Ganglionar neuroma—A tumor composed of a solid mass of ganglia and 

nerve fibers. Usually found in abdominal tissues. 

Gardner’s syndrome—Multiple polyposis predisposing to carcinoma of the 

colon; also multiple tumors, osteomas of the skull, epidermoid cysts, 

and fibromas; autosomal dominant inheritance, caused by mutation in 

the adenomatous polyposis coli gene (APC) on chromosome 5q. This 

disorder is allelic to familial adenomatous polyposis (FAP). (Stedman’s 

medical dictionary 28th ed., 2005)

Garrison—A military post; a permanent military installation. 

Gastroenteritis—Inflammation of the mucous membrane of both stomach 

and intestine. (Stedman’s medical dictionary 28th ed., 2005)

Gastrointestinal disorder—A disorder relating to the stomach and 

intestines.

Generalizability—The degree to which the inference drawn from a study 

can be extended to a different population. Such generalization is warranted when appropriate account is taken of the study methods, the 

representativeness of the study sample, and the nature of the population from which it is drawn. (Adapted from Last, 2001)

Geneva Convention—One of a series of agreements concerning the treatment of prisoners of war and of the sick, wounded, and dead in battle 

first made at Geneva, Switzerland, in 1864 and subsequently accepted 

in later revisions by most nations.

Genitourinary—Relating to the organs of reproduction and urination 

collectively. (Stedman’s medical dictionary 28th ed., 2005)

Genotoxicity—Denoting a substance that by damaging DNA may cause 

mutation or cancer. (Stedman’s medical dictionary 28th ed., 2005)

Glomus tumor—A vascular neoplasm composed of specialized pericytes 

(sometimes termed glomus cells), usually in single encapsulated nodular 

masses that may be several millimeters in diameter and occur almost 

exclusively in the skin, often subungually in the upper extremity; it 

is exquisitely tender and may be so painful that patients voluntarily 

immobilize an extremity, sometimes leading to atrophy of muscles; 

multiple glomus tumors occur, sometimes with autosomal dominant 
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APPENDIX C 371

inheritance. Tumors with cavernous spaces lined by glomus cells are 

called glomangiomas. (Stedman’s medical dictionary 28th ed., 2005)

Goldenhar syndrome—A syndrome characterized by epibulbar dermoids, 

preauricular appendages, micrognathia, and vertebral and other anomalies. (Stedman’s medical dictionary 28th ed., 2005) 

Gout—A disorder of purine metabolism, occurring especially in men, characterized by a raised but variable blood uric acid level and severe recurrent acute arthritis of sudden onset resulting from deposition of crystals 

of sodium urate in connective tissues and articular cartilage; most 

cases are inherited, resulting from a variety of abnormalities of purine 

metabolism. The familial aggregation is for the most part galtonian 

with a threshold of expression determined by the solubility of uric acid. 

However, gout is also a feature of the Lesch-Nyhan syndrome, an Xlinked disorder. (Stedman’s medical dictionary 28th ed., 2005)

Gulf War—A conflict (August 2, 1990–February 28, 1991) between Iraq and 

a coalition force of approximately 30 nations led by the United States 

and mandated by the United Nations in order to liberate Kuwait. 

Gulf War Syndrome—A syndrome of various health problems experienced 

by U.S. military personnel after serving in the Persian Gulf conflict 

of 1991; includes fatigue, musculoskeletal pain, headaches, dyspnea, 

memory loss, and diarrhea; thought to be related to exposure to low 

levels of neurotoxins, including sarin, pesticides, and pyridostigmine 

bromide (the latter supplied to troops as a protective anti-toxin). 

(Stedman’s medical dictionary 28th ed., 2005) 

Hansen’s disease (also known as Leprosy)—A chronic granulomatous infection caused by Mycobacterium leprae affecting the cooler body parts, 

especially the skin, peripheral nerves, and testes. Leprosy is classified into 

two main types, lepromatous and tuberculoid, representing extremes of 

immunologic response. (Stedman’s medical dictionary 28th ed., 2005)

HARDTACK (Operation)—A series of 72 nuclear tests conducted by 

the United States in 1958; HARDTACK I was carried out in the 

Pacific Ocean at Bikini Atoll, Enewetak Atoll, and Johnston Island; 

HARDTACK II was carried out at the Nevada Test Site. 

Heart disease—An abnormal organic condition of the heart or of the heart 

and circulation.

Helminthiasis—The condition of having intestinal vermiform parasites. 

Syn: helminthism, invermination. (Stedman’s medical dictionary 28th 

ed., 2005)

Hemangiopericytoma—An uncommon vascular, usually benign, neoplasm 

composed of round and spindle cells that are derived from the pericytes 

and surround endothelium-lined vessels; malignant hemangiopericytomas are difficult to distinguish microscopically from the benign. 

(Stedman’s medical dictionary 28th ed., 2005)
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372 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Hematocrit—(1) Percentage of the volume of a blood sample occupied 

by cells. (2) Obsolete term for a centrifuge or device for separating 

the cells and other particulate elements of the blood from the plasma. 

(Stedman’s medical dictionary 28th ed., 2005)

Hemochromatosis—A disorder of iron metabolism characterized by excessive absorption of ingested iron, saturation of iron-binding protein, and 

deposition of hemosiderin in tissue, particularly in the liver, pancreas, 

and skin; cirrhosis of the liver, diabetes (bronze diabetes), bronze pigmentation of the skin, and, eventually heart failure may occur; also can 

result from administration of large amounts of iron orally, by injection, 

or in forms of blood transfusion therapy. (Stedman’s medical dictionary 

28th ed., 2005)

Hemoglobin (Hb)—The red respiratory protein of erythrocytes, consisting 

of approximately 3.8 percent heme and 96.2 percent globin, with a 

molecular weight of 64,450, which as oxyhemoglobin (HbO2) transports oxygen from the lungs to the tissues where the oxygen is readily 

released and HbO2 becomes Hb. When Hb is exposed to certain chemicals, its normal respiratory function is blocked; e.g., the oxygen in 

HbO2 is easily displaced by carbon monoxide, thereby resulting in the 

formation of fairly stable carboxyhemoglobin (HbCO), as in asphyxiation resulting from inhalation of exhaust fumes from gasoline engines. 

When the iron in Hb is oxidized from the ferrous to the ferric state, as 

in poisoning with nitrates and certain other chemicals, a nonrespiratory 

compound, methemoglobin (MetHb), is formed. 

 In humans there are at least five kinds of normal Hb: two embryonic Hb’s (Hb Gower-1, Hb Gower-2), fetal (Hb F), and two adult 

types (Hb A, Hb A2). There are two a globin chains containing 141 

amino acid residues, and two of another kind (b, g, d, e, or z), each containing 146 amino acid residues in four of the Hb’s. Hb Gower-1 has 

two z chains and two e chains. The production of each kind of globin 

chain is controlled by a structural gene of similar Greek letter designation; normal individuals are homozygous for the normal allele at each 

locus. Substitutions of one amino acid for another in the polypeptide 

chain can occur at any codon in any of the five loci and have resulted 

in the production of many hundreds of abnormal Hb types, most of 

no known clinical significance. In addition, deletions of one or more 

amino acid residues are known, as well as gene rearrangements due 

to unequal crossing over between homologous chromosomes. Newly 

discovered abnormal Hb types are first assigned a name, usually the 

location where discovered, and a molecular formula is added when 

determined. (Stedman’s medical dictionary 28th ed., 2005)

Hemoglobinuria (paroxysmal)—The presence of hemoglobin in the urine, 

including certain closely related pigments that are formed from slight 
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APPENDIX C 373

alteration of the hemoglobin molecule; when present in sufficient quantities, they result in the urine being colored in shades varying from light 

reddish-yellow to fairly dark red. (Stedman’s medical dictionary 28th 

ed., 2005)

Hemophilia—An inherited disorder of blood coagulation characterized 

by a permanent tendency to hemorrhages, spontaneous or traumatic, 

because of a defect in the blood coagulating mechanism. (Stedman’s 

medical dictionary 28th ed., 2005)

Hemorrhagic—Relating to or marked by hemorrhage. (Stedman’s medical 

dictionary 28th ed., 2005)

Hepatitis B—A virus disease with a long incubation period (usually 50-160 

days), caused by a hepatitis B virus, a DNA virus and member of the 

family Hepadnaviridae, usually transmitted by injection of infected 

blood or blood derivatives or by use of contaminated needles, lancets, 

or other instruments; clinically and pathologically similar to viral hepatitis type A, but there is no cross-protective immunity; HBs

Ag is found 

in the serum and the hepatitis delta virus occurs in some patients. 

May lead to acute or chronic liver disease. Syn: viral hepatitis type b.

(Stedman’s medical dictionary 28th ed., 2005)

Herbicide—An agent used to destroy or inhibit plant growth.

Heterozygous—Having different alleles at one locus on the pair of chromosomes present at the diploid state; for example, having a normal 

beta globin gene (coding for normal hemoglobin, HbA) at locus p15.5 

on one chromosome 11 and an abnormal gene (coding for sickle-cell 

hemoglobin, Hb S) at the same locus on the other chromosome 11. 

(Stedman’s medical dictionary 28th ed., 2005)

Hirsutism—Presence of excessive bodily and facial hair, usually in a male 

pattern, especially in women; may be present in normal adults as an 

expression of an ethnic characteristic or may develop in children or 

adults as the result of androgen excess due to tumors or drugs, or of 

non­androgenetic or other drugs. (Stedman’s medical dictionary 28th 

ed., 2005)

Hodgkin’s disease—A disease marked by chronic enlargement of the 

lymph nodes, often local at the onset and later generalized, together 

with enlargement of the spleen and often of the liver, no pronounced 

leukocytosis, and commonly anemia and continuous or remittent (PelEbstein) fever; considered to be a malignant neoplasm of lymphoid cells 

of uncertain origin (Reed-Sternberg cells), associated with inflammatory infiltration of lymphocytes and eosinophilic leukocytes and fibrosis; can be classified into lymphocytic predominant, nodular sclerosing, 

mixed cellularity, and lymphocytic depletion type. (Stedman’s medical 

dictionary 28th ed., 2005)
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374 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Homozygous—Having identical alleles at one or more loci. (Stedman’s 

medical dictionary 28th ed., 2005)

Hydrocephalus—A condition marked by an excessive accumulation of fluid 

resulting in dilation of the cerebral ventricles and raised intracranial 

pressure; may also result in enlargement of the cranium and atrophy of 

the brain. (Stedman’s medical dictionary 28th ed., 2005)

Hypercoagulability—Abnormally increased coagulability. (Stedman’s medical dictionary 28th ed., 2005)

Hyperglycemia—An abnormally high concentration of glucose in the 

circulating blood, seen especially in patients with diabetes mellitus. 

(Stedman’s medical dictionary 28th ed., 2005)

Hyperinsulinemia—Increased levels of insulin in the plasma due to increased 

secretion of insulin by the beta cells of the pancreatic islets. Decreased 

hepatic removal of insulin is a cause in some patients, although hyperinsulinism usually is associated with insulin resistance and is commonly 

found in obesity in association with varying degrees of hyperglycemia. 

Syn: hyperinsulinism. (Stedman’s medical dictionary 28th ed., 2005)

Hyperlipidemia—Elevated levels of lipids in the blood plasma. There are 

several types of hyperlipidemia; one is associated with a deficiency of 

a-aminoadipic semialdehyde synthase. (Stedman’s medical dictionary 

28th ed., 2005)

Hyperpigmentation—An excess of pigment in a tissue or part. (Stedman’s 

medical dictionary 28th ed., 2005)

Hypertension—High blood pressure; transitory or sustained elevation 

of systemic arterial blood pressure to a level likely to induce cardiovascular damage or other adverse consequences. Hypertension has been 

arbitrarily defined as a systolic blood pressure above 140 mm Hg or 

a diastolic blood pressure above 90 mm Hg. Consequences of uncontrolled hypertension include retinal vascular damage (Keith-WagenerBarker changes), cerebrovascular disease and stroke, left ventricular 

hypertrophy and failure, myocardial infarction, dissecting aneurysm, 

and renovascular disease. An underlying disorder (e.g., renal disease, 

Cushing’s syndrome, pheochromocytoma) is identified in fewer than 

10 percent of all cases of hypertension. The remainder, traditionally 

labeled “essential” hypertension, probably arise from a variety of disturbances in normal pressure-regulating mechanisms (which involve 

baroreceptors, autonomic influences on the rate and force of cardiac 

contraction and vascular tone, renal retention of salt and water, formation of angiotensin II under the influence of renin and angiotensinconverting enzyme, and other factors known and unknown), and most 

are probably genetically conditioned. (Stedman’s medical dictionary 

28th ed., 2005)

Hypertrophy—General increase in bulk of a part of organ, not due to 
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APPENDIX C 375

tumor formation. Use of the term may be restricted to denote greater 

bulk through increase in size, but not in number, of cells or other individual tissue elements. (Stedman’s medical dictionary 28th ed., 2005)

Hypochondriasis—A morbid concern about one’s own health and exaggerated attention to any unusual bodily or mental sensations; a delusion 

that one is suffering from some disease for which no physical basis is 

evident. (Stedman’s medical dictionary 28th ed., 2005)

Hypomania—A mild degree of mania. (Stedman’s medical dictionary 28th 

ed., 2005) 

Hypothyroidism—Diminished production of thyroid hormone, leading to 

clinical manifestations of thyroid insufficiency, including low metabolic 

rate, tendency to weight gain, somnolence, and sometimes myxedema. 

(Stedman’s medical dictionary 28th ed., 2005)

Hysteria—Denoting maladies involving physical symptoms that seem better 

explained by psychological factors. The concept of hysteria is historically differentiated into somatization disorder and conversion disorder, 

both of which are considered types of somatoform disorders in the 

DSM. The current ICD-10, however, places conversion disorder with 

dissociative disorders, not with somatoform disorders. (Adapted from 

Stedman’s medical dictionary 28th ed., 2005)

Inactive duty training—(A) Duty (other than full-time duty) prescribed 

for Reserves (including commissioned officers of the Reserve Corps 

of the Public Health Service) by the Secretary concerned under section 206 of title 37 (37 U.S.C.S. § 206) or any other provision of law; 

(B) Special additional duties authorized for Reserves (including commissioned officers of the Reserve Corps of the Public Health Service) 

by an authority designated by the Secretary concerned and performed 

by them on a voluntary basis in connection with the prescribed training or maintenance activities of the units to which they are assigned; 

and (C) Training (other than active duty for training) by a member of, 

or applicant for membership (as defined in section 8140[g] of title 5 

[5 U.S.C.S. § 8140(g)]) in, the Senior Reserve Officers’ Training Corps 

prescribed under chapter 103 of title 10 (10 U.S.C.S. § 2101 et seq.). 

In the case of a member of the National Guard or Air National Guard 

of any State, such term means duty (other than full-time duty) under 

sections 316, 502, 503, 504, or 505 of title 32 (32 U.S.C.S. § 316, 502, 

503, 504, or 505), or the prior corresponding provisions of law. Such 

term does not include (i) work or study performed in connection with 

correspondence courses, (ii) attendance at an educational institution in 

an inactive status, or (iii) duty performed as a temporary member of the 

Coast Guard Reserve. (Definitions. 2006. 38 U.S.C. § 101.)

Incidence—The number of instances of illness commencing, or of persons falling ill, during a given period in a specified population. More 
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376 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

generally, the number of new events, e.g., new cases of disease in a 

defined population, within a specified period of time. The term incidence is sometimes wrongly used to denote incidence rate. Syn: incident 

number. (Last, 2001)

Indemnity—A security against hurt, loss, or damage; exemption from 

incurred penalties or liabilities. 

Influenza—An acute infectious respiratory disease, caused by influenza 

viruses, which are found in the family Orthomyxoviridae, in which 

the inhaled virus attacks the respiratory epothelial cells of susceptible 

persons and produces a cararrhal inflammation; characterized by sudden onset, chills, fever of short duration (3-4 days), severe prostration, 

headache, muscle aches, and a cough that usually is dry and may be 

followed by secondary bacterial infections that can last up to 10 days. 

The disease commonly occurs in epidemics, sometimes in pandemics, 

which develop quickly and spread rapidly; mortality rate is usually 

low, but may be high in cases with secondary bacterial pneumonia, 

particularly in the elderly and those with underlying debilitating diseases; strain-specific immunity develops, but mutations in the virus are 

frequent, and the immunity usually does not affect antigenically different strains. (Stedman’s medical dictionary 28th ed., 2005)

Information bias (observational bias)—A flaw in measuring exposure or 

outcome data that results in different quality (accuracy) or information 

between comparison groups. (Last, 2001)

Instrumental variable—A factor related directly to the putative cause, but 

independent of all potential confounders, used to estimate the strength 

of causal influence even in the presence of confounding.

Instrumental variable (IV) estimation—In linear regression, used when the 

error distribution cannot be considered independent of the regressor’s 

distribution.

Interaction—(1) The interdependent operation of two or more causes to 

produce or prevent an effect. Biological interaction means the interdependent operation of two or more causes to produce, prevent, or 

control disease. (2) Differences in the effects of one or more factors 

according to the level of the remaining factor(s). (Last, 2001) In epidemiology, synonymous with effect modification (see Effect modification).

Ionizing radiation—Either particle radiation or electromagnetic radiation 

in which an individual particle/photon carries enough energy to ionize 

an atom or molecule by completely removing an electron from its orbit; 

if enough occur, can be very destructive to living tissue and can cause 

DNA damage and mutations. (Last, 2001)

Irritable bowel syndrome (IBS)—A condition characterized by gastrointestinal signs and symptoms including constipation, diarrhea, gas, and 

bloating, all in the absence of organic pathology. Associated with unco-
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APPENDIX C 377

ordinated and inefficient contractions of the large intestine. (Stedman’s 

medical dictionary 28th ed., 2005)

Ischemic heart disease—Deficient supply of blood to the heart that is due 

to obstruction of the inflow of arterial blood (as by the narrowing of 

arteries by spasm or disease).

Jaundice—A yellowish staining of the integument, sclerae, deeper tissues, 

and excretions with bile pigments, resulting from increased levels in the 

plasma. (Stedman’s medical dictionary 28th ed., 2005)

Kala-azar—(1) A chronic disease, occurring in India, China, Pakistan, the 

Mediterranean littoral, the Middle East, South and Central America, 

Asia, and Africa caused by Leishmania donovani and transmitted by 

the bite of an appropriate species of sandfly of the genus Phlebotomus or Lutzomyia; the organisms grow and multiply in macrophages, 

eventually causing them to burst and liberate amastigote parasites that 

then invade other macrophages; proliferation of macrophages in the 

bone marrow causes crowding out of erythroid and myeloid elements, 

resulting in leukopenia, and anemia, splenomegaly, and hepatomegaly, 

which are characteristic, along with enlargement of lymph nodes; fever, 

fatigue, malaise, and secondary infections also occur; different strains 

of L. donovani occur; L. infantum in Eurasia, L. chagasi in Latin 

America. (2) Visceral leishmaniasis caused by Leishmania tropica, cultured from bone marrow aspirates of some military patients following 

the Gulf War. Syn: visceral leishmaniasis. (Stedman’s medical dictionary 

28th ed., 2005)

Kaposi’s sarcoma—A multifocal malignant neoplasm of primitive vasoformative tissue, occurring in the skin and sometimes in lymph nodes 

or viscera, consisting of spindle cells and irregular small vascular 

spaces frequently infiltrated by hemosiderin-pigmented macrophages 

and extravasated red cells; clinically manifested by cutaneous lesions 

consisting of reddish-purple to dark-blue macules, plaques, or nodules; 

seen most commonly in men over 60 years of age and, in AIDS patients, 

as an opportunistic disease associated with human herpes virus 8 infection. (Stedman’s medical dictionary 28th ed., 2005)

Keratitis—Inflammation of the cornea. (Stedman’s medical dictionary 28th 

ed., 2005)

Korean conflict—The period beginning on June 27, 1950, and ending on 

January 31, 1955. (Definitions. 2006. 38 U.S.C. § 101.)

K-Z syndrome (POW syndrome)—Marked by severe, permanent psychological scars and nonspecific physical problems and is attributed to 

organic brain disease.

Laryngeal cancer—Cancer of the organ of voice production, the part of the 

respiratory tract between the pharynx and the trachea. 
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378 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Laryngitis—Inflammation of the mucous membrane of the larynx. (Stedman’s 

medical dictionary 28th ed., 2005)

Leiomyosarcoma—A malignant neoplasm derived from smooth (nonstriated) muscle. (Stedman’s medical dictionary 28th ed., 2005)

Leishmaniasis—Infection with a species of Leishmania resulting in a clinically ill-defined group of diseases traditionally divided into four major 

types: (1) visceral leishmaniasis (kala-azar); (2) Old World cutaneous 

leishmaniasis; (3) New World cutaneous leishmaniasis; (4) mucocutaneous leishmaniasis. Each is clinically and geographically distinct 

and each has in recent years been subdivided further into clinical and 

epidemiological categories. Transmission is by various sandfly species 

of the genus Phlebotomus or Lutzomyia. (Stedman’s medical dictionary 

28th ed., 2005)

Leprosy (Hansen’s disease)—(1) A chronic granulomatous infection caused 

by Mycobacterium leprae affecting the cooler body parts, especially the 

skin, peripheral nerves, and testes. Leprosy is classified into two main 

types, lepromatous and tuberculoid, representing extremes of immunologic response. (Stedman’s medical dictionary 28th ed., 2005)

Leukemia—Progressive proliferation of abnormal leukocytes found in hemopoietic tissues, other organs, and usually in the blood in increased numbers. Leukemia is classified by the dominant cell type, and by duration 

from onset to death. This occurs in acute leukemia within a few months 

in most cases, and is associated with acute symptoms including severe 

anemia, hemorrhages, and slight enlargement of the lymph nodes or the 

spleen. The duration of chronic leukemia exceeds one year, with a gradual onset of symptoms of anemia or marked enlargement of the spleen, 

liver, or lymph nodes. (Stedman’s medical dictionary 28th ed., 2005)

Lewisite—A war gas; a vesicant, a lung irritant like mustard gas; a systemic 

poison entering the circulation through the lungs or skin, and a mitotic 

poison arresting mitosis in the metaphase. Dimercaprol is the antidote. 

(Stedman’s medical dictionary 28th ed., 2005)

Likelihood ratio—The ratio of the likelihood of the observed data in a 

sample for two competing hypotheses about the true unknown characteristic (“parameter value”) of the population sampled; or comparison 

of various model conditions to assess which model provides the best fit.

Likelihood ratios are used to evaluate screening and diagnostic tests in 

clinical epidemiology. (Last, 2001)

Limited/suggestive evidence—From the IOM series Veterans and Agent 

Orange; “evidence is suggestive of an association between herbicides 

and the outcome but is limited because chance, bias, and confounding could not be ruled out with confidence. For example, at least one 

high-quality study shows a positive association, but the results of other 

studies are inconsistent.”
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APPENDIX C 379

Line of duty—All that is authorized, required, or normally associated with 

some field of responsibility.

Linear relationship—The condition in which a given variable changes by an 

absolute constant amount with each unit change in another variable. 

Liposarcoma—A malignant neoplasm of adults that occurs especially in 

the retroperitoneal tissues and the thigh, usually deep in the intermuscular or periarticular planes; histologically, liposarcoma is a large 

tumor that may be composed of well-differentiated fat cells or may be 

dedifferentiated, either myxoid, round-celled, or pleomorphic, usually 

in association with a rich network of capillaries; recurrences are common, and dedifferentiated liposarcoma metastasizes to the lungs or 

serosal surfaces. (Stedman’s medical dictionary 28th ed., 2005)

Loiasis—A chronic disease caused by the filarial nematode Loa loa, with 

symptoms and signs first occurring approximately 3-4 years after a 

bite by an infected tabanid fly. When the infective larvae mature, the 

adult worms move about in an irregular course through the connective 

tissue of the body (as rapidly as 1 cm per minute), frequently becoming visible beneath the skin and mucous membranes; e.g., in the back, 

scalp, chest, inner surface of the lip, and especially on the conjunctiva. 

The worms provoke hyperemia and exudation of fluid, often a host 

response to the worm products, a Calabar or fugitive swelling that 

causes no serious damage and subsides as the parasites move on; the 

patient is annoyed by the “creeping” in the tissues and intense itching, 

as well as occasional pain, especially when the swelling is in the region 

of tendons and joints. Most patients have marked eosinophilia of 10-40 

percent. (Stedman’s medical dictionary 28th ed., 2005)

Long Shot—A nuclear device detonated beneath Amchitka Island, Alaska, 

in 1965.

Longitudinal study—See Cohort study.

Lung epithelium—The purely cellular avascular layer covering the lung’s 

internal surfaces.

Lung fibrosis—Formation of fibrous tissue as a reparative or reactive 

process, as opposed to formation of fibrous tissue as a normal constituent of the lung.

Lung pleura (visceral pleura)—The serous membrane investing the lungs 

and dipping into the fissures between the lobes of the lungs. (Stedman’s 

medical dictionary 28th ed., 2005)

Lupus erythematosus (systemic)—An inflammatory connective tissue disease with variable features, frequently including fever, weakness and 

fatigability, joint pains or arthritis resembling rheumatoid arthritis, diffuse erythematous skin lesions on the face, neck, or upper 

extremities, with liquefaction degeneration of the basal layer and epidermal atrophy, lymphadenopathy, pleurisy or pericarditis, glomerular 
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380 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

lesions, anemia, hyperglobulinemia, and a positive LE cell test result, 

with serum antibodies to nuclear protein and sometimes to doublestranded DNA and other substances. (Stedman’s medical dictionary 

28th ed., 2005)

Luteinizing hormone (lutropin)—One of two glycoprotein hormones that 

stimulate the final ripening of the follicles and the secretion of progesterone by them, their rupture to release the egg, and the conversion of 

the ruptured follicle into the corpus luteum. Syn: lutropin. (Stedman’s 

medical dictionary 28th ed., 2005)

Lymphocyte—A white blood cell formed in bone marrow and distributed 

throughout the body in lymphatic tissue (e.g., lymph nodes, spleen, 

thymus, tonsils, Peyer patches), where it undergoes proliferation. In 

normal adults, lymphocytes make up 22-28 percent of the total number 

of leukocytes in the circulating blood. Lymphocytes are generally small 

(7-8 μm), although larger forms (10-20 μm) occur frequently. With 

Wright or similar stain, the nucleus is colored a deep purple-blue and 

is composed of dense aggregates of chromatin within a sharply defined 

nuclear membrane; the nucleus usually is round, but may be slightly 

indented, and is eccentrically situated within a relatively small amount 

of light blue cytoplasm that ordinarily contains no granules; especially 

in larger forms, the cytoplasm may be fairly abundant and include several fine granules of bright red-violet; unlike granules of the myeloid 

series of cells, those in lymphocytes do not yield a positive oxidase 

or peroxidase reaction. Lymphocytes are divided into two principal 

groups, T and B cells, based on their function and on characteristics 

of their surface molecules. Null cells, which include natural killer cells, 

represent a small percentage of the lymphocyte population. (Stedman’s 

medical dictionary 28th ed., 2005)

Lymphohaematopoietic cancer—Cancer of the lymph (a clear, transparent, 

sometimes faintly yellow and slightly opalescent fluid that is collected 

from the tissues throughout the body, flows in the lymphatic vessels, 

and is eventually added to the venous blood circulation) and the blood 

cells. 

Lymphoma—Any neoplasm of lymphoid or reticuloendothelial tissues, 

in general use, synonymous with malignant lymphoma; present as 

apparently solid tumors composed of cells that appear primitive or 

resemble lymphocytes, plasma cells, or histiocytes. Lymphomas appear 

most frequently in the lymph nodes, spleen, or other normal sites of 

lympho­reticular cells; may invade other organs or manifest as leukemia. 

Lymphomas are now classified by histology, immunophenotype, and 

cytogenic analysis, according to cell or origin (B or T cells) and degree 

of maturation. The current World Health Organization (WHO) classification of lymphoid neoplasms is based on the Revised European-
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APPENDIX C 381

American Lymphoma (REAL) classification and effectively replaces 

older schemes such as the Working Formulation and Rappaport classification, which were based solely on morphology. (Stedman’s medical 

dictionary 28th ed., 2005)

Malaria—A disease caused by the presence of the sporozoan Plasmodium

in human or other vertebrate red blood cells, usually transmitted 

to humans by the bite of an infected female mosquito of the genus 

Anopheles that previously sucked the blood from a person with 

malaria. Human infection begins with the exoerythrocytic cycle in liver 

parenchyma cells, followed by a series of erythrocytic schizogenous 

cycles repeated at regular intervals; production of gametocytes in 

other red cells provides future gametes for another mosquito infection; characterized by episodic severe chills and high fever, prostration, occasionally fatal termination. (Stedman’s medical dictionary 

28th ed., 2005)

Malnutrition (including optic atrophy)—Faulty nutrition resulting from 

malabsorption, poor diet, or overeating. (Stedman’s medical dictionary 

28th ed., 2005)

Manhattan Project—The project to develop the first nuclear weapons during 

World War II by the United States, the United Kingdom, and Canada. 

Refers specifically to the period of the project from 1942 to 1946.

Measurement error/bias—Systematic error arising from inaccurate measurements (or classification) of subjects of study variable(s). 

Melioidosis—An infectious disease of rodents in India and Southeast Asia 

that is caused by Pseudomonas pseudomallei and is communicable 

to humans. The characteristic lesion is a small caseous nodule, found 

generally throughout the body, which breaks down into an abscess; 

symptoms vary according to the tracts or organs involved. (Stedman’s 

medical dictionary 28th ed., 2005)

Mesenchymoma—Rarely used term for a neoplasm in which there is a 

mixture of mesenchymal derivatives, other than fibrous tissue. A benign 

mesenchymoma may contain foci of vascular, muscular, adipose, osteoid, 

osseous, and cartilaginous tissue; such neoplasms are sometimes classed 

under a compounded name, e.g., angioleiomyolipoma, and the like, but 

the broader term may be preferred. A malignant mesenchymoma may 

also occur as a similar mixture of two or more types of mesenchymal 

cells that are malignant (other than fibrous tissue cells). (Stedman’s 

medical dictionary 28th ed., 2005)

Mesothelioma—A rare neoplasm derived from the lining cells of the pleura 

and peritoneum, which grows as a thick sheet covering the viscera, and 

is composed of spindle cells or fibrous tissue that may enclose glandlike spaces lined by cuboidal cells. (Stedman’s medical dictionary 28th 

ed., 2005)
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382 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Meta-analysis—A statistical synthesis of the data from separate but similar, i.e., comparable, studies, leading to a quantitative summary of the 

pooled results. In the biomedical sciences, the systematic, organized, 

and structured evaluation of a problem of interest, using information 

(commonly in the form of statistical tables or other data) from a number of independent studies of the problem. A frequent application has 

been the pooling of results from a set of randomized controlled trials, 

none in itself necessarily powerful enough to demonstrate statistically 

significant differences, but in aggregate capable of doing so. Metaanalysis has a qualitative component, i.e., application of predetermined 

criteria of quality (e.g., completeness of data, absence of biases) and 

a quantitative component, i.e., integration of the numerical information. The aim is to integrate the findings, pool the data, and identify 

the overall trend of results. An essential prerequisite is that the studies 

must stand up to critical appraisal, and various biases, e.g., publication 

bias, must be allowed for. (Last, 2001)

Mexican border period—The period beginning on May 9, 1916, and ending on April 5, 1917, in the case of a veteran who during such period 

served in Mexico, on the borders thereof, or in the waters adjacent 

thereto. (Definitions. 2006. 38 U.S.C. § 101.)

Milrow—A nuclear device detonated beneath Amchitka Island, Alaska, in 

1969.

Misclassification—The erroneous classification of an individual, value, or 

an attribute into a category other than that to which it should be 

assigned. The probability of misclassification may be the same in all 

study groups (nondifferential misclassification) or may vary between 

groups (differential misclassifications). (Last, 2001)

Model averaging—Computing the average of a parameter from a model.

Monocyte—A relatively large mononuclear leukocyte (16-22 μm in diameter), that normally constitutes 3-7 percent of the leukocytes of the 

circulating blood, and is normally found in lymph nodes, spleen, bone 

marrow, and loose connective tissue. When treated with the usual dyes, 

monocytes manifest an abundant pale blue or blue-gray cytoplasm that 

contains numerous, fine, dustlike, red-blue granules; vacuoles are frequently present; the nucleus is usually indented, or slightly folded, and 

has a stringy chromatin structure that seems more condensed where 

the delicate strands are in contact. Monocytes that leave the blood 

stream and enter the connective tissue spaces are called macrophages. 

(Stedman’s medical dictionary 28th ed., 2005)

Mononucleosis—Presence of abnormally large number of mononuclear 

leukocytes in the circulating blood, especially with reference to forms 

that are not normal. (Stedman’s medical dictionary 28th ed., 2005)

Monozygotic twins—Twins resulting from one zygote that at an early stage 
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APPENDIX C 383

of development becomes separated into independently growing cell 

aggregations giving rise to two individuals of the same sex and identical 

genetic constitution. (Stedman’s medical dictionary 28th ed., 2005)

Multiple myeloma—An uncommon disease that occurs more frequently in 

men than in women and is associated with anemia, hemorrhage, recurrent infections, and weakness. Ordinarily, it is regarded as a malignant 

neoplasm that originates in bone marrow and involves chiefly the 

skeleton, with clinical features attributable to the sites of involvement 

and to abnormalities in formation of plasma protein; characterized 

by numerous diffuse foci or nodular accumulations of abnormal or 

malignant plasma cells in the marrow of various bones (especially the 

skull), causing palpable swellings of the bones, and occasionally in 

extraskeletal sites; radiologically, the bone lesions have a characteristic punched-out appearance. The myeloma cells produce abnormal 

proteins in the serum and urine; those formed in any one example 

of multiple myeloma are different from other myeloma proteins, as 

well as from normal serum proteins, the most frequent abnormalities 

in the metabolism of protein being (1) the occurrence of Bence Jones 

proteinuria, (2) a great increase in monoclonal g-globulin in the plasma, 

(3) the occasional formation of cryoglobulin, and (4) a form of primary 

amyloidosis. The Bence Jones protein is not a derivative of abnormal 

serum protein, but seems to be formed de novo from amino acid precursors. (Stedman’s medical dictionary 28th ed., 2005)

Multiple regression model—Given data on an outcome variable y and more 

than one possible predictive variables x1, x2, etc., regression analysis 

involves finding the “best” mathematical model (within some restricted 

class of models) to describe y as a function of the x’s, or to predict y

from the x’s. Not to be confused with multivariate analysis. 

Multiple sclerosis (MS)—Common demyelinating disorder of the central 

nervous system, causing patches of sclerosis (plaques) in the brain and 

spinal cord; occurs primarily in young adults, and has protean clinical 

manifestations, depending upon the location and size of the plaque; 

typical symptoms include visual loss, diplopia, nystagmus, dysarthria, 

weakness, paresthesias, bladder abnormalities, and mood alterations; 

characteristically, the plaques are “separated in time and space” and 

clinically the symptoms show exacerbations and remissions. (Stedman’s 

medical dictionary 28th ed., 2005)

Multiplicative model—A model in which the joint effect of two or more 

causes is the product of their individual effects. For instance, if factor a 

multiplies risk by the amount a in the absence of factor b, and factor b 

multiplies risk by the amount b in the absence of factor a, the combined 

effect of factors a and b on risk is a × b. (Last, 2001)

Multivariate model—A model where the variation in several variables is 
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384 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

studied simultaneously; in statistics, any analytic method that allows 

the simultaneous study of two or more dependent variables. 

Mustard gas—An irritant, vesicant, oily liquid used especially as a chemical 

weapon.

Mutagenic—Promoting mutation.

Myasthenia gravis—A disorder of neuromuscular transmission marked by 

fluctuating weakness and fatigue of certain voluntary muscles, including 

those innervated by brainstem motor nuclei; caused by a marked reduction in the number of acetylcholine receptors in the post­synaptic membrane of the neuromuscular junction, resulting from an auto­immune 

mechanism. (Stedman’s medical dictionary 28th ed., 2005)

Mycosis (mycoses)—Any disease caused by a fungus. (Stedman’s medical 

dictionary 28th ed., 2005)

Myelitis—(1) Inflammation of the spinal cord. (2) Inflammation of the bone 

marrow. (Stedman’s medical dictionary 28th ed., 2005)

Myelodysplastic syndrome (MDS)—A heterogeneous group of clonal 

hemato­poietic stem cell disorders characterized by the presence of 

dysplastic changes in one or more of hematopoietic lineages. The common clinical picture may include anemia, infections, and bleeding problems. Occurs generally in elderly patients, or those with prior exposure 

to leukemogenic agents. Transformation rates to acute leukemia range 

from 10 to 80 percent. Cytogenetic abnormalities are associated with a 

poor prognosis. (Stedman’s medical dictionary 28th ed., 2005)

Myocarditis—Inflammation of the muscular walls of the heart. (Stedman’s 

medical dictionary 28th ed., 2005)

Nasopharyngeal cancer—Cancer of the nose or naval cavity and the 

pharynx.

National Childhood Vaccine Injury Act—Enacted in 1986 to reduce the 

potential financial liability of vaccine makers due to vaccine injury 

claims; created the National Vaccine Injury Compensation Program 

to provide a federal no-fault system for compensating vaccine-related 

injuries or death. 

Necessary cause—A causal factor whose presence is required for the occurrence of a given effect. 

Negative predictive value (NPV)—The probability that a person with a 

negative test does not have the disease or condition (Last, 2001); specifically, the ratio of those who are identified by a test not to have the 

condition who in fact do not have it, divided by all those identified by 

a test not to have the condition (i.e., true negatives, divided by the sum 

of true negatives and false negatives). See Positive predictive value.

Nephritis—Inflammation of the kidneys. (Stedman’s medical dictionary 

28th ed., 2005)
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APPENDIX C 385

Nephrolithiasis—Presence of renal calculi. (Stedman’s medical dictionary 

28th ed., 2005)

Neuropsychiatric disease—A disease of both neurology (nervous system) 

and psychiatry (mental disorders).

Neutrophil—(1) A mature white blood cell in the granulocytic series, formed 

by myelopoietic tissue of the bone marrow (sometimes also in extramedullary sites), and released into the circulating blood, where they 

normally represent 54-65 percent of the total number of leukocytes. 

When stained with the usual Romanovsky type of dyes, neutrophils are 

characterized by (a) a dark purple-blue nucleus, lobated (three to five 

distinct lobes joined by thin strands of chromatin), and with a rather 

coarse network of fairly dense chromatin; and (b) a cytoplasm that is 

faintly pink (sharply contrasted with the nucleus) and contains numerous fine pink or violet-pink granules, i.e., not acidophilic or basophilic 

(as in eosinophils or basophils). The precursors of neutrophils, in order 

of increasing maturity, are: myeloblasts, promyelocytes, myelocytes, 

metamyelocytes, and band forms. Although the terms neutrophilic leukocytes and neutrophilic granulocytes include younger cells in which 

neutrophilic granules are recognized, the two expressions are frequently 

used as synonyms for neutrophils, which are mature forms unless 

other­wise indicated by a modifying term, such as immature neutrophil. 

(2) Any cell or tissue that manifests no special affinity for acid or basic 

dyes, i.e., the cytoplasm stains approximately equally with either type 

of dye. (Stedman’s medical dictionary 28th ed., 2005)

Nodule—A small node; in skin, a node up to 1.0 cm in diameter, solid, with 

palpable depth; a pulmonary or pleural lesion seen on a radiographic 

image as a well-defined, discrete, roughly circular opacity 2-30 mm in 

diameter. (Stedman’s medical dictionary 28th ed., 2005)

Non-Hodgkin’s lymphoma (NHL)—A lymphoma other than Hodgkin’s 

disease, classified by Rappaport into a nodular or diffuse tumor pattern 

and by cell type; a working or international formulation separates such 

lymphomas into low-, intermediate-, and high-grade malignancy and 

into cytologic subtypes reflecting follicular center cell or other origin. 

(Stedman’s medical dictionary 28th ed., 2005)

Nonlymphocytic leukemia—A malignant neoplasm of blood-forming tissues 

characterized by the uncontrolled proliferation of immature granular 

leukocytes. The risk of the disease is increased among people who have 

been exposed to massive doses of radiation. 

Non-service-connected—With respect to disability or death, that such disability was not incurred or aggravated, or that the death did not result 

from a disability incurred or aggravated, in line of duty in the active 

military, naval, or air service. (Definitions. 2006. 38 U.S.C. § 101.)
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Normalized data—Data that are continuous and have a symmetrical distribution, both tails extend to infinity; the arithmetic mean, mode, and 

median are identical; the distribution shape is completely determined 

by the mean and standard deviation.

Null hypothesis—The statistical hypothesis that one variable has no association with another variable or set of variables, or that two or more 

population distributions do not differ from one another; states that the 

results observed in a study, experiment, or test are no different from 

what might have have occurred as a result of the operation of chance 

alone. (Last, 2001)

Nursing home care—The accommodation of convalescents or other persons who are not acutely ill and not in need of hospital care but who 

require nursing care and related medical services. (Definitions. 2006. 

38 U.S.C. § 101.)

Obesity—An excess of subcutaneous fat in proportion to lean body mass. 

Excess fat accumulation is associated with increase in the size (hypertrophy) as well as the number (hyperplasia) of adipose tissue cells. 

Obesity is variously defined in terms of absolute weight, weight-height 

ratio, distribution of subcutaneous fat, and societal and esthetic norms. 

Measures of weight in proportion to height include relative weight 

(RW, body weight divided by median desirable weight for a person of 

the same height and medium frame according to actuarial tables), body 

mass index (BMI, kg/m2), and ponderal index (kg/m3). These do not 

differentiate between excess adiposity and increased lean body mass. 

In contrast, subscapular and triceps skinfold measurements and determination of the waist-to-hip ratio help define the regional deposition 

of fat and differentiate the more medically significant central obesity 

from peripheral obesity in adults. No single cause can explain all cases 

of obesity. Ultimately it results from an imbalance between energy 

intake and energy expenditure. While faulty eating habits related to 

failure of normal satiety feedback mechanisms may be responsible for 

some cases, many obese persons neither consume more calories nor eat 

different proportions of foodstuffs than nonobese persons. Contrary to 

popular belief, obesity is not caused by disorders of pituitary, thyroid, 

or adrenal gland metabolism. However, it is often associated with 

hyperinsulinism and relative insulin resistance. Studies of obese twins 

strongly suggest the presence of genetic influences on resting metabolic 

rate, feeding behavior, changes in energy expenditures in response 

to overfeeding, lipoprotein lipase activity, and basal rate of lipolysis. 

Environmental factors associated with obesity include socioeconomic 

status, race, region of residence, season, urban living, and being part 

of a smaller family. The prevalence of obesity is greater when weight 

is measured during winter rather than summer. Obesity is much more 
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APPENDIX C 387

common in the southeastern United States, although the northeastern 

and midwestern states also have high rates, a phenomenon independent 

of race, population density, and season. (Stedman’s medical dictionary 

28th ed., 2005)

Observational study—An epidemiologic study that does not involve any 

experimental intervention, such as randomizing exposure or treatment. 

Obstructive pulmonary disease—A progressive and irreversible condition 

characterized by diminished inspiratory and expiratory capacity of the 

lungs. 

Occult blood—Blood in the feces in amount too small to be seen but detectable by chemical tests. (Stedman’s medical dictionary 28th ed., 2005)

Ochronosis—A rare, autosomal recessive disease characterized by 

alkaptonuria with pigmentation of the cartilages and sometimes 

tissues such as muscle, epithelial cells, and dense connective tissue; 

may affect also the sclera, mucous membrane of the lips, and skin of 

the ears, face, and hands, and cause standing urine to be dark-colored 

and contain pigmented casts; pigmentation is thought to result from 

oxidized homogentisic acid, and cartilage degeneration results in 

osteoarthritis, particularly of the spine. (Stedman’s medical dictionary 

28th ed., 2005)

Odds ratio (OR)—The ratio of two odds, often used in case-control studies as an estimate of relative risk. Consider the following notation for 

the distribution of a binary exposure and a disease in a population or 

a sample.

 Exposed Unexposed

 Disease a b

 No disease c d

The odds ratio (cross-product ratio) is ad/bc. Syn: cross-product ratio, 

relative odds. (Adapted from Last, 2001)

Onchocerciasis—Infection with Onchocerca (especially O. volvulus, a 

filarial nematode transmitted from person to person by black flies of 

the genus Simulium), marked by nodular swellings forming a fibrous 

cyst enveloping the coiled parasites (onchocercoma); microfilariae move 

freely out of the nodule and escape into the intercellular lymph in 

the dermis. Dermatologic changes often develop, especially in Africa, 

resulting in intense pruritus, scaly or lichenoid skin, depigmentation, 

and destruction of elastic fibers. Most important are the ocular complications that may develop after a long chronic course, with blindness 

frequently occurring in advanced cases, caused by the presence of living 

or dead microfilariae seen by slitlamp biomicroscopy. (Stedman’s medical dictionary 28th ed., 2005)
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388 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Operation Ranch Hand—The military code name for the spraying of herbicides from U.S. Air Force aircraft in Southeast Asia from 1962 through 

1971.

Operation TOP HAT—Conducted in Fort McClellan, Alabama, in 1953; 

used Chemical Corps personnel in tests of decontamination methods 

for biological welfare agents, sulfur mustard, and nerve gases.

Ophthalmological changes—Changes concerned with the eye, its disease, 

and refractive errors.

Organic disease of the nervous system (organic disease)—A disease in 

which there are anatomic or pathophysiologic changes in some bodily 

tissue or organ, in contrast to a functional disorder; particularly one of 

psychogenic origin. (Stedman’s medical dictionary 28th ed., 2005)

Organic residuals of frostbite—Any detectable or observable changes due 

to frostbite.

Oroya fever (also known as bartonellosis and carrion)—A generalized, acute, 

febrile, endemic, and systemic form of bartonellosis; marked by high 

fever, rheumatic pains, progressive, severe anemia, and albuminuria. 

(Stedman’s medical dictionary 28th ed., 2005)

Osteitis (Paget’s disease)—Inflammation of bone. (Stedman’s medical dictionary 28th ed., 2005)

Osteoarthritis—Arthritis characterized by erosion of articular cartilage, 

either primary or secondary to trauma or other conditions, which 

becomes soft, frayed, and thinned with eburnation of subchondral 

bone and outgrowths of marginal osteophytes; pain and loss of function result; mainly affects weight-bearing joints, is more common 

in old people and animals. (Stedman’s medical dictionary 28th ed., 

2005)

Osteomalacia—A disease in adults characterized by a gradual softening 

and bending of the bones with varying severity of pain; softening 

occurs because the bones contain osteoid tissue that has failed to calcify because of lack of vitamin D or renal tubular dysfunction; more 

common in women than in men, osteomalacia often begins during 

pregnancy. (Stedman’s medical dictionary 28th ed., 2005)

Osteopathy—(1) Any disease of bone. (2) A school of medicine based upon 

a concept of the normal body as a vital machine capable, when in correct adjustment, of making its own remedies against infections and 

other toxic conditions; practitioners use the diagnostic and therapeutic 

measures of conventional medicine in addition to manipulative measures. (Stedman’s medical dictionary 28th ed., 2005)

Osteoporosis—Reduction in the quantity of bone or atrophy of skeletal 

tissue; an age-related disorder characterized by decreased bone mass 

and loss of normal skeletal microarchitecture, leading to increased susceptibility to fractures. (Stedman’s medical dictionary 28th ed., 2005)
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APPENDIX C 389

Osteosarcoma—The most common and malignant of bone sarcomas, which 

arises from bone-forming cells and affects chiefly the ends of long 

bones. Its greatest incidence is in the age group between 10 and 25 

years. (Stedman’s medical dictionary 28th ed., 2005)

Paget’s disease—(1) A generalized skeletal disease, frequently familial, 

of older persons in which bone resorption and formation are both 

increased, leading to thickening and softening of bones (e.g., the skull), 

and bending of weight-bearing bones; Syn: osteitis deformans. (2) A 

disease of elderly women, characterized by an infiltrated, somewhat 

eczematous lesion surrounding and involving the nipple and areola, and 

associated with subjacent intraductal cancer of the breast and infiltration of the lower epidermis by malignant cells. (3) Syn: extramammary 

Paget’s disease. (Stedman’s medical dictionary 28th ed., 2005)

Palsy—Paralysis or paresis. (Stedman’s medical dictionary 28th ed., 2005)

Paralysis agitans—Obsolete term for parkinsonism. (Stedman’s medical 

dictionary 28th ed., 2005)

Paranoia—A severe but relatively rare mental disorder characterized by 

the presence of systematized delusions often of a persecutory character 

involving being followed, poisoned, or harmed by other means, in an 

otherwise intact personality. (Stedman’s medical dictionary 28th ed., 

2005)

Parathyroid adenoma—Tumors of the parathyroid glands, which are located 

in the neck and help regulate calcium metabolism.

Parent—A father, a mother, a father through adoption, a mother through 

adoption, or an individual who for a period of not less than one year 

stood in the relationship of a parent to a veteran at any time before 

the veteran’s entry into active military, naval, or air service or if two 

persons stood in the relationship of a father or a mother for one year or 

more, the person who last stood in the relationship of father or mother 

before the veteran’s last entry into active military, naval, or air service 

(except for purposes of chapter 19 of this title [38 U.S.C.S. § 1901 et 

seq.]). (Definitions. 2006. 38 U.S.C. § 101.)

Parkinson’s disease (also called paralysis agitans, parkinsonism)—(1) A 

neurologic syndrome usually resulting from deficiency of the neurotransmitter dopamine as the consequence of degenerative, vascular, or 

inflammatory changes in the basal ganglia; characterized by rhythmic 

muscular tremors, rigidity of movement, festination, droopy posture, 

and masklike facies. (2) A syndrome similar to parkinsonism. Some 

features seen with Parkinson disease that occur with other disorders 

(e.g., progressive supranuclear palsy) or as a side effect of certain medications. (Stedman’s medical dictionary 28th ed., 2005)

Parsimonious model—A model with as few parameters as possible.

Pathogenesis—The postulated mechanisms by which the etiologic agent 
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390 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

produces disease. The difference between etiology and pathogenesis 

should be noted: The etiology of a disease or disability consists of the 

postulated causes that initiate the pathogenetic mechanisms; control of 

these causes might lead to prevention of the disease. (Last, 2001)

Pellagra—An affection characterized by gastrointestinal disturbances, 

erythema (particularly of exposed areas) followed by desquamation, 

and nervous and mental disorders; may occur because of a poor diet, 

alcoholism, or some other disease causing impairment of nutrition; 

commonly seen when corn (maize) is a main nutrient in the diet, resulting in a deficiency of niacin. (Stedman’s medical dictionary 28th ed., 

2005)

Pension—A monthly or other periodic payment made by the Secretary to a 

veteran because of service, age, or non-service-connected disability, or 

to a surviving spouse or child of a veteran because of the non-serviceconnected death of the veteran. (Definitions. 2006. 38 U.S.C. § 101.)

Peptic ulcer (gastric or duodenal)—An ulcer of the alimentary mucosa, 

usually in the stomach or duodenum, exposed to gastric secretion. 

(Stedman’s medical dictionary 28th ed., 2005)

Period of war—The Spanish-American War, the Mexican border period, 

World War I, World War II, the Korean conflict, the Vietnam era, the 

Persian Gulf War, and the period beginning on the date of any future 

declaration of war by the Congress and ending on the date prescribed 

by Presidential proclamation or concurrent resolution of the Congress. 

(Definitions. 2006. 38 U.S.C. § 101.)

Peripheral arterial hemodynamics—Blood circulation outside the arteries. 

Peripheral nerve disease—See Peripheral neuropathy.

Peripheral neuropathy (acute and subacute)—A disease or degenerative 

state of the peripheral nerves in which motor, sensory, or vasomotor 

nerve fibers may be affected and which is marked by muscle weakness 

and atrophy, pain, and numbness.

Peripheral vasculature—Affecting extremities and abdominal blood vessels.

Persian Gulf War—The period beginning on August 2, 1990, and ending on 

the date thereafter prescribed by Presidential proclamation or by law. 

(Definitions. 2006. 38 U.S.C. § 101.)

Pharynx—The superior expanded portion of the alimentary tract, between 

the mouth and nasal cavities (superiorly and anteriorly) and the 

esophagus (inferiorly); consisting of the nasopharynx, oropharynx, and 

laryngo­pharynx, the first two being shared with the respiratory tract; 

the pharynx is distinct from the rest of the alimentary tract in that it 

is composed exclusively of voluntary skeletal muscle arranged in outer 

circular and inner longitudinal layers. (Stedman’s medical dictionary 

28th ed., 2005)

Phenoxyherbicides—Related to the growth hormone indoleacetic acid; 
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APPENDIX C 391

when sprayed on broad-leaf plants they induce rapid and uncontrolled 

growth, eventually killing them.

Phenytoin—An anticonvulsant used in the treatment of generalized tonic 

clonic and complex partial epilepsy. (Stedman’s medical dictionary 28th 

ed., 2005)

Picloram—A systemic herbicide used for control of woody plants and a 

wide range of broad-leaved weeds. 

Pinta—A disease caused by a spirochete Treponema carateum, endemic in 

Mexico and Central America, and characterized by a small primary 

papule followed by an enlarging plaque and disseminated secondary macules of varying color called pintids that finally become white. 

(Stedman’s medical dictionary 28th ed., 2005)

Plague—(1) Any disease of wide prevalence or of excessive mortality. (2) An 

acute infectious disease caused by the bacterium Yersinia pestis and 

marked clinically by high fever, toxemia, prostration, a petechial eruption, lymph node enlargement, pneumonia, or hemorrhage from the 

mucous membranes; primarily a disease of rodents, transmitted to 

humans by fleas that have bitten infected animals. In humans the 

disease takes one of four clinical forms: bubonic plague, septicemic 

plague, pneumonic plague, or ambulant plague. (Stedman’s medical 

dictionary 28th ed., 2005)

Platelet—An irregularly shaped disklike cytoplasmic fragment of a megakaryocyte that is shed in the marrow sinus and subsequently found 

in the peripheral blood, where it functions in clotting. A platelet contains granules in the central part (granulomere) and, peripherally, clear 

protoplasm (hyalomere), but no definite nucleus; is about one-third 

to one-half the size of an erythrocyte; and contains no hemoglobin. 

(Stedman’s medical dictionary 28th ed., 2005)

Plutonium (Pu)—A transuranium artificial radioactive element, atomic no. 

94, atomic wt. 244.064. The best-known a-emitting isotope is 239Pu 

(half-life 24,110 years) which, like 235U, is fissionable and can be used 

in atomic bombs and nuclear power plants; 238Pu (half-life 87.74 years) 

is used as an energy source in pacemakers. Pu ions are bone-seekers; 

ingestion is a radiation hazard, as with radium and radiostrontium. 

(Stedman’s medical dictionary 28th ed., 2005)

Pneumonia—Inflammation of the lung parenchyma characterized by consolidation of the affected part, the alveolar air spaces being filled with 

exudated, inflammatory cells, and fibrin. Most cases are due to infection by bacteria or viruses, a few to inhalation of chemicals or trauma 

to the chest wall, and a small minority to rickettsias, fungi, and yeasts. 

Distribution may be lobar, segmental, or lobular; when lobular and in 

associated with bronchitis, it is termed bronchopneumonia. (Stedman’s 

medical dictionary 28th ed., 2005)
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392 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

Polycythemia (erythremia)—A condition marked by an abnormal increase 

in the number of circulating red blood cells.

Polydipsia—Excessive thirst that is relatively prolonged. (Stedman’s medical 

dictionary 28th ed., 2005)

Polyuria—Excessive excretion of urine resulting in profuse and frequent 

micturition. (Stedman’s medical dictionary 28th ed., 2005)

Population attributable fraction (PAF)—PAF is the attributable fraction 

(AF) in the entire population rather than in just the exposed population. To calculate PAF, AF in the exposed is multiplied by the fraction 

of the entire population that is exposed (i.e., by the prevalence of exposure). See Attributable fraction.

Porphyria cutanea tarda (PCT)—Familial or sporadic porphyria characterized by liver dysfunction and photosensitive cutaneous lesions, 

with bullae, hyperpigmentation, and scleroderma-like changes in the 

skin and increased excretion of uroporphyrin; caused by a deficiency 

of uroporphyrinogen decarboxylase induced in sporadic cases by 

chronic alcoholism; autosomal dominant inheritance in familial cases. 

(Stedman’s medical dictionary 28th ed., 2005)

Portability—The degree to which the relative risk estimated from one population can be properly applied to another population. 

Positive predictive value (PPV)—The probability that a person with a positive test is a true positive (i.e., does have the disease or condition); 

specifically, the ratio of those who are identified by a test to have the 

condition who in fact have it, divided by all those identified by a test 

to have the condition (i.e, true positives, divided by the sum of true 

positives and false positives). See Negative predictive value.

Posterior subcapsular cataracts—A cataract involving the cortex at the 

posterior pole of the lens. (Stedman’s medical dictionary 28th ed., 

2005)

Postirradiation osteosarcoma—Osteosarcoma after radiation therapy; see 

Osteosarcoma.

Post-traumatic stress disorder (PTSD)—(1) Development of characteristic 

long-term symptoms following a psychologically traumatic event that 

is generally outside the range of usual human experience; symptoms 

include persistently reexperiencing the event and attempting to avoid 

stimuli reminiscent of the trauma, numbed responsiveness to environmental stimuli, a variety of autonomic and cognitive dysfunctions, and 

dysphoria. (2) A DSM diagnosis that is established when the specified 

criteria are met. (Stedman’s medical dictionary 28th ed., 2005)

Presumption—A procedural device that dictates that once basic fact A is 

established, the existence of fact B must be assumed unless the presumed fact is rebutted. 

Prevalence—The ratio of the number of those with a given condition in a 
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APPENDIX C 393

population (or sample) divided by the number of the entire population 

(or sample). 

Prima facie—At first view; on the first appearance; legally sufficient to 

establish a fact or a case unless disproved.

Prisoner of War—A combatant who is imprisoned by an enemy power during or immediately after an armed conflict. 

Probability distribution—For a discrete (non-continuous) random variable, 

the function that given the probabilities that the variable equals each 

of a sequence of possible values; examples include the binomial and 

Poisson distributions. For a continuous random variable, often used 

synonymously with the probability density function; an example is the 

normal distribution. (Adapted from Last, 2001)

Probability of causation (PC)—The fraction of disease risk in an exposed 

individual that is due to the exposure. This is expressed as (r1i – r0i) / r1i, 

where r1i is the disease risk in individual i if exposed and r0i is the disease risk in that same individual if unexposed (i.e., the counterfactual). 

PC is also often defined as the probability that the exposure caused the 

disease in an exposed individual. PC has also been used to refer to the 

AF when AF is applied to individuals, but this usage is incorrect. Since 

we can know neither r1i nor r0i, and there is substantial variation in 

these across individuals in even relatively homogeneous populations, 

for any individual AF cannot be known to be a good estimate of PC.

Proportionate recovery—A defendant compensates a claimant for a fraction of his/her injury that represents the defendant’s statistical share in 

that injury.

Prosthetics—The art and science of making and adjusting artificial parts of 

the human body. (Stedman’s medical dictionary 28th ed., 2005)

Prothrombin—A glycoprotein, molecular weight approximately 72,500, 

formed and stored in the parenchymal cells of the liver and present 

in blood in a concentration of approximately 20 mg/100 ml. In the 

presence of thromboplastin and calcium ion, prothrombin is converted 

to thrombin, which in turn converts fibrinogen to fibrin, this process 

resulting in coagulation of blood; a deficiency of prothrombin leads to 

impaired blood coagulation. (Stedman’s medical dictionary 28th ed., 

2005)

Proximal limb amputations—An amputation of a limb situated nearest the 

trunk or the point of origin. 

Psychoneurosis—A mental or behavioral disorder of mild or moderate 

severity; formerly a classification of neurosis that included hysteria, 

psychasthenia, neurasthenia, and the anxiety and phobic disorders. 

(Stedman’s medical dictionary 28th ed., 2005)

Psychosis (psychoses)—(1) A mental and behavioral disorder causing gross 

distortion or disorganization of a person’s mental capacity, affective 
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394 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

response, and capacity to recognize reality, communicate and relate to 

others to the degree of interfering with a person’s capacity to cope with 

the ordinary demands of everyday life. The psychoses are divided into 

two major classifications according to their origins: those associated 

with organic brain syndromes (e.g., Korsakoff’s syndrome); and those 

less clearly organic and having some functional component(s) (e.g., 

the schizophrenias, bipolar disorder). (2) Generic term for any of the 

so-called insanities, the most common forms of which are the schizophrenias. (3) A severe emotional and behavioral disorder. (Stedman’s 

medical dictionary 28th ed., 2005)

Purpura—A condition characterized by hemorrhage into the skin. Appearance of the lesions varies with the type of purpura, the duration of the 

lesions, and the acuteness of the onset. The color is first red, gradually 

darkens to purple, fades to a brownish yellow, and usually disappears in 2-3 weeks; color of residual permanent pigmentation depends 

largely on the type of unabsorbed pigment of the extravasated blood; 

extravasations may occur also into the mucous membranes and internal 

organs. (Stedman’s medical dictionary 28th ed., 2005)

Putative cause—A commonly accepted or assumed cause.

P-value—The probability that a test statistic (such as relative risk) would 

be as extreme as or more extreme than observed if the null hypothesis 

were true. The letter P, followed by the abbreviation n.s. (not significant) or by the symbol < (less than) or > (greater than) and a decimal 

notation, such as 0.01, 0.05, is a statement of the probability that the 

difference observed could have occurred by chance if the groups were 

really alike, i.e., under the null hypothesis. 

 Investigators may arbitrarily set their own significance levels, but in 

most biomedical and epidemiologic work, a study result whose probability value is less than 5 percent (P < 0.05) or 1 percent (P < 0.01) is 

considered sufficiently unlikely to have occurred by chance to justify 

the designation “statistically significant.” (Adapted from Last, 2001)

Pyridostigmine bromide—A cholinesterase inhibitor useful in the treatment 

of the disorder of neuromuscular transmission. 

Radioepidemiological Tables—Developed by the National Institutes of 

Health working group in 1985; serve as a reference tool providing 

probability of causation estimates for individuals with cancer who were 

exposed to ionizing radiation. 

Radiogenic disease—A disease that may be induced by ionizing radiation. 

Radionuclide—An isotope of artificial or natural origin that exhibits radioactivity. (Stedman’s medical dictionary 28th ed., 2005)

Radium—A metallic element, atomic no. 88, extracted in very minute quantities from pitchblende; 226Ra, its longest-lived isotope, is produced as 

an intermediate in the uranium series by the emission of an a particle 
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APPENDIX C 395

from thorium-230 (ionium); 226Ra emits a particles and gamma rays 

with a half-life of 1,599 years breaking down to 222Rn; chemically, it 

is an alkaline earth metal with properties similar to those of barium. 

Its therapeutic action is similar to that of x-rays, since the a emission 

is filtered out. (Stedman’s medical dictionary 28th ed., 2005) 

Randomized clinical (or controlled) trial (RCT)—An experiment in which 

subjects in a population are randomly allocated into groups, usually 

called study and control groups, to receive or not to receive an experimental preventive or therapeutic procedure, maneuver, or intervention. 

The results are assessed by rigorous comparison of rates of disease, 

death, recovery, or other appropriate outcome in the study and control 

groups. Randomized controlled trials are generally regarded as the 

most scientifically rigorous method of hypothesis testing available. 

(Last, 2001)

Rating schedule—Certain criteria and/or levels of disability are required for 

entitlement to ancillary and special purpose benefits. 

Raynaud’s syndrome—Idiopathic paroxysmal bilateral cyanosis of the digits due to arterial and arteriolar contraction; caused by cold or emotion. Syn: Raynaud Syndrome. (Stedman’s medical dictionary 28th ed., 

2005)

Readjustment Counseling Program—Services provided to combat veterans 

in the effort to make a satisfying transition from military to civilian 

life. 

Receiver operator characteristics (ROC) curve—(1) A plot of percentage of 

true positive results versus percentage of false positive results, typically 

used in assessing the value of a diagnostic test. (2) A graphic means for 

assessing the ability of a screening or diagnostic test to discriminate 

between healthy and diseased persons. (Adapted from Stedman’s medical dictionary 28th ed., 2005)

Registry—An organized system for the collection, storage, retrieval, analysis and dissemination of information on individual persons who have 

either a particular disease, a condition that predisposes to the occurrence of a health-related event, or prior exposure to substances known 

or suspected to cause adverse health effects (definition from www.

ncvhs.hhs.gov/9701138b.htm).

Relative risk (RR)—(1) The ratio of the risk of disease or death among the 

exposed compared to the risk among the unexposed. (2) Alternatively, 

the ratio of the cumulative incidence rate in the exposed to the cumulative incidence rate in the unexposed, i.e., the rate ratio. (3) The term 

relative risk has also been used synonymously with odds ratio and, in 

some biostatistical articles, has been used for the ratio of force of morbidity. The use of the term relative risk for several different quantities 

arises from the fact that for “rare” diseases (e.g., neonatal mortality in 
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396 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

infants under 1,500-g birth weight), the approximations do not hold. 

(Last, 2001)

Reserve—A member of a reserve component of one of the Armed Forces. 

Reserve component: With respect to the Armed Forces—(A) The 

Army Reserve; (B) The Navy Reserve; (C) The Marine Corps Reserve; 

(D) The Air Force Reserve; (E) The Coast Guard Reserve; (F) The Army 

National Guard of the United States; and (G) The Air National Guard 

of the United States. (Definitions. 2006. 38 U.S.C. § 101.)

Residual confounding—Confounding that persists after incomplete or 

unsuccessful attempts to account or adjust for it. 

Retirement—Leaving the military after at least 20 years of active service.

Reverse causality—An association that arises when the purported cause is 

actually the effect (A is thought to cause B, when in fact B causes A). 

See Cross-sectional study.

Rhabdomyosarcoma—A malignant neoplasm derived from skeletal (striated) muscle, occurring in children or, less commonly, in adults; classified as embryonal alveolar (composed of loose aggregates of small 

round cells) or pleomorphic (containing rhabdomyoblasts). (Stedman’s 

medical dictionary 28th ed., 2005)

Rheumatoid arthritis—A generalized disease, occurring more often in 

women, that primarily affects connective tissue; arthritis is the dominant clinical manifestation, involving many joints, especially those 

of the hands and feet, accompanied by thickening of articular soft 

tissue, with extension of synovial tissue over articular cartilages, which 

become eroded; the course is variable but often is chronic and progressive, leading to deformities and disability. (Stedman’s medical dictionary 28th ed., 2005)

Rickets—A disease due to vitamin D deficiency and characterized by overproduction and deficient calcification of osteoid tissue, with associated 

skeletal deformities, disturbances in growth, hypocalcemia, and sometimes tetany; usually accompanied by irritability, listlessness, and generalized muscular weakness; fractures are frequent. (Stedman’s medical 

dictionary 28th ed., 2005)

Risk estimate—Combining risk characterization, dose-response relationships, and exposure estimates to quantify the risk level in a specific 

population. The end result is a qualitative and quantitative statement 

about the health effects expected and the proportion and number of 

affected people in a target population. Sometimes used as a general 

term for effect measure in an epidemiological analysis. (Adapted from 

Last, 2001)

Roentgenogram (radiograph)—A negative image on photographic film 

made by exposure to x-rays or gamma rays that have passed through 

matter or tissue. (Stedman’s medical dictionary 28th ed., 2005)
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APPENDIX C 397

Saccharin—In dilute aqueous solutions it is 300 to 500 times sweeter than 

sucrose; used as a sweetening agent. 

“Safe” dose—A threshold below which there is no increase in risk. 

Sandfly fever—An infectious but not contagious disease occurring in the 

Balkan Peninsula and other parts of southern Europe, caused by several 

viruses in the family Bunyaviridae apparently introduced by the bite 

of the sandfly, Phlebotomus papatasii; symptoms resemble those of 

dengue but are less severe and of shorter duration. Syn: Phlebotomus 

fever. (Stedman’s medical dictionary 28th ed., 2005)

Sarcoidosis—A systemic granulomatous disease of unknown cause, especially involving the lungs with resulting interstitial fibrosis, but also 

involving lymph nodes, skin, liver, spleen, eyes, phalangeal bones, and 

parotid glands; granulomas are composed of epithelioid and multinucleated giant cells with little or no necrosis. (Stedman’s medical 

dictionary 28th ed., 2005)

Sarcoma—A connective tissue neoplasm, usually highly malignant, formed 

by proliferation of mesodermal cells. (Stedman’s medical dictionary 

28th ed., 2005)

Sarin—A nerve poison similar to diisopropyl fluorophosphate and tetraethyl pyrophosphate; a very potent irreversible cholinesterase inhibitor 

and a more toxic nerve gas than tabun or soman. (Stedman’s medical 

dictionary 28th ed., 2005)

Schistosomiasis—Infection with a species of Schistosoma; manifestations 

of this often chronic and debilitating disease vary with the infecting 

species but depend in large measure upon tissue reaction (granulation 

and fibrosis) to the eggs deposited in venules and in the hepatic portals, 

the latter resulting in portal hypertension and esophageal varices, as 

well as liver damage leading to cirrhosis. (Stedman’s medical dictionary 

28th ed., 2005)

Schizoaffective disorder—(1) An illness manifested by an enduring major 

depressive, manic, or mixed episode along with delusions, hallucinations, disorganized speech and behavior, and negative symptoms of 

schizophrenia. In the absence of major depressive, manic, or mixed 

episode, there must be delusions or hallucinations for several weeks. 

(2) A DSM diagnosis that is established when the specific criteria are 

met. (Stedman’s medical dictionary 28th ed., 2005)

Schizophrenia—A term coined by Bleuler, synonymous with and replacing 

dementia praecox, denoting a common type of psychosis, characterized by abnormalities in perception, content of thought, and thought 

process (hallucinations and delusions) and by extensive withdrawal of 

interest from other people and the outside world, with excessive focusing on one’s own mental life. Now considered a group or spectrum of 

disorders rather than a single entity, with distinction sometimes made 
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398 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

between process schizophrenia and reactive schizophrenia. The “split” 

personality of schizophrenia, in which individual psychic components 

or functions split off and become autonomous, is popularly but erroneously identified with multiple personality, in which two or more 

relatively complete personalities dominate by turns the psychic life of 

a patient. (Stedman’s medical dictionary 28th ed., 2005)

Schizophreniform disorder—(1) A disorder with essential features that are 

identical to those of schizophrenia, with the exception that the duration including prodromal, active, and residual phases is shorter than 

6 months. (2) A DSM diagnosis that is established when the specific 

criteria are met. (Stedman’s medical dictionary 28th ed., 2005)

Schwannoma—A benign, encapsulated neoplasm in which the fundamental 

component is structurally identical to a syncytium of Schwann cells; the 

neoplastic cells proliferate within the endoneurium, and the perineurium 

forms the capsule. The neoplasm may originate from a peripheral or 

sympathetic nerve, or from various cranial nerves, particularly the 

eighth nerve; when the nerve is small, it is usually found (if at all) in 

the capsule of the neoplasm; if the nerve is large, the neurilemoma 

may develop within the sheath of the nerve, the fibers of which may 

then spread over the surface of the capsule as the neoplasm enlarges. 

Microscopically, neurilemoma is composed of combinations of two 

patterns, Antoni types A and B, either of which may be predominant 

in various examples of neurilemomas. (Stedman’s medical dictionary 

28th ed., 2005)

Scleroderma—Thickening and induration of the skin caused by new collagen 

formation, with atrophy of pilosebaceous follicles; either a manifestation of progressive systemic sclerosis or localized (morphea). (Stedman’s 

medical dictionary 28th ed., 2005)

Sclerosis—In neuropathy, induration of nervous and other structures 

by a hyperplasia of the interstitial fibrous or glial connective tissue. 

(Stedman’s medical dictionary 28th ed., 2005)

Scurvy—A disease marked by inanition, debility, anemia, and edema of the 

dependent parts; a spongy condition sometimes with ulceration of the 

gums and loss of teeth, hemorrhages into the skin from the mucous 

membranes and internal organs, and poor wound healing; due to a diet 

lacking vitamin C. (Stedman’s medical dictionary 28th ed., 2005)

Seamless transition—The commitment of DoD and VA to work closely 

in harmonizing the medical records of Service members for a smooth 

transition from DoD care to VA care.

Secretary—Secretary of Veterans Affairs; Secretary concerned (A) The Secretary of the Army, with respect to matters concerning the Army; 

(B) The Secretary of the Navy, with respect to matters concerning 

the Navy; or the Marine Corps; (C) The Secretary of the Air Force, 
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APPENDIX C 399

with respect to matters concerning the Air Force; (D) The Secretary 

of Homeland Security, with respect to matters concerning the Coast 

Guard; (E) The Secretary of Health and Human Services, with respect 

to matters concerning the Public Health Service; and (F) The Secretary 

of Commerce, with respect to matters concerning the National Oceanic 

and Atmospheric Administration or its predecessor organization the 

Coast and Geodetic Survey. (Definitions. 2006. 38 U.S.C. § 101.)

Selection bias—In a case-control study, occurs when the chance of being 

selected as a case or a control is influenced by exposure status. In a 

cohort study, occurs when the chance of participation in a study as 

exposed or non-exposed is influenced by disease status. Also, error 

due to systematic differences in characteristics between those who take 

part in a study and those who do not. Selection bias can invalidate 

conclusions and generalizations that might otherwise be drawn from 

such studies. 

Sensitivity—The proportion of truly diseased persons in the screened population who are correctly identified as diseased by the screening test; a 

measure of the probability of correctly diagnosing a case, or the probability that any given case will be identified by the test; specifically, the 

ratio of those who are identified by a test to have the condition who 

in fact have it, divided by all those who have the condition (i.e., true 

positives, divided by the sum of true positives and false negatives).

Sensitivity analysis—A method to determine the robustness of a result by 

examining the extent to which the result is affected by changes in methods, values of variables, or assumptions. (Adapted from Last, 2001) 

Separation—Left the military before 20 years; cannot apply for retirement 

benefits (Source: Personal communication, Col. K. Cox, Department of 

Defense, January 5, 2007): 

1. The act of keeping apart or dividing, or the state of being held 

apart. 

2. In dentistry, the process of gaining slight spaces between the teeth 

preparatory to treatment. (Stedman’s medical dictionary 28th ed., 

2005)

Service-attributable disability—Disability caused by a veteran’s service.

Service-attributable fraction (SAF)—The attributable fraction (AF) when 

the specific exposure is military service (see Attributable fraction); 

in other words, the proportion of a disease attributable to military 

service.

Service-connected—With respect to disability or death, that such disability was incurred or aggravated, or that the death resulted from a 

disability incurred or aggravated, in line of duty in the active military, 

naval, or air service. (Definitions. 2006. 38 U.S.C. § 101.)

Seveso study—The study of a population exposed to dioxin from an indus-
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400 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

trial accident that occurred in 1976 in a small manufacturing plant in 

the Lombardy region in Italy. 

Shared psychotic disorder—A mental disorder in which a delusion develops 

in a person in a relationship with another person with an established 

delusion. (Stedman’s medical dictionary 28th ed., 2005)

Shigellosis—Bacillary dysentery caused by bacteria of the genus Shigella, 

often occurring in epidemic patterns; an opportunistic infection of person with AIDS. (Stedman’s medical dictionary 28th ed., 2005)

Sliding scale pension—A pension based on income level.

Spanish-American War—(A) The period beginning on April 21, 1898, and 

ending on July 4, 1902, (B) Includes the Philippine Insurrection and 

the Boxer Rebellion, and (C) In the case of a veteran who served with 

the United States military forces engaged in hostilities in the Moro 

Province, means the period beginning on April 21, 1898, and ending 

on July 15, 1903. (Definitions. 2006. 38 U.S.C. § 101.)

Specificity—The proportion of truly nondiseased persons who are correctly identified by the screening test; a measure of the probability 

of correctly identifying a nondiseased person with a screening test; 

specifically, the ratio of those who are identified by a test to not have 

the condition who in fact do not have it, divided by all those who do 

not have the condition (i.e., true negatives, divided by the sum of true 

negatives and false positives).

Spouse—A person of the opposite sex who is a wife or husband. (Definitions. 2006. 38 U.S.C. § 101.)

Spurious association—A noncausal association due to chance, bias, failure to 

control for extraneous variables, confounding, etc. (see Confounder).

Squamous cell carcinoma—A malignant neoplasm derived from stratified squamous epithelium, but which may also occur in sites such as 

bronchial mucosa where glandular or columnar epithelium is normally 

present; variable amounts of keratin are formed, in relation to the 

degree of differentiation, and, if the keratin is not on the surface, it may 

accumulate in the neoplasm as a keratin pearl; in instances in which 

the cells are well differentiated, intercellular bridges may be observed 

between adjacent cells. (Stedman’s medical dictionary 28th ed., 2005)

Stakeholder—One with an interest or share in an undertaking or enterprise. 

State—Each of the several States, Territories, and possessions of the United 

States, the District of Columbia, and the Commonwealth of Puerto 

Rico. For the purpose of section 2303 and chapters 34 and 35 of this 

title (38 U.S.C.S. § 2303, 3451 et seq., and 3500 et seq.), such term also 

includes the Canal Zone. (Definitions. 2006. 38 U.S.C. § 101.)

State home—A home established by a State (other than a possession) for 

veterans disabled by age, disease, or otherwise who by reason of such 

disability are incapable of earning a living. Such term also includes such 
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APPENDIX C 401

a home which furnishes nursing home care for veterans. (Definitions. 

2006. 38 U.S.C. § 101.)

Stratum (strata)—Subsamples according to specified criteria, such as age 

groups, socioeconomic status, etc. 

 One of the layers of differentiated tissue, the aggregate of which 

forms any given structure, such as the retina or the skin. (Stedman’s 

medical dictionary 28th ed., 2005)

Stroke—(1) Any acute clinical event, related to impairment of cerebral 

circulation, that lasts more than 24 hours. (2) A harmful discharge of 

lightning, particularly one that affects a human being. (3) A pulsation. 

(4) To pass the hand or any instrument gently over a surface. See also 

stroking. (5) A gliding movement over a surface. (Stedman’s medical 

dictionary 28th ed., 2005)

Subcapsular cataracts—A cataract in which the opacities are concentrated 

beneath the capsule. (Stedman’s medical dictionary 28th ed., 2005)

Sufficient cause—The minimum set of conditions, factors, or events needed 

to produce a given outcome. (Adapted from Last, 2001)

Sufficient component causes model—A model that postulates disease resulting from any of several sufficient causal constellations, each of which 

comprises components that are all necessary to make them a complete 

cause.

Sulfur mustard—Cytotoxic vesicant chemical warfare agent with the ability 

to form large blisters on exposed skin (e.g., mustard gas). 

Surveillance—Continuous monitoring of disease occurrence within a 

population. 

Surviving spouse—A person of the opposite sex who was the spouse of a 

veteran at the time of the veteran’s death, and who lived with the veteran continuously from the date of marriage to the date of the veteran’s 

death (except where there was a separation which was due to the misconduct of, or procured by, the veteran without the fault of the spouse) 

and who has not remarried or (in cases not involving remarriage) has 

not since the death of the veteran, and after September 19, 1962, lived 

with another person and held himself or herself out openly to the public 

to be the spouse of such other person (except for purposes of chapter 

19 of this title [38 U.S.C.S. § 1901 et seq.]). (Definitions. 2006. 38 

U.S.C. § 101.)

Synovial sarcoma—A rare malignant tumor of synovial origin, most commonly involving the knee joint and composed of spindle cells usually 

enclosing slits or pseudoglandular spaces that may be lined by radially 

disposed epitheliallike cells. (Stedman’s medical dictionary 28th ed., 

2005)

Syringomyelia—The presence in the spinal cord of longitudinal cavities 

lined by dense, gliogenous tissue, that are not caused by vascular insuf-
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402 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

ficiency. Syringomyelia is marked clinically by pain and paresthesia, 

followed by muscular atrophy of the hands and analgesia with thermoanesthesia of the hands and arms, but with the tactile sense preserved; 

later marked by painless whitlows, spastic paralysis in the lower 

extremities, and scoliosis of the lumbar spine. Some cases are associated with low-grade gliomas or vascular malformations of the spinal 

cord. (Stedman’s medical dictionary 28th ed., 2005)

Systematic error—One-sided variation of measurements from the true 

values; see also Bias.

Systemic lupus erythematosus—An inflammatory connective tissue disease with variable features, frequently including fever, weakness and 

fatigability, joint pains or arthritis resembling rheumatoid arthritis, 

diffuse erythematous skin lesions on the face, neck, or upper extremities, with liquefaction degeneration of the basal layer and epidermal 

atrophy, lymphadenopathy, pleurisy or pericarditis, glomerular lesions, 

anemia, hyperglobulinemia, and a positive LE cell test result, with 

serum antibodies to nuclear protein and sometimes to double-stranded 

DNA and other substances. (Stedman’s medical dictionary 28th ed., 

2005)

Testosterone—The most potent naturally occurring androgen, formed in 

greatest quantities by the interstitial cells of the testes, and possibly 

secreted also by the ovary and adrenal cortex; may be produced in 

nonglandular tissues from precursors such as androstenedione; used in 

the treatment of hypogonadism, cryptorchism, certain carcinomas, and 

menorrhagia. (Stedman’s medical dictionary 28th ed., 2005)

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)—See Dioxin.

Theater—A specific geographic area within which armed conflict occurs.

Thromboangiitis obliterans (Buerger’s disease)—Inflammation of the entire 

wall and connective tissue surrounding medium-sized arteries and veins, 

especially of the legs of young and middle-aged men; associated with 

thrombotic occlusion and commonly resulting in gangrene. (Stedman’s 

medical dictionary 28th ed., 2005)

Thyroid nodular disease—Presence of palpable thyroid nodules. These 

nodules may be solitary or one or more within a multi-nodular thyroid. 

Most are benign, colloid nodules.

Thyroxine—The l-isomer is the active iodine compound existing normally 

in the thyroid gland and extracted therefrom in crystalline form for 

therapeutic use; also prepared synthetically; used for the relief of hypothyroidism, cretinism, and myxedema. (Stedman’s medical dictionary 

28th ed., 2005)

Tolman Committee—Also known as the Committee on Declassification; 

appointed by General Groves in 1944 to study the declassification of 

Manhattan Project research. 
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Tonsillectomy—Removal of the entire tonsil. (Stedman’s medical dictionary 

28th ed., 2005)

Tort litigation—Legal proceeding for a wrongful act other than a breach 

of contract for which relief may be obtained in the form of damages 

or an injunction.

Toxicant—Any poisonous agent, specifically alcohol or other poison, causing symptoms of what is popularly called intoxication. (Stedman’s 

medical dictionary 28th ed., 2005)

Toxicogenomics—A scientific subdiscipline that combines toxicology (the 

study of the nature and effects of poisons) with genomics (the investigation of the way that our genetic makeup translates into biological 

functions).

Transparency—Characterized by visibility or accessibility of information, 

especially concerning business practices.

2,4,5-Trichlorophenoxyacetic acid—An herbicide and defoliant synthesized 

by condensation of chloracetic acid and 2,4,5-trichlorophenol, used as 

the principal constituent of Agent Orange.

Triglyceride—Glycerol esterified at each of its three hydroxyl groups by a 

fatty (aliphatic) acid. Syn: triacylglycerol. (Stedman’s medical dictionary 

28th ed., 2005)

Trypanosomiasis—Any disease caused by a trypanosome. (Stedman’s medical dictionary 28th ed., 2005)

Tuberculosis (TB)—A specific disease caused by infection with Mycobacterium tuberculosis, the tubercle bacillus, which can affect almost 

any tissue or organ of the body, the most common seat of the disease 

being the lungs. Primary tuberculosis is typically a mild or asymptomatic local pulmonary infection. Regional lymph nodes may become 

involved, but in otherwise healthy people generalized disease does not 

immediately develop. A cell-mediated immune response arrests the 

spread of organisms and walls off the zone of infection. Infected tissues and lymph nodes may eventually calcify. The tuberculin skin test 

becomes positive within a few weeks, and remains positive throughout 

life. Organisms in a primary lesion remain viable and can become 

reactivated months or years later to initiate secondary tuberculosis. 

Progression to the secondary stage eventually occurs in 10-15 percent 

of people who have had primary tuberculosis. The risk of reactivation 

is increased by diabetes mellitus, HIV infection, silicosis, and various 

systemic or malignant conditions, as well as in alcoholics, IV drug 

abusers, nursing home residents, and those receiving adrenocortical 

steroid or immunosuppressive therapy. Secondary or reactivation tuberculosis usually results in a chronic, spreading lung infection, most often 

involving the upper lobes. Minute granulomas (tubercles), just visible to 

the naked eye, develop in involved lung tissue, each consisting of a zone 
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404 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

of caseation necrosis surrounded by chronic inflammatory cells (epithelioid histiocytes and giant cells). These lesions, which give the disease its 

name, are also found in other tissues (lymph nodes, bowel, kidney, skin) 

to which the disease may spread. Rarely, reactivation results in widespread dissemination of tubercles throughout the body (miliary tuberculosis). The symptoms of active pulmonary tuberculosis are fatigue, 

anorexia, weight loss, low-grade fever, night sweats, chronic cough, 

and hemoptysis. Local symptoms depend on the parts affected. Active 

pulmonary tuberculosis is relentlessly chronic and, if untreated, leads 

to progressive destruction of lung tissue. Cavities form in the lungs, 

and erosion into pulmonary blood vessels can result in life-threatening 

hemorrhage. Gradual deterioration of nutritional status and general 

health culminates in death due to wasting, infection, or multiple organ 

failure. Variant syndromes (tuberculous lymphadenitis in children, 

severe systemic disease in persons with AIDS) are caused by organisms 

of the Mycobacterium avium-intracellulare complex (MAIC). The diagnosis of TB is based on tuberculin skin testing (negaitive in 20 percent 

of people with active TB), imaging studies (computed tomography is 

more sensitive than standard chest radiography in detecting pleural effusion, miliary disease, and cavitation), and the finding of the causative 

organism in sputum of tissue specimens by acid-fast or fluorochrome 

staining, nucleic acid amplification, or culture. (Stedman’s medical 

dictionary 28th ed., 2005)

Tumors—(1) Any swelling or tumefaction. (2) Syn: neoplasm. (3) One of 

the four signs of inflammation (t., calor, dolor, rubor) enunciated by 

Celsus. (Stedman’s medical dictionary 28th ed., 2005)

 Malignant tumor—A tumor that invades surrounding tissues, is 

usually capable of producing metastases, may recur after attempted 

removal, and is likely to cause death of the host unless adequately 

treated. (Stedman’s medical dictionary 28th ed., 2005)

Type I presumptions—Shifts both the burden of production and the burden 

of persuasion. 

Type II presumptions—Establishment of the basic fact does not shift to the 

opponent the burden of persuading the adjudicator that the presumed 

fact does not exist. The opponent of the presumption only has to produce evidence that is contrary to or meets the presumption.

Ulcer—A lesion through the skin or a mucous membrane resulting from 

loss of tissue, usually with inflammation. (Stedman’s medical dictionary 

28th ed., 2005)

Ulceration—(1) The formation of an ulcer. (2) An ulcer or aggregation of 

ulcers. (Stedman’s medical dictionary 28th ed., 2005)

Uncertainty—The state of being indeterminate, not certain to occur, not reliable, not having certain knowledge, or not clearly identified or defined.
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APPENDIX C 405

Undiagnosed illness (or unexplained illness)—A constellation of symptom 

complaints; was called “Gulf War Syndrome.”

Vaccine Injury Table—Lists and explains injuries/conditions that are presumed to be caused by vaccines and covered under the National Vaccine 

Injury Compensation Program. 

Valvulitis—Inflammation of a valve, especially a heart valve. (Stedman’s 

medical dictionary 28th ed., 2005)

Vesicant—An agent that produces a vesicle. (Stedman’s medical dictionary 

28th ed., 2005)

Veteran—A person who served in the active military, naval, or air service, 

and who was discharged or released therefrom under conditions other 

than dishonorable. (Definitions. 2006. 38 U.S.C. § 101.)

Veteran of any war—Any veteran who served in the active military, naval, 

or air service during a period of war. (Definitions. 2006. 38 U.S.C. 

§ 101.)

Vietnam era—(A) The period beginning on February 28, 1961, and ending 

on May 7, 1975, in the case of a veteran who served in the Republic 

of Vietnam during that period. (B) The period beginning on August 5, 

1964, and ending on May 7, 1975, in all other cases. (Definitions. 

2006. 38 U.S.C. § 101.)

Viral exanthemas—A skin eruption occurring as a symptoms of an actual 

viral disease.

von Recklinghausen’s neurofibromatosis (Type I neurofibromatosis)—

Characterized clinically by the combination of patches of hyperpigmentation and cutaneous and subcutaneous tumors. The hyperpigmented 

skin areas, present from birth and found anywhere on the body surface, 

can vary markedly in size and color—the dark brown ones are called 

café-au-lait spots. The multiple cutaneous and subcutaneous tumors, 

called neurofibromas, can develop anywhere along the peripheral nerve 

fibers, from the roots distally. Neurofibromas can become quite large, 

causing a major disfigurement, eroding bone, and compressing various 

peripheral nerve structures; a small hamartoma (Lisch nodule) can 

be found in the iris of almost all patients. Has autosomal dominant 

inheritance, with the gene locus on chromosome 17q11, and is caused 

by mutation in the NF1 gene that encodes neurofibromin. Syn: Type I 

neurofibromatosis. (Stedman’s medical dictionary 28th ed., 2005)

World War I—(A) The period beginning on April 6, 1917, and ending on 

November 11, 1918, and (B) In the case of a veteran who served with 

the United States military forces in Russia, means the period beginning 

on April 6, 1917, and ending on April 1, 1920. (Definitions. 2006. 38 

U.S.C. § 101.)

World War II—The period beginning on December 7, 1941, and ending on 

December 31, 1946 (except for purposes of chapters 31 and 37 of this 
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406 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS

title [38 U.S.C.S. § 3100 et seq. and 3701 et seq.]). (Definitions. 2006. 

38 U.S.C. § 101.)

Yaws—An infectious tropical disease caused by Treponema pertenue and 

characterized by the development of crusted granulomatous ulcers on 

the extremities; may involve bone, but, unlike syphilis, does not produce central nervous system or cardiovascular pathology. (Stedman’s 

medical dictionary 28th ed., 2005)

Yellow fever—A tropical mosquito-borne viral hepatitis, due to yellow 

fever virus, a member of the family Flaviviridae, with an urban 

form transmitted by Aedes aegypti, and a rural, jungle, or sylvatic 

form from tree-dwelling mammals by various mosquitoes of the 

Haemagogus species complex; characterized clinically by fever, slow 

pulse, albuminuria, jaundice, congestion of the face, and hemorrhages, 

especially hematemesis; used to occur in epidemics mainly in port cities, 

especially in late summer, with 20-40 percent case fatality rates; immunity to reinfection accompanies recovery. (Stedman’s medical dictionary 

28th ed., 2005)

Legislation

1818 Service Pension Law

1862 General Pension Act

1862 Homestead Act

1890 Dependent Pension Act 

1917 War Risk Insurance Act Amendments 

1918 Vocational Rehabilitation Act 

1924 World War Adjustment Compensation Act 

1933 Economy Act

1943 Disabled Veterans’ Rehabilitation Act 

1944 Servicemen’s Readjustment Act (GI Bill of Rights)

1950 Vocational Rehabilitation Act 

1952 Veteran’s Readjustment Assistance Act (Korean GI Bill)

1954 War Claims Act Amendments

1959 Veterans’ Pension Act 

1978 Veterans Disability Compensation and Survivor Act 

1979 The Veterans Health Care Amendments 

1979 Veterans Health Program Extension and Improvement Act 

1981 Former Prisoners of War Benefits Act 

1981 Veterans’ Health Care, Training, and Small Business Loan Act 

1984 The Veterans Dioxin and Radiation Exposure Compensation 

Standards Act (VDRECSA)

1984 Veterans’ Compensation and Program Improvements 

Amendments 
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APPENDIX C 407

1984 Veterans’ Dioxin and Radiation Exposure Compensation 

Standards Act 

1986 Veterans Benefits Improvement and Health Care Authorization 

Act 

1988 The Radiation-Exposed Veterans Compensation Act (REVCA)

1988 Veterans Benefits and Services Act 

1990 The Radiation Exposure Compensation Act (RECA)

1991 Agent Orange Act 

1994 Persian Gulf War Veterans’ Benefit Act 

2000 Veterans Millennium Health Care and Benefits Act 

2003 Veterans Benefits Act
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Committee on Evaluation of the Presumptive Disability

Decision-Making Process for Veterans

Board on Military and Veterans Health

Jonathan M. Samet and Catherine C. Bodurow, Editors
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D-1

Appendix D 

Historical Background1

FROM THE BEGINNING 

Our nation has recognized military veterans’ service and sacrifices since its very earliest 

days. On August 26, 1776, the Continental Congress adopted the first national pension law provided for compensation payments to be made to “every officer, soldier, or sailor losing a limb in 

any engagement or being so disabled in the service of the United States as to render him incapable of earning a livelihood” (VA, 1971, p. 306; VA, 2006a). 

The 1818 Service Pension Law “provided that every person who had served in the War for 

Independence and was in need of assistance would receive a fixed pension for life. The rate was 

$20 a month for officers and $8 a month for enlisted men” (VA, 2006a, p. 4). Because pensions 

had previously been to disabled veterans only, the number of pensioners quickly increased from 

2,200 to 17,730, and the cost from $120,000 to $1.4 million (VA, 2006a, p. 4). 

CIVIL WAR AND AFTERMATH 

When the Civil War broke out in 1861, the nation had about 80,000 war veterans. By the 

end of the war in 1865, another 1.9 million veterans had been added to the rolls. This included only veterans of Union forces. . . . The General Pension Act of 1862 provided disability payments based on rank and degree of disability, and liberalized benefits for widows, children, and dependent relatives. The law covered military service in time of peace 

as well as during the Civil War. The act included, for the first time, compensation for diseases such as tuberculosis incurred while in service. Union veterans also were assigned a 

special priority in the Homestead Act of 1862, which provided land in the West at $1.25 

an acre. The year 1862 also marked the establishment of the National Cemetery System 

to provide burial for the many Union dead of the Civil War. 

(VA, 2006a, p. 4) 

Until 1890, Civil War pensions were granted only to servicemen discharged because of 

illness or disability attributable to military service. The Dependent Pension Act of 1890 

substantially broadened the scope of eligibility, providing pensions to veterans incapable 

 1

 The Historical Background section is an adapted version of VA History in Brief (VA, 2006a) except where 

otherwise noted.
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D-2 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

of manual labor. Within the next three years the number of veterans on the pension roll 

increased from 489,000 to 996,000 and expenditures doubled. Legislation passed in the 

nineteenth century had established a general pension system that could be applied to future pension recipients. As a consequence, new pension laws did not follow the SpanishAmerican War in 1898 or the Philippine Insurrection, 1899 to 1901. 

(VA, 2006a, p. 5) 

WORLD WAR I 

The United States’ entry into World War I directed significant attention toward the existing 

system of benefits for veterans. “Some 4.7 million Americans fought in World War I. Of these, 

116,000 died in service and 204,000 were wounded” (VA, 2006a, p. 7). Many felt the existing 

system needed revision, and this new, huge mobilization provided the impetus. 

 

Among the provisions of the War Risk Insurance Act Amendments of 1917 was the authority to establish courses for rehabilitation and vocational training for veterans with 

dismemberment, sight, hearing, and other permanent disabilities. 

(VA, 2006a, p. 7) 

The Vocational Rehabilitation Act of 1918 authorized the establishment of an independent agency, the Federal Board for Vocational Education. Under the new law, any honorably discharged disabled veteran of World War I was eligible for vocational rehabilitation 

training. Those incapable of carrying on a gainful occupation were also eligible for special maintenance allowances. 

(VA, 2006a, p. 7) 

In addition to these provisions, the War Risk Insurance Act of 1917 addressed features of the 

pension system, or what today is known as “disability compensation.” 

There was a change in emphasis from payment of a gratuity towards indemnification, and 

there was elimination of rank as a factor in determining the amount of compensation. . . . 

[T]he new Bureau of War Risk Insurance was instructed to set up a schedule for rating 

disabilities. The schedule was to represent average impairments in earning capacity 

caused by specific injuries or combination of injuries. In this way the individual who 

overcame his handicap was not penalized but encouraged to reenter the labor force, with 

the knowledge that his payments would not be reduced or terminated. 

(VA, 1971, p. 308) 

THE DEPRESSION YEARS 

The Great Depression had a staggering economic impact across America. World War I veterans, like others, were seriously affected by this huge economic downturn. After returning from 

the Great War, many veterans faced destitution. Congress passed the World War Adjustment 

Compensation Act in 1924 that authorized a bonus to World War I veterans based on the length 

and location of their service. “The payments were intended to bring about economic balance between the veterans—who generally received low wages in the service—and those who stayed 

home and benefited from wartime industry” (VA, 2006a, p. 9). However, the certificates for 

payment, which generally had a face value of $1,500, were in the form of an endowment policy 

payable 20 years from the date of issue (VA, 2006a, p. 9). 
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APPENDIX D D-3 

As the Depression worsened, veterans began calling for immediate payment of their “bonuses,” as the certificates came to be known. In March 1932, a small group of veterans 

from Oregon began marching to Washington, DC, to demand payment. Word of the 

march spread like wildfire and soon small bands of unemployed veterans from across the 

country began descending on the nation’s capital. 

(VA, 2006a, p. 9) 

The thousands of veteran marchers became known as the “Bonus Expeditionary Forces.” 

They camped wherever they could, and living conditions quickly deteriorated. 

President Hoover knew he had to curb the escalating violence. He gave the order for 

Army Chief of Staff Gen. Douglas MacArthur to forcibly remove from the city the approximately 3,500 veterans, many with their wives and children, who refused to leave. 

No shots were fired, but many were injured. 

(VA, 2006a, p. 10) 

Though the marchers failed to get immediate results, in 1936 Congress authorized early 

payment of the bonuses. By June 30, 1937, the Veterans Administration (VA) had certified as payable nearly 3.5 million applications from World War I veterans for settlement 

of their certificates. 

(VA, 2006a, p. 10) 

President Hoover, in his 1929 State of the Union message, proposed consolidating agencies administering veterans benefits. The following year Congress created the Veterans 

Administration by uniting three bureaus. . . . The new agency was responsible for medical 

services for war veterans, disability compensation and allowances for World War I veterans, life insurance, and bonus certificates and other veterans benefits. 

(VA, 2006a, p. 12) 

In March 1933, President Roosevelt persuaded Congress to pass the Economy Act. A response to the Great Depression, the measure included a repeal of all previous laws granting benefits for veterans of the Spanish-American War and all subsequent conflicts and 

periods of peacetime service. It also gave the president authority to authorize new veterans benefits. Roosevelt then promulgated regulations that radically reduced veterans 

benefits. When the president’s authority to establish benefits by executive order expired 

in 1935, Congress reenacted most of the laws that had been in effect earlier. 

(VA, 2006a, p. 12) 

The Board of Veterans’ Appeals was established in July 1933. It was given authority to 

hear appeals on benefit decisions. Members were appointed by the administrator with the 

approval of the President. 

(VA, 2006a, p. 12) 

Demand for hospital care grew dramatically in the Depression years. 

(VA, 2006a, p. 12) 

From 1931 to 1941, the number of VA hospitals would increase from 64 to 91, and the 

number of beds would rise from 33,669 to 61,849. 

(VA, 2006a, p. 12) 
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At first, tuberculosis predominated among the conditions treated at VA hospitals. But by 

the middle of the 1930s, tuberculosis patients had dropped to only 13 percent—thanks 

partly to VA’s own research and treatment efforts. Neuropsychiatric conditions then accounted for more than half of the patients. 

(VA, 2006a, pp. 12-13) 

WORLD WAR II 

With war on the horizon, Congress in 1940 created a new insurance program for servicemen and veterans. National Service Life Insurance was designed to eliminate any inequities in premiums that would have resulted if the young men had been grouped with 

the older World War I veterans covered by U.S. Government Life Insurance. 

(VA, 2006a, p. 13) 

The Disabled Veterans’ Rehabilitation Act of 1943 established a vocational rehabilitation 

program for disabled World War II veterans who served after Dec. 6, 1941. As a result of 

this law, VA provided 621,000 disabled World War II veterans with job training. 

(VA, 2006a, p. 13) 

In 1944, the federal government foresaw the return of millions of servicemen and women. 

The need to accommodate their needs and to facilitate their readjustment to, and reentry into, civilian life resulted in the enactment of the Servicemen’s Readjustment Act, popularly known as 

the “GI Bill of Rights” (VA, 2006a, p. 13). The measure, signed into law by President Roosevelt, 

contained three key provisions that “dramatically transformed the concept of veterans benefits” 

(VA, 2006a, p. 13). 

The first benefit provided up to four years of education or training. The education package included the payment of up to $500 a school year for tuition, fees, books, and supplies, plus a monthly subsistence allowance. The second benefit provided veterans with 

federally guaranteed home, farm, and business loans with no down payment. This feature 

was designed to generate jobs in the housing industry while providing housing and assistance for veterans and their families. Veterans could apply for loans up to $2,000 with 

50 percent guaranteed by the government. The third feature was unemployment 

compensation. 

(VA, 2006a, pp. 13-14) 

This benefit was designed to ease the unemployment market, which was making the transition to a peacetime economy. 

The new law provided that veterans who had served a minimum of 90 days were entitled 

to a weekly payment of $20 for a maximum of 52 weeks. The new benefits were popular 

with veterans. When the World War II GI Bill program ended in 1956, some 7.8 million 

had received some kind of training, and VA had guaranteed 5.9 million home loans totaling $50.1 billion. 

(VA, 2006a, p. 14) 

The large influx of 15 million World War II veterans also placed great stress on the VA 

medical system. Existing VA hospitals were soon filled to capacity, and there were waiting lists 
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APPENDIX D D-5 

for admission at most hospitals. “Until more VA hospitals could be opened, the Navy and Army 

both made beds available” (VA, 2006a, p. 15). “To handle the dramatic increase in veterans 

claims, VA central office staff was increased” by 30 percent and field staff for medical care and 

benefits increased by nearly 76 percent (VA, 2006a, p. 15). 

KOREAN WAR 

Following the outbreak of the Korean War in June 1950, Congress passed the Vocational 

Rehabilitation Act of 1950, which reactivated vocational rehabilitation for veterans of the 

new war and extended the program to peacetime veterans. The Veterans’ Readjustment 

Assistance Act of 1952, called the “Korean GI Bill,” provided unemployment insurance, 

job placement, home loans, and mustering-out benefits similar to those offered World 

War II veterans. 

(VA, 2006a, p. 16) 

The Korean GI Bill made several changes, however, in education benefits, reducing financial benefits generally and imposing new restrictions. In contrast to the 48 months of 

education allowed by the 1944 law, the Korean GI Bill permitted a maximum of 36 

months. 

(VA, 2006a, p. 16) 

Because of past abuses under the World War II GI Bill program, “[t]he Korean GI Bill also 

did not provide tuition payments to the colleges. Instead, veterans were paid subsistence checks, 

which were also to cover their college expenses. The effect of the changes was that the benefit no 

longer completely covered the cost of the veteran’s education” (VA, 2006a, p. 16). 

In the late 1950s, [VA’s] Chief Medical Director William Middleton expanded VA’s research programs to address the chronic-care problems of most of its patients, including 

the aged. Congress, agreeing on its importance, began earmarking funds for research 

within the VA budget. 

(VA, 2006a, pp. 16-17) 

Following a study of pensions and resulting legislation, VA introduced a sliding scale of pension payments for non-service-connected disabilities in 1959, based on the recipient’s income, 

rather than a flat-rate pension. “The net assets of the veteran’s and spouse’s income were considered in determining the veteran’s level of need. The Veterans’ Pension Act of 1959 also specified 

that anyone already on the pension rolls as of June 30, 1960, could elect to remain under the old 

law” (VA, 2006a, p. 17). 

VIETNAM WAR 

During this [Vietnam War] period, more than 6 million Vietnam-era veterans were separated from military service. A major difference of Vietnam-era veterans from those of 

earlier wars was the larger percentage of disabled. Advances in airlift and medical treatment meant that many wounded and injured personnel survived who would have died in 

earlier wars. By 1972 there were 308,000 Vietnam veterans with disabilities connected to 

military service. 

(VA, 2006a, p. 18) 
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“The return within days of veterans from combat zones to civilian life also was new” and 

added to their difficulties in readjusting to civilian life (VA, 2006a, p. 18). To complicate matters, returning Vietnam veterans were often reluctant to seek treatment at VA medical facilities, 

an institutional setting they often regarded with discomfort and distrust. To help address this issue VA instituted a new program aimed specifically at the wary Vietnam veterans: the Readjustment Counseling program, or Vet Centers. These new Vet Centers were established as storefront operations located in downtown areas, away from VA Medical Centers. They were staffed 

with Vietnam combat veterans and trained counselors who offered a relaxed, informal setting. 

The program has been successful and has expanded over the last two decades. 

Environmental exposures also became an important issue for Vietnam veterans. 

Between 1962 and 1971, U.S. military forces sprayed nearly 19 million gallons of herbicides over approximately 3.6 million acres in Vietnam. The preparation known as Agent 

Orange accounted for approximately 11.2 million gallons of the total amount sprayed. 

Herbicides were used to strip the thick jungle canopy that helped conceal opposition 

forces, to destroy crops that enemy forces might depend upon, and to clear tall grass and 

bushes from around the perimeters of U.S. base camps and outlying fire support bases. 

Most large-scale spraying operations were conducted using airplanes and helicopters, but 

considerable quantities of herbicides were sprayed from boats and ground vehicles, as 

well as by soldiers wearing back-mounted equipment. Spraying began in 1962 and increased greatly in 1967. After a scientific report in 1969 concluded that one of the primary chemicals used in Agent Orange, namely, 2,4,5-trichlorophenoxyacetic acid (2,4,5-

T) could cause birth defects in laboratory animals, U.S. forces suspended use of this herbicide in 1970 and halted all herbicide spraying in Vietnam the next year. 

(IOM, 1994, p. 1) 

As the decade wore on, concern about possible long-term health consequences of Agent Orange and other herbicides heightened. This concern was fueled in particular by reports from 

growing numbers of Vietnam veterans that they had developed cancer or fathered handicapped 

children, which they attributed to wartime exposure to the herbicides. 

VA’s position was that none of the veterans’ health problems were caused by Agent Orange 

with the exception of chloracne. All other disability claims were routinely turned down, though 

in 1981 VA did begin providing free health care for those who claimed their illnesses were attributable to Agent Orange (Veterans’ Health Care, Training and Small Business Loan Act. 

1981. Public Law 97-72. 97th Cong., 1st Sess.). 

The veterans then turned to the courts. The first lawsuit was filed in July 1978; in it the plaintiff alleged that the herbicide had caused his abdominal cancer (Shuck, 1987, p. 37). Eventually, 

more than 600 separate actions were filed by more than 15,000 individuals throughout the United 

States. These actions were ultimately consolidated in the U.S. District Court for the Eastern District of New York into one class action on behalf of 2.4 million Vietnam veterans, their wives 

and children, and others (Shuck, 1987, pp. 4-5, 45). In addition, there were almost 400 individual 

cases that were not included in the class action (Shuck, 1987, p. 4). On May 7, 1984, the class 

action was settled, only hours before jury selection was to begin, for $180 million, then the largest tort settlement in history (Shuck, 1987, pp. 5, 166). The individual suits were dismissed on 

the ground that plaintiffs could not establish specific causation due to the lack of exposure data 

and positive epidemiologic findings (Shuck, 1987). 

The lawsuits garnered enormous publicity and contributed a focus around which the Vietnam 

veterans could organize. Although the lawsuits failed to establish that Agent Orange was the 
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APPENDIX D D-7 

cause of diseases and birth defects from which veterans and their children suffered, Congress in 

1984 took a first step in establishing service-connected presumptions for Vietnam veterans (Economic Systems Inc., 2004, p. 68; Shuck, 1987). 

To address this difficult issue, Congress enacted the Veterans’ Dioxin and Radiation Exposure Compensation Standards Act in 1984 (Public Law 98-542. 98th Cong., 2d Sess.). This act 

“provided a presumption of service connection for the occurrence of certain diseases related to 

exposure to herbicides or other environmental hazards or conditions in veterans who served in 

Southeast Asia during the Vietnam era” (Economic Systems Inc., 2004, p. 68). It “directed the 

administrator of Veterans Affairs to establish guidelines and criteria for resolving claims for 

benefits resulting from a service-connected death or disability based on a veteran’s exposure during active duty service to . . . herbicides containing dioxin in Vietnam” (as well as to radiation 

exposure prior to July 1, 1946) (Economic Systems Inc., 2004, p. 68). The measure directed VA 

to determine whether any of several specified diseases should be considered service connected if 

they developed after a veteran’s departure from Vietnam (Economic Systems Inc., 2004, p. 68). 

This legislation did not resolve the issue as veterans continued to present claims for Vietnam 

service-related diseases, for which they received what they considered to be less than satisfactory 

responses. As a result of the continuing controversy, Congress passed the Agent Orange Act of 

1991 (Public Law 102-4. 102d Cong., 1st Sess.). This law designated certain diseases to be service connected and resulting from exposure to dioxins and other herbicide agents during service 

in Vietnam during the Vietnam era. It also established a mechanism for periodic reviews of scientific evidence (by the National Academy of Sciences) concerning the association between exposure to an herbicide agent during service in Vietnam and each disease suspected to be associated with such exposure (Economic Systems Inc., 2004, p. 74). 

GULF WAR PERIOD 

The Gulf War “brought with it a number of difficult-to-diagnose conditions, syndromes, and 

diseases” and “[t]he presumption of service connection question became a matter of much scientific, social, and political debate” (Economic Systems Inc., 2004, p. 78). Congress addressed 

many of the concerns through legislation in 1994 with the Persian Gulf War Veterans’ Benefits 

Act (Public Law 103-446. 103d Cong., 2d Sess.). Among its provisions were requirements to 

implement a uniform medical evaluation protocol for returning Gulf War veterans; a comprehensive outreach program regarding available benefits; disability compensation payments for 

chronic disability resulting from an “undiagnosed illness” that manifested during or within a presumptive period after Gulf War service; and the establishment of a scientific review protocol 

similar to that in the Agent Orange Act of 1991 (Economic Systems Inc., 2004, pp. 78-79). 

With a high number of Service members still experiencing combat situations in Iraq and Afghanistan, these issues continue to be a concern. 

VA PROGRAMS AND BENEFITS TODAY 

The mission of VA was encapsulated in the words of President Lincoln over 140 years ago: 

To care for him who shall have borne the battle and for his widow and his orphan. 

(VA, 2006c) 
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D-8 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

To fulfill this pledge, VA programs are intended to provide timely, high-quality benefits and 

services to the 24 million living men and women who have served this country with honor in the 

military. Operating with outlays of over $72 billion during fiscal year (FY) 2006 and a workforce 

of almost 220,000 employees, VA provided medical care, benefits, social support, and lasting 

memorials to veterans and their dependents in recognition of veterans’ service to this nation 

(VA, 2006b, p. 15; VA, 2007a, sec. 2, p. 20). These services were provided through three administrations within the department: Veterans Health Administration (VHA), Veterans Benefits 

Administration (VBA), and the National Cemetery Administration (VA, 2007a). 

Through VHA, VA operates the largest direct health-care delivery system in the country, 

which includes 156 medical centers and more than 1,300 additional sites of care (VA, 2006c, p. 

6). In this context, VA meets the health-care needs of America’s veterans by providing a broad 

range of primary care, specialized care, and related medical and social support services. VA focuses on providing health-care services that are uniquely related to veterans’ health or special 

needs. 

VA provided care to nearly 5.5 million unique patients enrolled in its system in FY 2006 

(VA, 2006b, p. 12). For FY 2006, it handled over 60 million outpatient visits and provided care 

to approximately 744,000 inpatients (VA, 2007a, sec. 3B, p. 17). In FY 2008 VA expects to treat 

5.8 million patients of which 263,000 will be Operation Iraqi Freedom/Operation Enduring Freedom veterans (Nicholson, 2007). To provide this comprehensive medical care VA employed 

nearly 200,000 people and operated with a budget of approximately $32 billion (VA, 2007a, sec. 

3B, pp. 12, 18). About $350 million of this amount was spent on outpatient mental health services for veterans (VA, 2007a, sec. 3B, p. 12). Another $1.25 billion was spent on the purchase 

and repair of medical equipment and prosthetics (VA, 2007a, sec. 3B, p. 12). 

VA has developed an increasing reputation for delivering high-quality care in a cost-efficient 

manner and has received numerous awards. For the past 6 years VA has outranked private-sector 

hospitals on patient satisfaction in an annual consumer survey conducted by the National Quality 

Research Center at the University of Michigan. In December 2004 RAND investigators found 

that VA outperformed all other sectors of American health care across a spectrum of 294 measures of quality in disease prevention and treatment (VA, 2006b, p. 119). 

VA is the nation’s largest provider of health-care education and training for medical residents 

and other health-care trainees. Its education and training programs are designed to help ensure an 

adequate supply of clinical care providers for veterans and the nation (VA, 2007a). 

“VA advances medical research and development in ways that support veterans’ needs by 

pursuing medical research in areas that most directly address the diseases and conditions that affect veterans. Shared VA medical research findings contribute to the public good by improving 

the nation’s overall knowledge of disease and disability” (VA, 2007a, sec. 1, p. 13). Its research 

budget, composed of VA direct appropriations as well as funds from other federal appropriations 

and private sources, is proposed to be $1.4 billion for FY 2008 (Nicholson, 2007). 

VBA, with 57 regional offices and a staff of over 13,000 employees, delivers a number of 

programs designed to aid veterans in consequence of their military service (VBA, 2006, p. 14; 

VA, 2007b, sec. 5, p. 2). The largest of these is the Disability Compensation Program which provides monthly payments and ancillary benefits totaling in excess of $30.8 billion to over 3.5 million veterans, in accordance with rates specified by law, in recognition of the average potential 

loss of earning capacity caused by a disability, disease, or death incurred or aggravated during 

active military service (VBA, 2006, p. 19). 
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APPENDIX D D-9 

About 48 percent of these veterans are rated 10-20 percent disabled with an additional 25 

percent rated 30-40 percent disabled (VBA, 2006, p. 21). Seriously disabled—those rated at 50 

percent or more—constitute 26 percent of those in receipt of compensation benefits (VBA, 2006, 

p. 21). The distribution of the most frequently occurring service-connected disabilities by body 

system for veterans receiving compensation at the end of FY 2005 is as follows: “Muscloskeletal 

System” (39 percent), “Impairment of Auditory Acuity” (11 percent), “Skin” (10 percent), “Neurological Conditions” (7 percent), “Mental Disorders” (7 percent), “Cardiovascular System” (6 

percent), and “Digestive System” (6 percent) (VBA, 2006, p. 28). 

In FY 2005, VA received nearly 800,000 claims for processing and determination (VBA, 

2006, p. 26). A growing number of these claims involve complex issues resulting from posttraumatic stress disorder, environmental and infectious risks, traumatic brain injuries, complex combat-related issues, and complications arising from diabetes. 

This program also provides monthly payments, as specified by law, to nearly 329,000 surviving spouses, dependent children, and dependent parents in recognition of the economic loss 

caused by the veteran’s death during active military service or, subsequent to discharge from 

military service, as a result of a service-connected disability (VBA, 2006, p. 39). 

VA’s pension program provides monthly payments, as specified by law, to needy wartime 

veterans at age 65 or over or who are permanently and totally disabled from non-serviceconnected causes at an annual cost of over $2.6 billion (VBA, 2006, p. 42). This program also 

provides monthly payments, as specified by law, to about 207,000 needy surviving spouses and 

dependent children of deceased wartime veterans who died as a result of a disability unrelated to 

military service (VBA, 2006, p. 47). 

VA’s education program assists eligible veterans, Service members, reservists, survivors, and 

dependents in achieving their educational or vocational goals. VA provided educational assistance benefits totaling over $2.6 billion to approximately 500,000 individuals in FY 2005 (VBA, 

2006, p. 55). 

The vocational rehabilitation and employment program assists veterans with serviceconnected disabilities to achieve functional independence in daily activities, become employable, 

and obtain and maintain suitable employment. Over 60,000 veterans applied for this form of 

benefits in FY 2005 (VBA, 2006, p. 87). 

VA’s housing program helps eligible veterans, active duty personnel, surviving spouses, and 

selected reservists purchase and retain homes. In FY 2006, VA assisted over 135,000 home buyers (VA, 2007a, sec. 6D, p. 3). 

VA’s insurance program provides 1.8 million veterans, 2.4 million Service members, and 3 

million family members with life insurance benefits, some of which are not available from other 

providers—such as the commercial insurance industry—because of lost or impaired insurability 

resulting from military service (VA, 2007a, sec. 3A, p. 36). Insurance coverage is made in reasonable amounts and at competitive premium rates comparable to those offered by commercial 

companies. The program ensures a competitive, secure rate of return on investments held on behalf of the insured. 

The National Cemetery Administration, with a budget of about $161 million, honors veterans 

with final resting places in national shrines and lasting memorials that commemorate the 

veterans’ service to the nation (VA, 2007b, sec. 1A, p. 4). VA maintains more than 2.8 million 

gravesites at 121 national cemeteries and 33 other cemeterial installations. It will inter about 

105,000 veterans in FY 2008 (Nicholson, 2007; VA, 2007a, sec. 3A, p. 36). 
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D-10 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

BASIC PRINCIPLES OF THE DISABILITY 

COMPENSATION PROGRAM 

VA’s disability compensation program provides monthly payments and ancillary benefits to 

veterans in recognition of the average potential loss for earning capacity caused by disability or 

disease incurred or aggravated during active military service. 

The statutory provision that entitles veterans to disability compensation is found in section 

1110 of title 38, United States Code (USC) as follows: 

For disability resulting from personal injury suffered or disease contracted in line of duty, 

or for aggravation of a preexisting injury suffered or disease contracted in line of duty, in 

the active military, naval, or air service, during a period of war, the United States will pay 

to any veteran thus disabled and who was discharged or released under conditions other 

than dishonorable from the period of service in which said injury or disease was incurred, 

or preexisting injury or disease was aggravated, compensation as provided in this subchapter . . ., but no compensation shall be paid if the disability is a result of the veteran’s 

own willful misconduct or abuse of alcohol or drugs. 

(Basic Entitlement. 2005. 38 USC § 1110) 

“In line of duty” is defined in VA regulations as occurring “during a period of active military, naval, or air service unless such injury or disease was a result of the veteran’s own willful 

misconduct or, for claims filed after October 31, 1990, was the result of his or her abuse of alcohol or drugs” (Pension, Compensation, and Dependency and Indemnity Compensation. 2006. 38 

CFR § 3.1[m]). For purposes of line-of-duty determinations, a Service member is regarded as 

being on duty continuously (i.e., around the clock, seven days a week). 

It is important to remember also that the disability need not have been directly “caused” by 

military service but only to have arisen during, or be aggravated coincident with, the period of 

military service. There is no time limit for filing of disability claims. A veteran may file at date 

of discharge or may make an initial claim decades later. 

Title 38 of the United States Code mandates the existence of a rating schedule for use in 

evaluating disability claims. This statutory authority is as follows: 

The VA Secretary shall adopt and apply a schedule of ratings of reductions in earning capacity from specific injuries or combination of injuries. The ratings shall be based, as far 

as practicable, upon the average impairments of earning capacity resulting from such injuries in civil occupations. The schedule shall be constructed so as to provide 10 grades of 

disability and no more, upon which payments of compensation shall be based, namely, 10 

percent, 20 percent, 30 percent, 40 percent, 50 percent, 60 percent, 70 percent, 80 percent, 

90 percent, and total, 100 percent. The VA Secretary shall from time to time readjust this 

schedule of ratings in accordance with experience. However, in no event shall such a readjustment in the rating schedule cause a veteran’s disability rating in effect on the effective date of the readjustment to be reduced unless an improvement in the veteran’s disability is shown to have occurred. 

(Authority for Schedule for Rating Disabilities. 2005. 38 USC § 1155) 

This rating schedule has been codified as 38 CFR, Part IV (Schedule for Rating Disabilities. 

2005. 38 CFR Part 4), and it provides detailed guidelines for assessing specific disabilities and 

assigning evaluation levels. The schedule lists hundreds of specific disabilities, with unique di-
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APPENDIX D D-11 

agnostic codes for each. It describes each condition and provides descriptors for assigning 

evaluation levels to the conditions. 

Veterans’ service-connected disabilities are assigned a percentage rating between 0 and 100 

percent in increments of 10, with higher ratings reflecting greater severity. Veterans with disabilities rated 0 percent generally do not receive compensation for their disabilities. However, 

this rating can provide improved access to health care and other VA benefits. 

Disabilities rated 10 percent or more are compensable. 

The 10 percent threshold is not defined explicitly in the law, except that it must be a 

medical determination. Throughout much of the legislative history of disability compensation for veterans, the percentage determination is based on medical opinion without any 

specific reference to economic loss or indicating exactly how a given physical impairment translates into a given percentage. 

(Economic Systems Inc., 2004, p. 3) 

 

Although the statutory language is couched in terms of “average impairment in earning capacity” it is apparent that other factors are taken into consideration in the payment of disability 

benefits (Schedule for Rating Disabilities. 2005. 38 CFR Part 4). The Bradley Commission in 

discussing the “basic purpose” of disability compensation acknowledged that it was a “complex 

and difficult subject because it deals with a wide range of human factors” including “impairment 

of earning capacity, loss of physical integrity, shortening of life, social inconvenience, disfigurement, pain, suffering, anguish, and possibly others” (President’s Commission on Veterans’ 

Pensions, 1956, p. 164). Although the statute specified that percentage awards were to be based 

on average impairments of earning capacity, the commission observed that there was evidence 

that VA ratings “make allowance for shortening of life and social inconvenience resulting from 

disablement” (President’s Commission on Veterans’ Pensions, 1956, p. 165). It declared that “[a] 

balanced compensation program must do more than merely replace lost earning capacity” and 

concluded that the rating schedule should also make allowance for “‘loss of physical integrity,’ 

‘social inadaptability’ and ‘shortened life expectancy’” (President’s Commission on Veterans’ 

Pensions, 1956, pp. 166, 169). 

VA acknowledged this in testimony before Congress in 1960 stating that although the schedule was devoted “almost exclusively to so-called economic factors such as loss of earning capacity. There is, for consideration, as we all know, the fact that in many diseases and disabilities 

there are so-called noneconomic losses or impairments such as shortened life expectancy, loss of 

physical integrity, or social inadaptability” (U.S. Congress, House of Representatives, 1970, 

p. 5). 

Two recent companion studies of VA’s disability compensation program concluded that congressional intent for program goals could include both “compensation for the average impairments of earnings capacity resulting from such injuries in civil occupations” and “compensation 

for reduction in quality of life due to service-connected disability” (Economic Systems Inc., 

2004, p. 2). It observed the following: 

The legislation does not explicitly state that intent of the disability program is to compensate for reduction in quality of life due to service-connected disability. However, this intent is implicit because Congress has set forth certain presumptions of eligibility for disability compensation and higher benefit levels for certain disabling conditions such as 

loss of a limb that reflect humanitarian concern about quality of life. The quality-of-life 
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D-12 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

factor may be a more critical issue than employability for amputees given advances in 

medical technology and emphasis on occupations not requiring physical labor. 

(Economic Systems Inc., 2004, p. 2) 

The study also suggests that “recruitment and retention” could be included in the range of 

possible program goals (Economic Systems Inc., 2004, p. 2): The “[l]egislation does not explicitly state that intent of the VA disability program . . . is to provide incentive value for recruitment 

and retention” (p. 4). However, “during wartime periods, Congress has provided greater benefits 

or liberalized rules for eligibility, reflecting the intention of attaining sufficient recruitment and 

retention. Also, Congress has legislated benefits for veterans using phrases similar to ‘in gratitude of service rendered for a grateful Nation,’ indicating that benefits are provided for a variety 

of different reasons” (Veterans’ Disability Benefits Commission, 2005, pp. 4-5). 

Finally, in looking at disability compensation benefits it should also be kept in mind that 

“compensation for . . . impairment in earnings capacity . . . is not based on the disabled person’s 

individual capacity loss but only on ‘average’ capacity” (Economic Systems Inc., 2004, p. 2). 

Claims may be established by direct evidence that an injury or disease or its aggravation 

occurred at a point in time coincident to military service. Medical exams, military service records, 

expert opinions, and credible statements by those with knowledge of the circumstances of the 

claim are frequently relied upon. Claims may also be established by unrebutted presumptions 

that have been adopted by VA either as a result of statutory amendment or by administrative 

regulation. 

EQUIPOISE AND BURDEN OF PROOF 

38 USC, Section 5107, sets forth standards for “burden of proof” and “benefit of the doubt” 

with respect to establishing disability benefits entitlement. Subsection 5107(b) further provides, 

in pertinent part, with respect to such claims that 

When, after consideration of all evidence . . . there is an approximate balance of positive 

and negative evidence regarding the merits of an issue material in the determination of 

the matter, the benefit of the doubt in resolving each such issue shall be given to the 

claimant. 

(see also 38 CFR § 3.102. Reasonable doubt) 

Evidence found to be in such “balance” has often been characterized in Board of Veteran Appeals decisions as being in “equipoise.” 

In Gilbert v. Derwinski, 1 Vet. App. 49 (1991), an early decision considering the rule, the 

court employed the following analogy: 

The “benefit of the doubt” standard is similar to the rule deeply embedded in sandlot 

baseball folklore that “the tie goes to the runner.” If the ball clearly beats the runner, he is 

out and the rule has no application; if the runner clearly beats the ball, he is safe and 

again the rule has no application; if however the play is close, then the runner is called 

safe by operation of the rule that “the tie goes to the runner.” . . . Similarly, if a fair preponderance of the evidence is against a veteran’s claim, it will be denied and the “benefit 

of the doubt” rule has no application; if the veteran “establishes a claim by a fair preponderance of the evidence, the claim will be granted and, again, the rule has no application; 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html

APPENDIX D D-13 

if however, the play is close, i.e., “there is an approximate balance of positive and negative evidence,” the veteran prevails by operation of 38 U.S.C. 3007 (b) (now 5107[b]). 

(VA, 2006d, p. 16470) 

As part of an ongoing project to “reorganize and rewrite in plain language” general provisions applicable to its compensation and pension regulations, the VA, citing Gilbert v. Derwinski, defines equipoise as follows: 

Equipoise means that there is an approximate balance between the weight of the evidence 

in support of and the weight of the evidence against a particular finding of fact, such that 

it is as likely as not that the fact is true. 

(VA, 2006d, p. 16470) 

REFERENCES 

Economic Systems Inc. 2004. VA disability compensation program: Legislative history. Washington, DC: 

VA Office of Policy, Planning, and Preparedness. 

IOM (Institute of Medicine). 1994. Health effects of herbicides used in Vietnam. Washington, DC: National Academy Press. 

Nicholson, R. J. 2007. Statement of the Honorable R. James Nicholson, Secretary of Veterans Affairs, for 

Presentation Before the House Committee on Veterans’ Affairs, February 8, 2007. 

http://www.va.gov/OCA/testimony/hvac/07020800.asp (accessed July 11, 2007). 

President’s Commission on Veterans’ Pensions. 1956. A report to the President: Veterans benefits in the 

United States: Findings and recommendations. Vol. 1, Parts I and II. Washington, DC: Government 

Printing Office. 

Shuck, P. 1987. Agent Orange on trial: Mass toxic disasters in the courts. Enlarged ed. Cambridge, MA: 

Belknap-Harvard University Press. 

U.S. Congress, House of Representatives. 1970. Service-connected compensation increase for veterans. 

Report No. 91-1166. 91st Cong., 2nd Sess. 

VA (Department of Veterans Affairs). 1971. Economic validity of the rating schedule. In Veterans Administration proposed revision of Schedule for Rating Disabilities. Submitted to the Committee on 

Veterans Affairs, U.S. Senate, 93rd Cong., 1st Sess. February 12. Senate Committee Print No. 3. 

Washington, DC: U.S. Government Printing Office. 

VA. 2006a. VA history in brief. http://www1.va.gov/opa/feature/history/docs/histbrf.pdf (accessed March 

5, 2007). 

VA. 2006b. Strategic plan FY 2006-2011. 

http://www1.va.gov/op3/docs/VA_2006_2011_Strategic_Plan.pdf (accessed March 6, 2007). 

VA. 2006c. About VA: Mission, vision, core values, & goals. http://www.va.gov/about_va/mission.asp 

(accessed June 11, 2007). 

VA. 2006d. General provisions. Proposed Rule. March 31, 2006. Federal Register 71(62):16464-16475. 

VA. 2007a. Fiscal Year 2008 budget submission. Volume IV: Summary.

http://www.va.gov/budget/summary/VolumeIVSummaryVolume.pdf (accessed March 6, 2007). 

VA. 2007b. Fiscal Year 2008 budget submission. Volume II: National Cemetery Administration, Benefits 

Programs, and Departmental Administration.

http://www.va.gov/budget/summary/VolumeIINationalCemeteryAdministrationBenefitsProgramsand

DepartmentalAdmin.pdf (accessed July 10, 2007). 

VBA (Veterans Benefits Administration). 2006. Annual benefits report, fiscal year 2005. Washington, 

DC: Department of Veterans Affairs, Under Secretary of Veterans Affairs for Benefits. 

http://www.vba.va.gov/bln/dmo/reports/fy2005/2005_abr.pdf (accessed March 6, 2007). 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html

D-14 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Veterans’ Disability Benefits Commission. 2005. Approved research questions. https://www.1888932-

2946.ws/vetscommission/edocumentmanager/gallery/Documents/Reference_Materials/ApprovedResearchQuestions_10-14-

05.pdf (accessed June 13, 2006). 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html

E-1 

Appendix E 

Arguments Favoring and Opposing 

Presumptions1

 1

 VA (Veterans Administration). 2006 (unpublished). Presumption of service connection. The public policy debate. Washington, DC: VA. 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html E-2 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Arguments Favoring Presumptions Arguments Opposing Presumptions Medical uncertainty. “The proposal (by the Bradley Commission) to throw out . . . the pre- sumption for service connection of certain chronic diseases—tropical 

diseases—was tried and it did not work. The doctors could not agree about whether the disease discovered 1 year of 2 years after separation from the service had its inception while in the service or not. The Congress became so tired of the subject that it decided they would be given a period of time of the subject that it decided they would be given a period of time in which it would be presumed that the disease had its inception while in the service.” 

O.W. Clark, National Director of Legislation, DAV

Hearings Before the House Comm. on Veterans’ Affairs, 

84th Cong., 2d Sess. (1956)

“Question of fact.” “Last year it was determined—and I had hoped permanently—that a service-connected disability is a question of fact rather than a question of law. In other words, each individual case should and must be considered on it merits, and there is no justification for legislative dicta which, contrary to fact, provide that thousands of individual cases of sickness which commenced 4, 5, or 6 years after the termination of the war are caused by war services.” 

Veto message of President Roosevelt, Independent Offices

Appropriation Bill (1935)

H.R. Doc. No. 291, 73d Cong., 2d Sess. (1934)

“It is the opinion of the American Legion that until American medicine has reached a point where it can determine with more than a reasonable degree of accuracy whether in fact certain types of disease did or did not have their inception during the course of a man’s service, the veteran should be entitled, in the areas of doubt . . . to the presumption that his disease or disability, within reasonable periods now or to be specified, was the result of his service.” 

Statement of Donald R. Wilson, past National Commander,

American Legion

Id., 3654-55 (1957)

Relationship to service. “The present list of ‘chronic’ diseases for which service connection is granted is one deeply rooted in the history of the claims program, but one regarding which it would be futile to contend that inclusion of a disease in the list is substantiated by any likelihood of actual incurrence in service or in any way resulting from the circumstances of service. The diseases when correctly diagnosticated, are indeed of chronic type, and their presence within a year after discharge raises a strong probability that part of the course of the disease (not necessarily an early part, unless the service was much longer than the minimum 90 days required) coincided with the ‘period of service, but the likelihood that any of their course was influenced by the facts or circumstances of service is extremely remote.” 

Internal Memorandum from Assistant Administrator for

Claims to Assistant Administrator for Legislation

October 20, 1947
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX E E-3 Arguments Favoring Presumptions For the purpose of providing hospital and nursing home care to veterans exposed during service to dioxin or ionizing radiation for conditions not shown to result from a cause other than exposure under P.L. 97-72. 

“. . . [U]ntil the scientific community [is] able to make a determination as to the possible cause and effect relationship of the toxic herbicides utilized as defoliants in the Republic of Vietnam during the Vietnam conflict, the Veterans’ Administration should do everything possible to provide the care to such veterans. When a doubt exists, the doubt should be resolved in favor of the veteran.” 

H.R. Rep. No. 79, 97th Cong., 1st Sess. 3

Inadequacy of service records and examinations. “. . . [P]hysical examinations were hurried and, in many instances, incomplete. As a consequence men were taken into the service with physical and mental defects. The changed life and rigors of service, whether of an active fighting nature or simple employment in and around the military establishment, in many cases, aggravated these defects so that upon discharge these veterans were in need of financial relief and medical treatment.” 

Federal Laws Relating to Veterans of Wars of the United States, S.

Doc. No. 131, 72nd Congress, 1st Sess., 117

1932

Arguments Opposing Presumptions “Although the exact cause of the disease is unknown, there is nothing in the circumstances of military service in time of war which from a medical and scientific standpoint would warrant a presumption of fact that a manifestation of the disease 3 years after discharge is in any way related to the fact or circumstances of service. In this connection, it does not appear that the disease is any more prevalent among the veteran population than the nonveteran population.” 

Letter from Carl R. Gray, Jr., Administrator of Veterans Affairs, to Chairman, Senate Committee on Finance

June 29, 1951

Administrative function. 

Developing presumptions of service connection: statutory or regulatory activity? 

“It is believed that extreme care should be exercised in augmenting the list of diseases to be afforded the presumption. It is the view of the Veterans’ Administration that this can best be accomplished by continuing the existing Veterans Regulation No. 1(a), part I, paragraph I(c), and administrative authority to make the medical and adjudicatory determinations. “Determination governing the selection of diseases to be included under the regulation is essentially one of an involved medical and adjudicatory nature. If a list of diseases is provided by statute it is suggested that the consideration of additions . . . would require detailed technical considerations by the Congress which in the opinion of the Veterans’ Administration can best be handled administratively. . . . This statement is made in the light of experience under the War Risk Insurance Act, as amended, and the World War Veterans Act of 1924, as amended. . . .” 

Letter from General Omar Bradley, Administrator of 

Veterans Affairs

1947
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html E-4 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Arguments Favoring Presumptions “Some feel that Congress should abide by its longstanding tradition that benefits should be paid only where substantive evidence is clearly 

available to establish that the disabling conditions existed while on active duty or are clearly related to such period of service. It has become apparent that such evidence will never be available in the cases of veterans covered under the provisions of the reported bill because the level of exposure cannot be verified.” 

H.R. Rep. No. 235, 100th Cong., 1st Sess. 4

1987 

Excessive burden of proof on veteran. “In my opinion, that provision of the law which places the burden upon the disabled veteran of connecting his disease with his service has been responsible for more complaints, dissatisfaction and disappointment . . . than any other single provision. . . . “Consequently, I propose to offer an amendment to section 18 which will shift the burden of proof in the case of two classes of disease only—tubercular and neuropsychiatric. I propose that when it is proved by an incapacitated soldier that he has either of these two types of disease he shall immediately be entitled to compensation unless the Government proves—the burden thus being shifted to the Government—that he has contracted the disease since the time of his discharge and it is not traceable to service in line of duty.” 

Senator Walsh, 61 Cong. Rec. 4105

1921

Arguments Opposing Presumptions Regarding Senate bill S. 1651, 98th Cong. 1st Sess. (1983) “VA opposed the bill, which directed VA to follow a rulemaking process that involved public participation and consultation with an advisory committee. VA held that legislative action to create presumptions could not be supported on the basis of available evidence, so it would be inappropriate to refer the matter for rulemaking. VA also stated that the procedural process defined in the bill would impede resolution of the issues involved and that the bill would create false expectations among affected veterans and their families.” 

Letter from Harry N. Walters, Administrator, to Alan K. Simpson,

Chairman, Senate Committee on Veterans’ Affairs

April 10, 1984

Improved military procedures/records. “[T]he facilities and procedures of the service departments in the examination of recruits prior to their induction into service and their facilities for rendering medical care and treatment, the maintenance of records in individual cases and the furnishing of these records to the Veterans’ Administration all represent a great advancement and improvement over comparable situations as they existed during World War I.” 

Letter from Carl R. Gray, Jr., Administrator of Veterans Affairs

February 1950
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX E E-5 Arguments Favoring Presumptions “. . . [T]he question is not entirely a medical one. It is also in part a legal one. The purpose of a presumption is to free the veteran from carrying an unconscionable burden of proof in the establishment of the serviceconnected origin of a disease or a disability. . . . [T]he principle behind 

the granting of a presumption says to the American veteran that it would be unfair in some cases to require him to prove medically that a given disease or disability did in fact have its inception during the course of his service, or resulted directly from that service. It states in substance that, in those instances in which it would be unfair to impose such a burden upon him, he is entitled to a presumption that the disease or disability did emanate from his service. This is a rebuttable presumption. . . . It enables the Government, if medical knowledge is what the Bradley Commission says that it is, to rebut the presumption. . . .” 

Statement of Donald R. Wilson, past National Commander,

American Legion Id., 3654-55

1957

Incidence of disease. “It is very apparent to me that this wave of tuberculosis and of nervous and mental disease that has taken such a deadly hold and grip of late upon our ex-service men must have been contracted in the service. I feel, therefore, that we ought not continue this requirement of endless affidavits, necessarily involving long delay, in demonstrating the fact that their illness is of service origin. The delays resulting from this affidavit requirement have often resulted in men dying before they ever got their compensation. . . .” 

Senator Walsh, 61 Cong. Rec. 4105

1921

Arguments Opposing Presumptions Advances in medical science. “. . . [T]he advances in medical science since World War I have facilitated the detection and diagnosis of diseases to such an extent that further extension of statutory presumptions of service connection is not believed to be indicated.” 

Letter from Carl R. Gray, Jr., Administrator of Veterans Affairs

February 1950

Philosophy of program. “A statutory provision which requires a finding of service connection for a disability which cannot be shown to be due to service is inconsistent with the theory of providing compensation for disability or death resulting from injury or disease incurred in line of duty in active military or naval service, and results in providing compensation for disability or death due to causes which are not in any way connected with military or naval service.” 

Letter from Carl R. Gray, Jr., Administrator of Veterans Affairs

Feb. 23, 1950

Elevates cases without merit. 

In opposition to a proposal to extend the presumptive period/or service connection of multiple sclerosis. 

“VA commented that singling out multiple sclerosis for a longer presumptive period would be discriminatory and could serve as a precedent for extending the presumptive period for other chronic diseases. The amendment would place ‘cases without merit, from the standpoint of service connection’ on a par with cases involving conditions medically proven to be service connected.” 

Letter from Carl R. Gray, Jr., Administrator of Veterans Affairs

June 29, 1951
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html E-6 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Arguments Favoring Presumptions Difficult/delayed Diagnoses. “[I]t is frequently true that tuberculosis is an active process, and yet the person afflicted with it does not have knowledge of the fact that he has 

tuberculosis. As a matter of fact, most tubercular patients think: that they have something else or think: they are not afflicted with tuberculosis.” 

Senator Robinson, 61 Cong. Rec. 4105

1921

“It is also recommended that this 5-year presumption should not only extend to neuropsychiatric and tubercular disease, but also to other internal [dis]orders which might be placed in like category, such as heart trouble, cancer, diabetes, sleeping sickness, etc. Some of these are even very difficult to ascertain or even see by means of X rays. It is hard to determine just when they did commence. Take the instance of a cancer, it is the general presumption that it must be existent in a small state at least a year before it is found, therefore, it is urged that these diseases be included in the 5-year presumption.” 

Edwin S. Bettelheim, VFW, in letter to Special Committee of Senate

Investigations

November 5, 1923

According to a Senate report, only medical specialists, primarily neurologists, were likely to diagnose the disease (MS) in its early stages. The average person “would not be inclined to consult a neurologist for the original symptoms.” VA opposed extension of the presumptive period on the grounds that it lacked a sound medical basis. 

S. Rep. No. 660, 86 Cong., 1st Sess.

1959

Arguments Opposing Presumptions Provisions are adequate without presumptions. “There is otherwise in the law sufficient protection for the veteran to establish service connection of any and all diseases. Accepted medical principles can reasonably and accurately establish the onset of a disease and the disability process. Where there is reasonable doubt, the law provides for the doubt to be resolved in favor of the veteran. . . . “With respect to chronic and tropical diseases, psychoses, and multiple sclerosis, the physicians surveyed were in general agreement that service-connection should be determined in accordance with sound medical principles, and not by fiat. As to tuberculosis in particular, modern methods of diagnosis have made rapid strides since enactment of the original presumption for this disease 35 years ago. The presumptive period of 4 years is not in accord with present-day accepted medical principles.” 

President’s Commission on Veterans’ Pensions (the Bradley

Commission), Veterans’ Benefits in the United States 

1957

With regard to additional presumptions specific to former POWs. “The VA position was that the conditions under consideration (peripheral neuropathy; irritable bowel syndrome; and duodenal and peptic ulcers) would ordinarily manifest themselves and require treatment upon repatriation or shortly thereafter. Under these circumstances the veteran would be entitled to direct rather than presumptive service connection. Moreover, VA pointed out that the conditions at issue did not lend themselves to presumption. Irritable bowel syndrome, for example, was described as a functional disorder of unknown etiology and pathogenesis.” 

From Statement of R. J. Vogel, Chief Benefits Director

VA Compensation and Other Service-Connected Benefits: Hearing 

Before the Senate Committee on Veterans’ Affairs 

100th Congress, 1st Sess.

1987
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX E E-7 Arguments Favoring Presumptions “[P]resumptions are based on the need to ensure that diseases and dis- abilities incurred in or aggravated during service are, in fact, determined to be service connected. This need arises most clearly in the cases of 

diseases that have a latency period of varying length causing early manifestations to be easily overlooked or misdiagnosed or diseases that are otherwise difficult to diagnose. “SLE is such a disease. . . . Although the disease may start acutely, the course is usually chronic and irregular with periods of activity alternating with periods of remission, thereby making diagnosis very difficult and the manifestations quite diverse . . . SLE is instigated by a combination of genetic predisposition and environmental factors. Current data stress the importance of various environmental factors as accelerating or causal elements to a greater degree than previously had been assumed. Accordingly, factors present during the veteran’s service may trigger onset of the disease and yet not appear on the veteran’s service record. . . .” 

S. Rep. No. 215, 100th Cong., 1st Sess. 73

1987

Social benefits. 

Regarding extension of the presumptive period for active pulmonary tuberculosis from one year to three years after separation provided in Act of June 23, 1950. 

Extension of the presumption was “fully justified, in view of the nature of this particular chronic disease. . . . The entitlement to compensation and preference in hospitalization generally resulting will lessen the need of veterans to engage in labor injurious to their health, encourage them to take proper measures for recovery, and thus result in improving the health of the Nation generally.” The report also noted that the World War Veterans’ Act of 1924 provided a longer presumptive period for active tuberculosis in World I veterans. 

S. Rep. No. 1745, 81st Congress, 2d Sess.

1950 

Arguments Opposing Presumptions Qualifying criteria excessively liberal. “The bill makes no distinction as to the length, or type of service or as to the various diseases. Certain diseases, particularly cardiovascular-renal disease, endocrinopathies, organic diseases of the central nervous system, and the psychoses, reflect a multitude of etiologies, some of which, when analyzed are not even remotely affected by any stress or strain of service. Under the terms of this bill, if enacted into law, a veteran with only 1 day active service in World War II and whose disease was first detected 5 years less 1 day from termination of his active service . . . might very well obtain presumptive, service connection. . . .” 

Letter from Frank T. Hines, Administrator to

John E. Rankin, Chairman, House Committee on Veterans’ 

Legislation

Aug. 9, 1945
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html E-8 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Arguments Favoring Presumptions The Act of October 30, 1951, provided a presumption of service connection for active psychosis developing within two years of separation. This presumption was enacted 

for treatment purposes only. Disability compensation would not be paid unless the condition were found directly service connected or arose within the one-year presumptive period provided for chronic diseases generally. At the time there were an estimated 9,000 World War II veterans awaiting hospitalization for nonserviceconnected psychosis. 

The Senate Committee on Finance noted that psychosis “is not only an individual problem but involves broad social aspects as well.” In view of this and other considerations, the Committee thought it important to provide priority care at VA facilities. 

S. Rep. No. 749, 82d Cong., 2d Sess.

1952

Enforce Congress’s view. “[T]he reason we passed [the presumption statute] was because Congress did not agree with many of the medical findings [of VA doctors]. . . . Many doctors have [refused to service connect disabilities] . . . where nearly everyone would agree, [the veteran] should be given the benefit of the doubt. . . . The only way we can force proper administration is by setting up a presumptive right by law. . . . Otherwise they could disagree with us.” 

Olin E. Teague, Chairman, House Committee on Veterans’ Affairs

Hearings, 85th Cong., 1st Sess. 942

1957 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX E E-9 rences Arguments Favoring Presumptions Association with risk factors. 

Since the amount of exposure of the “radiation-exposed veteran”, as defined in the reported bill, is less than certain, the Committee has deliberately ignored the issue of level of exposure and has concentrated instead on the likelihood of relationship of disease entities to radiation exposure. The proposed legislation (later enacted as P.L. 100-321) includes those malignancies considered most likely to be related to ionizing radiation exposure. 

H.R. Rep. No. 235, 100th Cong., 1st Sess. 4

1987

Promote health. 

Regarding extension of the presumptive period for active pulmonary tuberculosis from one year to three years after separation provided in Act of June 23,1950. 

Extension of the presumption was “fully justified, in view of the nature of this particular chronic disease. . . . The entitlement to compensation and preference in hospitalization generally resulting will lessen the need of veterans to engage in labor injurious to their health, encourage them to take proper measures for recovery, and thus result in improving the health of the Nation generally.” The report also noted that the World War Veterans’ Act of 1924 provided a longer presumptive period for active tuberculosis in World I veterans. 

Senate Report No. 1745, 81st Congress, Second Session

1950
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html

F-1 

Appendix F 

Tables: Summary of Presumptive Disability 

Decision-Making Legislative History 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-2 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS TABLE F-1 Summary of PDDM Legislative History (by Date) Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information August 9, 1921 Veterans’ Bureau. Public Law 67-47. 1921. 67th Cong., 

1st Sess. Ch. 57, Sec. 18, 42 Stat. 147, 153 

Chronic Diseases: • Neuropsychiatric disease 

[later called psychoses] 

• Tuberculosis, pulmonary 

(active) [March 4, 1923 Act expanded the presumption to include all forms of active tuberculosis] 

Disease contracted during active military service 

On or after April 6, 1917 Or Discharged or resigned active service on or before November 11, 1918 

Within 2 years after separation from active military or naval service Characteristic manifestations of the disease to 10 percent or more 

November 12, 1921 December 2, 1921 

Internal Memorandum implementing Veterans’ Bureau Regulation No. 11 Office Memorandum No. 36 

Chronic Constitutional Diseases: • Anemia (primary) • Arteriosclerosis • Beriberi • Diabetes insipidus • Diabetes mellitus • Endocrinopathies • Gout • Hemochromatosis • Hemoglobinuria 

(paroxysmal) 

• Hemophilia • Hodgkin’s disease • Leukemia (all types) • Ochronosis • Pellagra • Polycythemia 

(erythremia) 

• Purpura • Rickets • Scurvy 

Chronic constitutional disease contracted during active military service 

 Within 1 year after 

the date of separation from service 

November 12, 1921, stated connection to active military service And Constitutional diseases were defined on December 2, 1921
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-3

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

June 7, 1924 World War 

Veterans’ Act, 1924. Public Law 68-242. 68th Cong., 1st Sess. Title II. Compensation and Treatment. Ch. 320, Sec. 200, 43 Stat. 607, 615 

Chronic Diseases: • Dysentery (amebic) 

(tropical disease added as chronic disease) 

• Encephalitis lethargica • Neuropsychiatric disease • Paralysis agitans • Tuberculous (active) 

Disease contracted during active military or naval service 

Between April 6, 1917, and July 2, 1921 Or Discharged or resigned prior to July 2, 1921 Or Discharged or resigned on or before November 11, 1918, or on or after July 2, 1921 

By January 1, 1925 Characteristic manifestations of the disease to 10 percent or more 

1925 Veterans’ Bureau 

Schedule for Rating Disabilities (based upon the WW Veterans Act, 1924) 

Constitutional Diseases: • Arthritis (deformans and 

chronic) 

• Carcinoma, sarcoma, and 

other tumors

• Cardiovascular-renal 

disease, including hypertension 

• Endocarditis, chronic • Leprosy (tropical disease 

added as a chronic disease) 

• Myocarditis, chronic 

• Nephritis, chronic forms  (was not carried forward, 

• cholecystitis, chronic, 

proceeding to gall-stone formation 

Disease contracted during military or naval services in the World War I 

During World War I 

Characteristic manifestation within 1 year from date of separation from active service Or If medical evidence affirmatively establishes conclusive service connection after 1 year of separation 

Amends list of constitutional diseases 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-4 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information • nephrolithiasis • valvulitis, chronic) November 2, 1928 Veterans’ Bureau Schedule of 

Disability Ratings, Extension 6 

• Ulcers (gastric or 

duodenal)

 Manifest within 6 

months from discharge from military service and shown present within 1 year after discharge 

Establishes service connection for ulcers 

April 12, 1933 

Executive Order 6089. Instruction No. 2, Implementing Vet. Reg. No. 1. April 12, 1933 

Chronic Diseases • Epilepsies • Organic diseases of the 

nervous system 

Tuberculosis: Manifest to a degree of 10 percent within 1 year of discharge; second-year diagnoses presumptive if at 6 months for minimal cases, 9 months for moderately advanced cases, and 12 months for far advanced cases 

Amends list of chronic diseases and presumption of tuberculosis Carried forward prior presumptions of chronic diseases except rickets, obesity, acidosis, beriberi, chronic cholecystitis, diabetes insipidus, gout, hemophilia, hemochromatosis, hemoglobinuria, nephrolithiasis, ochronosis, pellagra, purpura, scurvy, polycythemia (erythremia), and chronic valvulitis 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-5

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

August 14, 1935 

Executive Order 6089. Instruction No. 2-A, Implementing Vet. Reg. No. 1. August 14, 1935 

Chronic Diseases: • Osteitis deformans 

(Paget’s disease) 

 Amends list of 

chronic diseases 

December 28, 1945 

VA Circular No. 8, section I 

Tropical Diseases: • Malaria 

Disease contracted during active 

 Within 1 year after 

separation of active service military service 

January 3, 1947 

Disability ratings for malaria and chronic diseases characteristically tropical in origin. Veterans Administration Technical Bulletin 8-6. Washington, DC: VA 

Tropical Diseases: • Dysentery (amebic, 

bacillary) 

• Filariasis (Bancroft’s 

type) 

• Leishmaniasis (including 

kala-azar) 

• Malaria • Schistosomiasis • Trypanosomiasis • Yaws 

Disease contracted during wartime service 

Service in the tropics or a place having a high incidence of the disease under consideration 

Within 1 year after separation of active wartime service 

Relapses of malaria (after the 1 year separation) need others, under oath to establish frequency of relapse over a period of time relating back to the 1-year period following discharge 

June 24, 1948 

Act of June 24, 1948. Public Law 80-748. 80th Cong., 2d Sess. Ch. 612, Sec. 1, 62 Stat. 581 

Chronic Diseases: • Anemia (primary) 

• Arteriosclerosis • Arthritis • Bronchiectasis • Calculi of the kidney, 

bladder, or gall bladder 

• Cardiovascular-renal 

disease (hypertension, myocarditis, Buerger’s disease, Raynaud’s disease) 

Disease contracted during active service 

 At least 6 months 

of service and honorably discharged Within 1 year after separation from active service or at a time when standard and accepted treatises indicate that the incubation period 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-6 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information • Cirrhosis of the liver • Coccidioidomycosis • Diabetes mellitus 

• Encephalitis lethargica 

residuals 

• Endocarditis • Endocrinopathies • Epilepsies • Hodgkin’s disease • Leukemia (nephritis) • Organic diseases of the 

nervous system (tumors of the brain, cord, peripheral nerves) 

• Osteitis (deformans) • Osteomalacia • Peptic ulcers (gastric or 

duodenal) 

• Scleroderma • Tuberculosis (active) • Tumors (malignant) Tropical Diseases: • Black water fever • Cholera • Dracontiasis • Dysentery • Filariasis • Leishmaniasis • Leprosy • Loiasis • Malaria • Onchocerciasis 

thereof commenced during active service 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-7

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

• Oroya fever • Pinta • Plague • Schistosomiasis • Yaws • Yellow fever 

February 9, 1949 

Pensions, bonuses, and veterans’ relief. Part 3: Veterans’ claims; miscellaneous amendments. Federal Register

14(26):568-578. Former 39 CFR Sec. 3.80; Sec. 3.86(a), 3.95 

Chronic Diseases: • Anemia (primary) 

• Arteriosclerosis • Arthritis • Atrophy, progressive 

muscular 

• Brain hemorrhage • Brain thrombosis • Bronchiectasis • Calculi of the kidney, 

bladder, or gall bladder 

• Cardiovascular-renal 

disease (hypertension) 

• Cirrhosis of the liver • Coccidioidomycosis • Diabetes mellitus • Encephalitis lethargica 

residuals 

• Endocarditis • Endocrinopathies • Epilepsies • Hodgkin’s disease • Leprosy • Leukemia (nephritis) • Myasthenia gravis • Myelitis • Myocarditis 

Disease contracted during military service 

Wartime service prior to January 1, 1947, to July 25, 1947 Tropical Diseases:Service in the tropics or a place having a high incidence of the disease under consideration Ulcer (peptic):Within 6 months from date of active service or within 6 months of July 25, 1947; or if more than 6 months, then evidence of continuity of characteristic symptoms during the first 6 months after termination of active service 

Within 1 year after 

separation from active wartime service Within 1 year after the date prior to which a disability must have been incurred Chronic Disease:Manifestations sufficient to identify the disease entity and sufficient observations to establish chronicity at the time Tropical Disease: When shown to exist at a time when standard and accepted treatises indicate that the 

Factual Basis:Established by medical evidence, competent lay evidence, or both Pulmonary Tuberculosis: Specific assumptions for diagnosis in second year after service 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-8 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information • Nephritis • Organic diseases of the nervous system 

• Osteitis (deformans) • Osteomalacia • Palsy, bulbar • Paralysis agitans • Peptic ulcers (gastric or 

duodenal) 

• Psychoses • Raynaud’s disease • Scleroderma • Sclerosis (amyotrophic 

lateral, multiple) 

• Syringomyelia • Thromboangiitis 

Obliterans (Buerger’s disease) 

• Tuberculosis (active) • Tumors (malignant) of 

the brain or spinal cord or peripheral nerves 

Tropical Diseases: • Black water fever • Cholera • Dracontiasis • Dysentery • Filariasis • Leishmaniasis • Leprosy • Loiasis • Malaria 

 incubation period 

of the diseases commenced during active service Characteristic manifestations of the disease to 10 percent or more, except pulmonary tuberculosis
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-9

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

• Onchocerciasis • Oroya fever • Pinta • Plague • Schistosomiasis • Yaws • Yellow fever 

October 12, 1949 

Pensions, bonuses, and veterans’ relief. Part 3: Veterans’ claims; miscellaneous amendments. Federal Register

14(197):6174-6180. Former 38 CFR Sec. 3.86(a) 

Chronic Diseases: Pupura idiopathic (hemorrhagic) 

Military service Amends list of 

chronic diseases 

August 31, 1950 

Pensions, bonuses, and veterans’ relief. Part 3: Veterans’ claims; miscellaneous amendments. Federal Register

15(169):5902-5910. Former 38 CFR 

Chronic Disease: Sarcoidosis Tropical Disease: Amebiasis 

Disease contracted during military service 

See Veterans Regulation 1 (38 USC Ch. 12) 

See Veterans Regulation 1 (38 USC Ch. 12) 

Added to list of chronic and tropical diseases 

June 17, 1957 

Veterans’ Benefits Act of 1957. Public Law 85-56. Sec. 301. 85th 

Chronic and Tropical Diseases: Same diseases as above three entries (1949 and 1950 

Disease contracted during active military, naval, or air service 

Veteran who engaged in combat with the enemy in active service with 

Tropical Diseases: Serves 6 months or more and contracts 

Summarizes previous rules and legislation and amends 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-10 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information Cong., 1st Sess. Sec. 301(3 and 4). 71 Stat. 83, 95 entries) a military, naval, or air organization of the U.S. during a period of war, 

campaign, or expedition Period of service after November 11, 1918, and before July 2, 1921, if served after April 5, 1917, and before November 12, 1918 Period after December 31, 1946, and before July 26, 1947, if period began before January 1, 1947 

tropical or disease because of therapy in connection with tropical disease Within 1 year after separation from active service or when standard and accepted treatises indicate incubation period Psychosis: WWII or Korean service within 2 years after discharge or release and before July 26, 1949 (WWII) or February 1, 1957 (Korean) 

dates/location of service and presumption 

February 24, 1961 

Disease subject to presumptive service connection. Federal Register

26(36):1581-1582 

Chronic and Tropical Diseases: Same as June 17, 1957 

Disease contracted during active military, naval, or air service 

 Lays out criteria 

for presumption wartime service connection for chronic or tropical disease Factual Basis:May be established by medical evidence, 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-11

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information competent lay evidence or both 

August 12, 1970 

Public Law 91-376. Sec. 3. 91st Cong., 2d Sess., 1970. Sec 3. 84 Stat. 787, 788 

Former Prisoner of War Associated Diseases: • Avitaminosis 

• Beriberi (including 

beriberi heart disease) 

• Chronic dysentery • Helminthiasis • Malnutrition (including 

optic atrophy associated with malnutrition) 

• Other nutritional 

deficiency 

• Pellagra • Psychosis 

Active military, naval, or air service and was held prisoner of war 

Held by Imperial Japanese Government or the German Government during World War II, Government of North Korea during the Korean conflict, or the Government of North Vietnam, or the Viet Cong during the Vietnam era 

Detained or interned for not less than 6 months Characteristic manifestations of the disease (except psychosis) to 10 percent or more after service Psychosis:Characteristic manifestations of the disease to 10 percent or more within 2 years after separation from service 

Service connection presumption for former prisoners of war 

December 1, 1970 

Pensions, bonuses, and veterans’ relief. Part 3: Adjudication. Subpart A: Pension, compensation, and dependency and indemnity compensation. Federal Register

35(232):18280-

Diseases Associated with Former Prisoners of War Chronic and Tropical Diseases 

Active service Former Prisons of War: Held by an enemy government or its agents during WWII, Korean conflict, or the Vietnam era, suffered from dietary deficiencies, 

Service of 90 days or more during a war period on or after January 31, 1955 

Chronic Diseases: Manifest to a degree of 10 percent or more within 1 year for Hansen’s disease (leprosy) and tuberculosis within 3 years; multiple sclerosis within 7 years from date of separation from 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-12 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information 18283. 38 CFR Part 3 forced labor, or inhumane treatment service Tropical Diseases: Manifest 

to a degree of 10 percent or more within 1 year from date of separation from service or at a time when standard treatises indicate that the incubation period commenced during such service Prisoners of War: Manifest to a degree of 10 percent or more at any time after service, except

psychosis, 10 percent within 2 years from date of separation from service 

September 26, 1974 

Increase of disability compensation and dependency and indemnity compensation rates. 

Chronic, Tropical, or Former Prisoner of War Associated Diseases: No new ones 

Active service on or after January 1, 1947 Chronic Before January 1, 1947: No presumption 

Service of 90 days or more during a war period on or after December 31, 1946 

Tropical Before January 1, 1947: Manifest to a degree of 10 percent or more within 1 year after separation from 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-13

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

Federal Register39(188)34529-34533. 38 CFR Part 3 

Tropical: Before January 1, 1947: Veteran with 6 or months of service 

active service or at a time when standard and accepted treatises indicate that the incubation period commenced during active service 

December 23, 1976 

Increased disability compensation and dependency and indemnity compensation; burial benefits. Federal Register

41(248):55872-55875. 38 CFR Part 3 

Chronic and Tropical Diseases: 

• Hansen’s disease 

Chronic Diseases: Following service in a period of war or following peacetime service on or after January 1, 1947 Tropical Diseases: Tropical service following service in a period of war or following peacetime service 

Used term Hansen’s disease instead of leprosy 

October 2, 1978 

Pension, compensation, and dependence and indemnity. Final regulation. Federal Register

43(191):45347-45362. 38 CFR Part 3 

Chronic Disease: • Pulmonary tuberculosis 

 Removes the 

presumptive period of 6, 9, and 12 months for minimally, moderately, and far advanced TB to developing within 3 years from the date of separation from active service 

Amends presumptive period 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-14 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information August 28, 1979 Pension, compensation, and dependency and indemnity 

compensation, proximate results, secondary conditions. Federal Register

44(168):50339-50340. 38 CFR Part 3, Sec 3.310 

Diseases Associated with Service Amputation: Ischemic heart disease (or other cardiovascular disease) 

Service-connected amputation of one lower extremity at or above the knee or serviceconnected amputations of both lower extremities at or above the ankles 

August 14, 1981 

Former Prisoner of War Benefits Act of 1981. Public Law 97-37. 97th Cong., 1st Sess. Sec 4. 95 Stat. 935, 936 

Diseases Associated with Former Prisoner of War: • Avitaminosis 

• Beriberi (including 

beriberi heart disease) 

• Chronic dysentery • Helminthiasis • Malnutrition (including 

optic atrophy associated with malnutrition) 

• Other nutritional 

deficiency 

• Pellagra • Psychosis • Any of the anxiety states 

Former prisoner of war 

While serving in active military, naval, or air service, was forcibly detained or interned in line of duty by an enemy government or its agents, or a hostile force during a period of war 

Characteristic manifestations of the disease to 10 percent or more after service Detained or interned for not less than 30 days 

The previous prisoner of war presumption is for the period of time not less than 6 months. This act changes that period of time to not less than 30 days 

March 18, 1982 

Veterans Benefits; Former Prisoners of War. Final regulations. Federal Register

47(53):11655-

Former Prisoner of War • Avitaminosis 

• Beriberi (including 

beriberi heart disease) 

• Chronic dysentery 

Former prisoner of war 

While serving in active military, naval, or air service, was forcibly detained or interned in line of 

Characteristic manifestations of the disease to 10 percent or more after service 

Implementing the new Former Prisoner of War Benefits Act of 1981 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-15

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

11656.38 CFR Part 3 

• Helminthiasis 

• Malnutrition (including 

optic atrophy associated with malnutrition) 

• Other nutritional 

deficiency 

• Pellagra 

• Psychosis • Any of the anxiety states 

duty by an enemy government or its agents, or a hostile force during a period of war on or after January 1, 1947 

Detained or interned for not less than 30 days 

Amended period of detainment for presumption of disease 

March 2, 1984 

Veterans’ Compensation and Program Improvements Amendments of 1984. Public Law 98-223. 98th Cong., 2d Sess. Sec 111 98 Stat. 37, 40 

Former Prisoner of War Diseases: Dysthymic disorder (or depressive neurosis) 

Prisoner of war Amends list of 

diseases associated with former prisoner of war 

August 26, 1985 Adjudication of claims based on 

exposure to dioxin or ionizing radiation. Final rules. Federal Register50(165):34452-34461. 38 CFR Parts 1 and 3 

Diseases Associated with Herbicide Exposure: Chloracne Radiogenic Diseases: • All forms of leukemia 

(except chronic lymphatic leukemia) 

• Cancer (bone, colon, 

esophageal, female breast, kidney, liver, lung, pancreatic, salivary gland, skin, stomach, thyroid, urinary bladder) 

• Multiple myeloma 

Herbicide • Dioxin 

(2,3,7,8 tetrachlorodibenzo-pdioxin) 

Radiation • Ionizing 

Dioxin Vietnam era Ionizing Hiroshima or Nagasaki, Japan (September 1945 until July 1946) 

Dioxin Exposure:No later than 3 months from the date of exposure Ionizing: Leukemias and bone cancer must become manifest within 30 years after exposure; other forms of cancer must become manifest 5 years 

Dioxin: Presumed to have been exposed if served in the Vietnam era Ionizing:Exposure at the highest level of the dose range estimated will be presumed; several factors to be considered in determining 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-16 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information or more after exposure whether disease resulted from exposure during service 

October 28, 1986 

Veterans’ Benefits Improvements and Health-Care Authorization Act of 1986. Public Law 99-576. 99th Cong., 2d Sess. Sec 108. 100 Stat. 3248, 3252

Former Prisoner of War Associated Diseases: • Organic residuals of 

frostbite 

• Posttraumatic 

osteoarthritis 

Former prisoner of war 

 Amends list of 

associated diseases of former prisoners of war 

May 20, 1988 

Veterans’ Benefits and Services Act of 1988. Public Law 100-322. 100th Cong., 2d Sess. Sec 312, 313. 102 Stat. 487, 535 

Chronic Diseases: • Lupus erythematosus 

(systemic) 

Diseases Associated with Former Prisoner of War: • Irritable bowel syndrome • Peptic ulcer disease • Peripheral neuropathy 

(except where directly related to infectious causes) 

• Chronic disease 

contracted during military service 

• Prisoner of war 

Amended list of diseases related to former prisoners of war and service connection of chronic diseases 

May 20, 1988 

RadiationExposed Veterans Compensation Act of 1988. Public Law 100-321. 100th Cong., 2d Sess., Section 2, 102 Stat. 485 

Diseases Associated with Radiation Exposure (radiation-risk activity): • Cancer (bile ducts, breast, 

esophagus, gall bladder, pharynx, primary liver, pancreas, small intestine, stomach, thyroid) 

• Leukemia (other than 

chronic lymphocytic 

Radiation risk activity 

• Participation 

in a test involving atmospheric detonation of a nuclear device 

• Occupation of 

Hiroshima or 

Japan WWI (August 6, 1945, to July 1, 1946) Others 

40-year period beginning on the last date where the veteran participated in a radiation-risk activity except leukemia (30-year period after radiation-risk 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-17

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

leukemia)

• Lymphomas (except 

Hodgkin’s disease)

• Multiple myeloma

Nagasaki, Japan (August 6, 1945, to July 1, 1946) 

• Prisoner of 

war in Japan during WWII exposure of ionizing radiation 

activity) 

October 18, 1989 

Claims based on exposure to ionizing radiation. Final regulations. Federal Register

54(200):42802-42803. 38 CFR Part 3 

Radiogenic Diseases: 

• Cancer (breast, salivary 

gland)

• Leukemia (other than 

chronic lymphatic [lymphocytic] leukemia)

• Multiple myeloma

• Nonmalignant thyroid 

nodular disease

• Posterior subcapsular 

cataracts

Ionizing radiation Bone Cancer: 

Manifest within 30 years after exposure Leukemia: Manifest any time after exposure Posterior Subcapsular Cataracts: Manifest 6 months or more after exposure Other Diseases: Manifest 5 years or more after exposure 

Amended diseases considered to be radiogenic Withdrew proposed clarification concerning when service connection can be established based upon claimed exposure to ionizing radiation and herbicides containing dioxin 

October 15, 1990 

Radiation Exposure Compensation Act of 1990. Public 

Diseases Associated with Radiation Exposure: Above-Ground Nuclear Tests 

Radiation exposure 

• Above-ground 

nuclear tests 

Government’s above-ground nuclear tests in Nevada and lived 

Childhood leukemia and other diseases (January 21, 1951, to 

Individuals not in military • Uranium 

miners 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-18 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information Law 101-426. 101st Cong., 2d Sess., 104 STAT 920 • Leukemia (not chronic lymphocytic) • Lymphomas (other than Hodgkin’s disease 

• Multiple myeloma • Primary cancer of the: 

Bile ducts Esophagus Female breast Gall bladder Liver Pancreas Pharynx Small intestine Stomach Thyroid 

Uranium Miners • Lung cancer • Nonmalignant 

respiratory disease (fibrosis of the lung, pulmonary fibrosis, and corpulmonale) 

• Uranium 

miners 

downwind in Nevada, Utah, and Arizona Underground uranium mines 

October 31, 1958, or June 30, 1962, to July 31, 1962) For miners: Any individual who was employed in a uranium mine located in Colorado, New Mexico, Arizona, Wyoming, or Utah at any time during the period beginning on January 1, 1947, and ending on December 31, 1971 

• Downwind to 

nuclear tests 

October 26, 1990 

Claims based on service in Vietnam. Final regulations. Federal Register

55(208):43123-43125. 38 CFR Parts 3 and 4 

Diseases Associated with Vietnam Service: 

• Non-Hodgkin’s 

lymphoma 

Service in Vietnam 

Vietnam (includes waters offshore, or service in other locations if the conditions of service involved duty or visitation in Vietnam) 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-19

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

During the Vietnam era 

February 6, 1991 

Agent Orange Act of 1981. Public Law 102-4. 102d Cong., 1st Sess. 105 STAT. 11 

Diseases Associated with Herbicide Exposure: 

• Chloracne (or another 

acneform disease)

• Non-Hodgkin’s 

lymphoma

• Soft tissue sarcoma

Active military, naval, or air service Exposure to herbicide agent containing dioxin or 2,4-dichlorophenoxyacetic acid or other chemical compound in an herbicide agent 

Republic of Vietnam; Vietnam era 

Non-Hodgkin’s Lymphoma and Soft Tissue Sarcoma (other than osteosarcoma, chondrosarcoma, kaposi’s sarcoma, or mesothelioma):Manifest 10 percent or more disability Chloracne: 10 percent or more disability within 1 year after the last date active duty in Republic of Vietnam 

August 14, 1991 

Veterans’ Benefits Programs Improvement Act of 1991. Public Law 102-86. 102d Cong., 1st Sess., Sec. 104,105. 105 Stat. 414 

Diseases Associated with Radiation Exposure: 

• Leukemia (presumptive 

period) 

Radiation exposure 

Amends service to during active military, naval, or air service or reserve component of the Armed Forces, participated in a radiation-risk activity during a period of active duty for training or 

 Amends 

presumptive period for occurrence of leukemia and location of radiation exposure 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-20 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information inactive duty training October 15, 1991 Claims based on exposure to 

herbicides containing dioxin (soft tissue sarcomas). Final regulation. Federal Register

56(199):51651-51653. 38 CFR Parts 3 and 4 

Diseases Associated with Herbicide Exposure (containing dioxin): 

• Chloracne • Soft-tissue sarcoma 

(adult fibrosarcoma; dermatofibrosarcoma protuberans; malignant fibrous histiocytoma; liposarcoma; leiomyosarcoma; epithelioid leiomyosarcoma; rhabdomyosarcoma; ectomesenchymoma; angiosarcoma; proliferating angioendotheliomatosis; malignant glomus tumor; malignant hemangiopericytoma; synovial sarcoma; malignant giant cell tumor of tendon sheath; malignant schwannoma; malignant mesenchymoma; malignant granular cell tumor; alveolar soft part sarcoma; epithelioid sarcoma; clear cell sarcoma of tendons and aponeuroses) 

Exposure to herbicides containing dioxin 

Republic of Vietnam; Vietnam era 

Chloracne: Manifested not later than 3 months from the date of exposure Soft-Tissue Sarcoma:Manifest at any time after service 

Lists diseases associated with exposure to herbicides containing dioxin 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-21

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

January 15, 1992 

Claims based on chronic effects of exposure to mustard gas. Proposed rule. Federal Register

57(10):1699-1700.38 CFR Part 3 

Diseases Associated with Exposure to Mustard Gas: 

• Asthma

• Bronchitis

• Conjunctivitis• Corneal opacities

• Emphysema

• Keratitis• Laryngitis

Mustard gas exposure by participating in full-body, field, or chamber experiments to test protective clothing or equipment 

During World War II; participating in full-body, field, or chamber experiments to test protective clothing or equipment 

Chronic forms of the diseases manifested after exposure 

Proposed rule for chronic effects of in-service exposure to mustard gas 

January 21, 1992 

Claims based on exposure to herbicides containing dioxin (peripheral neuropathy/lung cancer). Proposed rule. Federal 

Register

57(13):2236-2238. 38 CFR Part 3 

Diseases Associated with Exposure to Herbicides (containing dioxin): 

• Peripheral neuropathy 

Herbicide (containing dioxin) exposure Military service 

Military service Peripheral 

Neuropathy: Manifested not later than 10 years following the date of exposure 

Proposed rule amends diseases associated with exposure to herbicides containing dioxin Diseases NOT Associated with Exposure to Herbicides (containing dioxin): • Lung cancer 

• Porphyria 

cutanea tarda 

July 31, 1992 Claims based on 

chronic effects of exposure to mustard gas. Final rule. Federal 

Register

57(148):33875-33877. 38 CFR Part 3 

Diseases Associated with Exposure to Mustard Gas: 

• Asthma

• Bronchitis

• Conjunctivitis• Corneal opacities

• Emphysema

• Keratitis• Laryngitis

Mustard gas exposure by participating in full-body, field, or chamber experiments to test protective clothing or equipment 

During World War II; participating in full-body, field, or chamber experiments to test protective clothing or equipment 

Chronic forms of the diseases manifested after exposure 

Final rule from January 15, 1992 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-22 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information October 30, 1992 Veterans’ Radiation Exposure Amendments of 

1992. Public Law 102-578. 102d Cong., 2d Sess., Sec 2. 106 Stat. 4774 

Diseases Associated with Exposure to Radiation: 

• Cancer of the: 

Salivary gland Urinary tract 

Radiation exposure 

 Adds diseases to 

the list associated with exposure to radiation and elimination of latency-period limitations 

March 26, 1993 

Claims based on exposure to ionizing radiation. Final rule. Federal Register

58(57):16358-16359. 38 CFR Part 3 

Diseases Associated with Exposure to Radiation: 

• Ovarian cancer 

• Parathyroid adenoma 

Ionizing radiation Amends diseases 

associated with exposure to ionizing radiation 

April 27, 1993 

Radiation Exposure Compensation Act of 1990. Final Rule. Federal Register58(79):25564-25565. 38 CFR Part 3 

Diseases Associated with Exposure to Radiation: NONE

 Establishes 

compensation to any individual under the provisions of the Radiation Exposure Compensation Act of 1990 

May 19, 1993a 

Direct service connection (posttraumatic stress disorder). Final rule. Federal Register

58(95):29109-29110. 

Diseases Associated with Service: 

• Posttraumatic stress 

disorder 

Military service Stressor actually occurred in service (engaged in combat or evidence of the claimed in service 

Military service or former prisoner of war 

 Amends list of 

diseases associated with military service 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-23

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

38 CFR Part 3 stressor) or 

prisoner of war experience 

May 19, 1993b 

Republic of Vietnam. Final rule. Federal 

Register

58(95):29107-29109. 38 CFR Part 3 3.309(e) 

Diseases Associated with Service in the Republic of Vietnam: • Chloracne • Congenital and infantile 

fibrosarcoma 

• Extraskeletal Ewing’s 

sarcoma 

• Malignant ganglionar 

neuroma 

• Non-Hodgkin’s 

lymphoma 

• Soft-tissue sarcoma (see 

October 19, 1991) 

Wartime and service in the Republic of Vietnam 

On or after January 1, 1947 

Disease manifest to 10 percent or more at any time after service Exception: Chloracne (or another acneform disease): 10 percent or more within a year after the last date veteran performed active military, naval, or air service in the Republic of Vietnam 

“Service in the Republic of Vietnam” includes service in the waters offshore and service in other locations if the conditions of service involved duty or visitation in the Republic of Vietnam 

January 24, 1994 

Claims based on chronic effects of exposure to vesicant agents. Proposed rule. Federal Register

59(15):3532-3534. 38 CFR Part 3 

Diseases Associated with Exposure to Mustard Gas and Other Vesicant Agents During Military Service: 

• Asthma • Bronchitis • Cancers: 

Laryngeal Lung (except mesothelioma) Nasopharyngeal Squamous cell carcinoma of the skin 

Mustard gas and other vesicant agents Full-body exposure to nitrogen or sulfur mustard or Lewisite Active military service 

Full-Body Exposure to Nitrogen or Sulfur Mustard:Conjunctivitis, keratitis, corneal opacities, scar formation, or the following cancers: nasopharyngeal, laryngeal, lung (except mesothelioma), or 

Chronic manifestation of the diseases after military service and either fullbody exposure to nitrogen or sulfur mustard gas or Lewisite 

Amends regulation concerning chronic diseases from exposure to mustard gas and other vesicant agents in response to NAS report 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-24 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information • Conjunctivitis (chronic) • Corneal opacities • Emphysema 

• Keratitis • Laryngitis • Nonlymphocytic 

leukemia (acute) 

• Obstructive pulmonary 

disease (chronic) 

• Scar formation 

squamous cell carcinoma of the skin Full-Body Exposure to Nitrogen or Sulfur Mustard or Lewisite:Laryngitis, bronchitis, emphysema, asthma, or chronic obstructive pulmonary disease Full-Body Exposure to Nitrogen Mustard: Acute nonlymphocytic leukemia 

February 3, 1994 

Disease associated with exposure to certain herbicide agents. Final rule. Federal Register

59(23):5106-5107. 38 CFR Part 3 

Diseases Associated with Exposure to Certain Herbicide Agents: 

• Hodgkin’s disease

• Porphyria cutanea tarda

Herbicide agent exposure, specifically, 2,4-D; 2,4,5-T, and its contaminant TCDD; cacodylic acid; and picloram During active military, naval, or air service 

Republic of Vietnam; Vietnam era And wartime and service on or after January 1, 1947 

Disease manifest to 10 percent or more at any time after service Porphyria Cutanea Tarda: 10 percent or more manifested within a year after the last date veteran was exposed to an 

Amends list of diseases to other chronic, tropical, or prisoner-of-war related diseases or disease associated with exposure to certain herbicide agents; wartime and service on or after January 1, 1947 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

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F-25

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

herbicide agent during active military, naval, or air service

June 9, 1994 Disease associated 

with exposure to certain herbicide agents (multiple myeloma and respiratory cancers). Final rule. Federal 

Register

59(110):29723-29724. 38 CFR Part 3 

Diseases Associated with Exposure to Certain Herbicide Agents: 

• Multiple myeloma

• Respiratory cancers:

Bronchus Larynx Lung Trachea

Herbicide agent exposure During active military, naval, or air service 

Republic of Vietnam; Vietnam era And wartime and service on or after January 1, 1947 

Multiple Myeloma: Disease manifest to 10 percent or more at any time after service Respiratory Cancers: Within 30 years after the last date on which the veteran was exposed to an herbicide agent during active military, naval, or air service 

Amends list of diseases associated with chronic, tropical, or prisoner of war, or exposure to certain herbicide agents 

August 18, 1994 

Claims based on chronic effects of exposure to mustard gas or lewisite. Final rule. Federal 

Register

59(159):42497-42500. 38 CFR Part 3 

Diseases Associated with Chronic Effects of Exposure to Mustard Gas or Lewisite During Military Service: Nitrogen or Sulfur Mustard (38 CFR 3.316[a][1]) 

• Chronic conjunctivitis • Corneal opacities • Keratitis 

Mustard gas and other vesicant agents Active military service Full-body exposure to nitrogen or sulfur mustard or Lewisite 

Full-Body Exposure to Nitrogen or Sulfur Mustard: Conjunctivitis, keratitis, corneal opacities, scar formation, or the following cancers: nasopharyngeal, laryngeal, lung (except 

Chronic manifestation of the diseases after military service and either fullbody exposure to nitrogen or sulfur mustard gas or Lewisite 

Final rule based on NAS study and regulation on July 31, 1992, establishing service connection from exposure from field or chamber experiments during WWII 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-26 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information • Laryngeal cancer • Lung cancer (except mesothelioma) 

• Nasopharyngeal cancer • Scar formation • Squamous cell 

carcinoma of the skin 

Nitrogen or Sulfur Mustard or Lewisite (38 CFR 3.316[a][2]) • Asthma

• Chronic form of 

bronchitis

• Chronic form of 

laryngitis

• Chronic obstructive 

pulmonary disease

• Emphysema

Nitrogen Mustard (38 CFR 3.316[a][3]) • Acute nonlymphocytic 

leukemia

mesothelioma), or squamous cell carcinoma of the skin Full-Body Exposure to Nitrogen or Sulfur Mustard or Lewisite:

Laryngitis, bronchitis, emphysema, asthma, or chronic obstructive pulmonary diseaseFull-Body Exposure to Nitrogen Mustard: Acute nonlymphocytic leukemia 

September 6, 1994 

Claims based on exposure to ionizing radiation. Final rule. Federal Register 59(171):45975. 38 CFR Part 3 

Diseases Associated with Exposure to Radiation: • Tumors of the brain and 

central nervous system 

Ionizing radiation Amended 

diseases associated with exposure to ionizing radiation 

November 2, 1994 

Persian Gulf War Veterans’ Benefits Act of 1994. 

Diseases Associated with Exposure to Certain Herbicide Agents: 

Herbicide agent exposure 

Hodgkin’s Disease and Multiple 

Codified these diseases to the list of herbicide-
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-27

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

Public Law 103-446. 103d Cong., 2d. Sess. 108 Stat. 4645 

• Hodgkin’s disease • Multiple myeloma 

• Porphyria cutanea tarda 

• Respiratory cancers 

(lung, bronchus, larynx, or trachea) 

During active military, naval, or air service 

Myeloma: Mnifest to 10 percent disability or more Porphyria Cutanea Tarda: 10 percent or more manifested within a year after the last date veteran was exposed to an herbicide agent during active military, naval, or air service Respiratory Cancers: Within 30 years after the last date on which the veteran was exposed to an herbicide agent during active military, naval, or air service 

exposure presumptions 

December 8, 1994 

Compensation for certain undiagnosed illnesses. Proposed rule. Federal Register

59(235):63283-

Diseases Associated with Undiagnosed Illnesses During the Persian Gulf War: Signs or symptoms of: • Abnormal weight loss

• Cardiovascular signs or 

Active military, naval, or air service 

Southwest Asia theatre during the Persian Gulf War (Iraq, Kuwait, Saudi Arabia, neutral zone between Iraq and 

Chronic (6 months or more) disability resulting in one or more signs and symptoms and manifested either during active 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-28 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information 63285. 38 CFR Part 3 symptoms • Fatigue • Gastrointestinal signs or symptoms

• Headache• Joint pain

• Menstrual disorders• Muscle pain

• Neurologic signs or 

symptoms

• Neuropsychological 

signs or symptoms

• Signs or symptoms 

involving skin

• Signs or symptoms 

involving the respiratory system (upper or lower)

• Sleep disturbances

Saudi Arabia, Bahrain, Qatar, the United Arab Emirates, Oman, the Gulf of Aden, the Gulf of Oman, the Persian Gulf, the Arabian Sea, the Red Sea, and the airspace above these locations 

service or to a 10 percent degree or more no later than 2 years after the date the veteran last performed active service in the Southwest Asia theater of operations during the Persian Gulf War 

February 3, 1995 

Compensation for certain undiagnosed illnesses. Final rule. Federal 

Register

60(23):6660-6666. 38 CFR Part 3 

Diseases Associated with Undiagnosed Illnesses During the Persian Gulf War: Signs or symptoms of: • Abnormal weight loss • Cardiovascular signs or 

symptoms

• Fatigue

• Gastrointestinal signs or 

symptoms

• Headache• Joint pain• Menstrual disorders • Muscle pain

Active military, naval, or air service 

Southwest Asia theatre during the Persian Gulf War (Iraq, Kuwait, Saudi Arabia, neutral zone between Iraq and Saudi Arabia, Bahrain, Qatar, the United Arab Emirates, Oman, the Gulf of Aden, the Gulf of Oman, the Persian Gulf, the Arabian Sea, the Red Sea, and 

Chronic (6 months or more or intermittent episodes of improvement and worsening over a 6-month period) disability resulting in one or more signs and symptoms and manifested either during active service or to a 10 percent degree or more no later than 

Final rule for undiagnosed illnesses during service in the Persian Gulf War 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

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F-29

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

• Neurologic signs or 

symptoms

• Neuropsychological 

signs or symptoms

• Signs or symptoms 

involving skin

• Signs or symptoms 

involving the respiratory system (upper or lower)

• Sleep disturbances 

the airspace above these locations 

2 years after the date the veteran last performed active service in the Southwest Asia theater of operations during the Persian Gulf War 

October 13, 1995 

Claims based on exposure to ionizing radiation (lymphomas other than Hodgkin’s disease and cancer of the rectum). Final rule. Federal Register

60(198):53276-53277. 38 CFR Part 3 

Diseases Associated with Exposure to Ionizing Radiation: • Cancer of the rectum • Lymphomas other than 

Hodgkin’s disease 

Ionizing radiation Amends diseases 

associated with exposure to ionizing radiation 

October 9, 1996 

Veterans’ Benefits Improvements Act of 1996 Public Law 104-275. 104th Cong., 2d Sess., Sec. 505. 110 Stat. 3322 

Expansion of period of Vietnam Era for certain veterans NONE 

“Vietnam era” • For a Veteran 

who served in the Republic of Vietnam—February 28, 1961, to May 7, 1975 

• In all other 

cases—August 5, 1964, to May 7, 1975
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-30 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information November 7, 1996 Diseases associated with exposure to certain herbicide 

agents (prostate cancer and acute and subacute peripheral neuropathy). Final rule. Federal 

Register

61(217):57586-57589. 38 CFR Part 3 

Diseases Associated with Exposure to Certain Herbicide Agents: • Acute and subacute 

peripheral neuropathy 

• Prostate cancer 

Herbicide agent exposure During active military, naval, or air service 

Republic of Vietnam; Vietnam era And wartime and service on or after January 1, 1947 

Manifest to 10 percent disability or more after service Note: acute and subacute peripheral neuropathy by definition appears within weeks or months of exposure to a herbicide agent and resolves within 2 years of the date of onset

Amends list of diseases associated with exposure to certain herbicide agents 

April 29, 1997 

Compensation for certain undiagnosed illnesses. Interim rule with request for comments. Federal Register

62(82):23138-23139. 38 CFR Part 3 

Diseases Associated with Undiagnosed Illnesses: Extension of the period of disease to manifest 

Persian Gulf War service 

 Interim rule 

extending the period of disease to manifest from “two years after the date on which the veteran last performed active military, naval, or air service in the Southwest Asia theater of operations during the Persian Gulf War” to “December 31, 2001” 

Interim rule to expand the period within diseases must manifest 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-31

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

July 1, 1997 Veterans’ Benefits 

Improvements Act of 1996. Final rule. Federal 

Register

62(126):35421-35423. 38 CFR Part 3 

Vietnam era inclusion dates NONE 

 “Vietnam era” 

February 28, 1961, to May 7, 1975, inclusive for a veteran who served in the Republic of Vietnam 

March 6, 1998 

Compensation for certain undiagnosed illnesses. Final rule. Federal 

Register

63(44):11122-11123. 38 CFR Part 3 

Persian Gulf Veterans presumptive period NONE 

 Extend the 

presumptive period (to December 31, 2001) in such a manner that no Persian Gulf veterans with qualifying disabilities would be denied compensation 

Final rule for extending the presumptive period for Persian Gulf veterans 

September 24, 1998 

Claims based on exposure to ionizing radiation (prostate cancer and any other cancer). Final rule. Federal 

Register

63(185):50993-50995. 38 CFR Part 3 

Diseases Associated with Exposure to Radiation: 

• Prostate cancer 

• Any other cancer 

Ionizing radiation Amends diseases 

associated with exposure to ionizing radiation 

October 21, 1998 

Persian Gulf War Veterans Act of 1998. Public Law 

Illnesses Associated with Persian Gulf War 

Establishes service connection for illnesses 

Veteran who served on active duty in the Southwest Asia 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-32 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information 105-277. 105th Cong., 2d Sess., Sec. 1601, 1602, 1603 Language for the National Academy of Sciences report for presumption of service connection for illnesses 

associated with service in the Persian Gulf War 

associated with the Persian Gulf War Diseases having an association with exposure to a biological, chemical, or other toxic agent, environmental or wartime hazard, or preventive medicine or vaccine 

theater during the Persian Gulf War 

November 30, 1999 

Veterans Millennium Health Care and Benefits Act of 1999. Public Law 106-117. 106th Cong., 1st Sess., Sec. 503. 113 Stat. 1545 

Diseases Associated with Radiation Exposure: • Bronchiolo-alveolar 

carcinoma 

Disease contracted during military service 

July 10, 2000 Radiation 

Exposure Compensation Act Amendments of 2000. Public Law 106-245. 106th Cong., 2d Sess. 114 Stat. 501 

Diseases Associated with Radiation Exposure: Nuclear Atmospheric Testing • Brain cancer • Colon cancer • Gall bladder cancer • Male breast cancer • Ovary cancer 

Nuclear atmospheric testing Uranium mining 

Leukemia: Physically present in affected area for at least 1 year January 21, 1951, through October 31, 1958; or June 30, 1962, through July 31, 1962 

Lung Cancer: Onset of disease at least 2 years after first exposure 

Amends list of diseases associated to radiation exposure and manifestation of diseases Amends dates/location of 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-33

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

• Salivary gland cancer • Urinary bladder cancer 

Uranium Mining 

• Lung cancer • Nonmalignant 

respiratory disease 

• Renal cancers • Other chronic renal 

disease (nephritis, kidney tubal tissue injury) 

service for leukemia 

July 14, 2000 Veterans 

Millennium Health Care and Benefits Act. Final rule. Federal Register

65(136):43699-43700. 38 CFR Part 3 

Diseases Associated with Exposure to Radiation and Service: • Bronchiolo-alveolar 

carcinoma 

Active military service Radiation exposure 

 Amended list of 

diseases related to exposure to radiation and active service 

April 6, 2001 Claims based on 

the effects of tobacco products. Final rule. Federal Register

66(67):18195-18198. 38 CFR Part 3 

Diseases or Death NOT Associated with Military Service: • Disease attributable to 

use of tobacco products 

Active military, naval, or air service 

 Veterans’ use of 

tobacco products are NOT considered to be service-connected 

May 8, 2001 Disease associated 

with exposure to certain herbicide agents: Type 2 diabetes. Final 

Diseases Associated with Exposure to Herbicides: • Type 2 diabetes

Herbicide exposure 

In the Republic of Vietnam during the Vietnam Era Or active military 

Illness manifest to a degree of 10 percent or more 

Amends diseases associated to exposure to herbicides 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-34 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information rule. Federal Register 66(89):23166- 23169. 

38 CFR Part 3 

service 

August 8, 2001 

Diseases specific to radiationexposed veterans. Proposed rule. Federal Register

66(153):41483-41485. 38 CFR Part 3 

Diseases Associated with Radiation-Risk Activity: Add cancers: • Cancer of the bone • Cancer of the brain • Cancer of the colon • Cancer of the lung • Cancer of the ovary 

Radiation-risk activity Ionizing radiation Military service 

Total of at least 250 days before February 1, 1992 (Paducah, KY; Portsmouth, OH; K25 at Oak Ridge, TN) Service before January 1, 1974 (Amchitka Island, AL) and performance of duty related to Long Shot, Milrow, or Cannikin underground nuclear tests 

 Amends list of 

diseases associated with radiation-risk activities and date/location of service 

November 9, 2001 

Extension of the presumptive period for compensation for Gulf War veterans’ undiagnosed illnesses. Interim final rule with request for comments. Federal Register

Undiagnosed Illnesses: Presumptive period extension 

Persian Gulf War active military, naval, or air service 

Veteran who served on active duty in the Southwest Asia theater during the Persian Gulf War 

Undiagnosed illness manifest to a degree of 10 percent or more through December 31, 2006 

Extension of presumptive period for compensation for Gulf War Veteran’s undiagnosed illnesses
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-35

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

66(218):56614-56615. 38 CFR Part 3 

December 27, 2001 

Veterans Education and Benefits Expansion Act of 2001. Public Law 107-103. 107th Cong., 1st Sess. 

Diseases Associated with Service-Connection or Herbicide Exposure: • Diabetes mellitus (type 

2) 

• Respiratory cancers 

Diseases Associated with Persian Gulf War: 

• Chronic multisymptom 

illness: Chronic fatigue syndrome, fibromyalgia, and irritable bowel syndrome 

• Undiagnosed illness or 

chronic multisymptom illness: Abnormal weight loss, cardiovascular signs or symptoms, fatigue, gastrointestinal signs or symptoms, headache, joint pain, menstrual disorders, muscle pain, neurological signs and symptoms, neuropsychological signs or symptoms, signs or symptoms involving the upper or lower 

Herbicide exposure Military Service Vietnam Veteran active service Persian Gulf Exposure: Persian Gulf War service active military, naval, or air service 

Persian Gulf Exposure Active duty in the Armed Forces in the Southwest Asia theatre of operations during the Persian Gulf War 

Herbicide Exposure Additional diseases: Up to September 30, 2015 Respiratory cancers: Presumptive period amended from “within 30 years” through “May 7, 1975” Persian Gulf Exposure Additional diseases: “On September 30, 2011” 

Extension of presumptive period for respiratory cancers and additional diseases associated with herbicide exposure and Persian Gulf exposure Amended list of diseases associated with military service, Persian Gulf War 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-36 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information respiratory system, sleep disturbances, unexplained rashes or other dermatological 

signs or symptoms 

January 25, 2002 

Diseases specific to radiationexposed veterans. Final rule. Federal Register

67(17):3612-3616. 38 CFR Part 3 

Diseases Associated with Radiation-Risk Activity and Military Service: Add cancers: • Cancer of the bone • Cancer of the brain • Cancer of the colon • Cancer of the lung • Cancer of the ovary 

Ionizing radiation Military service Radiation-risk activity definition: Participation in a test involving atmospheric detonation of a nuclear device; occupation of Hiroshima or Nagasaki, Japan (August 6, 1945, to July 1, 1946); or internment as a prisoner of war in Japan or service on active duty in Japan following such internment during WWII with opportunity for exposure to ionizing radiation 

Total of at least 250 days before February 1, 1992 (Paducah, KY; Portsmouth, OH; K25 at Oak Ridge, TN) Service before January 1, 1974 (Amchitka Island, AL) and performance of duty related to Long Shot, Milrow, or Cannikin underground nuclear tests 

Amends diseases associated with radiation-risk activity and military service Amends definition of radiation-risk activity 

February 14, 2002 

Claims based on exposure to 

Diseases Associated with Exposure to Radiation: 

Radiation exposure 

 Amends diseases 

from exposure to 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-37

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

ionizing radiation. Final rule. Federal Register67(31):6870-6871. 38 CFR Part 3 

• Polycythemia vera Ionizing radiation ionizing radiation; 

VA did not have evidence to add to the list of “radiogenic diseases,” but the VA will consider a claim that polycythemia vera is a radiogenic disease as long as there is scientific or medical evidence to support the claim 

November 7, 2002 

Service connection by presumption of aggravation of a chronic preexisting disease. Final rule. Federal 

Register 67(216):67792-67793. 38 CFR Part 3 

Preexisting chronic disease Military service Amended 

presumption of a preexisting disease that was aggravated by veteran’s military service 

December 27, 2002 

Extension of the presumptive period for compensation for Gulf War veterans’ 

Undiagnosed illnesses associated with Persian Gulf War NONE 

 Southwest Asia 

theater of operations during the Persian Gulf War 

Through December 31, 2006 

Extends the period within which disabilities must become manifest for entitlement for 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-38 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information undiagnosed illnesses. Final rule. Federal Register

67(249):78979-78980. 38 CFR Part 3 

compensation 

February 10, 2003 

Presumption of service connection for cirrhosis of the liver in former prisoners of war. Proposed rule.Federal Register 68(27):6679-6680. 38 CFR Part 3 

Diseases Associated with Prisoners of War: 

• Cirrhosis of the liver 

Former prisoners of war Evidence: Significantly higher risk of death from cirrhosis in former WWII POWs than the general population 

 Detained for at 

least 30 days 

Amended list of diseases associated with prisoners of war 

June 10, 2003 

Compensation and pension provisions of the Veterans Education and Benefits Expansion Act of 2001. Final Rule. Federal Register

68(111):34539-34543. 38 CFR Parts 3 and 13 

Diseases Associated with the Persian Gulf Veterans: • Undiagnosed illness• Chronic multisymptom 

illness:Chronic fatigue syndrome, fibromyalgia, irritable bowel syndrome 

Herbicide Exposure: Amends date of presumption and exposure candidates 

 Amends what a 

“qualifying chronic disability” includes Herbicide Exposure: Eliminates respiratory cancer must manifest within 30 years of departure form Vietnam to qualify for presumption 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-39

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information based on herbicide exposure and expand presumption of exposure to herbicides to all Vietnam veterans 

July 18, 2003 Presumption of 

service connection for cirrhosis of the liver in former prisoners of war. Final rule. Federal Register

68(138):42602-42603. 38 CFR Part 3 

Diseases Associated with Former Prisoners of War: • Cirrhosis of the liver 

Former prisoners of war 

Amends list of diseases associated with former prisoners of war 

October 16, 2003 

Disease associated with exposure to certain herbicide agents: Chronic lymphocytic leukemia. Final rule. Federal 

Register

68(200):59540-59542. 38 CFR Part 3 

Disease Associated with Exposure to Herbicide: • Chronic lymphocytic 

leukemia

Herbicide exposure Military service 

Republic of Vietnam during the Vietnam era 

 Amends list of 

diseases associated with exposure to herbicide agents 

October 21, 2003 

Veterans Benefits Enhancement Act of 2003 S. Rep. No. 108-169. 108th Cong. 

Diseases Associated with Former Prisoners of War: • Any of the anxiety states • *Any other nutritional 

deficiency 

Former prisoners of war veteran active military, naval, or air service 

Former prisoner of war 

Disease to manifest to a degree of 10 percent or more after active service

Proposed Act that would amend the diseases associated with former prisoners 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-40 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information 1st Sess. 11 (proposed Act) • *Avitaminosis • *Beriberi (including beriberi heart disease) 

• *Chronic dysentery • *Cirrhosis of the liver • Dysthymic disorder (or 

depressive neurosis) 

• *Helminthiasis • *Irritable bowel 

syndrome 

• *Malnutrition (including 

optic atrophy associated with malnutrition) 

• Organic residuals of 

frostbite 

• *Pellagra • *Peptic ulcer disease • *Peripheral neuropathy 

(except where directly related to infectious causes) 

• Posttraumatic 

osteoarthritis 

• Psychosis 

*Detained or interned for not less than 30 days 

of war 

December 16, 2003 

Veterans Benefits Act of 2003. Public Law 108-183. 108th Cong., 1st Sess., Sec. 201. 117 Stat. 2651 

Diseases Associated with Former Prisoners of War: • Any of the anxiety states • *Any other nutritional 

deficiency 

• *Avitaminosis • *Beriberi (including 

beriberi heart disease) 

Former prisoners of war veteran active military, naval, or air service 

Former prisoner of war 

Disease to manifest to a degree of 10 percent or more after active service *Detained or interned for not less than 30 days 

Final act amending list of diseases associated with former prisoners of war 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

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F-41

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

• *Chronic dysentery • *Cirrhosis of the liver • Dysthymic disorder (or 

depressive neurosis) 

• *Helminthiasis • *Irritable bowel 

syndrome 

• *Malnutrition (including 

optic atrophy associated with malnutrition) 

• Organic residuals of 

frostbite 

• *Pellagra • *Peptic ulcer disease • *Peripheral neuropathy 

(except where directly related to infectious causes) 

• Posttraumatic 

osteoarthritis 

• Psychosis 

June 8, 2004 Change of effecttive date of rule 

adding a disease associated with exposure to certain herbicide agents: Type 2 diabetes. Final rule. Federal 

Register 69(110): 

31882-31883. 38 CFR Part 3 

Disease Associated with Exposure to Certain Herbicides: • Type 2 diabetes 

Change of effective date of presumption to May 8, 2001 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-42 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information October 7, 2004 Presumptions of service connection for diseases associated with 

service involving detention or internment as a prisoner of war. Interim final rule. Federal Register

69(194):60083-60090. 38 CFR Parts 1 and 3 

Diseases Associated with Former Prisoner of War: • Atherosclerotic disease 

or hypertensive vascular disease (including hypertensive heart disease) and their complications (including myocardial infarction, congestive heart failure, arrhythmia) 

• Stroke and its 

complications

Former prisoner of war 

 Eliminated the 30-

day detained requirement for psychosis, any anxiety state, dysthymic disorders, organic residuals of frostbite, and posttraumatic osteoarthritis The new diseases in this rule are presumed to be service connected following any period of prisoner of war activity 

Amended diseases associated with former prisoner of war and amended the 30-day requirement for some of the related diseases Defines the evidence necessary to determine presumption of service connection 

December 10, 2004 

Veterans Benefits Improvement Act of 2004. Public Law 108-454. 108th Cong., 2d Sess., Sec. 306. 118 Stat 3598 

Diseases Associated with Radiation-Risk Activity and Military Service: Add cancers: • Cancer of the bone • Cancer of the brain • Cancer of the colon • Cancer of the lung • Cancer of the ovary 

Radiation-risk activity Ionizing Military service 

Amended “radiation-risk activity” to include service in a capacity if performed as an employee of the Department of Energy (DOE) would qualify inclusion as a member of the Special Exposure Cohort 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-43

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

June 20, 2005 

Prisoner of War Benefits Act of 2005. 109th Cong., 1st Sess. Senate Bill 1271 (proposed act)

Diseases Associated with Former Prisoners of War: 

• Diabetes (type 2)

• Heart disease

• Osteoporosis

• Stroke

Former prisoners of war 

 Proposed act to 

amend the list of diseases associated with former prisoners of war 

June 28, 2005 

Presumptions of service connection for diseases associated with service involving detention or internment as a prisoner of war. Affirmation of interim final rule as final rule. Federal Register

70(123):37040-37042. 38 CFR Parts 1 and 3 

Diseases Associated with Former Prisoners of War: 

• Atherosclerotic disease 

or hypertensive heart disease (including hypertensive vascular disease) and their complications (including myocardial infarction, congestive heart failure, arrhythmia) 

• Stroke and its 

complications 

 Final rule without 

change from October 7, 2004, interim rule 

December 18, 2006 

Extension of the presumptive period for compensation for Gulf War veterans. Interim final rule. Federal 

Register

7(242):75669-75672. 38 CFR Part 3 

Undiagnosed illnesses associated with Persian Gulf War 

NONE 

 Southwest Asia 

theater of operations during the Persian Gulf War 

Through December 31, 2011 

Extends the period within which disabilities must become manifest for entitlement for compensation 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-44 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information U.S. Code Title 38. Veterans’ Benefits 

Part II. General Benefits. Title 42. The Public Health and Welfare Chapter 23. 

Approved February 27, 2006 

38 USC § 101 NONE 

Definitions: Veteran Spanish-American War World War I World War II Korean conflict Armed Forces Veteran of any war Service-connected Non-service-connected Active duty Active duty for training Inactive duty training Active military, naval, or air 

service 

Former prisoner of war Reserve Vietnam era Persian Gulf war 

Approved February 27, 2006 

38 USC § 108 Death 7-year absence 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-45

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

Approved February 27, 2006 

38 USC § 501 NONE 

Secretary has authority to prescribe rules and regulations to carry out laws administered by the VA 

Approved February 27, 2006 

38 USC § 1110 Entitlement to compensation 

for disability resulting from diseases contracted in line of duty in the active military, naval, or air service, during a period of war 

Approved February 27, 2006 

38 USC § 1111 Presumption of sound 

condition at the time of examination, acceptance, and enrollment into service 

Approved February 27, 2006 

38 USC § 1112 Presumptions Relating to 

Certain Diseases and Disabilities: • Chronic disease • Tropical disease • Tuberculous (active) • Multiple sclerosis • Hansen’s disease • Prisoner of war-related 

diseases Any of the anxiety states, *any other nutritional deficiency, *avitaminosis, *beriberi (including beriberi heart disease), *chronic dysentery, *cirrhosis of the liver, *helminthiasis, *irritable bowel 

Active military service Tropical Disease: Disorders or disease originating because of therapy, administered in connection with such disease, or as a preventative RadiationExposed Veteran: Radiation risk activity 

Veteran who served for 90 days or more during a period of war *Prisoner of War Associated Diseases: Not less than 30 days as a prisoner of war RadiationExposed Veteran: 

Participation in a test involving atmospheric detonation of a nuclear device; occupation of 

Chronic Disease: Disease manifest to 10 percent or more within 1 year from separation of such service Tropical Disease: Disease manifest to 10 percent or more within 1 year from separation of such service Or Standard or accepted incubation periods 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-46 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information syndrome,*malnutrition, organic residuals of frostbite, *pellagra, *peptic ulcer disease, 

*peripheral neuropathy dysthymic disorder (or depressive neurosis), posttraumatic osteoarthritis, psychosis 

• Radiation-Exposed 

Veteran-Related Diseases: Bronchiolo-alveolar carcinoma; cancer: bile ducts, bone, brain, breast, colon, esophagus, gall bladder, lung, ovary, pancreas, pharynx, primary liver, salivary gland, small intestine, stomach, thyroid, urinary tract; leukemia; lymphomas (except Hodgkin’s disease); multiple myeloma 

Hiroshima or Nagasaki, Japan (August 6, 1945, to July 1, 1946); 

internment as a prisoner of war in Japan or service on active duty in Japan following such internment during WWII with opportunity for exposure to ionizing radiation; Or Performed as an employee of the DOE 

Tuberculous Disease (active) and Hansen’s Disease: Disease manifest to 10 percent or more within 3 years from separation of such service Multiple Sclerosis: Disease 

manifest to 10 percent or more within 7 years from separation of such service Prisoner of War: Disease manifest to 10 percent or more after active military, naval, or air service RadiationExposed Veterans: Disease manifest after active military, naval, or air service 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-47

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

Approved February 27, 2006 

38 USC § 1116 Presumptions of service 

connection for diseases associated with exposure to certain herbicide agents Presumption of exposure for veterans who served in the

Republic of Vietnam • Chloracne • Diabetes mellitus 

(type 2) 

• Hodgkin’s disease • Multiple myeloma • Non-Hodgkin’s 

lymphoma 

• Porphyria cutanea tarda • Respiratory cancers 

(bronchus, larynx, lung, or trachea) 

• Soft tissue sarcoma 

Active military naval, or air service Herbicide agent (containing dioxin or 2,4-dichlorophenoxyacetic acid) 

Republic of Vietnam (January 9, 1962, to May 7, 1975) 

Republic of Vietnam Diseases: Manifest disease 10 percent disability or more, except for diabetes mellitus In addition: Porphyria cutanea tarda and chloracne:within 1 year from active military service 

Approved February 27, 2006 

38 USC § 1117 Compensation for disabilities 

occurring in the Persian Gulf War:• Undiagnosed illness 

(abnormal weight loss; cardiovascular signs or symptoms; fatigue; gastrointestinal signs or symptoms; headache; joint pain; menstrual disorders; muscle pain; neurological signs and symptoms; neuropsychological signs 

Active duty in the Armed Forces during the Persian Gulf War 

Southwest Asia theater during the Persian Gulf War 

Medical or scientific evidence and historical treatment of manifestation periods that have been established 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-48 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information or symptoms; signs or symptoms involving the upper or lower respiratory system; sleep 

disturbances; unexplained rashes or other dermatological signs or symptoms) 

• Chronic multisymptom 

illness (chronic fatigue syndrome; fibromyalgia; irritable bowel syndrome) 

Approved February 27, 2006 

38 USC § 1118 Presumptions of service 

connection for illness associated with service in the Persian Gulf War 

(see 38 USC § 1117 for diseases) 

Association with exposure to a biological, chemical, or other toxic agent, environmental or wartime hazard, or preventive medicine or vaccine 

Service in the Armed Forces in the Southwest Asia theater of operations during the Persian Gulf War 

Within a period (if any) that is prescribed in a regulation 

Approved February 27, 2006 

38 USC § 1153 Aggravation to a preexisting 

injury or disease 

Increase in disability during active military, naval, or air service, unless the increase is due to the natural progress of the disease 

Approved February 27, 

38 USC § 1521 Veteran’s service 

requirements for nonActive military, naval, or air Service requirements: 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-49

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

2006 service-connected disability service • 90 days or more 

during a period of war 

• Period of war 

and was discharged or released for a serviceconnected disability 

• 90 consecutive 

days or more and began or ended during a period of war 

• Aggregate of 90 

days or more in two or more separate periods of service during more than one period of war 

Code of Federal Regulations

 38 CFR 1.18 Guidelines for establishing 

presumptions of service connection for former prisoners of war 

Former prisoners of war 

 May give a 

minimum duration of detention or internment for application of the presumption Defines “evidence” 

Secretary may establish a presumption of service connection for a disease when there is at least limited/suggestive evidence that an increased risk of 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-50 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information such disease is associated with service involving detention or 

internment as a prisoner of war and an association between the two is biologically plausible 

 38 CFR 3.307 Presumptive service 

connection for chronic, tropical, or prisoner-of-war related disease or disease associated with exposure to certain herbicide agents 

Former prisoners of war Herbicide agent exposure (specifically 2,4, D; 2,4,5-T and its contaminant TCDD; cacodylic acid; and picloram) Military service 

Herbicide Agent Exposure: Republic of Vietnam (January 9, 1962, to May 7, 1975) active military, naval, or air service (including the waters off-shore and service in other locations involving duty or visitation in the Republic of Vietnam 

Wartime and service on or after January 1, 1947 90 days or more during a war period or after December 31, 1946 Chronic: manifest to degree of 10 percent or more within 1 year (for Hansen’s disease; and tuberculosis within 3 years; multiple sclerosis within 7 years) from separation of service Tropical: Manifest to a 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-51

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

degree of 10 percent or more within 1 year from separation of service or time when standard accepted treatises indicate incubation period; diseases resulting from therapy administered Former Prisoners of War: Manifest to a degree of 10 percent or more after discharge or release for active service Herbicide Agent Exposure: Manifest to a degree of 10 percent or more at any time after service except chloracne, porphyria cutanea tarda, and acute and subacute peripheral neuropathy 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-52 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information manifest to a degree of 10 percent or more within 1 year after 

last date veteran was exposed to an herbicide agent 

 38 CFR 3.309 Disease subject to 

presumptive service connection • Chronic Diseases: 

Anemia, primary; arteriosclerosis; arthritis; atrophy, progressive muscular; brain hemorrhage; brain thrombosis; bronchiectasis; calculi of the kidney, bladder, or gallbladder; cardiovascular-renal disease, including hypertension; cirrhosis of the liver; coccidioidomycosis; diabetes mellitus; encephalitis lethargica residuals; endocarditis; endocrinopathies; epilepsies; Hansen’s disease; Hodgkin’s disease; leukemia; lupus erythematosus, systemic; myasthenia gravis; 

Military Service Former Prisoner of War RadiationExposed Veteran: Serving active duty or Armed Forces active duty or training or inactive duty training and participated in a “radiation-risk activity” 

Chronic Diseases: On or after January 1, 1947, following service in a period of war or peacetime service RadiationExposed Veteran: • Participation in 

test atmospheric detonation of nuclear device 

• Occupation of 

Hiroshima or Nagasaki, Japan (August 6, 1945, to July 1, 1946) 

• Prisoner of war 

in Japan exposure of ionizing radiation comparable to above exposure 

Chronic Diseases: see section 3.307 above Tropical Diseases: See section 3.307 above RadiationExposed Veteran: See section 3.307 above Exposure to Herbicide agents: See section 3.307 above Former Prisoner of War: Manifest to a degree of 10 percent or more after release or discharge from active military, 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-53

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

myelitis; myocarditis; nephritis; osteitis deformans (Paget’s disease); osteomalacia; other organic diseases of the nervous system; palsy, bulbar; paralysis agitans; psychoses; purpura idiopathic, hemorrhagic; Raynaud’s disease; sarcoidosis; scleroderma; sclerosis, amyotrophic lateral; sclerosis, multiple; syringomyelia; thromboangiitis obliterans (Buerger’s disease); tuberculosis, active; tumors, malignant; ulcers, peptic (gastric or duodenal) 

• Tropical Diseases: 

Amebiasis; backwater fever; cholera; dracontiasis; dysentery; filariasis; leishmaniasis, including kala-azar; loiasis; malaria; onchocerciasis; oroya fever; pinta; plague; schistosomiasis; yaws; yellow fever 

• Prisoners of War:

Any of the anxiety 

• Total of 250 

days before February 1, 1992, on grounds of gaseous diffusion plant (Paducah, KY; Portsmouth OH; K25 Oak Ridge, TN) 

• Service before 

January 1, 1974, on Amchitka Island, AL, and exposed to underground nuclear tests at Long Shot, Milrow, or Cannikin 

naval, or air service *Indicate only for veteran that was detained or interned for not less than 30 days 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-54 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information states; *any other nutritional deficiency; *avitaminosis; *beriberi (including beriberi heart 

disease; *chronic dysentery; *cirrhosis of the liver; dysthymic disorder (or depressive neurosis); *helminthiasis; *irritable bowel syndrome; *malnutrition; organic residuals of frostbite; *pellagra; *peptic ulcer disease; *peripheral neuropathy atherosclerotic heart disease or hypertensive vascular disease; posttraumatic osteoarthritis; psychosis; stroke and its complications 

• Radiation-Exposed 

Veterans:Bronchiolo-alveolar carcinoma; cancer of the bile ducts, bone, brain, breast, colon, esophagus, gall bladder, lung, ovary, pancreas, pharynx, salivary gland, small intestine, stomach, thyroid, urinary tract; 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-55

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

leukemia; lymphomas; multiple myeloma; primary liver cancer 

• Exposure to Certain 

Herbicide Agents:Acute and subacute peripheral neuropathy; chloracne or other acneform disease; chronic lymphocytic leukemia; Hodgkin’s disease; multiple myeloma; nonHodgkin’s lymphoma; porphyria cutanea tarda; prostate cancer; respiratory cancers (lung, bronchus, larynx, or trachea); soft tissue sarcoma (adult fibrosarcoma; dermatofibrosarcoma protuberans; malignant fibrous histocytoma; liposarcoma; leiomyosarcoma; epithelioid leiomyosarcoma; rhabdomyosarcoma; ectomesenchymoma; angiosarcoma; proliferating angioendotheliomatosis; malignant glomus tumor; 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-56 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information malignant hemangiopericytoma; synovial sarcoma; malignant giant cell 

tumor of tendon sheath; malignant schwannoma; malignant mesenchymoma; malignant granular cell tumor; alveolar soft part sarcoma; epithelioid sarcoma; clear cell sarcoma of tendons and aponeuroses; extraskeletal Ewing’s sarcoma; congenital and infantile fibrosarcoma; malignant ganglionar neuroma); type 2 diabetes 

 38 CFR 3.310 Secondary condition 

established as service connection of the original condition • Cardiovascular disease 

for service-connected amputation 

Service-connected amputation of one lower extremity at or above the knee or serviceconnected amputations of both lower extremities at or above the ankles 

 38 CFR 3.311 Claims based on exposure to 

ionizing radiation: 

Cancer of the breast, bone, colon, esophageal, 

Ionizing radiation Service 

Occupation of Hiroshima or Nagasaki, Japan (September 1945 to 

Manifest 5 years or more after exposure 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-57

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

kidney, liver, lung, ovarian, pancreatic, prostate, rectum, salivary gland, skin, stomach, thyroid, urinary bladder; any other cancer; leukemia; lymphomas; multiple myeloma; nonmalignant thyroid nodular disease; parathyroid adenoma; posterior subcapsular cataracts; tumors of the brain and central nervous system 

July 1946) or other activities where they participated in atmospheric testing of nuclear weapons 

Bone Cancer: Manifest within 30 years after exposure Leukemia:Manifest any time after exposure Posterior Subcapsular Cataracts: Manifest 6 months or more after exposure 

 38 CFR 3.313 Service in Vietnam 

• Non-Hodgkin’s 

lymphoma 

Service in Vietnam 

Service in Vietnam during the Vietnam Era 

Subsequent to service 

 38 CFR 3.316 Claims based on chronic 

effects of exposure to mustard gas • Nitrogen or Sulfur 

Mustard: Cancers: lung (except mesothelioma), nasopharyngeal, laryngeal, squamous cell carcinoma of the skin; chronic conjunctivitis; corneal opacities; keratitis; scar formation 

• Nitrogen or Sulfur 

Mustard or Lewisite:Chronic form of asthma, 

Exposure to nitrogen or sulfur mustard or Lewisite 

Active military service 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-58 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Date Legislation or Regulation Presumptive Disease Etiology of Disease Location/Date of Service Presumptive Period Additional Information bronchitis, emphysema, laryngitis, chronic obstructive pulmonary disease 

• Nitrogen Mustard:

Acute nonlymphocytic leukemia 

 38 CFR 3.317 Compensation for certain 

disabilities due to undiagnosed illnessesduring Persian Gulf War • Undiagnosed illness • Medically unexplained 

chronic multisymptom illnesses defined by a cluster of signs or symptoms: chronic fatigue syndrome; fibromyalgia; irritable bowel syndrome 

• Signs or symptoms 

which may be manifestations of undiagnosed illness or medially unexplained chronic multisymptom illness: abnormal weight loss; cardiovascular signs or symptoms; fatigue; gastrointestinal signs or symptoms; headache; joint pain; menstrual disorders; muscle pain; 

Southwest Asia Theater during the Persian Gulf War Southwest Asia Theater includes Iraq, Kuwait, Saudi Arabia, neutral zone between Iraq and Saudi Arabia, Bahrain, Qatar, United Arab Emirates, Oman, Gulf of Aden, Gulf of Oman, Persian Gulf, Arabian Sea, Red Sea, and air space above these locations) 

Manifest either during active military, naval, or air service or to a degree of 10 percent or more not later than December 31, 2006 

Chronic disabilities for a period of 6 months or more or intermittent episodes of improvement and worsening over a 6-month period 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-59

Date 

Legislation or Regulation Presumptive Disease 

Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

neurological signs and symptoms; neuropsychological signs or symptoms; signs or symptoms involving skin; signs or symptoms involving the respiratory system (upper and lower); sleep disturbances 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-60 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS TABLE F-2 Summary of PDDM Legislative History (by Health Outcome) Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Chronic Constitutional Diseases Internal Memorandum 

implementing Veterans’ Bureau Regulation No. 11

November 12, 1921 

Chronic constitutional disease contracted during active military service 

Within 1 year after the date of separation from service 

November 12, 1921, stated connection to active military service 

• Anemia (primary) • Arteriosclerosis 

• Beriberi • Diabetes insipidus • Diabetes mellitus 

• Endocrinopathies • Gout • Haemochromatosis 

• Hemoglobinuria 

(paroxysmal) 

• Hemophilia • Hodgkin’s disease 

• Leukemia (all types) • Ochronosis • Pellagra 

• Polycythemia 

(Erythremia) 

• Purpura • Rickets 

• Scurvy 

Office Memorandum No. 36

December 2, 1921 

Constitutional diseases were defined on December 2, 1921

• Arthritis (deformans 

and chronic) 

• Carcinoma, sarcoma, 

and other tumors 

• Cardiovascular-renal 

disease, including hypertension 

• Endocarditis, chronic • Leprosy (tropical 

disease added as a chronic disease)

Veterans’ Bureau Schedule for Rating Disabilities (based upon the WW Veterans Act, 1924) 

1925 Disease contracted 

during military or naval services in World War I

During World War I

Characteristic manifestation within 1 year from date of separation from active service Or If medical evidence affirmatively 

Amends list of constitutional diseases
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-61 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information • Myocarditis, chronic • Nephritis, chronic forms 

(was not carried 

forward, 

• cholecystitis, chronic, 

proceeding to gallstone formation 

• nephrolithiasis • valvulitis, chronic)

establishes conclusive service connection after 1 year of separation

Chronic Diseases• Dysentery (amoebic) • Encephalitis 

lethargica 

• Paralysis agitans • Psychoses (originally 

called neuropsychiatric disease) 

• Tuberculous (active) 

World War Veterans’ Act, 1924. Public Law 68-242. 68th Cong., 1st Sess. Title II. Compensation and Treatment Ch. 320, Sec. 200, 43 Stat. 607, 615

June 7, 1924 Disease contracted 

during active military or naval service 

Between April 6, 1917, and July 2, 1921 Or Discharged or resigned prior to July 2, 1921 Or Discharged or resigned on or before November 11, 1918, or on or after July 2, 1921

By January 1, 1925 Characteristic manifestations of the disease to 10 percent or more

• Anemia (primary) • Arteriosclerosis 

• Arthritis • Cardiovascular-renal 

disease (including hypertension) 

• Diabetes mellitus 

Executive Order 6089. Instruction No. 2, Implementing Vet. Reg. No. 1. April 12, 1933 

April 12, 1933

Amends list of chronic diseases and presumption of tuberculosis
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-62 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information • Encephalitis lethargica • Endocarditis 

• Endocrinopathies • Epilepsies • Hodgkin’s disease 

• Leukemia • Myocarditis • Nephritis 

• Organic diseases of 

the nervous system 

• Tumors, malignant, 

or of the brain 

• Bronchiectasis • Calculi of the kidney, 

bladder, or gall bladder 

• Cirrhosis of the liver • Coccidioidomycosis • Osteitis (deformans) 

(also called Paget’s disease) 

• Osteomalacia • Raynaud’s disease • Scleroderma 

• Thromboangiitis 

obliterans (Buerger’s disease) 

Act of June 24, 1948. Public Law 80-748. 80th Cong., 2d Sess. 

Ch. 612, Sec 1, 62 Stat. 581. 

June 24, 1948

Disease contracted during active service 

At least 6 months of service and honorably discharged Within 1 year after separation from active service or at a time when standard and accepted treatises indicate that the incubation period thereof commenced during active service

• Atrophy, progressive 

muscular 

• Brain hemorrhage 

Pensions, bonuses, and veterans’ relief. 

February 9, 1949

Disease contracted during military service 

Wartime service prior to January 1, 1947, to July 25, 

Within 1 year after separation from active 

Factual Basis:Established by medical evidence, 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-63 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information • Brain thrombosis • Myasthenia gravis • Myelitis 

• Palsy, bulbar • Paralysis agitans 

• Sclerosis 

(amyotrophic lateral, multiple) 

• Syringomyelia 

Part 3: Veterans’ claims; miscellaneous amendments. Federal Register14(26):568-578. Former 39 CFR Sec. 3.80; Sec. 3.86 (a), 3.95

1947 wartime service 

Within 1 year after the date prior to which a disability must have been incurred Chronic disease:Manifestations sufficient to identify the disease entity and sufficient observations to establish chronicity at the time

competent lay evidence, or both 

• Sarcoidosis Veterans’ 

Benefits Act of 1957. Public Law 85-56. Sec. 301. 85th Cong., 1st Sess. Sec 301(3 and 4). 71 Stat. 83, 95.

June 17, 1957

Disease contracted during active military, naval, or air service 

Veteran who engaged in combat with the enemy in active service with a military, naval, or air organization of the U.S. during a period of war, campaign, or expedition Period of service after November 11, 1918, and 

Within 1 year after separation from active service or when standard and accepted treatises indicate incubation period 

Summarizes previous rules and legislation and amends dates/location of service and presumption
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-64 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information before July 2, 1921, if served after April 5, 1917, and before 

November 12, 1918 Period after December 31, 1946, and before July 26, 1947, if period began before January 1, 1947

Disease subject to presumptive service connection. Federal Register26(36):1581-1582. 

February 24, 1961

Disease contracted during active military, naval, or air service

Lays out criteria for presumption wartime service connection for chronic or tropical disease Factual Basis: May be established by medical evidence, competent lay evidence, or both

Pensions, bonuses, and veterans’ relief. Part 3: Adjudication. Subpart A: Pension, compensation, 

December 1, 1970

Active service Service of 90 

days or more during a war period on or after January 31, 1955 

Chronic Diseases: Manifest to a degree of 10 percent or more within 1 year for Hansen’s disease (leprosy) and 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-65 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information and dependency and indemnity compensation. Federal Register

35(232):18280-18283. 38 CFR Part 3

tuberculosis within 3 years; multiple sclerosis within 7 years from date of separation from service

Increase of disability compensation and dependency and indemnity compensation rates. Federal Register39(188):34529-34533. 38 CFR Part 3

September 26, 1974

No new ones Active service on 

or after January 1, 1947 Chronic Before January 1, 1947: No presumption 

Service of 90 days or more during a war period on or after December 31, 1946 

38 CFR 3.307 Former prisoners of 

war Military service 

Wartime and service on or after January 1, 1947 90 days or more during a war period or after December 31, 1946 Chronic: manifest to degree of 10 percent or more within 1 year (for Hansen’s disease; 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-66 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information and tuberculosis within 3 years; multiple sclerosis within 7 years) 

from separation of service

38 CFR 3.309 Military service Chronic 

Diseases: On or after January 1, 1947, following service in a period of war or peacetime service

Chronic Diseases: See section 3.307 above 

Executive Order 6089. Instruction No. 2, Implementing Vet. Reg. No. 1. April 12, 1933 

April 12, 1933 

Amends list of chronic diseases and presumption of tuberculosis 

Leprosy (also called Hansen’s disease)

Pensions, bonuses, and veterans’ relief. Part 3: Veterans’ claims; miscellaneous amendments. Federal Register14(26):568-578. Former 39 CFR Sec. 3.80; Sec. 3.86 (a), 3.95 

February 9, 1949 

Disease contracted during military service 

Wartime service prior to January 1, 1947, to July 25, 1947 

Within 1 year after separation from active wartime service Within 1 year after the date prior to which a disability must have been incurred Chronic Disease:Manifestations 

Factual Basis:Established by medical evidence, competent lay evidence, or both 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-67 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information sufficient to identify the disease entity and sufficient 

observations to establish chronicity at the time 

Veterans’ Benefits Act of 1957. Public Law 85-56. Sec. 301. 85th Cong., 1st Sess. Sec 301(3 and 4). 71 Stat. 83, 95 

June 17, 1957 

Disease contracted during active military, naval, or air service 

Veteran who engaged in combat with the enemy in active service with a military, naval, or air organization of the U.S. during a period of war, campaign, or expedition Period of service after November 11, 1918, and before July 2, 1921, if served after April 5, 1917, and before November 12, 1918 Period after December 31, 1946, and before July 26, 1947, if 

Within 1 year after separation from active service or when standard and accepted treatises indicate incubation period 

Summarizes previous rules and legislation and amends dates/location of service and presumption 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-68 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information period began before January 1, 1947 Disease subject to 

presumptive service connection. Federal Register26(36):1581-1582 

February 24, 1961 

Disease contracted during active military, naval, or air service 

Lays out criteria for 

presumption wartime service connection for chronic or tropical disease Factual Basis: May be established by medical evidence, competent lay evidence or both 

Pensions, bonuses, and veterans’ relief. Part 3: Adjudication. Subpart A: Pension, compensation, and dependency and indemnity compensation. Federal Register35(232):18280-18283. 38 CFR Part 3 

December 1, 1970 

Active service Service of 90 

days or more during a war period on or after January 31, 1955 

Chronic Diseases: Manifest to a degree of 10 percent or more within 1 year for Hansen’s disease (leprosy) and tuberculosis within 3 years; multiple sclerosis within 7 years from date of separation from service 

Increased disability compensation and dependency and 

December 23, 1976 

Chronic Diseases: Following service in a period of war 

Used term Hansen’s disease instead of leprosy 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-69 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information indemnity compensation; burial benefits. Federal Register

41(248):55872-55875. 38 CFR Part 3 

or following peacetime service on or after January 1, 1947 

38 CFR 3.307 Former prisoners of 

war Military service 

 Wartime and 

service on or after January 1, 1947 90 days or more during a war period or after December 31, 1946 Chronic: Manifest to degree of 10 percent or more within 1 year (for Hansen’s disease; and tuberculosis within 3 years; multiple sclerosis within 7 years) from separation of service 

38 CFR 3.309 Military 

service 

Chronic Diseases: On or after January 1, 1947, following service in a period of 

Chronic Diseases: See section 3.307 above 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-70 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information war or peacetime service 38 USC § 1112 Approved February 27, 

2006 

Active military service 

Veteran who served for 90 days or more during a period of war 

Chronic Disease: Disease manifest to 10 percent or more within 1 year from separation of such service Tuberculous Disease (active) and Hansen’s Disease: Disease manifest to 10 percent or more within 3 years from separation of such service 

Lupus erythematosus (systemic) 

Veterans’ Benefits and Services Act of 1988. Public Law 100-322. 100th Cong., 2d Sess. Sec 312, 313. 102 Stat. 487, 535 

May 20, 1988 

Chronic disease contracted during military service 

Amended list of diseases related to service connection of chronic diseases 

Osteitis (deformans) (also called Paget’s disease) 

Executive Order 6089. Instruction No. 2-A, Implementing Vet. Reg. No. 1. August 14, 1935 

August 14, 1935 

Amends list of chronic diseases 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-71 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Veterans’ Bureau. Public Law 67-47. 1921. 67th Cong., 1st 

Sess. Ch. 57, Sec. 18, 42 Stat. 147, 153 

August 9, 1921 

Disease contracted during active military service 

On or after April 6, 1917 Or Discharged or resigned active service on or before November 11, 1918 

Within 2 years after separation from active military or naval service Characteristic manifestations of the disease to 10 percent or more 

Executive Order 6089. Instruction No. 2, Implementing Vet. Reg. No. 1. April 12, 1933 

April 12, 1933 

 Amends list of 

chronic diseases and presumption of tuberculosis 

Psychoses (originally called neuropsychiatric disease) 

Pensions, bonuses, and veterans’ relief. Part 3: Veterans’ claims; miscellaneous amendments. Federal Register

14(26):568-578. Former 39 CFR Sec. 3.80; Sec. 3.86 (a), 3.95 

February 9, 1949 

Disease contracted during military service 

Wartime service prior to January 1, 1947, to July 25, 1947 

Within 1 year after separation from active wartime service Within 1 year after the date prior to which a disability must have been incurred Chronic Disease:Manifestations sufficient to identify the disease entity and sufficient 

Factual Basis:Established by medical evidence, competent lay evidence, or both 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-72 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information observations to establish chronicity at the time 

Veterans’ Benefits Act of 1957. Public Law 85-56. Sec. 301. 85th Cong., 1st Sess. Sec 301 (3 and 4). 71 Stat. 83, 95 

June 17, 1957 

Disease contracted during active military, naval, or air service 

Veteran who engaged in combat with the enemy in active service with a military, naval, or air organization of the U.S. during a period of war, campaign, or expedition Period of service after November 11, 1918, and before July 2, 1921, if served after April 5, 1917, and before November 12, 1918 Period after December 31, 1946, and before July 26, 1947, if period began before January 1, 1947 

Within 1 year after separation from active service or when standard and accepted treatises indicate incubation period 

Summarizes previous rules and legislation and amends dates/location of service and presumption 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-73 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Disease subject to presumptive service connection. 

Federal Register26(36):1581-1582 

February 24, 1961 

Disease contracted during active military, naval, or air service 

Lays out criteria for presumption wartime service connection for chronic or tropical disease Factual Basis: May be established by medical evidence, competent lay evidence or both 

Pensions, bonuses, and veterans’ relief. Part 3: Adjudication. Subpart A: Pension, compensation, and dependency and indemnity compensation. Federal Register35(232):18280-18283. 38 CFR Part 3 

December 1, 1970 

Active service Service of 90 

days or more during a war period on or after January 31, 1955 

Chronic Diseases: Manifest to a degree of 10 percent or more within 1 year for Hansen’s disease (leprosy) and tuberculosis within 3 years; multiple sclerosis within 7 years from date of separation from service 

38 CFR 3.307 Former prisoners of 

war Military service 

 Wartime and 

service on or after January 1, 1947 90 days or more during a war period or after 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-74 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information December 31, 1946 Chronic: 

Manifest to degree of 10 percent or more within 1 year (for Hansen’s disease; and tuberculosis within 3 years; multiple sclerosis within 7 years) from separation of service 

38 CFR 3.309 Military service Chronic 

Diseases: On or after January 1, 1947, following service in a period of war or peacetime service 

Chronic Diseases: See section 3.307 above 

Pupura idiopathic (hemorrhagic) 

Pensions, bonuses, and veterans’ relief. Part 3: Veterans’ claims; miscellaneous amendments. Federal Register 14(197): 6174-6180. Former 38 CFR Sec. 3.86 (a) 

October 12, 1949 

Military service Amends list of 

chronic diseases 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-75 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Sarcoidosis Pensions, bonuses, and veterans’ relief. Part 3: Veterans’ 

claims; miscellaneous amendments. Federal Register

15(169):5902-5910. Former 38 CFR 

August 31, 1950 

Disease contracted during military service

See Veterans Regulation 1 (38 USC Ch. 12) 

See Veterans Regulation 1 (38 USC Ch. 12) 

Added to list of chronic and tropical diseases 

Veterans’ Bureau. Public Law 67-47. 1921. 67th Cong., 1st Sess. Ch. 57, Sec. 18, 42 Stat. 147, 153 

August 9, 1921 

Disease contracted during active military service during service 

On or after April 6, 1917 Or discharged or resigned active service on or before November 11, 1918 

Within 2 years after separation from active military or naval service Characteristic manifestations of the disease to 10 percent or more 

March 4, 1923, Act expanded the presumption to include all forms of tuberculosis 

Tuberculous (active) 

Executive Order 6089. Instruction No. 2, Implementing Vet. Reg. No. 1. April 12, 1933 

April 12, 1933 

Tuberculosis: Manifest to a degree of 10 percent within 1 year of discharge; second-year diagnoses presumptive if at 6 months for minimal cases, 9 months moderately advanced cases, 

Amends list of chronic diseases and presumption of tuberculosis 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-76 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information and 12 months far advanced cases Act of June 24, 1948. Public Law 

80-748. 80th Cong., 2d Sess. 

Ch. 612, Sec 1, 62 Stat. 581. 

June 24, 1948 

Disease contracted during active service 

Within 1 year after separation from active service or at a time when standard and accepted treatises indicate that the incubation period thereof commenced during active service 

At least 6 months of service and honorably discharged 

Pensions, bonuses, and veterans’ relief. Part 3: Veterans’ claims; miscellaneous amendments. Federal Register14(26):568-578. Former 39 CFR Sec. 3.80; Sec. 3.86 (a), 3.95 

February 9, 1949 

Disease contracted during military service 

Wartime service prior to January 1, 1947, to July 25, 1947 

Within 1 year after separation from active wartime service Within 1 year after the date prior to which a disability must have been incurred Chronic Disease:Manifestations sufficient to identify the disease entity and sufficient observations to 

Factual Basis:Established by medical evidence, competent lay evidence, or bothPulmonary Tuberculosis: Specific assumptions for diagnosis in second year after service 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-77 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information establish chronicity at the time Veterans’ 

Benefits Act of 1957. Public Law 85-56. Sec. 301. 85th Cong., 1st Sess. Sec 301(3 and 4). 71 Stat. 83, 95 

June 17, 1957 

Disease contracted during active military, naval, or air service 

Veteran who engaged in combat with the enemy in active service with a military, naval, or air organization of the U.S. during a period of war, campaign, or expedition Period of service after November 11, 1918, and before July 2, 1921, if served after April 5, 1917, and before November 12, 1918 Period after December 31, 1946, and before July 26, 1947, if period began before January 1, 1947 

Within 1 year after separation from active service or when standard and accepted treatises indicate incubation period 

Summarizes previous rules and legislation and amends dates/location of service and presumption 

Disease subject to presumptive 

February 24, 1961 

Disease contracted during active military, 

 Lays out criteria for 

presumption 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-78 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information service connection. Federal Register 26(36):1581-

1582. 

naval, or air service wartime service 

connection for chronic or tropical disease Factual Basis: May 

be established by medical evidence, competent lay evidence or both 

Pensions, bonuses, and veterans’ relief. Part 3: Adjudication. Subpart A: Pension, compensation, and dependency and indemnity compensation. Federal Register35(232):18280-18283. 38 CFR Part 3 

December 1, 1970 

Active service Service of 90 

days or more during a war period on or after January 31, 1955 

Chronic Diseases: Manifest to a degree of 10 percent or more within 1 year for Hansen’s disease (leprosy) and tuberculosis within 3 years; multiple sclerosis within 7 years from date of separation from service 

Pension, compensation, and dependence and indemnity. Final regulation. Federal Register43(191):45347-45362. 38 CFR Part 3 

October 2, 1978 

 Removes the 

presumptive period of 6, 9, and 12 months for minimally, moderately, and far advanced tuberculosis to: 

Amends presumptive period 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-79 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Developing within 3 years from the date of separation from 

active service 

38 CFR 3.307 Former prisoners of 

war Military service 

 Wartime and 

service on or after January 1, 1947 90 days or more during a war period or after December 31, 1946 Chronic: Manifest to degree of 10 percent or more within 1 year (for Hansen’s disease; and tuberculosis within 3 years; multiple sclerosis within 7 years) from separation of service 

38 CFR 3.309 Military service Chronic 

Diseases: On or after January 1, 1947, following service in a period of war or peacetime service 

Chronic Diseases: See section 3.307 above 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-80 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information 38 USC § 1112 Approved February 27, 2006 Active military service Veteran who served for 90 days or more during a period of war Chronic Disease: Disease manifest to 10 percent or more within 1 

year from separation of such service Tuberculous Disease (active) and Hansen’s Disease: Disease manifest to 10 percent or more within 3 years from separation of such service 

Veterans’ Bureau Schedule of Disability Ratings Extension 6 

November 2, 1928 

Manifest within 6 

months from discharge from military service and shown present within 1 year after discharge 

Establishes service connection for ulcers 

Ulcers, peptic (gastric or duodenal) 

Act of June 24, 1948. Public Law 80-748. 80th Cong., 2d Sess. 

Ch. 612, Sec 1, 62 Stat. 581 

June 24, 1948 

Disease contracted during active service 

At least 6 months of service and honorably discharged Within 1 year after separation from active 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-81 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information service or at a time when standard and accepted treatises 

indicate that the incubation period thereof commenced during active service 

Pensions, bonuses, and veterans’ relief. Part 3: Veterans’ claims; miscellaneous amendments. Federal Register14(26):568-578. Former 39 CFR Sec. 3.80; Sec. 3.86 (a), 3.95 

February 9, 1949 

Disease contracted during military service 

Wartime service prior to January 1, 1947, to July 25, 1947 Ulcer (peptic):within 6 months form date of active service or within 6 months of July 25, 1947; or more than 6 months then evidence of continuity of characteristic symptoms during the first 6 months after termination of active service 

Within 1 year after separation from active wartime service Within 1 year after the date prior to which a disability must have been incurred Chronic disease:Manifestations sufficient to identify the disease entity and sufficient observations to establish chronicity at the time 

Factual Basis:Established by medical evidence, competent lay evidence, or both 

Veterans’ Benefits Act of 

June 17, 1957 

Disease contracted during active military, 

Veteran who engaged in 

Within 1 year after separation 

Summarizes previous rules and 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-82 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information 1957. Public Law 85-56. Sec. 301. 85th Cong., 1st Sess. Sec 301(3 

and 4). 71 Stat. 83, 95. 

naval, or air service combat with the 

enemy in active service with a military, naval, or air organization of the U.S. during a period of war, campaign, or expedition Period of service after November 11, 1918, and before July 2, 1921, if served after April 5, 1917, and before November 12, 1918 Period after December 31, 1946, and before July 26, 1947, if period began before January 1, 1947 

from active service or when standard and accepted treatises indicate incubation period 

legislation and amends dates/location of service and presumption 

Disease subject to presumptive service connection. Federal Register26(36):1581-1582 

February 24, 1961 

Disease contracted during active military, naval, or air service 

Lays out criteria for presumption wartime service connection for chronic or tropical disease 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-83 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Factual Basis: May be established by medical evidence, competent lay 

evidence, or both 

Pensions, bonuses, and veterans’ relief. Part 3: Adjudication. Subpart A: Pension, compensation, and dependency and indemnity compensation. Federal Register35(232):18280-18283. 38 CFR Part 3 

December 1, 1970 

Active service Service of 90 

days or more during a war period on or after January 31, 1955 

Chronic Diseases: Manifest to a degree of 10 percent or more within 1 year for Hansen’s disease (leprosy) and tuberculosis within 3 years; multiple sclerosis within 7 years from date of separation from service 

38 CFR 3.307 Former prisoners of 

war Military service 

 Wartime and 

service on or after January 1, 1947 90 days or more during a war period or after December 31, 1946 Chronic: Manifest to degree of 10 percent or more 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-84 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information within 1 year (for Hansen’s disease; and tuberculosis within 3 years; 

multiple sclerosis within 7 years) from separation of service 

38 CFR 3.309 Military service Chronic 

Diseases: On or after January 1, 1947, following service in a period of war or peacetime service 

Chronic Diseases: See section 3.307 above 

Preexisting chronic disease before entry into service. Assumption any disease considered chronic because does not specify diseases 

Service connection by presumption of aggravation of a chronic preexisting disease. Final rule. Federal Register 67(216):67792-67793. 38 CFR Part 3 

November 7, 2002 

Military service Chronic Disease:

Manifests to a 10 percent degree of disability within a specified period after service. Aggravated by the veteran’s military service 

Made ruling based on the decision of the United States Court of Appeals for the Federal Circuit. Splane v. West, 216 F. 3d 1058 (2000) Amends 38 CFR Part 3 

Tropical Diseases• Malaria VA Circular No. 

8, section I 

December 28, 1945 

Disease contracted during active service 

 Within 1 year 

after separation of active service military service 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F 

F-85

Presumptive Disease 

Legislation or Regulation Date Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

• Dysentery (amebic, 

bacillary) 

• Filariasis (Bancroft’s 

type) 

• Leishmaniasis 

(including kala-azar) 

• Malaria • Schistosomiasis 

• Trypanosomiasis • Yaws 

Disability ratings for malaria and chronic diseases characteristically tropical in origin. Veterans Administration Technical Bulletin 8-6. Washington, DC: VA 

January 3, 1947 

Disease contracted during wartime service 

Service in the tropics or a place having a high incidence of the disease under consideration 

Within 1 year after separation of active wartime service 

Relapses of malaria (after the 1 year separation) need others, under oath to establish frequency of relapse over a period of time relating back to the 1-year period following discharge 

Act of June 24, 1948. Public Law 80-748. 80th Cong., 2d Sess. 

Ch. 612, Sec 1, 62 Stat. 581 

June 24, 1948 

Disease contracted during active service 

At least 6 months of service and honorably discharged Within 1 year after separation from active service or at a time when standard and accepted treatises indicate that the incubation period thereof commenced during active service 

• Black water fever • Cholera 

• Dracontiasis • Dysentery • Filariasis 

• Leishmaniasis • Leprosy • Loiasis 

• Malaria • Onchocerciasis • Oroya fever 

• Pinta • Plague • Schistosomiasis 

• Yaws • Yellow fever 

Pensions, bonuses, and veterans’ relief. Part 3: Veterans’ claims; 

February 9, 1949 

Disease contracted during military service 

Wartime service prior to January 1, 1947, to July 25, 1947 

Within one year after separation from active wartime service 

Factual Basis:Established by medical evidence, competent lay evidence, or both 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-86 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information miscellaneous amendments. Federal Register 14(26):568-578. 

Former 39 CFR Sec. 3.80; Sec. 3.86 (a), 3.95 

Tropical Diseases: Service in the tropics or a place having a high incidence of the disease under consideration 

Within 1 year after the date prior to which a disability must have been incurred Tropical Disease:When shown to exist at a time when standard and accepted treatises indicate that the incubation period of the diseases commenced during active service Characteristic manifestations of the disease to 10 percent or more, except pulmonary tuberculosis 

• Amebiasis Pensions, 

bonuses, and veterans’ relief. Part 3: Veterans’ claims; miscellaneous amendments. Federal Register

August 31, 1950 

Disease contracted during military service

See Veterans Regulation 1 (38 USC Ch. 12) 

See Veterans Regulation 1 (38 USC Ch. 12) 

Added to list of chronic and tropical diseases 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-87 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information 15(169):5902- 5910. Former 38 CFR Veterans’ 

Benefits Act of 1957. Public Law 85-56. Sec. 301. 85th Cong., 1st Sess. Sec 301(3 and 4). 71 Stat. 83, 95 

June 17, 1957 

Disease contracted during active military, naval, or air service 

Veteran who engaged in combat with the enemy in active service with a military, naval, or air organization of the U.S. during a period of war, campaign, or expedition Period of service after November 11, 1918, and before July 2, 1921, if served after April 5, 1917, and before November 12, 1918 Period after December 31, 1946, and before July 26, 1947, if period began before January 1, 1947 

Tropical Diseases: Serves 6 months or more and contracts tropical or disease because of therapy in connection with tropical disease Within 1 year after separation from active service or when standard and accepted treatises indicate incubation period 

Summarizes previous rules and legislation and amends dates/location of service and presumption 

Disease subject to presumptive 

February 24, 1961 

Disease contracted during active military, 

 Lays out criteria for 

presumption 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-88 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information service connection. Federal Register 26(36):1581-

1582 

naval, or air service wartime service 

connection for chronic or tropical disease Factual Basis: May 

be established by medical evidence, competent lay evidence or both 

Pensions, bonuses, and veterans’ relief. Part 3: Adjudication. Subpart A: Pension, compensation, and dependency and indemnity compensation. Federal Register35(232):18280-18283. 38 CFR Part 3 

December 1, 1970 

Active service Service of 90 

days or more during a war period on or after January 31, 1955 

Tropical Diseases: Manifest to a degree of 10 percent or more within 1 year from date of separation from service or at a time when standard treatises indicate that the incubation period commenced during such service 

Increase of disability compensation and dependency and indemnity compensation rates. Federal Register

September 26, 1974 

Active service on or after January 1, 1947 Tropical Before January 1, 1947: Veteran with 6 or months of service 

Service of 90 days or more during a war period on or after December 31, 1946 

Tropical Before January 1, 1947: Manifest to a degree of 10 percent or more within 1 year after separation from active service or 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-89 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information 39(188):34529- 34533. 38 CFR Part 3 at a time when standard and accepted treatises indicate that the 

incubation period commenced during active service 

• Hansen’s disease Increased 

disability compensation and dependency and indemnity compensation; burial benefits. Federal Register41(248):55872-55875. 38 CFR Part 3 

December 23, 1976 

Tropical Diseases: Tropical service following service in a period of war or following peacetime service 

Used term Hansen’s disease instead of leprosy 

All tropical diseases listed. 

38 CFR 3.307 Former prisoners of 

war Military service 

 Wartime and 

service on or after January 1, 1947 90 days or more during a war period or after December 31, 1946 Tropical: Manifest to a degree of 10 percent or more within 1 year 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-90 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information from separation of service or time when standard accepted treatises 

indicate incubation period; diseases resulting from therapy administered 

38 CFR 3.309 Military service Tropical 

Diseases: See section 3.307 above 

38 USC § 1112 Approved 

February 27, 2006 

Active military service Tropical Disease: Disorders or disease originating because of therapy, administered in connection with such disease, or as a preventative 

Veteran who served for 90 days or more during a period of war 

Tropical Disease:Disease manifest to 10 percent or more within 1 year from separation of such service Or Standard or accepted incubation periods Hansen’s Disease: Disease manifest to 10 percent or more within 3 years from separation of such service 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-91 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Prisoner of War Diseases Public Law 91- 376. Sec. 3. 91st Cong., 2d Sess., 

1970. Sec 3. 84 Stat. 787, 788 

August 12, 1970 

Active military, naval, or air service and was held prisoner of war 

Held by Imperial Japanese government or the German government during World War II, government of North Korea during the Korean conflict, or the government of North Vietnam, or the Viet Cong during the Vietnam era 

Detained or interned for not less than 6 months Characteristic manifestations of the disease (except psychosis) to 10 percent or more after service Psychosis: Characteristic manifestations of the disease to 10 percent or more within 2 years after separation from service 

Service connection presumption for former prisoners of war 

• Avitaminosis • Beriberi (including 

beriberi heart disease) 

• Chronic dysentery • Helminthiasis • Malnutrition 

(including optic atrophy associated with malnutrition) 

• Other nutritional 

deficiency 

• Pellagra • Psychosis 

Pensions, bonuses, and veterans’ relief. Part 3: Adjudication. Subpart A: Pension, compensation, and dependency and indemnity compensation. Federal Register35(232):18280-18283. 38 CFR Part 3 

December 1, 1970 

Active service Former Prisoners of War: Held by an enemy government or its agents during WWII, Korean conflict, or the Vietnam era, suffered from dietary deficiencies, forced labor, or inhumane treatment 

Service of 90 days or more during a war period on or after January 31, 1955 

Prisoners of War: Manifest to a degree of 10 percent or more at any time after service, except

psychosis, 10 percent within 2 years from date of separation from service 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-92 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Increase of disability compensation and dependency and 

indemnity compensation rates. Federal Register39(188):34529-34533. 38 CFR Part 3 

September 26, 1974 

Active service on or after January 1, 1947 

Service of 90 days or more during a war period on or after December 31, 1946 

Former Prisoner of War Benefits Act of 1981. Public Law 97-37. 97th Cong., 1st Sess. Sec 4. 95 Stat. 935, 936 

August 14, 1981 

Former prisoner of war 

While serving in active military, naval, or air service, was forcibly detained or interned in line of duty by an enemy government or its agents, or a hostile force during a period of war 

Characteristic manifestations of the disease to 10 percent or more after service Detained or interned for not less than 30 days 

Amends list of associated diseases of former prisoners of war The previous prisoner of war presumption is for the period of time not less than 6 months. This act changes that period of time to not less than 30 days 

• Any of the anxiety 

states 

Veterans Benefits; Former Prisoners of War. Final regulations. Federal Register47(53):11655-11656. 38 CFR Part 3 

March 18, 1982 

Former prisoner of war 

While serving in active military, naval, or air service, was forcibly detained or interned in line of duty by an enemy government or its 

Characteristic manifestations of the disease to 10 percent or more after service Detained or interned for not less than 30 days 

Implementing the new Former Prisoner of War Benefits Act of 1981 Amended period of detainment for presumption of 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-93 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information agents, or a hostile force during a period of war on or after 

January 1, 1947 

disease 

• Dysthymic disorder 

(or depressive neurosis) 

Veterans’ Compensation and Program Improvements Amendments of 1984, Public Law 98-223. 98th Cong., 2d Sess. Sec. 111 98 Stat. 37, 40 

March 2, 1984 

Prisoner of war Amends list of 

diseases associated with former prisoner of war 

• Organic residuals of 

frostbite 

• Posttraumatic 

osteoarthritis 

Veterans’ Benefits Improvements and Health-Care Authorization Act of 1986. Public Law 99-576. 99th Cong., 2d Sess. Sec 108. 100 Stat. 3248, 3252 

October 28, 1986 

Former prisoner of war 

Amends list of associated diseases of former prisoners of war 

• Irritable bowel 

syndrome 

• Peptic ulcer disease 

• Peripheral 

neuropathy (except where directly related to infectious causes) 

Veterans’ Benefits and Services Act of 1988. Public Law 100-322. 100th Cong., 2d Sess. Sec 312, 313. 102 Stat. 487, 535 

May 20, 1988 

Prisoner of war Amended list of 

diseases related to Former prisoners of war and service connection of chronic diseases 

• Cirrhosis of the liver Presumption of February 10, Former prisoners of Detained for at Amended list of 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-94 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information service connection for cirrhosis of the liver in former 

prisoners of war. Proposed rule.Federal Register 68(27):6679-6680. 38 CFR Part 3 

2003 war 

Evidence: Significantly higher risk of death from cirrhosis in former WWII prisoners of war than the general population 

least 30 days diseases associated 

with prisoners of war 

Presumption of service connection for cirrhosis of the liver in former prisoners of war. Final rule. Federal Register68(138):42602-42603. 38 CFR Part 3

July 18, 2003

No change from proposed rule 

Veterans Benefits Enhancement Act of 2003 S. Rep. No. 108-169 108th Cong. 1st Sess. 11 (proposed Act) 

October 21, 2003 

Former prisoners of war veteran active military, naval, or air service 

Former prisoner of war 

Disease to manifest to a degree of 10 percent or more after active service 

Proposed act that would amend the diseases associated with former prisoners of war 

Veterans Benefits Act of 2003. Public Law 108-183. 108th Cong., 

December 16, 2003

Detained or interned for not less than 30 days (for following 

No change from proposed act
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-95 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information 1st Sess., Sec. 201. 117 Stat. 2651 diseases: any other nutritional deficiency, avitaminosis, 

beriberi, chronic dysentery, cirrhosis of the liver, helminthiasis, irritable bowel syndrome, malnutrition, pellagra, peptic ulcer disease, peripheral neuropathy)

• Atherosclerotic 

disease or Hypertensive vascular disease (including hypertensive heart disease and their complications [including myocardial infarction, congestive heart failure, arrhythmia]) 

• Stroke and its 

complications 

Presumptions of service connection for diseases associated with service involving detention or internment as a prisoner of war. Interim final rule. Federal Register69(194):60083-60090. 38 CFR Parts 1 and 3 

October 7, 2004 

Former prisoner of war

Eliminated the 30-day detained requirement for psychosis, any anxiety state, dysthymic disorders, organic residuals of frostbite, and posttraumatic osteoarthritis The new diseases in this rule are presumed to be service connected following any period of prisoner-of-war 

Amended diseases associated with former prisoner of war and amended the 30-day requirement for some of the related diseases Defines the evidence necessary to determine presumption of service connection 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-96 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information activity Presumptions of service connection for 

diseases associated with service involving detention or internment as a prisoner of war. Affirmation of interim final rule as final rule.Federal Register70(123):37040-37042. 38 CFR Parts 1 and 3

June 28, 2005

Final rule without change from October 7, 2004 interim rule

Prisoner of War Benefits Act of 2005 (proposed act). 109th Cong. 

1st Sess. Senate Bill 1271 

June 20, 2005 

Former prisoners of war 

Proposed act to amend the list of diseases associated with former prisoners of war 

• Diabetes (type 2)• Heart disease• Osteoporosis • Stroke

38 CFR 3.307 Former prisoners of 

war Military service 

 Wartime and 

service on or after January 1, 1947 90 days or more during a war period or after December 31, 1946 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-97 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Former Prisoners of War: Manifest to a degree of 10 

percent or more after discharge or release for active service 

38 CFR 3.309 Former prisoner of 

war 

Former Prisoner of War: Manifest to a degree of 10 percent or more after release or discharge from active military, naval, or air service Prisoner of war associated diseases: not less 

than 30 days as a prisoner of war (for the following diseases: any other nutritional deficiency, avitaminosis, beriberi, chronic dysentery, cirrhosis of the liver, helminthiasis, irritable bowel 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-98 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information syndrome, malnutrition, pellagra, peptic ulcer disease, 

peripheral neuropathy) 

38 USC § 1112 Approved 

February 27, 2006 

Active military service 

Veteran who served for 90 days or more during a period of war Prisoner of War Associated Diseases: Not less than 30 days as a prisoner of war (for the following diseases: any other nutritional deficiency, avitaminosis, beriberi, chronic dysentery, cirrhosis of the liver, helminthiasis, irritable bowel syndrome, malnutrition, pellagra, peptic ulcer disease, peripheral neuropathy) 

Prisoner of War: Disease manifest to 10 percent or more after active military, naval, or air service 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-99 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Diseases Associated with Service Amputation Ischemic heart disease (or other cardiovascular disease) Pension, compensation, and dependency 

and indemnity compensation, proximate results, secondary conditions. Federal Register

44(168):50339-50340. 38 CFR Part 3, Sec. 3.310 

August 28, 1979 

Service-connected amputation of one lower extremity at or above the knee or service-connected amputations of both lower extremities at or above the ankles 

Diseases Associated with Herbicide Exposure• Chloracne Adjudication of 

claims based on exposure to dioxin or ionizing radiation. Final rules. Federal Register50(165):34452-34461. 38 CFR Parts 1 and 3 

August 26, 1985 

Herbicide • Dioxin (2,3,7,8 

tetrachlorodibenzo-p-dioxin) 

Dioxin Vietnam era 

Dioxin Exposure: No later than 3 months from the date of exposure 

Dioxin: Presumed to have been exposed if served in the Vietnam era 

• Chloracne (or another 

acneform disease)

• Non-Hodgkin’s 

lymphoma

• Soft tissue sarcoma

Agent Orange Act of 1981. Public Law 102-4. 102d Cong., 1st Sess. 105 Stat. 11 

February 6, 1991 

Active military, naval, or air service Exposure to herbicide agent containing dioxin or 2,4-dichlorophenoxyacetic acid or other chemical 

Republic of Vietnam; Vietnam era 

Non-Hodgkin’s Lymphoma and Soft Tissue Sarcoma (other than osteosarcoma, chondrosarcoma, kaposi’s 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-100 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information compound in an herbicide agent sarcoma, or mesothelioma): Manifest 10 percent or more 

disability Chloracne: 10 percent or more disability within 1 year after the last date active duty in Republic of Vietnam 

• Chloracne • Soft tissue sarcoma 

(adult fibrosarcoma; dermatofibrosarcoma protuberans; malignant fibrous histocytoma; liposarcoma; leiomyosarcoma; epithelioid leiomyosarcoma; rhabdomyosarcoma; ectomesenchymoma; angiosarcoma; proliferating angioendotheliomato-sis; malignant glomus tumor; malignant hemangiopericytoma; synovial sarcoma; malignant giant cell tumor of tendon sheath; 

Claims based on exposure to herbicides containing dioxin (soft tissue sarcomas). Final regulation. Federal Register56(199):51651-51653. 38 CFR Parts 3 and 4 

October 15, 1991 

Exposure to herbicides containing dioxin 

Republic of Vietnam; Vietnam era 

Chloracne: Manifested not later than 3 months from the date of exposure Soft Tissue Sarcoma:Manifest at any time after service 

Lists diseases associated with exposure to herbicides containing dioxin
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-101 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information malignant schwannoma; malignant mesenchymoma; malignant granular cell 

tumor; alveolar soft part sarcoma; epithelioid sarcoma; clear cell sarcoma of tendons and aponeuroses) 

• Peripheral 

neuropathy 

Claims based on exposure to herbicides containing dioxin (peripheral neuropathy/lung cancer). Proposed rule. Federal Register57(13):2236-2238. 38 CFR Part 3 

January 21, 1992 

Herbicide (containing dioxin) exposure Military service

Military service Peripheral 

Neuropathy: Manifested not later than 10 years following the date of exposure

Proposed rule amends diseases associated with exposure to herbicides containing dioxin Diseases NOT Associated with Exposure to Herbicides (containing dioxin): 

• Lung cancer• Porphyria 

cutanea tarda

• Hodgkin’s disease• Porphyria cutanea 

tarda

Disease associated with exposure to certain herbicide agents. Final rule. Federal Register59(23):5106-5107. 38 CFR Part 3 

February 3, 1994 

Herbicide agent exposure: specifically, 2,4-D; 2,4,5-T, and its contaminant TCDD; cacodylic acid; and picloram During active 

Republic of Vietnam; Vietnam era And wartime and service on or after January 1, 1947 

Disease manifest to 10 percent or more at any time after service Porphyria Cutanea Tarda: 10 percent or more manifested 

Amends list of diseases to other chronic, tropical, or prisoner-of-war related diseases or disease associated with exposure to certain herbicide agents; wartime and 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-102 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information military, naval, or air service within a year after the last date veteran was exposed to an 

herbicide agent during active military, naval, or air service 

service on or after January 1, 1947 

• Multiple myeloma

• Respiratory cancers: 

Bronchus Larynx Lung Trachea 

Disease associated with exposure to certain herbicide agents (multiple myeloma and respiratory cancers). Final rule. Federal Register59(110):29723-29724. 38 CFR Part 3 

June 9, 1994 Herbicide agent 

exposure During active military, naval, or air service 

Republic of Vietnam; Vietnam era And wartime and service on or after January 1, 1947 

Multiple Myeloma: Disease manifest to 10 percent or more at any time after service Respiratory Cancers: Within 30 years after the last date on which the veteran was exposed to an herbicide agent during active military, naval, or air service 

Amends list of diseases associated with chronic, tropical or prisoner of war, or exposure to certain herbicide agents 

• Hodgkin’s disease • Multiple myeloma 

• Porphyria cutanea 

tarda 

• Respiratory cancers: 

Bronchus Larynx Lung 

Persian Gulf War Veterans’ Benefits Act of 1994. Public Law 103-446. 103d Cong., 2d. Sess. 108 Stat. 4645 

November 2, 1994 

Herbicide agent exposure During active military, naval, or air service 

Hodgkin’s Disease and Multiple Myeloma: Manifest to 10 percent disability or more 

Codified these diseases to the list of herbicideexposure presumptions 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-103 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Trachea Porphyria Cutanea Tarda: 10 percent or more manifested 

within a year after the last date veteran was exposed to an herbicide agent during active military, naval, or air service Respiratory Cancers: Within 30 years after the last date on which the veteran was exposed to an herbicide agent during active military, naval, or air service 

• Acute and subacute 

peripheral neuropathy 

• Prostate cancer 

Diseases associated with exposure to certain herbicide agents (prostate cancer and acute and subacute peripheral neuropathy). Final rule. 

November 7, 1996 

Herbicide agent exposure During active military, naval, or air service 

Republic of Vietnam; Vietnam era And wartime and service on or after January 1, 1947 

Manifest to 10 percent disability or more after service Note: Acute and subacute peripheral neuropathy by definition appears 

Amends list of diseases associated with exposure to certain herbicide agents 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-104 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Federal Register 61(217):57586- 57589. 38 CFR Part 3 within weeks or months of exposure to a herbicide agent 

and resolves within 2 years of the date of onset

• Type 2 Diabetes Disease 

associated with exposure to certain herbicide agents: Type 2 diabetes. Final rule. Federal Register66(89):23166-23169. 38 CFR Part 3 

May 8, 2001 Herbicide exposure In the Republic of 

Vietnam during the Vietnam Era Or active military service 

Illness manifest to a degree of 10 percent or more 

Amends diseases associated to exposure to herbicides 

• Diabetes mellitus 

(type 2) 

• Respiratory cancers 

Veterans Education and Benefits Expansion Act of 2001. Public Law 107-103. 107th Cong., 1st Sess. 

December 27, 2001 

Herbicide exposure Military service Vietnam Veteran active service 

Herbicide Exposure Additional Diseases: Up to September 30, 2015 Respiratory Cancers: Presumptive period amended from “within 30 years” through “May 7, 1975” 

Extension of presumptive period for respiratory cancers and additional diseases associated with herbicide exposure and Persian Gulf exposure 

Amends date of presumption and exposure candidates 

Compensation and pension provisions of the 

June 10, 2003 

 Herbicide 

Exposure: Eliminates 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-105 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Veterans Education and Benefits Expansion Act of 

2001. Final Rule. Federal Register68(111):34539-34543. 38 CFR Parts 3 and 13 

respiratory cancer, must manifest within 30 years of departure from Vietnam to qualify for presumption based on herbicide exposure and expand presumption of exposure to herbicides to all Vietnam veterans 

• Chronic 

lymphocytic leukemia 

Disease associated with exposure to certain herbicide agents: Chronic lymphocytic leukemia. Final rule. Federal Register68(200):59540-59542. 38 CFR Part 3 

October 16, 2003 

Herbicide exposure Military service 

Republic of Vietnam during the Vietnam era 

Amends list of diseases associated with exposure to herbicide agents 

• Type 2 diabetes Change of 

effective date of rule adding a disease associated with exposure to certain herbicide agents: Type 2 diabetes. Final rule. Federal Register

June 8, 2004 Change of effective 

date of presumption to May 8, 2001 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-106 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information 69(110):31882- 31883. 38 CFR Part 3 Presumptions of service 

connection for diseases associated with exposure to certain herbicide agents

38 USC § 1116 Approved 

February 27, 2006 

Active military naval, or air service Herbicide agent (containing dioxin or 2,4-dichlorophenoxyacetic acid) 

Republic of Vietnam (January 9, 1962, to May 7, 1975) 

Republic of Vietnam Diseases: Manifest disease 10 percent disability or more In addition: Porphyria cutanea tarda and Chloracne:within 1 year from active military service 

Presumptive service connection for chronic, tropical, or prisoner-ofwar related disease or disease associated with exposure to certain herbicide agents

38 CFR 3.307 Former prisoners of 

war Herbicide agent exposure (specifically 2,4, D; 2,4,5-T and its contaminant TCDD; cacodylic acid; and picloram) Military service 

Herbicide Agent Exposure: Republic of Vietnam (January 9, 1962, to May 7, 1975) active military, naval, or air service (including the waters offshore and service in other locations involving duty or visitation in the Republic of Vietnam 

Wartime and service on or after January 1, 1947 90 days or more during a war period or after December 31, 1946 Herbicide Agent Exposure: Manifest to a degree of 10 percent or more at any time after service except 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-107 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information chloracne, porphyria cutanea tarda, and acute and subacute 

peripheral neuropathy manifest to a degree of 10 percent or more within 1 year after last date veteran was exposed to an herbicide agent 

38 CFR 3.309 Military service 

Former prisoner of war 

Exposure to Herbicide Agents: See section 3.307 above 

Radiogenic Disease• All forms of 

leukemia (except chronic lymphatic leukemia) 

• Cancer (bone, colon, 

esophageal, female breast, kidney, liver, lung, pancreatic, salivary gland, skin, stomach, thyroid, urinary bladder) 

• Multiple myeloma 

Adjudication of claims based on exposure to dioxin or ionizing radiation. Final rules. Federal Register50(165):34452-34461. 38 CFR Parts 1 and 3 

August 26, 1985 

Radiation • Ionizing 

Ionizing 

Hiroshima or Nagasaki, Japan (September 1945 until July 1946) 

Ionizing: Leukemias and bone cancer must become manifest within 30 years after exposure; other forms of cancer must become manifest 5 years or more after exposure 

Ionizing: Exposure at the highest level of the dose range estimated will be presumed; several factors to be considered in determining whether disease resulted from exposure during service 

• Cancer (breast, 

salivary gland)

• Leukemia (other than 

Claims based on exposure to ionizing 

October 18, 1989 

Ionizing radiation Bone Cancer: 

Manifest within 30 years after 

Amended diseases considered to be radiogenic 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-108 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information chronic lymphatic [lymphocytic] leukemia) • Multiple myeloma

• Nonmalignant 

thyroid nodular disease

• Posterior subcapsular 

cataracts

radiation. Final regulations. Federal Register54(200):42802-42803. 38 CFR Part 3 

exposure Leukemia: Manifest any time after exposure Posterior Subcapsular Cataracts: Manifest 6 months or more after exposure Other Diseases: Manifest 5 years or more after exposure 

Withdrew proposed clarification concerning when service connection can be established based upon claimed exposure to ionizing radiation and herbicides containing dioxin 

Diseases Associated with Radiation Exposure• Cancer (bile ducts, 

breast, esophagus, gall bladder, pancreas, pharynx, primary liver, small intestine, stomach, thyroid)

• Leukemia (other than 

chronic lymphocytic leukemia)

• Lymphomas (except 

Hodgkin’s disease)

• Multiple myeloma

RadiationExposed Veterans Compensation Act of 1988. Public Law 100-321. 100th Cong., 2d Sess., Section 2, 102 Stat. 485 

May 20, 1988 

Radiation-risk activity 

• Participation in a 

test involving atmospheric detonation of a nuclear device 

• Occupation of 

Hiroshima or Nagasaki, Japan (August 6, 1945, to July 1, 1946) 

• Prisoner of war in 

Japan during WWII exposure of ionizing radiation 

Japan WWI August 6, 1945, to July 1, 1946 Others 

40-year period beginning on the last date where the veteran participated in a radiation-risk activity except leukemia (30-year period after radiation-risk activity) 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-109 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Radiation Exposure Compensation Act of 1990. 

Public Law 101-426. 101st Cong., 2d Sess., 104 Stat. 920 

October 15, 1990 

Radiation exposure 

• Above-ground 

nuclear tests 

• Uranium miners 

Government’s above-ground nuclear tests in Nevada and lived downwind in Nevada, Utah, and Arizona Underground uranium mines 

Childhood leukemia and other diseases (January 21, 1951, to October 31, 1958; or June 30, 1962, to July 31, 1962) For miners: Any individual who was employed in a uranium mine located in Colorado, New Mexico, Arizona, Wyoming, or Utah at any time during the period beginning on January 1,1947, and ending on December 31, 1971 

Individuals not in military • Uranium miners • Downwind to 

nuclear tests 

Leukemia (presumptive period) 

Veterans’ Benefits Programs Improvement Act of 1991. Public Law 102-86. 102d Cong., 1st Sess., Sec. 104, 105. 105 Stat. 414 

August 14, 1991 

Radiation exposure Amends service 

to during active military, naval, or air service or reserve component of the Armed Forces, participated in a radiation-risk activity during a 

 Amends 

presumptive period for occurrence of leukemia and location of radiation exposure 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-110 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information period of active duty for training or inactive duty training 

• Cancer of the: 

salivary gland urinary tract 

Veterans’ Radiation Exposure Amendments of 1992. Public Law 102-578. 102d Cong., 2d Sess., Sec 2. 106 Stat. 4774 

October 30, 1992 

Radiation exposure Adds diseases to the 

list associated with exposure to radiation and elimination of latency-period limitations 

Claims based on exposure to ionizing radiation. Final rule. Federal Register58(57):16358-16359. 38 CFR Part 3 

March 26, 1993 

Ionizing radiation Amends diseases 

associated with exposure to ionizing radiation 

• Ovarian cancer • Parathyroid adenoma 

Radiation Exposure Compensation Act of 1990. Final Rule. Federal Register58(79):25564-25565. 38 CFR Part 3 

April 27, 1993 

 Establishes 

compensation to any individual under the provisions of the Radiation Exposure Compensation Act of 1990 

• Tumors of the brain 

and central nervous system 

Claims based on exposure to ionizing 

September 6, 1994 

Ionizing radiation Amended diseases 

associated with exposure to ionizing 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-111 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information radiation. Final rule. Federal Register 59(171):45975. 

38 CFR Part 3 

radiation 

• Cancer of the rectum • Lymphomas other than 

Hodgkin’s disease 

Claims based on exposure to ionizing radiation (lymphomas other than Hodgkin’s disease and cancer of the rectum). Final rule. Federal Register60(198):53276-53277. 38 CFR Part 3 

October 13, 1995 

Ionizing radiation Amends diseases 

associated with exposure to ionizing radiation 

• Prostate cancer • Any other cancer 

Claims based on exposure to ionizing radiation (prostate cancer and any other cancer). Final rule. Federal Register63(185):50993-50995. 38 CFR Part 3 

September 24, 1998 

Ionizing radiation Amends diseases 

associated with exposure to ionizing radiation 

Nuclear Atmospheric Testing: • Brain cancer • Colon cancer 

Radiation Exposure Compensation Act Amendments 

July 10, 2000 

Nuclear atmospheric testing Uranium mining 

Leukemia: Physically present in affected area for at least 1 year 

Lung Cancer: Onset of disease at least 2 years after first 

Amends list of diseases associated to radiation exposure and 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-112 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information • Gall bladder cancer • Male breast cancer • Ovary cancer 

• Salivary gland cancer • Urinary bladder 

cancer 

Uranium Mining 

• Lung cancer 

• Nonmalignant 

respiratory disease 

• Renal cancers • Other chronic renal 

disease (nephritis, kidney tubal tissue injury) 

of 2000. Public Law 106-245. 106th Cong., 2d Sess. 114 Stat. 501 

January 21, 1951, through October 31, 1958; or June 30, 1962, through July 31, 1962 

exposure manifestation of 

diseases Amends dates/location of service for leukemia 

• Bronchiolo-alveolar 

carcinoma 

Veterans Millennium Health Care and Benefits Act. Final rule. Federal Register65(136):43699-43700. 38 CFR Part 3 

July 14, 2000 

Active military service Radiation exposure 

Amended list of diseases related to exposure to radiation and active service 

• Polycythemia vera Claims based on 

exposure to ionizing radiation. Final rule. Federal Register67(31):6870-

February 14, 2002 

Radiation exposure Ionizing 

 Amends diseases 

from exposure to ionizing radiation; VA did not have evidence to add to the list of “radiogenic 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-113 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information 6871. 38 CFR Part 3 diseases,” but the VA will consider a claim that polycythemia vera 

is a radiogenic disease as long as there is scientific or medical evidence to support the claim 

All diseases listed above 38 USC § 1112 Approved 

February 27, 2006 

Active military service Radiation-Exposed Veteran: Radiationrisk activity 

Veteran who served for 90 days or more during a period of war RadiationExposed Veteran: 

Participation in a test involving atmospheric detonation of a nuclear device; Occupation of Hiroshima or Nagasaki, Japan (August 6, 1945, to July 1, 1946); 

Internment as a prisoner of war in Japan or service on active duty in Japan following 

RadiationExposed Veterans: Disease manifest after active military, naval, or air service 
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Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html F-114 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information such internment during WWII with opportunity for exposure to 

ionizing radiation; or Performed as an employee of the DOE 

All diseases listed above 38 CFR 3.309 Military Service 

Radiation-Exposed Veteran: Serving active duty or Armed Forces active duty or training or inactive duty training and participated in a “radiation-risk activity” 

RadiationExposed Veteran: • Participation 

in test atmospheric detonation of nuclear device 

• Occupation of 

Hiroshima or Nagasaki, Japan (August 6, 1945, to July 1, 1946) 

• Prisoner of 

War in Japan exposure of ionizing radiation comparable to above exposure 

• Total of 250 

days before 

Wartime and service on or after January 1, 1947 90 days or more during a war period or after December 31, 1946 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-115 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information February 1, 1992, on grounds of gaseous 

diffusion plant (Paducah, KY; Portsmouth OH; K25 Oak Ridge, TN) 

• Service before 

January 1, 1974 on Amchitka Island, Alaska, and exposed to underground nuclear tests at Long Shot, Milrow, or Cannikin 

• Cancer of the bone, 

breast, colon, esophageal, kidney, liver, lung, ovarian, pancreatic, prostate, rectum, salivary gland, skin, stomach, thyroid, urinary bladder, any other cancer 

• Nonmalignant 

38 CFR 3.311 Ionizing radiation 

Service 

Occupation of Hiroshima or Nagasaki, Japan (September 1945 to July 1946) or other activities where they participated in atmospheric testing of nuclear weapons 

Manifest 5 years or more after exposure Bone Cancer: Manifest within 30 years after exposure Leukemia:Manifest any time 
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http://www.nap.edu/catalog/11908.html F-116 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information thyroid nodular disease • Parathyroid adenoma 

• Posterior subcapsular 

cataracts 

• Tumors of the brain 

and central nervous system 

after exposure Posterior Subcapsular Cataracts: Manifest 6 months or more after exposure 

Diseases Associated with Vietnam Service

38 CFR 3.313 Service in Vietnam Service in 

Vietnam during the Vietnam Era 

Subsequent to service 

• Non-Hodgkin’s 

lymphoma 

Claims based on service in Vietnam. Final regulations. Federal Register55(208):43123-43125. 38 CFR Parts 3 and 4 

October 26, 1990 

Service in Vietnam Vietnam (includes 

waters offshore, or service in other locations if the conditions of service involved duty or visitation in Vietnam During the Vietnam era 

• Chloracne • Congenital and 

Republic of Vietnam. Final 

May 19, 1993 

Wartime and service in the Republic of 

On or after January 1, 1947 

Disease manifest to 10 percent or 

“Service in the Republic of 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-117 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information infantile fibrosarcoma • Extraskeletal Ewing’s sarcoma 

• Malignant 

ganglioneuroma 

• Soft tissue sarcoma 

(see October 19, 1991) 

rule. Federal Register58(95):29107-29109. 38 CFR Part 3 3.309(e) 

Vietnam more at any time 

after service Except: Chloracne (or another acneform disease): 10 percent or more within a year after the last date veteran performed active military, naval, or air service in the Republic of Vietnam 

Vietnam” includes service in the waters offshore and service in other locations if the conditions of service involved duty or visitation in the Republic of Vietnam 

Expansion of Period of Vietnam Era for Certain Veterans 

Veterans’ Benefits Improvements Act of 1996 Public Law 104-275. 104th Cong., 2d Sess., Sec. 1711 

October 9, 1996 

“Vietnam era” 

• For a Veteran 

who served in the Republic of Vietnam—February 28, 1961, to May 7, 1975 

• In all other 

cases—August 5, 1964, to May 7, 1975

Vietnam era inclusion dates 

Veterans’ Benefits Improvements 

July 1, 1997 “Vietnam era” 

February 28, 1961, to May 7, 
Copyright © National Academy of Sciences. All rights reserved.

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http://www.nap.edu/catalog/11908.html F-118 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Act of 1996, Final rule. Federal Register 62(126):35421-

35423. 38 CFR Part 3 

1975, inclusive who served in the Republic of Vietnam 

• Diabetes mellitus 

(type 2) 

• Hodgkin’s disease 

• Multiple myeloma • Porphyria cutanea 

tarda 

• Respiratory cancers 

(bronchus, larynx, lung, or trachea) 

38 USC § 1116 Approved 

February 27, 2006 

Active military naval, or air service Herbicide agent (containing dioxin or 2,4-dichlorophenoxyacetic acid) 

Republic of Vietnam (January 9, 1962, to May 7, 1975) 

Republic of Vietnam Diseases: Manifest disease 10 percent disability or more In addition: Porphyria cutanea tarda and chloracne:within 1 year from active military service 

Amends list of diseases associated with Vietnam service 

Diseases Associated with Exposure to Mustard Gas

Claims based on chronic effects of exposure to mustard gas. Proposed rule. Federal Register57(10):1699-1700.38 CFR Part 3 

January 15, 1992 

Mustard gas exposure by participating in full-body, field, or chamber experiments to test protective clothing or equipment 

During World War II; participating in full-body, field, or chamber experiments to test protective clothing or equipment 

Chronic forms of the diseases manifested after exposure 

Proposed rule for chronic effects of in-service exposure to mustard gas 

• Asthma

• Bronchitis

• Conjunctivitis

• Corneal opacities

• Emphysema

• Keratitis

• Laryngitis

Claims based on chronic effects of exposure to mustard gas. 

July 31, 1992 

No change from proposed rule 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-119 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Final rule. Federal Register 57(148):33875- 33877. 

38 CFR Part 3 

Nitrogen or sulfur mustard: • Cancers: carcinoma 

of the skin, lung, laryngeal, nasopharyngeal, squamous cell 

• Chronic 

conjunctivitis 

• Corneal opacities • Keratitis • Scar formation 

Nitrogen or sulfur mustard or Lewisite:

• Chronic form of: 

asthma, bronchitis, emphysema, laryngitis 

• Chronic obstructive 

pulmonary disease 

Nitrogen mustard: • Acute 

nonlymphocytic leukemia 

38 CFR 3.316 Exposure to nitrogen 

or sulfur mustard or Lewisite 

Active military service 

Diseases Associated with Service• Posttraumatic stress 

disorder 

Direct service connection (postMay 19, 1993 Military service Military service or former prisoner Amends list of diseases associated 
Copyright © National Academy of Sciences. All rights reserved.

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http://www.nap.edu/catalog/11908.html F-120 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information traumatic stress disorder). Final rule. Federal Register

58(95):29109-29110. 38 CFR Part 3 

Stressor actually occurred in service (engaged in combat or evidence of the claimed in service stressor) or prisoner of war experience 

of war with military service 

• Bronchiolo-alveolar 

carcinoma 

Veterans Millennium Health Care and Benefits Act of 1999. Public Law 106-117. 106th Cong., 1st Sess., Sec. 503. 113 Stat. 1545 

November 30, 1999 

Disease contracted during military service

Diseases Associated with Chronic Effects of Exposure to Mustard Gas or Lewisite During Military ServiceNitrogen or Sulfur Mustard (38 CFR 3.316[a][1]) • Chronic 

conjunctivitis 

• Corneal opacities 

• Keratitis • Laryngeal cancer • Lung cancer (except 

mesothelioma) 

• Nasopharyngeal 

cancer 

• Scar formation • Squamous cell 

carcinoma of the skin 

Claims based on chronic effects of exposure to vesicant agents. Proposed rule. Federal Register59(15):3532-3534. 38 CFR Part 3 

January 24, 1994 

Mustard gas and other vesicant agents Full-body exposure to nitrogen or sulfur mustard or Lewisite Active military service

Conjunctivitis, Keratitis, Corneal Opacities, Scar Formation, or the Following Cancers: Nasopharyngeal, Laryngeal, Lung (except mesothelioma), or Squamous Cell Carcinoma of the Skin: Full-body exposure to nitrogen or sulfur mustard 

Chronic manifestation of the diseases after military service and either fullbody exposure to nitrogen or sulfur mustard gas or Lewisite

Amends regulation concerning chronic diseases from exposure to mustard gas and other vesicant agents in response to NAS report 
Copyright © National Academy of Sciences. All rights reserved.

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http://www.nap.edu/catalog/11908.html APPENDIX F 

F-121

Presumptive Disease 

Legislation or Regulation Date Etiology of Disease 

Location/Date of Service 

Presumptive Period 

Additional Information 

Nitrogen or Sulfur Mustard or Lewisite (38 CFR 3.316[a][2]) 

• Asthma

• Chronic form of 

bronchitis

• Chronic form of 

laryngitis

• Chronic obstructive 

pulmonary disease

• Emphysema

Nitrogen Mustard (38 CFR 3.316[a][3]) 

• Acute nonlymphocytic 

leukemia

Claims based on chronic effects of exposure to mustard gas or lewisite. Final rule. Federal Register59(159):42497-42500. 38 CFR Part 3 

August 18, 1994

Laryngitis, Bronchitis, Emphysema, Asthma, or Chronic Obstructive Pulmonary Disease: Full-body exposure to nitrogen or sulfur mustard or Lewisite Acute nonlymphocytic leukemia: Full-body exposure to nitrogen mustard 

Final rule based on NAS study and regulation on July 31, 1992, establishing service connection from exposure from field or chamber experiments during WWII. No change from proposed rule

Diseases Associated with Undiagnosed Illnesses During the Persian Gulf WarUndiagnosed IllnessSigns or Symptoms of: 

• Abnormal weight 

loss

• Cardiovascular signs 

or symptoms

• Fatigue

• Gastrointestinal signs 

or symptoms

• Headache

• Joint pain

• Menstrual disorders

• Muscle pain 

Compensation for certain undiagnosed illnesses. Proposed rule. Federal Register59(235):63283-63285. 38 CFR Part 3 

December 8, 1994 

Active military, naval, or air service

Southwest Asia theatre during the Persian Gulf War (Iraq, Kuwait, Saudi Arabia, neutral zone between Iraq and Saudi Arabia, Bahrain, Qatar, the United Arab Emirates, Oman, the Gulf of Aden, the Gulf of Oman, the Persian Gulf, 

Chronic (6 months or more) disability resulting in one or more signs and symptoms and manifested either during active service or to a 10 percent degree or more no later than 2 years after the date the veteran last performed 
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http://www.nap.edu/catalog/11908.html F-122 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information the Arabian Sea, the Red Sea, and the airspace above these 

locations

active service in the Southwest Asia theater of operations during the Persian Gulf War

Compensation for certain undiagnosed illnesses. Final rule. Federal Register60(23):6660-6666. 38 CFR Part 3

February 3, 1995 

Final rule for undiagnosed illnesses during service in the Persian Gulf War

Compensation for certain undiagnosed illnesses. Interim rule with request for comments. Federal Register62(82):23138-23139. 38 CFR Part 3 

April 29, 1997 

Persian Gulf War service

Interim rule extending the period of disease to manifest from “two years after the date on which the veteran last performed active military, naval, or air service in the Southwest Asia theater of operations during the Persian Gulf War” to “December 31, 2001” 

Interim rule to expand the period within diseases must manifest 

• Neurologic signs or 

symptoms

• Neuropsychological 

signs or symptoms

• Signs or symptoms 

involving skin

• Signs or symptoms 

involving the respiratory system (upper or lower)

• Sleep disturbances

Compensation for certain 

March 6, 1998 

Extend the presumptive 

Final rule for extending the 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-123 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information undiagnosed illnesses. Final rule. Federal Register

63(44):11122-11123. 38 CFR Part 3 

period (to December 31, 2001) in such a manner that no Persian Gulf veterans with qualifying disabilities would be denied compensation (no specific dates)

presumptive period for Persian Gulf veterans

Veterans Education and Benefits Expansion Act of 2001. Public Law 107-103. 107th Cong., 1st Sess. 

December 27, 2001 

Military service Vietnam Veteran active service Persian Gulf Exposure: Persian Gulf War service active military, naval, or air service 

Persian Gulf Exposure: Active duty in the Armed Forces in the Southwest Asia theater of operations during the Persian Gulf War 

Persian Gulf Exposure Additional Diseases: “On September 30, 2011” 

Extension of presumptive period for respiratory cancers and additional diseases associated with herbicide exposure and Persian Gulf exposure Amended list of diseases associated with military service, Persian Gulf War 

• Chronic 

multisymptom illness: 

chronic fatigue syndrome, fibromyalgia, and irritable bowel syndrome 

Extension of the presumptive period for compensation for Gulf War veterans’ undiagnosed illnesses. Interim 

November 9, 2001 

Persian Gulf War active military, naval, or air service 

Veteran who served on active duty in the Southwest Asia theater during the Persian Gulf War 

Undiagnosed illness manifest to a degree of 10 percent or more through December 31, 2006 

Extension of presumptive period for compensation for Gulf War veteran’s undiagnosed illnesses 
Copyright © National Academy of Sciences. All rights reserved.

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http://www.nap.edu/catalog/11908.html F-124 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information final rule with request for comments. Federal Register

66(218):56614-56615. 38 CFR Part 3 Extension of the presumptive period for compensation for Gulf War veterans’ undiagnosed illnesses. Final rule. Federal Register67(249):78979-78980. 38 CFR Part 3

December 27, 2002

Southwest Asia theater of operations during the Persian Gulf War 

Through December 31, 2006

Extends the period within which disabilities must become manifest for entitlement for compensation 

Compensation and pension provisions of the Veterans Education and Benefits Expansion Act of 2001. Final Rule. Federal Register68(111):34539-34543. 38 CFR Parts 3 and 13 

June 10, 2003 

 Amends what a 

“qualifying chronic disability” includes 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-125 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Extension of the presumptive period for compensation for 

Gulf War veterans. Interim final rule. Federal Register7(242):75669-75672. 38 CFR Part 3 

December 18, 2006 

 Southwest Asia 

theater of operations during the Persian Gulf War 

Through December 31, 2011 

Extends the period within which disabilities must become manifest for entitlement for compensation 

38 USC § 1117 Approved 

February 27, 2006 

Active duty in the Armed Forces during the Persian Gulf War 

Southwest Asia theater during the Persian Gulf War 

Medical or scientific evidence and historical treatment of manifestation periods that have been established 

38 USC § 1118 Approved 

February 27, 2006 

Association with exposure to a biological, chemical, or other toxic agent, environmental or wartime hazard, or preventive medicine or vaccine 

Service in the Armed Forces in the Southwest Asia theater of operations during the Persian Gulf War 

Within a period (if any) that is prescribed in a regulation 

38 CFR 3.317 Southwest Asia 

theater during the Persian Gulf War Southwest Asia theater includes 

Manifest either during active military, naval, or air service or to a degree of 10 percent or more 

Chronic disabilities for a period of 6 months or more or intermittent episodes of improvement and 
Copyright © National Academy of Sciences. All rights reserved.

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http://www.nap.edu/catalog/11908.html F-126 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Iraq, Kuwait, Saudi Arabia, neutral zone between Iraq and 

Saudi Arabia, Bahrain, Qatar, United Arab Emirates, Oman, Gulf of Aden, Gulf of Oman, Persian Gulf, Arabian Sea, Red Sea, and air space above these locations 

not later than December 31, 2006 

worsening over a 6-month period 

Language for the National Academy of Sciences report for presumption of service connection for illnesses associated with service in the Persian Gulf War 

Persian Gulf War Veterans Act of 1998. Public Law 105-277. 105th Cong., 2d Sess., Sec. 1601, 1602, 1603 

October 21, 1998 

Establishes service connection for illnesses associated with the Persian Gulf War Diseases having an association with exposure to a biological, chemical, or other toxic agent, environmental or wartime hazard, or preventive medicine or vaccine 

Veteran who served on active duty in the Southwest Asia theater during the Persian Gulf War 

Diseases Associated with Radiation-Risk Activity

• Cancer of the bone • Cancer of the brain 

Diseases specific to radiationexposed veterans. 

August 8, 2001 

Radiation-risk activity Ionizing radiation 

Total of at least 250 days before February 1, 1992 

Amends list of diseases associated with radiation-risk 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-127 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Proposed rule. Federal Register 66(153):41483- 41485. 

38 CFR Part 3 

Military service 

(Paducah, KY; Portsmouth, OH; K25 at Oak Ridge, TN) 

activities and date/location of service 

Diseases specific to radiationexposed veterans. Final rule. Federal Register67(17):3612-3616. 38 CFR Part 3 

January 25, 2002

Radiation-risk activity 

Definition: Participation in a test involving atmospheric detonation of a nuclear device; 

occupation of Hiroshima or Nagasaki, Japan (August 6, 1945, to July 1, 1946); or internment as a prisoner of war in Japan or service on active duty in Japan following such internment during WWII with opportunity for exposure to ionizing radiation

Service before January 1, 1974 (Amchitka Island, AL) and performance of duty related to Long Shot, Milrow, or Cannikin underground nuclear tests

Amends definition of radiation-risk activity

• Cancer of the colon • Cancer of the lung 

• Cancer of the ovary 

Veterans Benefits Improvement Act of 2004. Public Law 108-454. 108th Cong., 2d Sess., Sec. 306. 118 Stat. 3598 

December 10, 2004 

Radiation-risk activity Ionizing Military service 

Amended “radiation-risk activity” to include service in a capacity if performed as an employee of the DOE would qualify inclusion as a 
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http://www.nap.edu/catalog/11908.html F-128 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information member of the Special Exposure Cohort Diseases or Death NOT Associated with Military Service

Disease attributable to use of tobacco products

Claims based on the effects of tobacco products. Final rule. Federal Register

66(67):18195-18198. 38 CFR Part 3 

April 6, 2001 Active military, naval, 

or air service 

Veterans’ use of tobacco products are NOT considered to be service connected 

MiscellaneousDefinitions: Veteran Spanish-American War World War I World War II Korean conflict Armed Forces Veteran of any war Service-connected Non-service-connected Active duty Active duty for training Inactive duty training Active military, naval, or 

air service 

Former prisoner of war Reserve Vietnam era Persian Gulf war 

38 USC § 101 Approved 

February 27, 2006 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-129 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information Death 38 USC § 108 Approved February 27, 2006 7-year absence Secretary has authority to 

prescribe rules and regulations to carry out laws administered by the VA 

38 USC § 501 Approved 

February 27, 2006 

Entitlement to compensation for disability resulting from diseases contracted in line of duty in the active military, naval, or air service, during a period of war 

38 USC § 1110 Approved 

February 27, 2006 

Presumption of sound condition at the time of examination, acceptance, and enrollment into service 

38 USC § 1111 Approved 

February 27, 2006 

Aggravation to a preexisting injury or disease 

38 USC § 1153 Approved 

February 27, 2006 

Increase in disability during active military, naval, or air service, unless the increase is due to the natural progress of the disease

Veteran’s service requirements for nonservice-connected disability 

38 USC § 1521 Approved 

February 27, 2006 

Active military, naval, or air service 

Service requirements: • 90 days or 

more during a period of war 

• Period of war 
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http://www.nap.edu/catalog/11908.html F-130 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information and was discharged or released for a serviceconnected 

disability 

• 90 

consecutive days or more and began or ended during a period of war 

• Aggregate of 

90 days or more in two or more separate periods of service during more than one period of war 

Guidelines for establishing presumptions of service connection for former prisoners of war 

38 CFR 1.18 Former prisoners of 

war 

May give a minimum duration of detention or internment for application of the presumption Defines “evidence” 

Secretary may establish a presumption of service connection for a disease when there is at least limited/suggestive evidence that an increased risk of such disease is associated with 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

http://www.nap.edu/catalog/11908.html APPENDIX F F-131 Presumptive Disease Legislation or Regulation Date Etiology of Disease Location/Date of Service Presumptive Period Additional Information service involving detention or internment as a prisoner of war and 

an association between the two is biologically plausible 

Secondary condition established as service connection of the original condition 

• Cardiovascular 

disease for serviceconnected amputation 

38 CFR 3.310 Service-connected 

amputation of one lower extremity at or above the knee or service-connected amputations of both lower extremities at or above the ankles 
Copyright © National Academy of Sciences. All rights reserved.

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Copyright © National Academy of Sciences. All rights reserved.

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http://www.nap.edu/catalog/11908.html

 

G-1 

Appendix G 

VA’s White Paper on the Presumptive Disability 

Decision-Making Process 

Internal VA Process for Reviewing Reports of the Institute of Medicine Under 

the Agent Orange Act of 1991 and the Persian Gulf War Veterans Act of 1998 

BACKGROUND 

The Agent Orange Act of 1991, Pub. L. No 102-4 (codified in part at 38 U.S.C. § 1116) and 

the Persian Gulf War Veterans Act of 1998, Pub. L. No. 105-277, title XVI (codified in part at 

38 U.S.C. § 1118), direct the Secretary of Veterans Affairs to contract with the National Academy of Sciences (NAS) to evaluate the available evidence concerning the health effects of exposure to herbicides and exposure to certain hazards suspected to be associated with Gulf War service and to prepare biennial reports to the Secretary summarizing its findings based on such 

evidence. Pursuant to those statutes, NAS’s Institute of Medicine (IOM) prepares such reports 

and provides them to the Secretary. 

Upon receipt of each such report, the Secretary is required to determine whether a presumption of service connection is warranted for any diseases discussed in the report, based on the Secretary’s finding that there is a “positive association” between the exposure in question and the 

development of the disease. For this purpose, a “positive association” exists if the credible evidence for an association is equal to or outweighs the credible evidence against the association. In 

making those determinations, the Secretary is required to take into account the IOM’s report and 

all other sound scientific and medical evidence available to the Secretary. Additionally, in evaluating any study for this purpose, the Secretary is directed to consider “whether the results are statistically significant, are capable of replication, and withstand peer review.” 

If the Secretary determines that a presumption is warranted for any disease, the Secretary 

must issue rules through notice-and-comment rule-making procedures to establish the presumption. Additionally, if the Secretary determines that presumptions are not warranted for certain 

diseases discussed in the IOM report, the Secretary must publish in the Federal Register a notice 

explaining the scientific bases for such determination. 

The IOM reports prepared pursuant to these two laws typically state conclusions for each 

disease with reference to one of four or five general categories describing the strength of the 

available evidence for an association between the disease and the exposure under investigation. 
Copyright © National Academy of Sciences. All rights reserved.

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G-2 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

The four categories used in the IOM reports under both laws are “sufficient evidence of an association,” “limited/suggestive evidence of an association,” “inadequate/insufficient evidence to 

determine whether an association exists,” and “limited/suggestive evidence of no association.” 

The IOM reports under the Persian Gulf War Veterans Act include a fifth category, “sufficient 

evidence of a causal relationship.” The IOM categories intentionally do not address the central 

issue in the Secretary’s determination, i.e., the existence of a “positive association.” Accordingly, 

the Secretary is ultimately responsible for determining how the IOM’s findings, together with 

any other evidence available to the Secretary, bear upon the resolution of that ultimate question. 

This paper describes the process by which the Department of Veterans Affairs (VA) evaluates the IOM reports in order to assist the Secretary in making the determinations described 

above. 

RECEIPT OF REPORT AND IOM COMMITTEE BRIEFING 

VA ordinarily receives an embargoed copy of the IOM report a short period (about one 

week) prior to the date of the report’s public release. On or about the day of the public release, a 

representative of the IOM committee ordinarily provides VA a briefing on the report. The briefing typically identifies any significant findings in the report, any changes in the IOM’s categorization of specific diseases in comparison to prior reports, and any significant changes in the 

scope or methodology of the IOM’s investigation in comparison to prior reports, and responds to 

any questions from VA participants. The briefing is ordinarily attended by the members of VA’s 

Working Group (described below) and other interested VA personnel. 

SUMMARY OF VA’S REVIEW PROCESS 

VA has not adopted formal procedures governing its internal review of IOM reports under 

the two statutes discussed above. However, a general practice has developed that VA usually, 

though not always, follows in conducting its internal review. The general practice involves a 

three-tiered review. In the first tier, a “Working Group” of VA employees from different operational elements of VA reviews the IOM report and any other relevant evidence and prepares a 

summary of its assessment and a statement of recommendations or options. This summary is intended for the benefit of a “Task Force” composed of high-level VA officials. In the second tier, 

the Task Force, based on the Working Group’s input, provides recommendations to the Secretary, usually in the form of a separate written report. In the third tier, the Secretary determines, 

based on the Task Force’s input, whether a presumption of service connection is warranted for 

any disease. 

VA WORKING GROUP 

The Working Group ordinarily consists of members of the Office of Public Health and Environmental Hazards (OPHEH) of the Veterans Health Administration (VHA), the Compensation 

and Pension Service (C&P Service) of the Veterans Benefits Administration (VBA), and Professional Staff Group II (PSG II) of the Office of the General Counsel (OGC). Additionally, the 

Working Group often includes other VHA personnel with specialized medical training or experience concerning a health issue implicated by a particular IOM report. The members generally are 

assigned to the Working Group by supervisory personnel within VHA, VBA, and OGC. 
Copyright © National Academy of Sciences. All rights reserved.

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APPENDIX G G-3 

The Working Group generally convenes within a short time after receiving the briefing from 

the IOM committee. Prior to the meeting, VHA personnel usually will seek to identify, based on 

the IOM report and the committee briefing, the diseases that may warrant special consideration 

because the IOM’s findings with respect to those diseases appear to be potentially significant. 

Prior to or at the initial Working Group meeting, VHA generally provides the Working Group 

members with additional information concerning those diseases, including copies of any significant scientific studies identified in the IOM report and other information concerning matters such 

as the course of the disease, known causes or risk factors, related conditions or health effects, 

latency periods (if any), and any other known relevant information. 

At the initial Working Group meeting, the OGC representative briefs the Working Group on 

the legal standard governing the Secretary’s decision. Members of the Working Group generally 

will discuss whether any of the IOM’s findings appear to be potentially significant, in that they 

might warrant a presumption of service connection for a particular disease or diseases, and will 

discuss the strength of the scientific evidence with respect to such diseases. The Working Group 

will try to reach consensus as to whether the scientific evidence appears to warrant a presumption of service connection for any diseases under the applicable legal standard. If the Working 

Group reaches agreement that a presumption is or is not warranted on the basis of the scientific 

evidence and the legal standard, it will agree to put forth a recommendation based on that conclusion. In arriving at such recommendations, the Working Group relies on scientific evidence 

and the legal standard, and generally does not consider matters of governmental policy or cost. 

If the Working Group concludes that the scientific evidence and legal standard do not provide a clear basis for recommending for or against establishing a presumption, but permit a range 

of options, the Working Group generally will agree to set forth a range of options for decision by 

VA policy-making officials. In those circumstances, the Working Group will discuss the factors 

that preclude a clear recommendation, which may include ambiguity in the governing statutory 

standard as applied to certain IOM findings, the limited or conditional nature of the IOM’s findings with respect to certain diseases, or other factors. The Working Group will discuss the decisional options available to the Secretary and may also discuss the factors that may be relevant to 

the Secretary’s decision among those options. To this extent, the Working Group may discuss the 

policy considerations that would be relevant to the Secretary’s choice among permissible courses 

of action. 

Once the Working Group has reached agreement concerning its recommendations or presentation of options, members of the group will prepare a written report. The Working Group Report 

typically will contain (1) a summary of the issues to be decided under applicable law and the 

IOM report, (2) a summary of the findings contained in the IOM report, (3) a summary of the 

legal standard governing VA’s decision, (4) a summary of the Working Group’s analysis of the 

medical evidence in relation to the legal standard, particularly with respect to any potentially 

significant findings in the IOM report, and (5) a statement of the Working Group’s recommendations or of the options identified by the Working Group. The Working Group does not prepare or 

obtain a cost estimate for the options, although it may provide general information concerning, 

e.g., the prevalence rates of certain diseases under consideration. If the Working Group report 

lists a range of options available to the Secretary, it ordinarily would identify the scientific and 

legal considerations relevant to the Secretary’s choice among those options, and may also identify policy implications associated with various options. 
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G-4 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

VA TASK FORCE 

The Task Force ordinarily consists of the Under Secretary for Health, the Under Secretary for 

Benefits, the General Counsel, and the Assistant Secretary for Policy and Planning. There is no 

generally established procedure for the Task Force’s deliberations. Task Force members generally receive a copy of the Working Group report and, based on that report, provide advice to the 

Secretary concerning the Secretary’s determination, which may include recommendations based 

upon the options, if any, outlined by the Working Group. The Task Force often, though not always, provides a separate report to the Secretary, which is based largely upon the Working 

Group’s report and is usually similar to the Working Group’s report in format and content. As a 

practical matter, these Task Force reports are usually drafted by members of the Working Group, 

based on guidance from members of the Task Force. Once the report is drafted, it is circulated to 

the Task Force members for signature and is then transmitted to the Secretary. 

SECRETARY 

Based on the Task Force’s report, the Secretary determines whether to establish presumptions for any diseases discussed in the IOM report and directs appropriate action to implement 

the decision. 

ESTABLISHMENT OF PRESUMPTIONS 

If the Secretary determines that a presumption of service connection is warranted for any disease, VBA (through the C&P Service staff) will prepare proposed rules to establish such presumptions. The preamble to the proposed rule will explain the scientific and legal basis for the 

presumption and will invite comments from the public on the rule. VBA staff will prepare an estimate of the costs associated with the rule, as required by executive order. Once drafted, the 

proposed rule will be circulated to appropriate VA offices, including VHA and OGC, for review 

and concurrence. Once all offices concur, VA will transmit the proposed rule and cost estimate 

to the Office of Management and Budget (OMB) for review. If OMB approves the proposed 

rule, it will be transmitted to the Secretary for signature. VA will then transmit the rule to the 

Federal Register for publication. Once the period for providing public comments on the rule has 

ended, VBA will prepare a final rule. Subject to the same process described above for internal 

concurrence, OMB review, and the Secretary’s signature, VA will submit the final rule to the 

Federal Register for publication. 

In certain circumstances, additional review procedures may be required. For example, if a 

proposed or final rule would have an annual budgetary impact of $100 million or more, VA must 

provide a copy of the rule to Congress for review prior to publication of the rule. 

NOTICE OF DECISION NOT TO ESTABLISH PRESUMPTIONS 

If the Secretary determines that a presumption of service connection is not warranted for 

certain diseases, VBA will prepare a notice explaining the scientific basis for that decision with 

respect to each such disease. The notice is circulated for concurrence within VA in the same 

manner as a proposed rule, although VA does not prepare cost estimates with respect to the diseases concerned in this notice. The notice also may be subject to review by OMB prior to publication. Once the Secretary has signed the notice, VA will transmit it to the Federal Register for 

publication. 
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H-1 

Appendix H 

IOM’s Statements of Task and Conclusions for 

Agent Orange and Gulf War Reports 

APPENDIX H-1 

Statements of Task for IOM Reports on Agent Orange 

1994. Veterans and Agent Orange: Health Effects of Herbicides Used in Vietnam 

Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides 

Statement of Task: 

Review and summarize the strength of the scientific evidence concerning the association between herbicide exposure during Vietnam service and each disease or condition suspected to 

be associated with such exposure. Determine, if possible: 

1. Whether there is a statistical association between the suspect diseases and herbicide use, 

taking into account the strength of the scientific evidence and the appropriateness of the 

methods used to detect the association; 

2. The increased risk of disease among individuals exposed to herbicides during service in 

Vietnam; and 

3. Whether there is a plausible biologic mechanism or other evidence of a causal relationship 

between herbicide exposure and a disease. 

The committee was also asked to make recommendations concerning the need, if any, for additional scientific studies to resolve areas of continuing scientific uncertainty and to comment 

on four particular programs mandated in Public Law 102-4 (the Agent Orange Act of 1991). 

1996. Veterans and Agent Orange: Update 1996 

Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides 

Statement of Task: 

Conduct a comprehensive review of the evidence that has become available since the previous (Veterans and Agent Orange) IOM committee report and reassess its determinations and 
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H-2 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

estimates of statistical association, risk, and biological plausibility. For each disease, determine, to the extent that available data permitted meaningful determinations: 

1. Whether a statistical association with herbicide exposure exists, taking into account the 

strength of the scientific evidence and the appropriateness of the statistical and epidemiological methods used to detect the association; 

2. The increased risk of the disease among those exposed to herbicides during Vietnam service; and 

3. Whether there is a plausible biological mechanism or other evidence of a causal relationship between herbicide exposure and the disease. 

The committee was also asked to address the following specific areas of concern as requested 

by the Department of Veterans Affairs (VA): 

• The relationship between exposure to herbicides and the development of acute and 

subacute peripheral neuropathy; 

• The relationship between exposure to herbicides and the development of prostate cancer, 

hepatobiliary cancer, and nasopharyngeal cancer; and 

• The relationship between the length of time since first exposed and the possible risk of 

cancer development. 

1999. Veterans and Agent Orange: Update 1998 

Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides (Second Biannual Update) 

Statement of Task: 

Conduct a second review and evaluation of the newly published scientific evidence regarding 

associations between diseases and exposure to dioxin and other chemical compounds in herbicides used in Vietnam. For each disease, determine, to the extent that available data permitted meaningful determinations: 

1. Whether a statistical association with herbicide exposure exists, taking into account the 

strength of the scientific evidence and the appropriateness of the statistical and epidemiologic methods used to detect the association; 

2. The increased risk of the disease among those exposed to herbicides during Vietnam service; and 

3. Whether there is a plausible biological mechanism or other evidence of a causal relationship between herbicide exposure and the disease. 

The committee also addressed the following specific areas of interest as identified by VA: 

 

• The relationship between exposure to herbicides and the subsequent development of diabetes; 

• The issue of the latency between exposure to herbicides and development of adverse 

health outcomes; 

• The classification of chondrosarcomas of the skull; 
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APPENDIX H H-3 

• Herbicide exposure assessment for Vietnam veterans; and 

• The potential for using data combination methodologies to informatively reexamine existing data on the health effects of herbicide or dioxin exposure. 

2000. Veterans and Agent Orange: Herbicide/Dioxin Exposure and Type 2 Diabetes 

Committee to Review the Evidence Regarding the Link Between Exposure to Agent Orange and 

Diabetes 

Statement of Task: 

Conduct a focused review of the scientific evidence regarding the association, if any, between type 2 diabetes and exposure to dioxin and other chemical compounds in herbicides 

used in Vietnam. Determine, to the extent that available data permitted meaningful determinations: 

1. Whether a statistical association with herbicide exposure exists, taking into account the 

strength of the scientific evidence and the appropriateness of the statistical and epidemiologic methods used to detect the association; 

2. The increased risk of the disease among those exposed to herbicides during Vietnam service; and 

3. Whether there is a plausible biological mechanism or other evidence of a causal relationship between herbicide exposure and the disease. 

2001. Veterans and Agent Orange: Update 2000 

Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides 

(Third Biennial Update) 

Statement of Task: 

 

Conduct a third review and evaluation of the newly published scientific evidence regarding 

associations between health outcomes and exposure to dioxin and other chemical compounds 

in herbicides used in Vietnam. For each disease, determine, to the extent that available data 

permitted meaningful determinations: 

1. Whether a statistical association with herbicide exposure exists, taking into account the 

strength of the scientific evidence and the appropriateness of the statistical and epidemiologic methods used to detect the association; 

2. The increased risk of the disease among those exposed to herbicides during Vietnam service; and 

3. Whether there is a plausible biologic mechanism or other evidence of a causal relationship between herbicide exposure and the disease. 

At VA’s request, the committee also examined the possible association between the herbicides of concern in this report and AL-type primary amyloidosis, a condition not examined in 

previous Veterans and Agent Orange reports. 
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H-4 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

2002. Veterans and Agent Orange: Herbicide/Dioxin Exposure and Acute Myelogenous 

Leukemia in the Children of Vietnam Veterans 

Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides 

Statement of Task: 

Conduct a review of the scientific evidence regarding the association between exposure to 

dioxin and other chemical compounds in herbicides used in Vietnam and acute myelogenous 

leukemia in the offspring of Vietnam veterans. Determine, to the extent that available data 

permitted meaningful determinations: 

1. Whether a statistical association with herbicide exposure exists, taking into account the 

strength of the scientific evidence and the appropriateness of the statistical and epidemiologic methods used to detect the association; 

2. The increased risk of the disease associated with exposure to herbicides during Vietnam 

service; and 

3. Whether there is a plausible biological mechanism or other evidence of a causal relationship between herbicide exposure and the disease. 

2003. Veterans and Agent Orange: Update 2002 

Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides (Fourth 

Biennial Update) 

Statement of Task: 

Conduct a fourth review and evaluation of the newly published scientific evidence regarding 

the association between exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other 

chemical compounds contained in herbicides used in Vietnam and a wide range of health effects. Determine, to the extent that available data permit meaningful determinations: 

1. Whether a statistical association with herbicide exposure exists, taking into account the 

strength of the scientific evidence and the appropriateness of the statistical and epidemiological methods used to detect the association; 

2. The increased risk of the disease among those exposed to herbicides during service in the 

Republic of Vietnam during the Vietnam era; and 

3. Whether there exists a plausible biological mechanism or other evidence of a causal relationship between herbicide exposure and the disease. 

2004. Veterans and Agent Orange: Length of Presumptive Period for Association Between 

Exposure and Respiratory Cancer 

Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides 

Statement of Task: 

Undertake a review and evaluation of the evidence regarding the period between cessation of 

exposure to herbicides used in Vietnam and their contaminants (2,4-D; 2,4,5-T and its contaminant TCDD; cacodylic acid; and picloram) and the occurrence of respiratory cancer. 
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APPENDIX H H-5 

2005. Veterans and Agent Orange: Update 2004 

Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides (Fifth 

Biennial Update) 

Statement of Task: 

Determine (to the extent that available scientific data permit meaningful determinations) the 

following regarding associations between specific health outcomes and exposure to TCDD 

and other chemical compounds in herbicides: 

1. Whether a statistical association with herbicide exposure exists, taking into account the 

strength of the scientific evidence and the appropriateness of the statistical and epidemiological methods used to detect the association; 

2. The increased risk of the disease among those exposed to herbicides during service in the 

Republic of Vietnam during the Vietnam era; and 

3. Whether there exists a plausible biological mechanism or other evidence of a causal relationship between herbicide exposure and the disease. 

2007. Veterans and Agent Orange: Update 2006. The Sixth Biennial Update report on Veterans and Agent Orange was released at the end of July 2007. The report was in development at 

the same time as and independent of the Committee’s report, and therefore, was unavailable to 

the Committee during their deliberations. 

REFERENCES

IOM (Institute of Medicine). 1994. Veterans and Agent Orange: Health effects of herbicides 

used in Vietnam. Washington, DC: National Academy Press. 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy 

Press. 

IOM. 1999. Veterans and Agent Orange: Update 1998. Washington, DC: National Academy 

Press. 

IOM. 2000. Veterans and Agent Orange: Herbicide/dioxin exposure and type 2 diabetes. Washington, DC: National Academy Press. 

IOM. 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy 

Press. 

IOM. 2002. Veterans and Agent Orange: Herbicide/dioxin exposure and acute myelogenous leukemia in the children of Vietnam veterans. Washington, DC: The National Academies Press. 

IOM. 2003. Veterans and Agent Orange: Update 2002. Washington, DC: The National Academies Press. 

IOM. 2004. Veterans and Agent Orange: Length of presumptive period for association between 

exposure and respiratory cancer. Washington, DC: The National Academies Press. 

IOM. 2005. Veterans and Agent Orange: Update 2004. Washington, DC: The National Academies Press. 

IOM. 2007. Veterans and Agent Orange: Update 2006. Washington, DC: The National Academies Press. 
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H-6 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

APPENDIX H-2 

Statements of Task for IOM Reports on Gulf War 

2000. Gulf War and Health, Volume 1: Depleted Uranium, Pyridostigmine Bromide, Sarin, 

Vaccines 

Committee on Health Effects Associated with Exposures During the Gulf War 

Summary of Charge: 

The purpose of this study was to conduct a review of the scientific and medical literature regarding adverse health effects associated with exposures experienced during the Persian Gulf 

War. The review included assessments of biological plausibility that exposures, or synergistic effects of combinations of exposures, are associated with illnesses experienced by Gulf 

War veterans. The review also included recommendations for additional scientific studies to 

resolve areas of continued scientific uncertainty related to the health consequences of Gulf 

War service. Exposures considered included depleted uranium, chemical warfare agents (sarin and cyclosarin), pyridostigmine bromide, and vaccines (anthrax and botulinum toxoid). 

2003. Gulf War and Health, Volume 2: Insecticides and Solvents 

Committee on Gulf War and Health: Literature Review of Pesticides and Solvents

Summary of Charge: 

This committee reviewed the peer-reviewed literature on long-term health outcomes associated with exposure to classes of insecticides (such as organophosphorous compounds) identified as having been used in the Persian Gulf, as well as 53 specific solvents. The committee’s 

review focused primarily on epidemiologic studies of humans who had been exposed to these 

insecticides and solvents in occupational settings. Where available, studies of Gulf War veterans were included as well. Information on plausible biologic mechanisms of health outcomes came from toxicological and experimental data studies of both humans and animals. 

2004. Gulf War and Health: Updated Literature Review of Sarin 

Committee on Gulf War and Health: Updated Literature Review of Sarin 

Summary of Charge: 

 Following publication of studies of sarin exposure from terrorist attacks in Japan, toxicological studies of low-dose exposure to sarin, and possible sarin exposure of veterans during the 

Gulf War, this ad hoc committee was formed and tasked with conducting an updated assessment of the literature on health outcomes associated with exposure to sarin and cyclosarin. 

The review built upon the information previously developed by earlier IOM reports on health 

outcomes associated with exposure to sarin and related compounds. In its final report, the 

committee also outlined recommendations for additional studies to resolve areas of continued 

scientific uncertainty. 

2005. Gulf War and Health, Volume 3: Fuels, Combustion Products, and Propellants 

Committee on Gulf War and Health: Literature Review of Selected Environmental Particulates, 

Pollutants, and Synthetic Chemical Compounds 

Summary of Charge: 
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APPENDIX H H-7 

This committee reviewed the scientific literature to examine the health effects of hydrazines, 

red fuming nitric acid, hydrogen sulfide, oil-fire by-products, diesel-heater fumes, and fuels 

(for example, jet fuel and gasoline). The committee’s review focused on epidemiologic studies but included other relevant literature with regard to chronic medical effects of exposure, 

including studies of Gulf War veterans. The committee was also charged with determining, 

to the extent permitted by available scientific data, the increased risk of illness among people 

exposed to the putative agents during service in the Persian Gulf. 

2006a. Gulf War and Health, Volume 4: Health Effects of Serving in the Gulf War 

Committee on Gulf War and Health: A Review of the Medical Literature Relative to Gulf War 

Veterans’ Health 

Summary of Charge: 

The work of this committee was different from that of prior Gulf War and Health committees 

in that this study was an attempt to summarize health outcomes associated with deployment, 

rather than health outcomes associated with a specific biologic or chemical agent believed to 

have been present in the Gulf. This study was developed to inform the VA of illnesses among 

Gulf War veterans that might not have been evident at the time. The committee’s specific 

charge was to review, evaluate, and summarize the peer-reviewed scientific and medical literature addressing the health status of Gulf War veterans. The committee reviewed epidemiologic studies to draw conclusions regarding long-term health outcomes (such as cancer, cardiovascular disease, and nervous system disorders) associated with serving in the Gulf War. 

2006b. Posttraumatic Stress Disorder: Diagnosis and Assessment 

Subcommittee on Posttraumatic Stress Disorder of the Committee on Gulf War and Health: 

Physiologic, Psychologic, and Psychosocial Effects of Deployment-Related Stress 

Summary of Charge: 

This committee’s task was to review the scientific and medical literature related to the diagnosis and assessment of posttraumatic stress disorder (PTSD). The committee was also given 

a series of specific questions from VA regarding diagnosis and assessment of PTSD. These 

included, among others, questions regarding accepted diagnostic criteria for PTSD, how best 

to diagnose and document stressful events, and the components of an evidence-based diagnosis of PTSD. The committee relied primarily on reviews and other well-documented sources 

to form conclusions regarding diagnosis and assessment of PTSD. The committee will, at a 

later date, deliver a second report on PTSD treatments and their efficacy, and also comment 

on the chronicity of PTSD, the potential for recovery, and the value of early intervention. 

2007. Gulf War and Health, Volume 5: Infectious Diseases 

Committee on Gulf War and Health: Infectious Diseases 

Summary of Charge: 

This committee evaluated the scientific and medical literature on long-term adverse human 

health outcomes associated with nine infectious diseases potentially acquired by veterans 

during the Gulf War. These infectious diseases included brucellosis, campylobacteriosis, 

leishmaniasis, malaria, Q fever, salmonellosis, shigellosis, tuberculosis, and West Nile fever. 
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H-8 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

The committee’s report also included information on specific diseases and agents reported 

in the published literature or popular press to have infectious agents and to have caused 

illnesses in veterans of the Gulf War, Operation Iraqi Freedom, and Operation Enduring 

Freedom. 

REFERENCES 

IOM (Institute of Medicine). 2000. Gulf War and health, volume 1: Depleted uranium, pyridostigmine bromide, sarin, vaccines. Washington, DC: National Academy Press. 

IOM. 2003. Gulf War and health, volume 2: Insecticides and solvents. Washington, DC: The National Academies Press. 

IOM. 2004. Gulf War and health: Updated literature review of sarin. Washington, DC: The National Academies Press. 

IOM. 2005. Gulf War and health, volume 3: Fuels, combustion products, and propellants. Washington, DC: The National Academies Press. 

IOM. 2006a. Gulf War and health, volume 4: Health effects of serving in the Gulf War. Washington, DC: The National Academies Press. 

IOM. 2006b. Posttraumatic stress disorder: Diagnosis and assessment. Washington, DC: The 

National Academies Press. 

IOM. 2007. Gulf War and health, volume 5: Infectious diseases. Washington, DC: The National 

Academies Press. 

APPENDIX H-3 

Conclusions from IOM’s Agent Orange Biennial Reports1

Sufficient Evidence of an Association 

Evidence is sufficient to conclude that there is a positive association. That is, a positive association has been observed between herbicides and the outcome in studies in which chance, bias, 

and confounding could be ruled out with reasonable confidence. For example, if several small 

studies that are free from bias and confounding show an association that is consistent in magnitude and direction, there may be sufficient evidence for an association. 

• Chloracne (1994) 

• Chronic lymphocytic leukemia (CLL) (2003)2

• Hodgkin’s disease (1994) 

• Non-Hodgkin’s lymphoma (1994) 

• Porphyria cutanea tarda (in genetically susceptible individuals) (1994) 

• Soft tissue sarcoma (1994) 

 

1

 NOTE: “Herbicides” refers to the major herbicides used in Vietnam, which include 2,4-D (2,4-

dichlorophenoxyacetic acid), 2,4,5-T (2,4,5-trichlorophenoxyacetic acid), TCDD (2,3,7,8-tetrachlorodibenzo-pdioxin)—2,4,5-T contaminant, cacodylic acid, picloram. The evidence regarding association was drawn from occupational and other studies in which subjects were exposed to a variety of herbicides and herbicide components. 

2

 Previously listed under Inadequate/Insufficient Evidence category (as leukemia). 
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APPENDIX H H-9 

Limited/Suggestive Evidence of an Association 

Evidence is suggestive of an association between herbicides and the outcome but is limited because chance, bias, and confounding could not be ruled out with confidence. For example, at 

least one high-quality study shows a positive association, but the results of other studies are 

inconsistent. 

• Acute and subacute peripheral neuropathy (1996); acute and subacute transient peripheral 

neuropathy (1999); early-onset transient peripheral neuropathy (2005) 

• Acute myelogenous leukemia (AML) in the children of veterans (2001) 

• Multiple myeloma (1994) 

• Porphyria cutanea tarda (1996)3

• Prostate cancer (1994) 

• Respiratory cancers (lung, larynx, trachea) (1994); respiratory cancers (lung/bronchus, 

larynx, trachea) (1999); respiratory cancer (of lung and bronchus, larynx, and trachea) 

(2003) 

• Spina bifida (1996); spina bifida in the children of veterans (1999); spina bifida in the offspring of exposed individuals (2005) 

• Type 2 diabetes (2000)4

Inadequate/Insufficient Evidence to Determine Whether an Association Exists 

The available studies are of insufficient quality, consistency, or statistical power to permit a 

conclusion regarding the presence or absence of an association. For example, studies fail to control for confounding, have inadequate exposure assessment, or fail to address latency. 

• Abnormal sperm parameters and infertility (1994); abnormal sperm characteristics and infertility (2003) 

• AL-type primary amyloidosis (2001) 

• Birth defects (1994); birth defects (other than spina bifida) (1996); birth defects (other 

than spina bifida) in the offspring of exposed individuals (2005) 

• Bone cancer (1994); bone and joint cancer (2005) 

• Breast cancer (1994) 

• Childhood cancer in offspring (1994); childhood cancer in offspring, other than AML 

(2001); childhood cancer in offspring, including AML (2003); childhood cancer (including AML) in offspring of exposed individuals (2005) 

• Circulatory disorders (1994) 

• Cognitive and neuropsychiatric disorders (1994); neurobehavioral disorders (cognitive and 

neuropsychiatric) (2005) 

• Effects on thyroid homeostasis (2003) 

• Endometriosis (2003) 

 

3

 Previously listed under Sufficient Evidence of an Association category (as porphyria cutanea tarda [in genetically 

susceptible individuals]). 

4

 Previously listed under Inadequate/Insufficient Evidence category (within metabolic and digestive disorders [diabetes, changes in liver enzymes, lipid abnormalities, ulcers]). 
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H-10 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

• Female reproductive cancers (cervical, uterine, ovarian) (1994) 

• Hepatobiliary cancers (1994) 

• Immune system disorders (immune modulation and autoimmunity) (1994); immune system disorders (immune suppression and autoimmunity) (1996) 

• Leukemia (1994); leukemia (other than CLL) (2003) 

• Low birthweight (1994); low birthweight in offspring of exposed individuals (2005) 

• Metabolic and digestive disorders (diabetes, changes in liver enzymes, lipid abnormalities, 

ulcers) (1994); gastrointestinal, metabolic and digestive disorders (changes in liver enzymes, lipid abnormalities, ulcers) (2001) 

• Motor/coordination dysfunction (1994); movement disorders, including Parkinson’s disease and amyotrophic lateral sclerosis (ALS) (2005) 

• Nasal/nasopharyngeal cancer (1994); oral, nasal, and pharyngeal cancer (2005) 

• Neonatal/infant death and stillbirths (1994); neonatal or infant death and stillbirth in offspring of exposed individuals (2005) 

• Peripheral nervous system disorders (1994); chronic peripheral nervous system disorders 

(1996) 

• Renal cancer (1994) 

• Respiratory disorders (1994) 

• Skin cancers (1996);5

 skin cancers (melanoma, basal, and squamous) (2001); skin cancers 

(melanoma, basal cell, and squamous cell) (2005) 

• Spontaneous abortion (1994) 

• Testicular cancer (1994) 

• Urinary bladder cancer (1999)6

Limited/Suggestive Evidence of No Association 

Several adequate studies, covering the full range of levels of exposure that human beings are 

known to encounter, are mutually consistent in not showing a positive association between exposure to herbicides and the outcome at any level of exposure. A conclusion of “no association” 

is inevitably limited to the conditions, level of exposure, and length of observation covered by 

the available studies. In addition, the possibility of a very small elevation in risk at the levels of 

exposure studied can never be excluded. 

• Bladder cancer (1994) 

• Brain tumors (1994) 

• Gastrointestinal tumors (stomach cancer, pancreatic cancer, colon cancer, rectal cancer) 

(1994); gastrointestinal tumors (esophagus, stomach, pancreas, colon, rectum) (2005) 

• Skin cancer (1994) 

REFERENCES 

IOM (Institute of Medicine). 1994. Veterans and Agent Orange: Health effects of herbicides 

used in Vietnam. Washington, DC: National Academy Press. 

 

5

 Previously listed under Limited/Suggestive Evidence of No Association category. 6

 Previously listed under Limited/Suggestive Evidence of No Association category (as bladder cancer). 
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APPENDIX H H-11 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy 

Press. 

IOM. 1999. Veterans and Agent Orange: Update 1998. Washington, DC: National Academy 

Press. 

IOM. 2000. Veterans and Agent Orange: Herbicide/dioxin exposure and type 2 diabetes. Washington, DC: National Academy Press. 

IOM. 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy 

Press. 

IOM. 2003. Veterans and Agent Orange: Update 2002. Washington, DC: The National Academies Press. 

IOM. 2005. Veterans and Agent Orange: Update 2004. Washington, DC: The National Academies Press. 

APPENDIX H-4 

Conclusions from IOM’s Gulf War and Health Series 

Volumes 1, 2, 3, 5, and Updated Literature Review of Sarin7

Sufficient Evidence of a Causal Relationship 

Evidence is sufficient to conclude that there is a causal association between exposure to a specific agent and a specific health outcome in humans. The evidence is supported by experimental 

data and fulfills the guidelines for sufficient evidence of an association (below). The evidence 

must be biologically plausible and satisfy several of the guidelines used to assess causality, such 

as strength of association, dose–response relationship, consistency of association, and a temporal relationship. 

• Benzene and 

• acute leukemia (2003) 

• aplastic anemia (2003) 

• Coxiella burnettii infection (Q fever) and osteomyelitis (2007) 

• Malarial infection and ophthamologic, hematologic, and renal manifestations as well as 

later presentation of or relapse of disease months to years after acute infection (2007) 

• Mycobacterium tuberculosis infection and occurrence of active (tuberculosis) TB months 

to decades after infection (2007) 

• Sarin and a dose-dependent acute cholinergic syndrome that is evident seconds to hours 

subsequent to sarin exposure and resolves in days to months (2000) 

Sufficient Evidence of an Association 

Evidence is sufficient to conclude that there is a positive association. That is, a consistent positive association has been observed between exposure to a specific agent and a specific health 

outcome in human studies in which chance and bias, including confounding, could be ruled out 

with reasonable confidence. For example, several high-quality studies report consistent positive 

 

7

 The Gulf War Volume 4 summary of evidence is not included in this review because that committee’s 

charge was to examine health outcomes related to deployment in general, rather than the specific biological 

or chemical agents believed to have been present in the Gulf region (IOM, 2006). 
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H-12 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

associations, and the studies are sufficiently free of bias, including adequate control for confounding. 

• Active TB and long-term adverse health outcomes due to irreversible tissue damage from 

severe forms of pulmonary and extrapulmonary TB (2007) 

• Anthrax vaccination and transient acute local and systemic effects (2000) 

• Benzene and adult leukemia (2003) 

• Botulinum toxoid vaccination and transient acute local and systemic effects (2000) 

• Brucellosis and 

• arthritis and spondylitis (2007) 

• cardiovascular, nervous, and respiratory system infections (2007) 

• chronic meningitis and meningoencephalitis (2007) 

• hepatic abnormalities, including granulomatous hepatitis (2007) 

• orchioepididymitis and infections of the genitourinary system (2007) 

• uveitis (2007) 

• Campylobacter infection and reactive arthritis (ReA) if ReA is manifest within 3 months 

of the infection (2007) 

• Campylobacter jejuni infection and Guillain-Barre syndrome (GBS) if GBS is manifest 

within 2 months of infection (2007) 

• Combustion products and lung cancer (2005) 

• Coxiella burnetii infection (Q fever) and 

• chronic hepatitis years after primary infection (2007) 

• endocarditis years after primary infection (2007) 

• vascular infection years after primary infection (2007) 

• Nontyphoid Salmonella infection and ReA if ReA is manifest within 3 months of the infection (2007) 

• Plasmodium falciparum infection with recrudescence weeks to months after the primary 

infection, but only in the case of inadequate therapy (2007) 

• Plasmodium malariae infection and manifestation of immune-complex glomerulonephritis 

years to decades later (2007) 

• Propylene glycol and allergic contact dermatitis (2003) 

• Pyridostigmine bromide and transient acute cholinergic effects in doses normally used in 

treatment and for diagnostic purposes (2000) 

• Shigella infection and 

• hemolytic-uremia syndrome (HUS) if HUS is manifest within 1 month of the infection 

(2007) 

• ReA if ReA is manifest within 3 months of the infection (2007) 

• Solvents and acute leukemia (2003) 

• Visceral leishmaniasis (kala-azar) and 

• delayed presentation of the acute clinical syndrome (2007) 

• Post-kala-azar dermal leishmaniasis (PKDL) if PKDL occurs generally within 2 years 

of the initial infection (2007) 
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APPENDIX H H-13 

• reactivation of visceral leishmaniasis in the context of future immunosuppression 

(2007) 

• West Nile virus infection and variable physical, functional, or cognitive disability, which 

may persist for months or years or be permanent (2007) 

Limited/Suggestive Evidence of an Association 

Evidence is suggestive of an association between exposure to a specific agent and a specific 

health outcome, but the body of evidence is limited by the inability to rule out chance and bias, 

including confounding, with confidence. For example, at least one high-quality study reports a 

positive association that is sufficiently free of bias, including adequate control for confounding. 

Other corroborating studies provide support for the association, but they were not sufficiently 

free of bias, including confounding. Alternatively, several studies of lower quality show consistent positive associations, and the results are probably not due to bias, including confounding. 

Cancers 

• Benzene and non-Hodgkin’s lymphoma (2003) 

• Carbamates and non-Hodgkin’s lymphoma (2003) 

• Combustion products and 

• bladder cancer (2005) 

• cancers of the nasal cavity and nasopharynx (2005) 

• cancers of the oral cavity and oropharynx (2005) 

• laryngeal cancer (2005) 

• Hydrazines and lung cancer (2005) 

• Organophosphorus insecticides and 

• adult leukemia (2003) 

• non-Hodgkin’s lymphoma (2003) 

• Solvents and 

• adult leukemia (2003) 

• bladder cancer (2003) 

• multiple myeloma (2003) 

• myelodysplastic syndromes (2003) 

• Tetrachloroethylene and dry-cleaning solvents and 

• bladder cancer (2003) 

• kidney cancer (2003) 

Neurologic Effects 

• Organophosphorus (OP) insecticide exposure with OP poisoning and long-term neurobehavioral effects (that is, abnormal results on neurobehavioral test batteries and symptom 

findings) (2003) 
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• Plasmodium falciparum infection and neurologic disease, neuropsychiatric disease, or both 

months to years after the acute infection (2007) 

• Plasmodium vivax and Plasmodium falciparum infections and demyelinating polyneuropathy and GBS (2007) 

• Sarin at doses sufficient to cause acute cholinergic signs and symptoms and a variety of 

subsequent long-term neurological effects (2004) 

• Solvents and neurobehavioral effects (that is, abnormal results on neurobehavioral test batteries and symptom findings) (2003) 

Other Health Effects 

• Brucellosis and 

• fatigue, inattention, amnesia, and depression (2007) 

• myelitis-radiculoneuritis, demyelinating meningovascular syndromes, deafness, sensorineural hearing loss, and GBS (2007) 

• papilledema, optic neuritis, episcleritis, nummular keratitis, and multifocal choroiditis 

(2007) 

• Campylobacter jejuni infection and development of uveitis if uveitis is manifest within 1 

month of infection (2007) 

• Coxiella burnetii infection and post–Q fever chronic fatigue syndrome years after the primary infection (2007) 

• Insecticides and allergic contact dermatitis (2003) 

• Sarin at doses sufficient to cause acute cholinergic signs and symptoms and subsequent 

long-term health effects (2000) 

• Solvents and 

• chronic glomerulonephritis (2003) 

• hepatic steatosis (2003) 

• reactive airways dysfunction syndrome, which would be evident with exposure and 

could persist for months or years (2003) 

Reproductive Effects 

• Combustion products and 

• low birthweight/intrauterine growth retardation and exposure during pregnancy (2005) 

• preterm birth and exposure during pregnancy (2005) 

Respiratory Effects 

• Combustion products and incident asthma (2005) 
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APPENDIX H H-15 

Inadequate/Insufficient Evidence to Determine Whether an Association Exists 

Evidence is of insufficient quantity, quality, or consistency to permit a conclusion regarding the 

existence of an association between exposure to a specific agent and a specific health outcome 

in humans. 

Cancers 

• Benzene and myelodysplastic syndromes (2003) 

• Combustion products and 

• colon cancer (2005) 

• esophageal cancer (2005) 

• female breast cancer (2005) 

• female genital cancers (cervical, endometrial, uterine, and ovarian cancers) (2005) 

• hepatic cancer (2005) 

• Hodgkin’s disease (2005) 

• kidney cancer (2005) 

• leukemia (2005) 

• male breast cancer (2005) 

• melanoma (2005) 

• multiple myeloma (2005) 

• nervous system cancers (2005) 

• non-Hodgkin’s lymphoma (2005) 

• ocular melanoma (2005) 

• pancreatic cancer (2005) 

• prostatic cancer (2005) 

• rectal cancer (2005) 

• stomach cancer (2005) 

• testicular cancer (2005) 

• Fuels and 

• bladder cancer (2005) 

• cancers of the nasal cavity and nasopharynx (2005) 

• cancers of the oral cavity and oropharynx (2005) 

• colon cancer (2005) 

• esophageal cancer (2005) 

• female breast cancer (2005) 

• female genital cancers (cervical, endometrial, uterine, and ovarian 

cancers) (2005) 

• hepatic cancer (2005) 

• Hodgkin’s disease (2005) 

• kidney cancer (2005) 

• laryngeal cancer (2005) 

• lung cancer (2005) 
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• male breast cancer (2005) 

• melanoma (2005) 

• multiple myeloma (2005) 

• myelodysplastic syndromes (2005) 

• nervous system cancers (2005) 

• non-Hodgkin’s lymphoma (2005) 

• nonmelanoma skin cancer (2005) 

• pancreatic cancer (2005) 

• prostatic cancer (2005) 

• rectal cancer (2005) 

• stomach cancer (2005) 

• testicular cancer (2005) 

• Hydrazines and 

• bladder cancer (2005) 

• digestive tract cancers (2005) 

• hematopoietic and lymphopoietic cancers (2005) 

• kidney cancer (2005) 

• pancreatic cancer (2005) 

• Insecticides and 

• brain and other central nervous system (CNS) cancers (2003) 

• lung cancer (2003) 

• pancreatic cancer (2003) 

• prostate, testicular, bladder, or kidney cancers (2003) 

• soft tissue sarcomas (2003) 

• Insecticides and solvents and 

• hepatobiliary cancers (2003) 

• Hodgkin’s disease (2003) 

• multiple myeloma (2003) 

• Insecticides, parental preconception exposure, and childhood leukemias, brain and other 

CNS cancers, and non-Hodgkin’s lymphoma (2003) 

• Lindane and solvents and breast cancer (2003) 

• Nitric acid and 

• bladder cancer (2005) 

• laryngeal cancer (2005) 

• lung cancer (2005) 

• lymphopoietic cancers (2005) 

• melanoma (2005) 

• multiple myeloma (2005) 

• pancreatic cancer (2005) 

• stomach cancer (2005) 
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APPENDIX H H-17 

• Solvents and 

• bone cancer (2003) 

• melanoma or nonmelanoma skin cancer (2003) 

• oral, nasal, or laryngeal cancer (2003) 

• ovarian or uterine cancer (2003) 

• prostate cancer (2003) 

• stomach, rectal, or pancreatic cancer (2003) 

• Solvents other than tetrachloroethylene and dry-cleaning solvents and 

• bladder cancer (2003) 

• esophageal cancer (2003) 

• kidney cancer (2003) 

• lung cancer (2003) 

• Solvents other than trichloroethylene and cervical cancer (2003) 

• Solvents other than trichloroethylene and mixtures of benzene, toluene, and xylene and colon cancer (2003) 

• Solvents, parental preconception exposure to solvents and neuroblastoma and childhood 

brain cancers (2003) 

• Specific solvents other than benzene and 

• acute and adult leukemia (2003) 

• brain and other central nervous system cancers (2003) 

• non-Hodgkin’s lymphoma (2003) 

• Uranium and 

• bone cancer (2000) 

• lung cancer at higher levels of cumulative exposure (>200 mSv or 25 cGy) (2000) 

• lymphatic cancer (2000) 

Cardiovascular Effects 

• Combustion products and ischemic heart disease or myocardial infarction (less than 2 

years of exposure) (2005) 

• Hydrazines and ischemic heart disease or myocardial infarction (2005) 

• Nitric acid and cardiovascular diseases (2005)

• Sarin and subsequent long-term cardiovascular effects (2004)

• Uranium and cardiovascular effects (2000)

Dermal Effects 

• Combustion products and dermatitis—irritant and allergic (2005)

• Fuels and dermatitis—irritant and allergic (2005) 

• Uranium and dermal effects (2000)
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H-18 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Neurologic Effects 

• Combustion products and 

• Multiple Chemical Sensitivity symptoms (2005) 

• nervous system subgroupings (or individual nervous system diseases) (2005) 

• neurobehavioral effects (2005) 

• posttraumatic stress disorder (2005) 

• Fuels and 

• Multiple Chemical Sensitivity symptoms (2005) 

• neurobehavioral effects (2005) 

• peripheral neuropathy (2005) 

• Insecticides and solvents and 

• ALS (2003) 

• Alzheimer’s disease (2003) 

• Parkinson’s disease (2003) 

• peripheral neuropathy (2003) 

• Sarin at low doses insufficient to cause acute cholinergic signs and symptoms and subsequent long-term adverse neurological health effects (2004) 

• Solvents and 

• long-term hearing loss (2003) 

• long-term reduction in color discrimination (2003) 

• long-term reduction in olfactory function (2003) 

• multiple sclerosis (2003) 

• Uranium and nervous system disease (2000) 

Reproductive Effects 

• Combustion products and 

• all childhood cancers identified, including acute lymphocytic leukemia, leukemia, 

neuroblastoma, and brain cancer (2005) 

• low birthweight and intrauterine growth retardation and exposure before gestation or 

during any specific period during pregnancy (for example, the first trimester) (2005) 

• preterm births and exposure during any specific time period during pregnancy (for example, the first trimester) (2005) 

• specific birth defects, including cardiac effects, and exposure before conception (maternal and paternal) or during early pregnancy (maternal) (2005) 

• Fuels and adverse reproductive or developmental outcomes (including infertility, spontaneous abortion, childhood leukemia, CNS tumors, neuroblastoma, and Prader-Willi syndrome) (2005) 

• Insecticides and solvents and male or female infertility after cessation of exposure (2003) 

• Insecticides or solvents, parental preconception exposure, and 
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APPENDIX H H-19 

• congenital malformations (2003) 

• spontaneous abortion or other adverse pregnancy outcomes (2003) 

• Uranium and reproductive or developmental dysfunction (2000) 

Respiratory Effects 

• Combustion products and 

• chronic bronchitis (less than 1 year of exposure) (2005) 

• chronic obstructive pulmonary disease (2005) 

• emphysema (2005) 

• Fuels and 

• asthma (2005) 

• chronic bronchitis (2005) 

• emphysema (2005) 

• nonmalignant respiratory disease (2005) 

• Hydrazines and emphysema (2005) 

• Uranium and nonmalignant respiratory disease (2000) 

Other Health Effects 

• Anthrax vaccination and long-term adverse health effects (2000) 

• Botulinum toxoid vaccination and long-term adverse health effects (2000) 

• Combustion products and sarcoidosis (2005) 

• Fuels and sarcoidosis (2005) 

• Hydrazines and hepatic disease (2005) 

• Insecticides and aplastic anemia (2003) 

• Insecticides and solvents and 

• irreversible cardiovascular outcomes (2003) 

• persistent respiratory symptoms or impairment after cessation of exposure (2003) 

• Multiple vaccinations and long-term adverse health effects (2000) 

• Pyridostigmine bromide and long-term adverse health effects (2000) 

• Sarin, exposure at low doses insufficient to cause acute cholinergic signs and symptoms 

and subsequent long-term adverse health effects (2000) 

• Solvents and 

• alterations in liver function tests after cessation of exposure (2003) 

• chronic pancreatitis and other persistent gastrointestinal outcomes (2003) 

• cirrhosis (2003) 

• the systemic rheumatic diseases: scleroderma, rheumatoid arthritis, undifferentiated 

connective tissue disorders, and systemic lupus erythematosus (2003) 

• Solvents other than benzene and aplastic anemia (2003) 
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H-20 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

• Uranium and 

• effects on hematological parameters (2000) 

• gastrointestinal disease (2000) 

• genotoxic effects (2000) 

• hepatic disease (2000) 

• immune-mediated disease (2000) 

• musculoskeletal effects (2000) 

• ocular effects (2000) 

Limited/Suggestive Evidence of No Association 

Evidence is consistent in not showing a positive association between exposure to a specific 

agent and a specific health outcome after exposure of any magnitude. A conclusion of no association is inevitably limited to the conditions, magnitudes of exposure, and length of observation 

in the available studies. The possibility of a very small increase in risk after exposure studied 

cannot be excluded. 

• Exposure to uranium and lung cancer at cumulative internal dose levels lower than 200 

mSv or 25 cGy (2000) 

• Uranium and clinically significant renal dysfunction (2000) 

Consensus Not Reached on Category of Association 

• Benzene and solvents and brain and other CNS cancers (2003) 

• Mixtures of benzene, toluene, and xylene and colon cancer (2003) 

• OP insecticide exposure without OP poisoning and long-term neurobehavioral effects (that 

is, abnormal results on neurobehavioral test batteries and symptom findings) (2003) 

• Parental preconception exposure to solvents and childhood leukemia (2003) 

• Solvents and kidney cancer (2003) 

• Tetrachloroethylene and dry-cleaning solvents and esophageal cancer (2003) 

• Tetrachloroethylene and dry-cleaning solvents and lung cancer (2003) 

• Trichloroethylene and cervical cancer (2003) 

• Trichloroethylene and colon cancer (2003) 

REFERENCES 

IOM (Institute of Medicine). 2000. Gulf War and health, volume 1: Depleted uranium, pyridostigmine bromide, sarin, vaccines. Washington, DC: National Academy Press. 

IOM. 2003. Gulf War and health, volume 2: Insecticides and solvents. Washington, DC: The National Academies Press. 

IOM. 2004. Gulf War and health: Updated literature review of sarin. Washington, DC: The National Academies Press. 

IOM. 2005. Gulf War and health, volume 3: Fuels, combustion products, and propellants. Washington, DC: The National Academies Press. 
Copyright © National Academy of Sciences. All rights reserved.

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APPENDIX H H-21 

IOM. 2006. Gulf War and health, volume 4: Health effects of serving in the Gulf War. Washington, DC: The National Academies Press. 

IOM. 2007. Gulf War and health, volume 5: Infectious diseases. Washington, DC: The National 

Academies Press. 
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I-1 

Appendix I 

Case Studies 

CASE STUDY 1: MENTAL DISORDERS’ PRESUMPTIONS 

War and combat have long been considered to have acute and chronic impacts on the emotional well-being and mental health of those exposed. Indeed, of the two initial presumptive disabilities recognized in 1921, one was “neuropsychiatric disease,” a mental disorder (Veterans’ 

Bureau Act. 1921. Public Law 67-47. 67th Cong., 1st Sess., p. 154). The scientific understanding 

of mental disorders, as well as the role of war and combat in triggering them, have evolved over 

time. These factors have influenced the inclusion of mental disorders as presumptive disabilities 

among U.S. veterans. This case study is intended to review factors influencing the inclusion of 

various mental disorders as presumptive disabilities among U.S. veterans to date. 

Scientific and Legislative History 

Following World War I, two of the most common causes for hospitalizations identified 

among U.S. veterans were “neuropsychiatric disease” and tuberculosis. At that time, neuropsychiatric disease was considered to consist of a combination of delusions, hallucinations, and illogical thinking. Because of the lack of effective treatments at the time, neuropsychiatric disease 

was considered to be chronic (VA, 2006). In 1921, Senator Walsh of Massachusetts proposed an 

amendment to pending legislation, which was adopted and later modified, that removed the burden of proof for connecting military service and the development of a disorder from the veteran 

by granting presumptions of service connection for veterans diagnosed with neuropsychiatric 

disease or tuberculosis causing at least 10 percent disability within 2 years of military service 

(Veterans’ Bureau Act. 1921. Public Law 67-47. 67th Cong., 1st Sess., p. 154). In support of 

these presumptions, Senator Walsh stated that 

It is very apparent to me that this wave of tuberculosis and of nervous and mental disease 

that has taken such a deadly hold and grip of late upon our ex-servicemen must have been 

contracted in the service. I feel, therefore, that we ought not continue this requirement of 

endless affidavits, necessarily involving long delay, in demonstrating the fact that their 

illness is of service origin. 

(61 Cong. Rec. 4105 [daily ed. July 20, 1921], as referenced in VA, 1993a, p. 8) 
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I-2 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

To emphasize the difficulty in particular for veterans with neuropsychiatric disease he added 

that 

I think really that the most human feature of this amendment is the assistance it will render to 

those afflicted with nervous and mental disease in obtaining their compensation. When it is 

considered that the most important proof, the essential proof, to establish a claim for compensation must come from the man himself, and when it is realized that he is mentally afflicted 

and therefore can not, for instance, file affidavits from officers and servicemen with whom he 

served—since memory is usually defective and he can not remember whom his officers or 

comrades were—it becomes apparent how important is the change made by the bill. 

(61 Cong. Rec. 4105 [daily ed. July 20, 1921], as referenced in VA, 1993a, p. 9) 

At the time the legislation was enacted in 1921, there were few scientific studies to support 

or refute these assertions, and a flood of demands for presumptions for other disorders and for 

enhancement of those already approved followed soon thereafter. 

By early 1923, the 2-year period from the time of discharge within which the neuropsychiatric disorder had to manifest itself was extended to 3 years despite administration objections that 

the extension was not supported by scientific evidence (VA, 1993a, p. 12). Later that same year 

veterans groups, including the Disabled American Veterans, the Veterans for Foreign Wars, and 

the American Legion, began calling to extend the period from 3 to 5 years. The lack of scientific 

evidence to justify the extension was noted by Dr. Earl Holt of the Veterans Bureau. In testimony 

to Congress, Dr. Holt stated that available statistics showed that neuropsychiatric disorder was 

just as common among the civilian population as among the military population, and that the extension of presumptions was unwarranted due to uncertainty over the causes of psychiatric disabilities arising after service (VA, 1993a, p. 14). In response to the Depression, the Economy Act 

of 1933 eliminated all benefits based on presumptive service connection. In its place the President was given broad authority to prescribe rules concerning eligibility for disability compensation including “the nature and extent of proofs, and presumptions” (emphasis added) for various 

classes of veterans (Economy Act of 1933 ch. 3 § 4, 48 Stat. at 9, as referenced in VA, 1993a, 

p. 17). 

Following strong protests from World War I veterans, Congress subsequently moved to reenact presumptive service-connection conditions. President Roosevelt vetoed the legislation stating 

that he thought the Economy Act had settled the issue that a service-connected disability was a 

“question of fact rather than a question of law” in which each individual case would be “considered on its merits” rather than by 

legislative dicta which, contrary to fact, provide that thousands of individual cases of 

sickness that commenced 4, 5, or 6 years after the termination of the war were caused by 

war services. 

(VA, 1993a, p. 19) 

Congress overrode the veto, and the measure was enacted into law (Independent Offices Appropriations Act. 1935. Public Law 141. 73rd Cong., 2d Sess.). The tension between those intent 

on being inclusive and generous in presumptive benefits to veterans and those wanting presumptions to be more firmly grounded by evidence of causation continues today. 

The pertinent provisions of that 1935 Act are now found in 38 USC § 1702, “Presumption 

Relating to Psychosis,” and provide that eligible veterans who developed an active psychosis 
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APPENDIX I I-3 

within 2 years of military discharge “shall be deemed to have incurred such a disability in the 

active military, naval, or air service.” That language has remained essentially unchanged except 

for the expansion of eligibility for veterans of subsequent periods of military conflict up to and 

including those serving in today’s current war. The Committee was unable to obtain information 

as to how many veterans rated for mental disabilities have been service connected by use of the 

presumption set forth in section 1702. 

Additional legislation concerning psychiatric presumptions has been confined to former prisoners of war (POWs). These psychiatric presumptions were the result of strong concern about 

the well-being of a group of veterans who suffered extreme privations and of POW studies undertaken to ascertain the effect of their captivity. 

Psychiatric disorders, by their very nature, have created challenges for decision making on 

presumptions. For many of these disorders, symptoms can only be obtained by self-reporting 

methods, making it more difficult to distinguish those who truly exhibit symptoms and those 

who do not. Many early studies focused on excessive hospitalizations for mental disorders 

among veterans and associations of these disorders with military service rather than causation 

(Beebe, 1975; Cohen and Cooper, 1954). In addition, as the medical community’s understanding 

of mental disorders has evolved over time so have the definitions of various mental disorders. 

Congress, the Department of Veterans Affairs (VA), the National Academy of Sciences (NAS), 

and a large collection of veterans groups and scientists have all been involved in questions related to presumptions and psychiatric disorders in veterans. 

The first legislation to create statutory presumptions specifically applicable to POWs was enacted in 1970 (Veterans Disability Compensation Increase Act. 1970. Public Law 91-376. 91st 

Cong., 2d Sess.). Under Public Law 91-376, psychosis was to be considered a service-connected 

disability provided it became manifest within 2 years of separation from service in the military. 

In justifying the statutory presumptions, the accompanying report said that because of the conditions of captivity and the “kinds of long-range harm that may have been caused,” it was “sometimes difficult for a former prisoner of war to establish some time after completion of military 

service” that a disability is related to military service (U.S. Congress, House of Representatives, 

Committee on Veterans’ Affairs, 1970, p. 7). 

From October 1972 through August 1976, VA issued a number of program guides with respect to Public Law 91-376. These guides were characterized as suggestions for the guidance of 

personnel in the handling of disability claims filed by former POWs. The program guides instructed that in light of the “frequent paucity of records” in POW claims, special attention should 

be given to POW experiences in determining the relationship of the disability to service (VA, 

1980, p. 118). The duration and circumstances of imprisonment were to be associated with pertinent medical principles in making determinations. 

The burden of proof as to the occurrence of a POW episode was shifted from the claimant to 

the government. The “unusual hardship and isolation from society” resulting from POW life 

meant that an “extended period of readjustment to ordinary conditions of life is essential.” 

Claims for individual unemployability (IU) were to receive liberal construction, and if the 

threshold disability percentage for the IU benefit was not met, the claim was to be submitted to 

the VA central office for further consideration. Finally, it was emphasized that presumptions 

were rebuttable only where there was “affirmative evidence to the contrary” (VA, 1980, p. 119). 

In 1975, the second phase of the Follow-Up Studies of World War II and Korean War Prisoners, entitled Morbidity, Disability, and Maladjustment, was issued (Beebe, 1975). Its author, 

Gilbert W. Beebe, observed at the outset that studies of the long-term effects of catastrophic 
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I-4 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

stress are “difficult to make and the frequently multidimensional character of such stress severely 

limits inferences about the etiologic role of specific components, such as malnutrition, social isolation, sensory deprivation, physical punishment, compulsory reeducation, and the like.” He further noted that recent studies of survivors of World War II German concentration camps provided useful information on a persistent defective state marked by “severe permanent psychiatric 

residuals and by nonspecific somatic symptoms” (Beebe, 1975, pp. 400-401). 

 Beebe’s findings were that morbidity, some types of maladjustment, and disability were elevated in POWs relative to controls especially for Pacific theater veterans. Beebe stated that the 

“most remarkable and long-lasting differentials” were seen in hospitalization for psychoneurosis 

and for psychosis (schizophrenia). Data obtained supported a finding that many Pacific theater 

and Korean War POWs had “permanent psychologic impairments.” Beebe also noted that European theater POWs did not go “unscathed” with respect to psychoneurosis hospitalization 

(Beebe, 1975, p. 421). 

 In the Veterans Disability Compensation and Survivor Benefits Act of 1978 (Public Law 95-

479. 95th Cong., 2d Sess.), Congress included provisions requiring VA to carry out a “comprehensive study on the compensation awarded to, and the health-care needs of” former POWs. The 

results of the study were to include such administrative and legislative recommendations as “may 

be necessary to assure that former prisoners of war receive compensation and health-care benefits for all disabilities which may reasonably be attributed to their internment” (Public Law 95-

479, sec. 305; emphasis added). The legislative history indicates that the study was prompted by 

questions about the adequacy of repatriation examinations and by concerns that health conditions 

that may have appeared minor at the time were becoming progressively more debilitating. It also 

cited Beebe’s 1975 follow-up study for the proposition that POWs had excess morbidity, and 

many were suffering from what was termed a “POW syndrome” (VA, 1993a, p. 51). 

As VA was preparing its study, the third phase of the follow-up studies entitled Mortality to 

January 1, 1976, authored by Robert J. Keehn (1980), was issued. That study continued to find 

increased risks of mortality among World War II Pacific theater and Korean War POWs, though 

the excess diminished over time. For Pacific theater veterans the principal cause for the mortality 

increase was tuberculosis and trauma, while for former Korean War POWs it was trauma. In describing this trauma, the report found that for Pacific theater POWs suicide was responsible for 

two-thirds and accidents one-third of the excess deaths (Keehn, 1980). The study also reported 

that anxiety neurosis accounted for 12.7 percent of all service-connected conditions for former 

POWs, compared to a rate of approximately 4 percent for all veterans receiving compensation. 

Given a consistent finding of persistent psychologic impairment and reported problems of adjustment to civilian life, the report concluded that 

The finding of increased mortality due to trauma, both accidental (including cases of 

masked suicide) and suicide, in former prisoners of war is not surprising. Increased feelings of frustration, anger, and tension lead to impatience and impulsive actions that are 

likely to contribute to both the risk and severity of accidental and self-inflicted injury. 

(Keehn, 1980, p. 209) 

Shortly thereafter VA delivered its Study of Former Prisoners of War (VA, 1980) to Congress as required by Public Law 95-479. The principal finding that VA stated was “essential to 

the entire study” was that 
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APPENDIX I I-5 

[T]he POW experience—characterized by starvation diet, poor quality or nonexistent 

medical care, “death marches,” executions, and tortures—has historically been an extremely harsh and brutal experience. 

(VA, 1980, p. 161) 

Concerning the quality of POW repatriation procedures, exams, and resultant medical records, the study found that the prescribed procedures were generally well designed and reflected 

“state-of-the art medical knowledge and technique at the time they were designed,” which “if 

followed would have provided former POWs with adequate records” (VA, 1980, p. 71). Examination of VA claims folders, however, found that less than 20 percent of European theater POWs 

who filed disability claims had evidence of a repatriation examination. For Pacific theater and 

Korean War veterans, records of repatriation examinations were located in 60 percent and 85 

percent of their files, respectively. In those cases where records were located, VA reviewer physicians judged 67 percent of World War II and 85 percent of Korean War POW repatriation exams as “providing a good or adequate basis for evaluating physical or psychiatric conditions.” 

The limitations were that over half of the examinations contained either no medical history or 

poor history of health status prior to capture. In addition, about one-third of the examinations had 

“inadequate evaluations of the POW’s mental status and psychiatric conditions” (VA, 1980, p. 

72).

The “most remarkable finding” of the study, according to VA, was that anxiety neurosis was 

“the most prevalent service-connected condition of the former POWs under study, from the time 

of their repatriation to the present.” Anxiety neurosis accounted for 12.7 percent of all serviceconnected conditions of former POWs, which was three times the rate of all veterans receiving 

compensation (VA, 1980, p. 95). VA stated that 

The significance of this disability relative to veterans controls remains regardless of the 

length of internment. This is especially apparent among former European theater POWs, 

in which those POWs interned less as well as more than 6 months exhibit significantly 

higher rates of anxiety neurosis compared to other service-connected World War II 

veterans. 

 (VA, 1980, p. 95) 

The study had also required VA to analyze procedures used to determine eligibility for benefits with a particular emphasis on the statutory and regulatory provisions unique to POWs. VA 

concluded that 

Former POWs generally have received special consideration in keeping with statutory 

and procedural provisions in terms of medical evaluations and disability compensation. 

Limitations in knowledge as to the long-term effects of the stresses and deprivations experienced by prisoners of war is a major obstacle for decision makers. 

(VA, 1980, p. 128) 

VA also reported that over the years it had changed its approach to the adjudication of 

POW claims by gradually developing flexibility in such areas as substantiation of claims in the 

absence of medical records for periods of internment and in the presumption of service incurrence for certain disabilities. This changed approach reflected the “evolution of the law,” and 

the degree of flexibility roughly coincided with “advancements in medical knowledge” concerning the serious effects of imprisonment on health (VA, 1980, p. 121). 
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The literature review of health problems of former POWs, a fourth requirement of the 

study, included eyewitness accounts of disabilities during captivity, epidemiologic follow-up 

studies, analysis of concentration camp populations, and discussions of former POW family 

and social problems. VA said that its review showed that the higher rate of health problems experienced were “related to the malnutrition, torture, climatic exposure, and other deprivations 

of internment.” The epidemiologic follow-up studies indicated that “residuals of these and 

other disabilities have persisted until the present time.” According to VA, it was particularly 

noteworthy that the psychological problems of former POWs, especially those of World War II, 

“closely resemble[d]” those of concentration camp survivors of the same period (VA, 1980, p. 

154). The K-Z syndrome, as discussed in Beebe’s 1975 report, included the symptoms: 

General anxiety and nervousness, “startle” reaction, insomnia and nightmares, phobias, 

psychosomatic complaints, memory lapses, moodiness, inferiority complex, obsession 

with the past, depression, apathy, and survivor guilt. 

(VA, 1980, p. 154) 

The psychological literature on K-Z syndrome and what VA termed “other forms of psychic stress” revealed a significantly higher amount of family and social maladjustment as evidenced by inadequate functioning in father and parent roles, and higher rates of unemployment 

and disability compensation among POWs (VA, 1980, p. 154). 

Two major legislative recommendations were contained in the study submitted to Congress. 

First, VA recommended that the law be amended to authorize eligibility for VA health care to 

former POWs for any disease or neuropsychiatric disability. VA observed that studies by the 

National Research Council (NRC) and NAS showed former POWs generally had higher mortality and morbidity rates and that this was reflected in their higher rates of service-connected 

disabilities. Yet, despite the special consideration given to POW claims, their adjudication was 

complicated by the frequent absence of medical information at the time of repatriation and by 

the fact that “medical science cannot, at this time, conclusively determine on an individual basis the origins of some disabilities particularly prevalent among former POWs” (emphasis 

added). Authorizing comprehensive VA inpatient and outpatient medical care for any disease 

or neuropsychiatric condition “would remove access barriers to VA medical care for those former POWs currently classified in a lower than 50 percent service-connected priority category” 

(VA, 1980, pp. 163-164). 

The second legislative recommendation was to modify the existing statutory presumption of 

service connection for psychosis. VA proposed to “eliminate the requirement that psychoses 

suffered by POWs must become manifest within 2 years following service separation before 

the rebuttable presumption of service connection arises” (VA, 1980, p. 164). VA said that its 

literature review indicated that psychosis related to the POW experience “frequently appears 

years after service, not just immediately after separation,” citing NAS/NRC follow-up studies 

published between 1946 and 1980 in support thereof (VA, 1980, p. 164). 

VA also reported that it was undertaking several administrative actions as a result of its 

study. First, forthcoming guidelines on “post-traumatic stress neurosis” would have “explicit 

reference to former POWs as well as other combat veterans.” Post-traumatic stress neurosis

was a term scheduled on October 1, 1980, to become part of VA’s official diagnostic classification system to describe this anxiety neurosis. The guidelines would “specifically be used to diagnose, treat, and rate former POWs with anxiety neurosis or similar neurotic disorders” (emphasis added). VA said this change was justified because former POWs had experienced a wide 
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APPENDIX I I-7 

range of psychological problems. In addition, anxiety neurosis had been the most prevalent disability among former POWs according to NRC epidemiologic studies and VA compensation 

data. VA also added that an analysis comparing anxiety neurosis and length of internment 

demonstrated that it remained a “statistically significant service-connected disability among 

former POWs regardless of the amount of time in prison camp” (VA, 1980, pp. 165-166; emphasis added).

VA announced that it would adopt a standardized protocol for disability compensation examinations for all former POWs similar to that developed by the military for former Vietnam 

POWs (VA, 1980). 

Congressional hearings followed the receipt of VA’s study of POWs in both 1980 and 

1981. Legislation was reported in June 1981 and enacted into law on August 14 as the Former 

Prisoner of War Benefits Act of 1981 (Public Law 97-37. 97th Cong., 1st Sess.). Among its 

provisions, the requirement that psychosis manifests itself within 2 years of separation of service in order to qualify for a service-connection presumption was deleted as recommended by 

VA. An additional presumption termed any of the anxiety states was added to the statute. As 

noted in House testimony, “. . . psychosis related to the POW experience frequently appears 

years after service, and not just immediately after separation. This is understandable in view of 

the psychological torture and ‘brainwashing’ to which these POWs were subjected” (U.S. Congress, House of Representatives, Committee on Veterans’ Affairs, 1981, p. 6). 

Three additional presumptions for POWs were added between 1984 and 1988. The first, in 

the Veterans’ Compensation and Program Improvements Amendments of 1984 (Public Law 

98-223. 98th Cong., 2d Sess.) added “dysthymic disorder” to the list of disabilities developing 

any time after a POW’s separation from service for which a presumption of service connection 

would apply. Senator Alan K. Simpson, chairman of the Senate Committee on Veterans Affairs, termed the inclusion a clarification of the original intent of the Former Prisoner of War 

Benefits Act of 1981. Speaking on the floor of the Senate during consideration of the measure 

he said that 

The complexity of anxiety states, anxiety neuroses, posttraumatic stress disorder, and 

dysthymic disorders and their associated and sometimes interrelated diagnoses inadvertently resulted in a lack of clarity regarding the granting of service connection for 

depression. 

(VA, 1993a, p. 55) 

Further explanation was contained in the committee’s report accompanying the measure 

that states that at the time the Senate reached agreement with the House on the 1981 Act: 

[The Senate] was not aware that there would be cases in which former POWS suffering 

from nonpsychotic depressive disorders would not be diagnosed as suffering from posttraumatic stress disorder and therefore not adjudged under VA guidelines to be serviceconnected disabled. . . . The committee intends that this addition would correct the inadvertent oversight in the original legislation and establish a presumption for a mental disorder that is linked in scientific literature to the POW experience. 

 (VA, 1993a, pp. 55-56) 

Since the late 1980s, a number of well-designed studies have supported increased psychiatric 

morbidity among former POWs as well as among other veterans experiencing combat. In 1988, 
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results from the Vietnam Experience Study (VES) conducted by the Centers for Disease Control 

and Prevention (CDC) were released. The VES selected a random sample of Army personnel 

discharged between 1965 and 1971. Those who served a single tour in Vietnam (n = 9,324) were 

compared to a random sample of Army personnel discharged during the same period and who 

served a single tour of duty elsewhere (n = 8,989). Veterans who were alive at the time of study 

completed a telephone interview, in-person psychological examinations, and assessments for reproductive outcomes (CDC, 1988, p. 2702). 

The VES found that Vietnam veterans had a 45 percent excess of deaths in the first 5 years 

after discharge in comparison to non-Vietnam veterans. These deaths were largely due to motor 

vehicle accidents, suicides, and homicides. After the initial 5-year period, the death rates among 

the two groups of veterans remained approximately the same. Nevertheless, Vietnam veterans 

were more likely to meet diagnostic criteria for alcohol abuse or dependence, generalized anxiety 

disorder, and depression. Among Vietnam veterans, 14.7 percent met criteria for posttraumatic 

stress disorder (PTSD) previously in life and 2.2 percent met criteria for PTSD during the month 

prior to the examination (CDC, 1988, p. 2705). Though a constellation of psychiatric symptoms 

among this Vietnam group was similar to studies previously conducted on World War II POWs, 

this study was significant in the fact that the veterans enrolled in this study were selected due to 

their combat theater rather than their POW status. 

Several studies published in 1991 examined chronic depression among former POWs. Engdahl et al. (1991) found that long-term chronic depressive symptomatology persisted over 40 

years and was elevated among POWs of all theaters when compared to control groups. Age, education, medical symptoms during captivity, and level of social support were found to be related 

to later levels of adjustment. A second, longitudinal study published the same year by Page et al. 

(1991) elaborated on previous research to show that not only was depressive symptomatology 

highly elevated in World War II and Korean War POWs, but it was elevated to the point where 

these populations closely resembled a clinical population of recovering depressives. Two major 

conclusions from this longitudinal study were that treatment during captivity is statistically 

linked with depressive symptoms, and that differences in these symptoms were attributable to 

captivity-related treatment, even when age at capture and education level were considered. 

Conducting a 40-year follow-up of U.S. World War II and Korean War former POWs, Engdahl and Page et al. (1991) measured captivity trauma variables and individual protective variables (i.e., age, education, medical symptoms during captivity, social support) to compare with 

current depressive symptoms. Although depressive symptoms persisted more than 40 years with 

the knowledge that PTSD and generalized anxiety disorders are known to occur with elevated 

frequency in POW populations, the degrees of individual protective variables were related to 

levels of adjustment. This study made a case for the need to examine former POWs that adjusted 

well in order to understand both the role of specific protective variables and posttrauma adjustment and resiliency. 

Page’s (1991) work continued with respect to the validity and reliability of some of the work 

cited above. Despite the heavy reliance on survey data, a noticeable shortage of reports on the 

effects of nonresponse bias on the measurement of depression existed. Longitudinal data presented opportunities for different types of nonresponse bias, but these data could also be useful in 

modeling for bias because of previously collected data. Page found that a predictive model 

shows nonresponse bias on the reporting of depressive symptoms among former World War II 

and Korean War POWs to be small. 
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APPENDIX I I-9 

In 1992, the Institute of Medicine (IOM) produced a report entitled The Health of Former 

Prisoners of War. This longitudinal study focused on morbidity and was initiated in 1986 and 

built on the earlier work of Cohen and Cooper (1954), Nefzger (1970), and Keehn (1980), which 

has been previously discussed. Veterans were invited to a medical center to undergo the VA protocol exam, which included a comprehensive physical and psychiatric examination. In addition, a 

face-to-face psychiatric interview and a battery of psychological tests were administered. A caution was provided at the outset of the report that due to low response rates there could be “no 

confidence . . . that the group of respondents accurately reflects the composition of all former 

POWs” (IOM, 1992, p. 4). Nevertheless, the results were presented as descriptive data that constituted the largest national collection of POW examinations ever gathered and analyzed. Some 

of the findings confirmed earlier studies while other findings were suggestive and served the 

purpose of generating more definitive research studies. The report urged a “maximum of reasonable caution in (the) interpretation” of the results (IOM, 1992, p. 5). The report brought attention 

to the high prevalence of a number of medical conditions for POWs as compared to the controls, 

especially with regard to psychiatric illness. Prevalence rates for over 20 different medical conditions were discussed, with key results including the following: 

• Pacific theater POWs had higher prevalence rates of PTSD, ulcer, schizophrenia, and 

generalized anxiety than European theater and Korean War POWs. 

• Visual symptoms were associated with higher prevalence rates of cerebrovascular 

disease, ulcers, asthma, and PTSD. 

• Korean War POWs showed higher prevalence rates for schizophrenia. 

 (IOM, 1992, pp. 6-11) 

The IOM report stated that many of the organ-specific findings were familiar and that the 

increased prevalence of depressive disorders, PTSD, and generalized anxiety among POWs 

was not unexpected. 

To better understand the characteristics that affect POWs’ reintegration into civilian life, 

Engdahl et al. published a report in 1993 that investigated long-term responses to captivity 

trauma among former POWs. Engdahl et al. reported that symptoms at 20 years following release were related to those at 40 years following release. Many factors known to affect POWs’ 

long-term adjustment were not included in the study (e.g., combat exposure, postwar social 

support). This was due in part to their statistical infrequency or skewed nature (i.e., family history of mental illness, marital status at capture, military rank at capture). Trauma response was 

found to be determined by an interaction of characteristics of the individual and characteristics 

of the trauma, not primarily one over the other. The authors suggested that trauma response, 

from an evolutionary standpoint, may be better understood as adaptive due to its persistent nature. 

As previously discussed, Congress has delegated to the VA Secretary the general authority to 

prescribe “all rules and regulations . . . with respect to the nature and extent of proof and evidence and the method of taking and furnishing them in order to establish the right to benefits under such laws” (38 USC § 501[a]). Pursuant to that authority, VA published evidentiary presumptions with respect to establishing PTSD claims in 1993 (VA, 1993b). The regulation 

initially observes that service connection for PTSD requires “medical evidence establishing a 

clear diagnosis of the condition, credible supporting evidence that the claimed in-service stressor 

actually occurred, and a link, establishing by medical evidence, between current symptomatology 

and the claimed in-service stressor” (VA, 1993b, p. 3). The regulation provided that 
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If the claimed stressor is related to combat, service department evidence that the veteran 

engaged in combat or that the veteran was awarded the Purple Heart, Combat Infantryman Badge, or similar combat citation will be accepted, in the absence of evidence to the 

contrary, as conclusive evidence of the claimed in-service stressor. 

 (VA, 1993b, pp. 3-4; emphasis added) 

In addition, the regulation provided that status as a POW would similarly be regarded as evidence of an in-service stressor. 

PTSD continued to gain great attention. Page et al. (1997) examined the literature on PTSD 

in POWs and compared lifetime PTSD prevalence among POWs and control subjects. After a 

follow-up period of 40 years, differences in prevalence rates existed between POWs and control 

subjects for depressive disorders as well as generalized anxiety. All groups of POWs shared 

nearly the same lifetime and current PTSD rates. Among World War II POWs, however, roughly 

half of the POWs who once suffered from PTSD were not currently diagnosed with that condition, suggesting the possible presence of chronic, stable PTSD in the other half of the POWs 

evaluated. However, the authors stated that this may be explained by the symptoms causing less 

stress on the first group of individuals. The authors suggested that those with higher distress levels should be evaluated for secondary symptoms of PTSD, such as depression. They concluded 

that 

 

Sensitivity toward older war veterans is vital. An awareness that their PTSD may have 

gone unnoticed by other health-care professionals for decades should encourage direct 

clinical inquiries about possible PTSD symptoms. We strongly recommend a structured 

interview. . . . PTSD symptoms have been all too common, yet undiagnosed among older 

war veterans, especially POWs. 

(Page et al., 1997, p. 157; emphasis added) 

Work on PTSD continued into the new millennium when World War II and the Korean War 

POW interviews were examined for two separate index measures at two points in time—1965 

and 1990. Results from Gold et al. (2000) supported previous research highlighting the severe 

psychological consequences of POW status 40-50 years following captivity. Trauma severity 

during captivity was found to be the best predictor of current PTSD symptomatology. 

The Veterans Benefits Act of 2003 (Public Law 108-183. 108th Cong., 1st Sess.) included 

provisions that removed the 30-day minimum confinement requirement for 5 of the 16 POW presumptive conditions. Included in those 5, for which no minimum confinement was required, 

were (a) psychosis, (b) any of the anxiety states, and (c) dysthymic disorder (or depressive neurosis). In justifying the change, a Senate committee report on a similar bill observed that POWs 

were often treated brutally and, even if treated humanely, often suffered extreme mental anguish. 

Thus, the “30-day minimum requirement for purposes of presumptive service connection may be 

too restrictive for certain conditions” (U.S. Congress, Senate, Committee on Veterans’ Affairs, 

2003, p. 10). 

Lessons Learned 

Presumptive decisions for mental disorders have been established for veterans who are former POWs and for veterans who developed chronic mental problems during or shortly after military service. The subjective nature and self-reporting aspects of mental disorders have made it 
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APPENDIX I I-11 

more difficult to determine the mental disorders that should be presumptively service connected. 

Although legislation has been informed by the scientific evidence available at the time (Beebe, 

1975; CDC, 1988; Cohen and Cooper, 1954; Engdahl and Page, 1991; Keehn, 1980; Nefgzer, 

1970; Page et al., 1997), the scientific evidence has been limited by inconsistency surrounding 

the disorders that have been included in the research. For example, if the limited and suggestive 

evidence led to presumptive decisions for PTSD, dysthymic disorders, and any anxiety state 

among former POWs, then there does not appear to be a clear basis for excluding other mental 

disorders with equal or stronger evidence of connection to being a POW, such as major depression or substance abuse. The presumptive decisions with regard to these mental disorders demonstrate that these decisions have been influenced not only by the evidence, but also by political 

and social considerations that apply to these veterans and the specific mental disorders they 

manifest. The need to develop stronger evidence and consistency with regard to these disorders 

is great, particularly in light of evidence of high rates of disorders among military personnel currently assigned to Iraq. This case study illustrates the need for a process that can continually 

carry out research while updating the scientific evidence used in presumptive disability decision 

making. Improved future studies will be aided by pre- and postdeployment mental health assessments of Service members and more thorough assessment and documentation of exposures 

while deployed. This information will facilitate a deeper understanding of the relationship between military service and the subsequent development of mental health disorders. 

References 

Beebe, G. W. 1975. Follow-up studies of World War II and Korean War prisoners: Morbidity, disability, 

and maladjustments. American Journal of Epidemiology 101(5):400-422. 

CDC (Centers for Disease Control). 1988. Vietnam experience study—psychosocial characteristics. Journal of the American Medical Association 259(18):2701-2707. 

Cohen, B. M., and M. Z. Cooper. 1954. A follow-up study of World War II prisoners of war. Washington, 

DC: Government Printing Office. 

Engdahl, B. E., and W. F. Page. 1991. Psychological effects of military captivity. In Epidemiology in 

military and veteran populations. Proceedings of the Second Biennial Conference, March 7, 1990. 

Washington, DC: National Academy Press. Pp. 49-66. 

Engdahl, B. E., W. F. Page, and T. W. Miller. 1991. Age, education, maltreatment, and social support as 

predictors of chronic depression in former prisoners of war. Social Psychiatry and Psychiatric Epidemiology 26(2):63-67. 

Engdahl, B. E., A. R. Harkness, R. E. Eberly, W. F. Page, and J. Bielinski. 1993. Structural models of captivity trauma, resilience, and trauma response among former prisoners of war 20 to 40 years after release. Social Psychiatry and Psychiatric Epidemiology 28(3):109-115. 

Gold, P. B., B. E. Engdahl, R. E. Eberly, R. J. Blake, W. F. Page, and B. C. Frueh. 2000. Trauma exposure, 

resilience, social support, and PTSD construct validity among former prisoners of war. Social Psychiatry and Psychiatric Epidemiology 35(1):36-42. 

IOM (Institute of Medicine). 1992. The health of former prisoners of war: Results from the medical examination survey of former POWs of World War II and the Korean Conflict. Washington, DC: National Academy Press. 

Keehn, R. J. 1980. Follow-up studies of World War II and Korean Conflict prisoners: Mortality to January 1, 1976. American Journal of Epidemiology 111(2):194-211. 

Nefzger, M. D. 1970. Follow-up studies of World War II and Korean War prisoners: Study plan and mortality findings. American Journal of Epidemiology 91(2):123-138. 

Page, W. F. 1991. Using longitudinal data to estimate non-response bias. Social Psychiatry and Psychiatric Epidemiology 26:127-131. 
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Page, W. F., B. E. Engdahl, and R. E. Eberly. 1991. Prevalence and correlates of depressive symptoms 

among former prisoners of war. Journal of Nervous and Mental Disease 179(11):670-677. 

Page, W. F., B. E. Engdahl, R. E. Eberly, C. S. Fullerton, and R. J. Ursano. 1997. Persistence of PTSD in 

former prisoners of war. In Posttraumatic stress disorder: Acute and long-term responses to trauma 

and disaster, edited by C. S. Fullerton and R. J. Ursano. Washington, DC: American Psychiatric 

Press. Pp. 147-158. 

U.S. Congress, House of Representatives, Committee on Veterans’ Affairs. 1970. Service-connected 

compensation increase for veterans. House Report 91-1166. 91st Cong., 2nd Sess. June 9. 

U.S. Congress, House of Representatives, Committee on Veterans’ Affairs. 1981. Prisoner of war benefits and health-care services act of 1981. House Report 97-28. 97th Cong., 1st Sess. May 4. 

U.S. Congress, Senate, Committee on Veterans’ Affairs. 2003. Veterans’ Benefits Enhancements Act. 

Senate Report 108-169. 108th Cong., 1st Sess. October 21. 

VA (Department of Veterans Affairs). 1980. Study of former prisoners of war. Washington, DC: Government Printing Office. 

VA. 1993a. Analysis of presumptions of service connection. Paper presented to the IOM’s Committee on 

the Evaluation of the Presumption Disability Decision-Making Process for Veterans, Washington, 

DC. 

VA. 1993b. Direct service connection (post-traumatic stress disorder). Final Rule. Federal Register

58(95):29109. 

VA. 2006. VA history in brief. http://www1.va.gov/opa/feature/history/index.asp (accessed July 5, 2007). 

CASE STUDY 2: MULTIPLE SCLEROSIS PRESUMPTION 

This case study examines the 1962 decision to grant presumptive service-connected disability 

to any veteran with multiple sclerosis (MS) whose disease is diagnosed within 7 years of separation from the military. This case study illustrates the challenges of evaluating scientific evidence 

and compensating veterans when the etiology of a disease is unknown and the possibility of a 

service-related cause cannot be excluded with certainty. 

Background 

MS is a neurological disease characterized by inflammation, destruction, and scarring of 

myelin cells that protect the neurons in the central nervous system. Symptoms of MS typically 

present in young adulthood, with a prevalence in the United States of 1 in 1,000 (IOM, 2001, p. 

17; Noseworthy et al., 2000). Women have higher rates of both incident and prevalent disease, 

and studies in the United States and Canada suggest that the female-to-male disease ratio has 

been increasing over time (Figures I-1 and I-2). 

Two features of MS have proven challenging in evaluating the scientific basis for a presumption of service connection. First, the point of onset of MS can be difficult to determine. There are 

no clinical symptoms unique to MS; rather, a variety of neurological symptoms are possible. 

These symptoms often occur in distinct episodes that may at least partially resolve, and the nature of the symptoms can vary over time. Diagnosis of MS can be delayed either because an affected individual may not seek medical attention for a neurological symptom that may be resolving or because physicians may not recognize symptoms as suggestive of MS. 

Second, the etiology and pathogenesis of MS remain largely unknown. A variety of environmental, genetic, and autoimmune factors have been implicated, and perhaps the most intriguing observation in the epidemiology of MS is the finding that individuals at higher latitudes are 

at increased risk of disease (IOM, 2001). In the Nurses’ Health Study, for example, a graded increase in risk of MS was observed in those in the northern United States compared with the 
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APPENDIX I I-13 

FIGURE I-1 Prevalence of multiple sclerosis in the United States (from the National Health Interview 

Survey).

SOURCE: Noonan et al., 2002. 

Year of Birth 

FIGURE I-2 Female-to-male ratio of multiple sclerosis in a Canadian registry. 

SOURCE: Orton et al., 2006. 

southern United States (Hernán et al., 1999). Individuals migrating from a high-risk to low-risk 

area appear to adopt the risk of their new home, although the age at migration may influence how 

this risk is reassigned (IOM, 2001). Why location may be important in the epidemiology of MS 
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I-14 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

is unknown, and the nature of the environmental exposure associated with higher latitudes that 

potentially contributes to MS risk is unclear. Triggers or exposures ranging from viral illness to 

lack of vitamin D related to lower levels of sun exposure have been postulated (IOM, 2001). 

The Need for a Presumption 

The rationale for the MS presumption is different from that of other presumptions discussed 

in the case studies and appears to have shifted over time. While most other presumptions serve to 

fill gaps in evidence for exposure (e.g., the Agent Orange presumptions) or gaps in evidence for 

association (e.g., cardiovascular disease among amputees), the original basis for this presumption 

fits in neither of these two categories. This presumption stems from the VA’s interest in compensating disease and disability that has its onset during military service. A defined list of chronic 

conditions have long been granted service connection if diagnosed within 1 year of separation 

from the military. These diseases are insidious in onset and difficult to diagnose. Presumption is 

granted because the possibility that these conditions were present during military service cannot 

be excluded with certainty. The presumption for MS, therefore, does not fill gaps in evidence for 

exposure or association, but rather gaps in evidence for the timing of disease onset. This distinction is important, because the scientific evidence needed to inform this presumption is neither the 

information about exposure during military service nor for association between military service 

and disease; rather the scientific evidence needed for this presumption is evidence for an insidious disease course that makes onset during military service nearly impossible to exclude. 

Over time, Congress created a special exception for MS in comparison to other presumptive 

health outcomes, extending the presumptive period for diagnosis of MS first from 1 to 2 years 

following military service (Veterans’ Benefits Act of 1957. Public Law 85-56. 85th Cong., 2d 

Sess.; VA, 1949; Act of October 12, 1951. ch. 499, 65 Stat. 421, as cited in VA, 1993). Subsequently, Congress extended the presumptive period for diagnosis of MS to 3 years (Act of August 25, 1959. Public Law 86-187. 86th Cong., 1st Sess., as cited in VA, 1993) and then finally 

to 7 years following military service in 1962 (Veterans’ Disability Compensation Increase Act of 

1962. Public Law 87-645. 87th Cong., 2d Sess., as cited in VA, 1993). The rationale for this exception was based in part on the continued evidence supporting the insidious onset of this disease. However, with this extension the debate in the Federal Register also shifted to the inability 

to exclude a military exposure as the possible etiological cause of MS in veterans. This shift is 

significant because the scientific evidence necessary to support this type of presumption would 

include evaluation of evidence for possible exposures during military service and evidence linking military service with MS. 

Because the debate surrounding the MS presumption has taken place over many years (since 

the 1930s) in congressional committees, the subtle but important shift in the rationale for this 

presumption and its implications for the scientific evidence needed to support it have not been 

systematically evaluated. As a result, considerable disagreement and uncertainty remain as to 

whether this presumption is supported by the scientific evidence. 

A Brief History of the MS Presumption 

A 1933 executive order first granted presumptive service connection to a defined list of 

chronic diseases if these were diagnosed within 1 year of separation from the military. The rationale for this order was that these conditions were 
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APPENDIX I I-15 

of “such an insidious nature” that the disease did not become manifest to a ten-percent 

degree immediately upon inception but required as much as a year from the date of inception to become manifest. 

(VA Solicitor, 46 Op. Sol. 140 [9-15-39] as cited in VA, 1993, p. 17) 

The assumption was that these conditions were eligible for direct service connection because 

of their temporal relation to military service; their insidious nature required this lag period outlined in the presumption. These chronic diseases were all characterized by their insidious onset 

and not by any direct evidence that military service caused these conditions. Other illnesses covered in this presumption, in addition to MS, include hypertension, diabetes, and atherosclerosis. 

The MS presumption was debated by Congress in 1948 and codified in 1949. Again, the language of the debate suggested that this presumption was meant to be an extension of direct service connection for a limited number of diseases that, though present during service, were difficult to diagnose during the period of service (Veterans’ Chronic and Tropical Diseases Act of 

1948. Public Law 80-748. 80th Cong., 2d Sess.; VA, 1949). 

An internal VA memorandum acknowledges this logic as the basis for this presumption and 

comments on the low likelihood that military service actually caused these illnesses. It states that 

The diseases . . . are indeed of chronic type, and their presence within a year after discharge raises a strong probability that part of the course of the disease . . . 

coincided with the period of military service, but the likelihood that any of their course 

was influenced by the facts or circumstances of service is extremely 

remote. 

 (Internal VA memorandum, as cited in VA, 1993, p. 28) 

In 1951, Congress singled out MS from the other chronic illnesses and extended the period of 

diagnosis from 1 to 2 years following military service. In 1959, Congress again extended this 

period to 3 years, and in 1962 the period was extended to 7 years following military service. The 

congressional decision was based in part on scientific testimony from the National Institutes of 

Health and the National Multiple Sclerosis Society that 7 years “was not an unreasonable period 

to recognize as the interval between onset and diagnosis” (VA, 1993, p. 33). The VA opposed 

these multiple extensions, noting that 

Although the exact cause of the disease is unknown, there is nothing in the circumstances 

of military service in time of war which from a medical and scientific standpoint would 

warrant a presumption of fact that a manifestation of the disease . . . years after discharge 

is in any way related to the factor or circumstances of services. In this connection it does 

not appear that the disease is any more prevalent among the veteran population than the 

nonveteran population. 

(VA statement, as cited in VA, 1993, p. 33) 

This debate illustrates the two different lines of reasoning that have entered the discussion 

regarding the MS presumption. On the one hand, the insidious nature of disease may make a presumption necessary because of the lag required for diagnosis; the scientific evidence necessary is 

simply that of the length of time on average required for diagnosis. On the other hand, because 

the etiology of MS is unknown and an exposure that occurs during military service cannot be 

ruled out as the cause of MS, a presumption may be necessary on this basis as well. Here the scientific basis for association between exposure and outcome becomes relevant. 
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During the same time in which the presumptive period for the diagnosis of MS was repeatedly extended, this disease was a focus of epidemiologic investigation by scientists at VA and 

the Medical Follow-Up Agency (MFUA) (Berkowitz and Santangelo, 1999). This research activity was driven largely by neurologists at VA who had become interested in developing treatments for MS (VA Multiple Sclerosis Study Group, 1956, 1957), and leaders of MFUA, who 

were interested in making use of the extensive medical records on young individuals to learn 

more about the manifestation of diseases in that population generally (Berkowitz and Santangelo, 

1999). The extension of the presumptive period for service connection to 7 years enhanced the 

ability to conduct these epidemiologic investigations; at one time, two-thirds of the cases of MS 

estimated to occur among all veterans of World War II were being studied by VA and MFUA 

investigators (Kurtzke et al., 1979, p. 1233). Studies of veterans with MS yielded insights into 

the epidemiology of this disease, confirming that MS appears to be a “disease of place” and that 

environmental exposures in childhood and young adulthood, as yet still unidentified, may likely 

play a role in the etiology of this disease (Kurtzke and Page, 1997, p. 204). In addition to the important insights into the epidemiology of MS, these studies of veterans notably failed to find any 

evidence that military service (or particular exposures during military service) placed veterans at 

a greater risk for MS than the general population (Kurtzke and Page, 1997; Kurtzke et al., 1979, 

1985, 1992; Norman et al., 1983; Page et al., 1993, 1995; Wallin et al., 2000).

Lessons Learned 

This presumption straddles the line between compensation for disease that manifests during 

military service and compensation for the future adverse health effects that occurred as a result 

of specific exposures during military service. Both lines of argument were used to justify or oppose the MS presumption, but the scientific basis for each of these arguments is very different. In 

the first case, timing is the standard (specifically the possibility of disease onset during military 

service), and evidence for association between an exposure and outcome is not required. In the 

second case, evidence from some association between exposure during service and future disease 

is necessary. Congress did not call for a systematic review of the scientific literature on this 

topic; such a review might have allowed for more evidentiary discussion of the premise behind 

this presumption and the type of evidence that might be necessary to support it. 

The exception of repeatedly lengthening the presumptive period of diagnosis following military service was justified because MS is difficult to diagnose and because of the possibility that 

some, as yet still unidentified, environmental exposures may play a role in its etiology. However, 

these two characteristics are also true of a variety of other chronic conditions for which presumptions have not been established. MS almost certainly received particular attention because of 

heightened awareness of MS as a result of the numerous high-profile publications on its epidemiology based on the study of veterans. 

The epidemiological insight on MS gained from the study of veterans deserves comment. 

These studies of MS have had far-reaching benefit beyond those realized by the veterans themselves and have formed the basis of much of the understanding of this complicated chronic 

disease. 

References 

Berkowitz, E. D., and M. J. Santangelo. 1999. The Medical Follow-Up Agency: The first fifty years 1946-

1996. Washington, DC: National Academy Press. 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

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APPENDIX I I-17 

Hernán, M. A., M. J. Olek, and A. Ascherio. 1999. Geographic variation of MS incidence in two prospective studies of US women. Neurology 53(8):1711-1718. 

IOM. 2001. Multiple sclerosis: Current status and strategies for the future. Washington, DC: National 

Academy Press. 

Kurtzke, J. F., and W. F. Page. 1997. Epidemiology of multiple sclerosis in U.S. veterans: 7. Risk factors 

for MS. Neurology 48(1):204-213. 

Kurtzke, J. F., G. W. Beebe, and J. E. Norman, Jr. 1979. Epidemiology of multiple sclerosis in U.S. veterans: 1. Race, sex, and geographic distribution. Neurology 29(9):1228-1235. 

Kurtzke, J. F., G. W. Beebe, and J. E. Norman, Jr. 1985. Epidemiology of multiple sclerosis in U.S. veterans: 3. Migration and the risk of MS. Neurology 35(5):672-678. 

Kurtzke, J. F., W. F. Page, F. M. Murphy, and J. E. Norman, Jr. 1992. Epidemiology of multiple sclerosis 

in U.S. veterans: 4. Age at onset. Neuroepidemiology 11(4-6):226-235. 

Noonan, C. W., S. J. Kathman, and M. C. White. 2002. Prevalence estimates for MS in the United States 

and evidence of an increasing trend for women. Neurology 58:136-138. 

Norman, J. E., Jr., J. F. Kurtzke, and G. W. Beebe. 1983. Epidemiology of multiple sclerosis in U.S. veterans: 2. Latitude, climate and the risk of multiple sclerosis. Journal of Chronic Diseases 36(8): 

551-559. 

Noseworthy, J. H., C. Lucchinetti, M. Rodriguez, and B. G. Weinshenker. 2000. Multiple sclerosis. New 

England Journal of Medicine 343(13):938-952. 

Orton, S. M., B. M. Herrera, I. M. Yee, W. Valdar, S. V. Ramagopalan, A. D. Sadovnick, and G. C. 

Ebers. 2006. Sex ratio of multiple sclerosis in Canada: A longitudinal study. The Lancet Neurology

5(11):932-936. 

Page, W. F., J. F. Kurtzke, F. M. Murphy, and J. E. Norman, Jr. 1993. Epidemiology of multiple sclerosis 

in U.S. veterans: 5. Ancestry and the risk of multiple sclerosis. Annals of Neurology 33(6):632-639. 

Page, W. F., T. M. Mack, J. F. Kurtzke, F. M. Murphy, and J. E. Norman, Jr. 1995. Epidemiology of multiple sclerosis in U.S. veterans: 6. Population ancestry and surname ethnicity as risk factors for multiple sclerosis. Neuroepidemiology 14(6):286-296. 

VA (Department of Veterans Affairs). 1949. Veterans claims miscellaneous amendments. Federal Register 14:568. 

VA. 1993. Analysis of presumptions of service connection. Washington, DC: Department of Veterans 

Affairs. 

VA Multiple Sclerosis Study Group. 1956. Isoniazid in the treatment of multiple sclerosis: Report on VA 

Cooperative Study. Transactions of the American Neurological Assocociation (81st meeting): 

128-131. 

VA Multiple Sclerosis Study Group. 1957. Isoniazid in the treatment of multiple sclerosis: Report on 

Veterans Administration Cooperative Study. JAMA 163(3):168-172. 

Wallin, M. T., W. F. Page, and J. F. Kurtzke. 2000. Epidemiology of multiple sclerosis in U.S. veterans: 

8. Long-term survival after onset of multiple sclerosis. Brain 123(Pt 8):1677-1687. 

CASE STUDY 3: PRISONERS OF WAR PRESUMPTIONS 

This study examines the scientific evidence and governmental policy decisions concerning 

veterans who were held as POWs. Covering a period of 60 years commencing with the end of 

World War II, the case study examines the policy considerations that resulted in the creation of 

various legal presumptions to facilitate former POWs’ access to VA health and disability benefits. It focuses particular attention on epidemiologic and other studies examining the residual 

health effects of the POW experience and their influence on the policy decisions reached. 
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Background 

In most wars a number of combatants are captured and interned as POWs. In our history 

there have been over 500,000 American POWs. Almost 70 percent of those were captured by 

both sides during the Civil War (VA, 2005, p. 4). 

In the 20th century over 142,000 service personnel were held as POWs, about 17,000 of 

which died while held prisoner. Ninety-eight percent of these deaths occurred during World War 

II and the Korean War (VA, 2006). POW deaths during World War II varied greatly depending 

on the theater of operation. About 40 percent of the nearly 28,000 Pacific theater POWs—most 

of whom were interned in the Philippines in the early months of 1942—died while in captivity 

(VA, 2005, p. 5). 

In the European/Mediterranean theater about 1 percent of the over 94,000 POWs perished 

while interned. One in four of the European/Mediterranean theater POWs were captured during 

the Battle of the Bulge in late December 1944 and January 1945. During the Korean War 2,700, 

or nearly 38 percent, of slightly more than 7,100 service personnel died while in captivity (VA, 

2005, p. 5). 

Of the 125,000 POWs returned to U.S. military control in the last century, almost 4,000 were 

veterans of World War I, none of whom are alive today. The 116,000 World War II veterans released at the end of hostilities constitute the largest cohort (93 percent) of 20th-century POWs 

with the remainder either veterans of Korea, Vietnam, or later conflicts (VA, 2006). 

VA estimates that at the end of 2005 there were just over 29,000 living POWs of whom 91 

percent are World War II veterans and 7 percent veterans of the Korean War. Almost 17,000 

POWs were receiving VA disability compensation as of August 2006, and 13,000 of them were 

rated 100 percent disabled (VA, 2006). 

World War II and Its Aftermath 

Congressional concern about the difficulties that combat veterans might encounter in establishing claims for service-connected disability benefits was manifested in legislation enacted 

within 2 weeks of the U.S. entry into World War II. That law, the Veterans Determination of 

Service Connection of Disabilities Act of 1941 (Public Law 77-361. 77th Cong., 1st Sess.), directed the VA Administrator, in considering benefit claims, to give “due consideration” to the 

“places, types and circumstances” of the claimant’s service and statutorily codified VA’s liberal 

evidentiary rules for establishing proof of service connection (VA, 1993, pp. 22-23). The legislative history reflects that it was intended to overcome the possible lack of official records that 

might occur under wartime conditions. 

Consistent with the 1941 legislation, VA, in issuing its 1945 Schedule for Rating Disabilities 

(the Rating Schedule), acknowledged the difficulties that former POWs might have in establishing service-connected disability claims. The rating schedule provided that in considering claims 

with respect to tropical diseases, dysentery, and other gastrointestinal diseases, “great weight

must be assigned to tropical service and to imprisonment or internment under unsanitary conditions, or food deprivation” (VA, 1993, pp. 43-44; emphasis added). Additional instructions issued in 1946 concerning the Rating Schedule provided that “prisoner of war experience requires 

special consideration” with respect to claims involving malnutrition, intestinal parasites, weakness and fatigability, and neuropsychiatric disorders. Claims examiners were instructed that the 

“existence of any chronic disease that may be associated with the circumstances of imprisonment 

should be carefully checked and reported on” (VA, 1993, pp. 43-44; emphasis added).
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APPENDIX I I-19 

The 1950s 

Growing concern by members of Congress about the well-being of POWs and the privations 

they experienced, particularly in the Pacific theater, led to the introduction of legislation and 

hearings in 1948. One measure would have provided that any veteran held prisoner for a continuous period of at least 2 years would have been conclusively presumed to be totally disabled 

for a period of 5 years from his release. In addition, any death occurring during that 5-year period would be presumed service connected in the absence of clear and convincing evidence to the 

contrary. After the initial 5-year period the presumption of total disability would be rebuttable 

but again only by clear and convincing evidence (VA, 1993). 

VA opposed the legislation on the ground that service connection should not be granted in 

the absence of a factual showing of disability. Additionally, it detailed the special consideration 

for POWs contained in its operating procedures. Although the measure was not acted upon by 

the House Veterans Affairs Committee, concern continued about the mental and physical effects 

of imprisonment as various members of Congress introduced bills in the early 1950s to require 

studies of POW mortality and morbidity. The sponsors anticipated that the studies might provide 

evidence to support a conclusive presumption for service connection for the purposes of VA 

hospitalization benefits as well as standards that could be employed in evaluations of POW disability claims. Again, VA demurred, noting the special consideration it was giving to POW 

claims. VA also pointed out that it was already conducting studies related to the POW experience 

(VA, 1993). 

Ultimately, Congress enacted the War Claims Act Amendments of 1954 that incorporated 

provisions of these bills with respect to studying mortality and morbidity experiences of POWs, 

while omitting any of the provisions relating to the proposed development of standards for conclusive presumptions (VA, 1993, p. 45). 

In September 1954, VA published A Follow-Up Study of World War II Prisoners of War, coauthored by Bernard Cohen of the NRC and Maurice Cooper of VA (Cohen and Cooper, 1954). 

The study, which was initiated prior to the passage of the War Claims Act, was characterized by 

the authors as an exploratory record follow-up study of POWs released at the end of World War 

II that “does not purport to be more than an examination of the surface of the problem.” Rather, 

its purpose was to “delineate the broader consequences of imprisonment that manifest themselves in increases in mortality, hospitalization, disability, health status, and work adjustment, to 

measure the magnitude of these changes and to describe the gross findings” (Cohen and Cooper, 

1954). 

A key finding of the study was that Pacific theater veterans had a high rate of mortality in the 

first 2 years following liberation. By contrast, returned European theater POWs did not have a 

significant difference in mortality compared with control groups. Some 64 percent of Pacific 

theater POW deaths were attributable to either tuberculosis or accidents. The frequency of tuberculosis deaths was not unexpected given malnutrition and crowded, unsanitary living quarters, 

but unanswered questions remained as to whether the degree and duration of malnutrition that 

Pacific theater POWs experienced could be sufficient to “result in obscure irreversible structural 

and functional changes that might be expected to affect longevity.” With respect to excess accidental deaths, the authors recommended more detailed examination in future studies, particularly 

as to whether there might be a psychological basis involved (Cohen and Cooper, 1954). 

The authors concluded that 
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[T]he mortality findings and their implications suggest the existence of organic and emotional residuals of imprisonment severe enough to be factors affecting survival, and raise 

many questions concerning the future survival potential of those still alive and their long 

run morbidity and disability expectations. 

(Cohen and Cooper, 1954; emphasis added) 

The early morbidity and disability observations were found to be “quite consistent with those 

of mortality.” Pacific prisoners exhibited a wide variety of illness that occurred with frequencies 

in nearly every major category of disease that were far in excess of those shown by European 

POWs or control groups. Chronic conditions that were noticeably frequent and persistent were 

tuberculosis, residuals of malnutrition, psychoneurosis, ophthalmologic changes, gastrointestinal 

disorders, and cardiovascular conditions. Among European POWs there was not found “a great 

deal more illness” than control groups although there was a “relative excess in malnutrition, 

psychoneurosis, and gastrointestinal disorders.” The authors suggested that “[s]ome if not all” of 

these conditions deserved “more intensive investigation” (Cohen and Cooper, 1954). 

The authors concluded their report by recommending a “continuation of the follow-up 

[study] to detect late effects or confirm early findings, and the desirability of more intensive 

study in certain areas” (Cohen and Cooper, 1954). The 1954 study was followed by a Department of Health, Education, and Welfare (HEW) study, Effects of Malnutrition and Other Hardships on the Mortality and Morbidity of Former United States POWs and Civilian Internees 

(HEW, 1956), issued in 1956 in response to the direction of the War Claims Act Amendments of 

1954 (Public Law 83-774. 83rd Cong., 2d Sess, as referenced in VA, 1993). It relied heavily on 

the NRC/VA study and its findings and conclusions mirrored that report. It recommended, “in 

conformity with the stated policy of VA,” that “[p]articular attention” should be given in evaluation of POW claims for claimed disabilities resulting from “prolonged malnutrition and other 

conditions shown by the NRC/VA study to exist in high incidence in Pacific POWs” as well as 

to the difficult question of “complaints which cannot today be evaluated by objective measurements or test” (HEW, 1956). 

For the remainder of the decade, there was little activity regarding establishment of statutory 

presumptions for POWs with the exception of a measure to officially declare all POWs to be disabled and entitled to full retirement pay, which did not receive favorable consideration from 

Congress (VA, 1993, pp. 45-46). 

The general issue of statutory presumptions, however, did receive considerable attention as a 

result of a 1956 report of the President’s Commission on Veteran’s Pensions. Established by executive order, the commission—typically referred to as the Bradley Commission after its chairman, General Omar Bradley who headed VA at the conclusion of World War II—addressed 

statutory presumptions in one of the 70 recommendations it issued in 1956. Specifically, it recommended withdrawing the “presumption of service connection for chronic disease, tropical diseases, psychoses, tuberculosis, and multiple sclerosis as now listed” (President’s Commission on 

Veterans’ Pensions, 1956, p. 178). Relying in large part on the result of a survey of physicians, 

the Bradley Commission asserted that as to those conditions: 

Accepted medical principles can reasonably and accurately establish the onset of a disease and the disability process. Where there is reasonable doubt, the law provides for the 

doubt to be resolved in favor of the veteran. . . . The physicians surveyed were in general 
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APPENDIX I I-21 

agreement that service connection should be determined in accordance with sound medical principles and not by fiat. 

(President’s Commission on Veterans’ Pensions, 1956, p. 178) 

Hearings on the Bradley Commission’s recommendations by the House Committee on Veterans Affairs in 1956 elicited strong reactions from national veteran service organizations 

(VSOs). Witnesses from the Disabled American Veterans challenged the assertion that physicians were in agreement about whether certain chronic diseases discovered 1 or 2 years after 

separation had their inception in service, and it was for this reason that Congress authorized 

statutory presumptions (VA, 1993). 

The American Legion representative testified that the question was “not entirely a medical 

one” and that the “purpose of a presumption is to free the veteran from carrying an unconscionable burden of proof” in establishing disability compensation entitlement. The witness added that 

it “is a rebuttable presumption . . . [which] enables the government, if medical knowledge is what 

the Bradley Commission says that it is, to rebut the presumption.” He concluded that until 

American medicine can “determine with more than a reasonable degree of accuracy” whether or 

not certain types of diseases had their inception in service, the veteran should be entitled “to a 

presumption that his disease or disability, within reasonable periods now or to be specified, was 

the result of his service” (VA, 1993, p. 41). 

This position was essentially endorsed by the committee which declined to act on the Bradley 

Commission recommendation. In hearings the following year, its chairman, Olin “Tiger” Teague 

from Texas stated that presumptions were enacted “because Congress did not agree with many of 

the medical findings” of VA physicians and consequently it was the “only way we can force 

proper administration” (VA, 1993, p. 42). The American Legion’s senior medical consultant testified that the Legion would not ask for presumptive service connection “unless the same was 

justified on reasonable medical grounds.” Presumptions were often required, he said, because of 

inadequately trained VA personnel which resulted in a lack of uniformity in the application of 

the law (VA, 1993, p. 42). 

The 1960s 

Legislation seeking to establish presumptions for POWs began to increase in the 1960s. 

Some measures would have established a presumption of service connection for any disability 

for which a veteran was seeking service connection if that veteran had been a Pacific theater 

POW confined for more than 2 years. Other bills would have increased the existing presumptive 

period for chronic and tropical diseases to 5 years in the case of any veteran who had been a 

POW. Still other proposals would have created an irrebuttable presumption that all former World 

War II and Korean War POWs who had been interned for at least 3 years were service-connected 

disabled to a 50 percent degree. Variants on that proposal would have reduced the minimum period of confinement to 1 year. None of these POW-specific presumptions received favorable 

consideration from Congress (VA, 1993). 

The 1970s 

In the late 1960s, a three-phase program of research, Follow-Up Studies of World War II and 

Korean War Prisoners, was undertaken by the NRC with funding from VA. The first phase,

Study Plan and Mortality, published in 1970, was authored by M. Dean Nefzger who acknowledged difficulties in obtaining generally useful information because 
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Prison experience is a manifold of inadequate food, exposure, disease, physical abuse, 

and emotional torment. These various ingredients appear to be thoroughly mixed and interdependent. Their relative intensities probably vary from time to time, from place to 

place, and from man to man; and it seems impossible to separate any one component of 

this complex experience for the total. 

 (Nefzger, 1970, p. 124) 

 

Although this “limits the scope and specificity of inferences that may be drawn statistically,” 

the author said that follow-up studies might offer the “hope of learning more about the late effects of stress that is recognized as severe even though not well differentiated.” They may also 

“suggest areas for more penetrating study by other methods” (Nefzger, 1970, p. 124). 

The report generally confirmed the earlier findings and trends of the 1954 report by Cohen 

and Cooper. Pacific theater POWs had excess mortality compared to control groups, although 

that significantly diminished over time. European POWs showed no significant excess mortality. 

The report did note, however, that mortality experience for a small group of European prisoners 

hospitalized for malnutrition immediately after release suggested causes similar to Pacific theater 

POWs (Bard, 1994). 

Korean War POWs, who were included in this report, also experienced excess mortality rates 

throughout a 12-year follow-up when compared to controls. For Korean War veterans, trauma 

was the most common cause of death whereas Pacific POW deaths were attributed to tuberculosis, accidents, and cirrhosis of the liver (Nefzger, 1970). 

On the question of excess mortality due to disease, Nefzger wrote 

There is a great temptation to conclude that the apparent excess of deaths from diseases 

of the digestive system, including cirrhosis, resulted from malnutrition during imprisonment. That might be the case, but so specific an interpretation is hard to defend. It is possible that such diseases are an indirect consequence of imprisonment if that experience 

has contributed to a different standard or manner of living since repatriation. 

(Nefzger, 1970, p. 137) 

Finally, the report concluded that the contrasts between European prisoners generally and 

those European POWs hospitalized for malnutrition, and the contrast between European and Pacific prisoners, “suggest a positive association of stress in prison with later mortality,” although 

no general conclusion could be drawn from the data (Nefzger, 1970, pp. 137-138). 

The first legislation to create statutory presumptions specifically applicable to POWs was enacted in 1970 (Veterans Disability Compensation Increase. 1970. Public Law 91-376. 91st 

Cong., 2d Sess.). The act had its origins in S. 3348 that, as introduced, would have presumed 

service connection for any disability suffered by any POW held captive for more than 6 months. 

VA opposed the measure, reiterating that it gave special consideration to claims by former 

POWs, and arguing that the mere fact of 180 days confinement by itself did not justify service 

connection for “any disability the veteran may acquire at any time during the balance of his life,” 

VA also maintained that it would be “discriminatory” to those POWs who may have sustained 

equal or greater privations but were confined for less than the specified period—a point agreed to 

by the American Legion (U.S. Congress, Senate, Committee on Finance, 1970, p. 10). 

As finally reported to and passed by the full Senate, the bill had been modified to eliminate 

any minimum confinement period. Instead, the Senate substituted a requirement that the veteran 
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APPENDIX I I-23 

had to have suffered from “dietary deficiencies, forced labor, or inhuman treatment in violation 

of the terms of the Geneva Convention of July 27, 1929” (U.S. Congress, Senate, Committee on 

Finance, 1970, p. 12). If former POWs met these criteria and had any of seven specified nutritional or gastrointestinal diseases, those diseases would be “considered to have been incurred in 

or aggravated by such service notwithstanding that there is no record of such disease during the 

period of service” (U.S. Congress, Senate, Committee on Finance, 1970, p. 12). 

Under the act, “psychosis” was also to be considered a service-connected disability provided 

it became manifest within 2 years of separation from service. 

In justifying the statutory presumptions, the accompanying report said that due to the conditions of captivity and the “kinds of long-range harm that may have been caused,” it was “sometimes difficult for a former prisoner of war to establish some time after completion of military 

service” that a disability is related to military service (U.S. Congress, Senate, Committee on Finance, 1970, p. 4).

When the Senate-passed measure was considered by the House, the bill was further amended 

to add back the provision of not less than 6 months of confinement in addition to the Geneva 

Code violations required by the Senate. No explanation was given as to the rationale for the 6-

month requirement. Following Senate concurrence in the amendments, the measure was enacted 

as Public Law 91-376 on August 12, 1970 (Veterans Disability Compensation Increase. 1970. 

Public Law 91-376. 91st Cong., 2d Sess.). 

From October 1972 through August 1976, VA issued a number of program guides with respect to Public Law 91-376. These guides were characterized as suggestions for the guidance of 

personnel in the handling of disability of claims filed by former POWs. The program guides instructed that in light of the “frequent paucity of records” in POW claims, “special attention 

should be given to POW experiences in determining the relationship of the disability to service.” 

The duration and circumstances of imprisonment were to be associated with pertinent medical 

principles in making determinations (VA, 1980, p. 118). 

The burden of proof as to the occurrence of a POW episode was shifted from the claimant to 

the government. A veteran’s statement as to wounds or injury just prior to imprisonment was to 

be accepted as proof of actual incurrence when residual disability attributable to service was 

found. The “unusual hardship and isolation from society” resulting from POW life meant that an 

“extended period of readjustment to ordinary conditions of life is essential.” Claims for IU were 

to receive liberal construction and if the threshold disability percentage for the IU benefit was 

not met, the claim was to be submitted to the VA Central Office for further consideration. Finally, it was emphasized that presumptions were rebuttable only where there was “affirmative 

evidence to the contrary” (VA, 1980, p. 119). 

In 1975, the second phase of the Follow-Up Studies of World War II and Korean War Prisoners, entitled Morbidity, Disability and Maladjustments, was issued (Beebe, 1975). Its author, 

Gilbert W. Beebe, observed at the outset that studies of the long-term effect of catastrophic stress 

are “difficult to make and the frequently multidimensional character of such stress severely limits inferences about the etiologic role of specific components, such as malnutrition, social isolation, sensory deprivation, physical punishment, compulsory reeducation, and the like.” He further noted that recent studies of survivors of World War II German concentration camps 

provided useful information on a persistent defective state marked by “severe permanent psychiatric residuals and by nonspecific somatic symptoms” (Beebe, 1975, pp. 400-401). The researchers who conducted those studies believed that 
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[S]tarvation caused permanent damage that went largely unrecognized in the early years 

after release and came to be appreciated only as rehabilitation programs proved ineffective for so many of those who had suffered most severely. 

(Beebe, 1975, p. 401) 

Beebe’s findings were that morbidity, some types of maladjustment, and disability were elevated in POWs relative to controls especially for Pacific theater veterans. The “most remarkable 

and long-lasting differentials” were seen in hospitalization for psychoneurosis and for psychosis 

(schizophrenia). Data obtained supported a finding that many Pacific theater and Korean War 

POWs had “permanent psychologic impairments.” But he also noted that European theater 

POWs did not go “unscathed” with respect to psychoneurosis hospitalization (Beebe, 1975, 

p. 421). 

Conditions causing excess morbidity among World War II Pacific theater POWs were nutritional disorders, neurologic problems, gastrointestinal, genitourinary, and bone diseases. Finally, 

the study also found higher rates of cardiovascular diseases for which atherosclerotic disease was 

a major contributor which warranted further scrutiny (Beebe, 1975, pp. 421-422). 

Following enactment of Public Law 91-376, several bills were introduced that would have 

added additional chronic diseases to the presumptive list and/or extended the period of time from 

separation from service that they first be manifested. None were enacted. The Veterans Health 

Care Amendments of 1979 (Public Law 96-22. 96th Cong., 1st Sess.) did, however, authorize 

outpatient dental care benefits for all former POWs detained for 6 months or more. Although the 

law did not base dental benefit entitlement upon an explicit presumption—nor authorize disability compensation benefits—the Senate committee report accompanying the measure stated that 

many POWs developed dental conditions as a result of prolonged nutritional deprivation suffered 

while captive. It justified the provision in order “to provide that VA has full authority to meet the 

dental needs of former prisoners of war resulting from the conditions of their captivity.” The requirement that the former POW have been confined for 6 months or more was added because 

such “nutritional deficiencies result from a prolonged state of deprivation” and it was consistent 

with the 6-month requirement that was attached to other POW-related diseases (VA, 1993, 

p. 50). 

In the Veterans Disability Compensation and Survivor Benefits Act of 1978 (Public Law 95-

479. 95th Cong., 2d Sess.), Congress included provisions requiring VA to carry out a “comprehensive study on the compensation awarded to, and the health care needs of” former POWs. The 

results of the study were to include such administrative and legislative recommendations as “may 

be necessary to assure that former prisoners of war receive compensation and health-care benefits for all disabilities which may reasonably be attributed to their internment” (VA, 1993, p. 58; 

emphasis added). 

The study had four requirements. First, VA was to analyze the adequacy of repatriation procedures and medical exams and the resultant medical records of POWs. Second, the study was to 

set forth the “types and severity of disabilities particularly prevalent” among former POWs “in 

various theaters of operations at various times” (emphasis added). Third, VA was charged with 

analyzing procedures used in determining health-care benefits and in adjudicating disability 

compensation claims, including an “analysis of the current use of statutory and regulatory provisions specifically relating to former prisoners of war.” Finally, VA was directed to survey and 

analyze “all of the medical literature on health-related problems of former prisoners of war” 

(Veterans Disability Compensation and Survivor Benefits Act of 1978. Public Law 95-479. 95th 

Cong., 2d Sess.). 
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APPENDIX I I-25 

The legislative history indicates that the study was prompted by questions about the adequacy of repatriation examinations and by concerns that health conditions that may have appeared minor at the time were becoming progressively more debilitating. It also cited Beebe’s 

1975 follow-up study for the proposition that POWs had excess morbidity, and many were suffering from what was termed a “POW syndrome” (VA, 1993, p. 51). 

The 1980s 

At the beginning of the decade, the third phase of the follow-up studies, Mortality to January 

1, 1976, authored by Robert Keehn, was issued (Keehn, 1980). That study continued to find increased risks of mortality among World War II Pacific theater and Korean War POWs, though 

the excess diminished over time. For Pacific theater veterans the principal cause for the mortality 

increase was tuberculosis and trauma, while for former Korean War POWs it was trauma. As to 

trauma, the report found that for Pacific theater POWs, suicide was responsible for two-thirds 

and accidents one-third of the excess deaths. 

Given a consistent finding of “persistent psychologic impairment” and reported problems of 

adjustment to civilian life, the report concluded that 

The finding of increased mortality due to trauma, both accidental (including cases of 

masked suicide) and suicide in former prisoners of war is not surprising. Increased feelings of frustration, anger, and tension lead to impatience and impulsive actions which are 

likely to contribute to both the risk and severity of accidental and self-inflicted injury. 

(Keehn, 1980, p. 209) 

Keehn also found excess deaths due to cirrhosis of the liver for all World War II and Korean 

War POWs appearing in the 10th year of follow-up. The author said that it was unclear if the increased deaths resulted from “poor nutrition as a prisoner, from the variety of diseases (viral, 

parasitic) experienced during captivity, or from increased alcohol consumption or a combination 

of these” (Keehn, 1980, p. 210). He added that 

Although the role of diet in the etiology of alcoholic cirrhosis has not been clearly defined, it seems likely that a poor diet during captivity might predispose the liver to alcohol damage. 

(Keehn, 1980, p. 210) 

Finally, the study did not find excess POW deaths from malignant neoplasms or chronic and 

degenerative diseases, concluding that there was “no evidence to support the hypothesis that the 

stresses of captivity have accelerated degenerative changes in former prisoners” (Keehn, 1980, 

p. 210). 

Thereafter, also in 1980, VA delivered its Study of Former Prisoners of War (VA, 1980) to 

Congress as required by Public Law 95-479 (Veterans Disability Compensation and Survivor 

Benefits Act of 1978. Public Law 95-479. 95th Cong., 2d Sess.). The principal finding which VA 

described as “essential to the entire study” was that 

[T]he POW experience—characterized by starvation, diet, poor quality or nonexistent 

medical care, “death marches,” executions and torture—has historically been an extremely harsh and brutal experience. 

(VA, 1980, p. 161) 
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Concerning the initial question about the quality of POW repatriation procedures, exams, and 

resultant medical records, the study found that the prescribed procedures were generally well designed and reflected “state-of-the-art medical knowledge and technique at the time they were designed,” which “if followed would have provided former POWs with adequate records” (VA, 

1980, p. 71). Examination of VA claims folders, however, found that less than 20 percent of 

European theater POWs who filed disability claims had evidence of a repatriation examination. 

For Pacific theater and Korean War veterans, records of repatriation examinations were located 

in 60 percent and 85 percent of their files, respectively. In those cases where records were located, VA reviewer physicians judged 67 percent of World War II and 85 percent of Korean War 

POW repatriation exams as “providing a good or adequate basis for evaluating physical or psychiatric conditions.” The limitations were that over half of the examinations contained either no 

medical history or poor history of health status prior to capture. And, significantly, about onethird of the examinations had “inadequate evaluations of the POWs mental status and psychiatric 

conditions” (VA, 1980, p. 72). 

 Addressing the question of the types and severity of disabilities particularly prevalent among 

POWs in various theaters at various times, VA relied heavily on the NRC-funded follow-up reports previously described (Beebe, 1975; Keehn, 1980; Nefzger, 1970), and on VA mortality and 

morbidity data. The study found that Pacific theater former POWs were the most severely disabled group followed closely by Korean War POWs. Although European POWs had lower rates 

of disability, those rates still exceeded that of other World War II veterans. Studies were still 

continuing on Vietnam era veterans and hence unavailable at that time (VA, 1980). 

Although the findings provided support for the contention that an Asian internment environment was harsher, the study cautioned that any attempt to apply it to individual cases would “be 

mistaken as conditions varied from camp to camp, thus resulting in a wide spectrum of disability 

even within the same theater.” The report specifically noted, contrary to popular opinion, that 

with the exception of some facilities where aviators were confined, most German stalags where 

American foot soldiers were held “did not abide by even minimum standards for POW treatment 

set forth in the Geneva Convention” (VA, 1980, p. 31). 

The “most remarkable finding” of the study according to VA was that anxiety neurosis was 

“the most prevalent disability among former POWS from time of repatriation to the present.” 

Anxiety neurosis accounted for 12.7 percent of all service-connected conditions of former 

POWs, which was three times the rate of all veterans receiving compensation (VA, 1980, p. 95). 

VA found that 

The significance of this disability relative to veteran controls remains regardless of the 

length of internment. This is especially apparent among former European theater POWs 

in which those POWs interned less as well as more than 6 months exhibit significantly higher rates of anxiety neurosis compared to other service-connected World War II 

veterans. 

(VA, 1980, p. 95) 

The study also confirmed that “systemic and malnutrition related diseases—malaria, beriberi, 

pellagra—are prevalent among former POWs, especially those interned in Asia.” Among former 

World War II Pacific theater and Korean War POWs there were also statistically significant service-connected disabilities with respect to eye diseases, respiratory diseases, and gastrointestinal 

diseases. Pacific theater former POWs also had statistically significant rates for genitourinary, 

psychoneurological, and cardiovascular diseases (VA, 1980, pp. 95-96). 
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APPENDIX I I-27 

The study’s third requirement was to analyze procedures used to determine eligibility for 

benefits with a particular emphasis on the statutory and regulatory provisions unique to POWs. 

VA concluded that 

Former POWs generally have received special consideration in keeping with statutory 

and procedural provisions in terms of medical evaluations and disability compensation. 

Limitations in knowledge as to the long-term effects of the stresses and deprivations experienced by prisoners of war is a major obstacle for decision makers. 

 (VA, 1980, p. 128) 

VA also reported that over the years it had changed its approach to the adjudication of 

POW claims by gradually developing flexibility in such areas as substantiation of claims in the 

absence of medical records for periods of internment and in the presumption of service incurrence for certain disabilities. This changed approach reflected the “evolution of the law” and 

the degree of flexibility roughly coincided with “advancements in medical knowledge” concerning the serious effects of imprisonment on health (VA, 1980, p. 121). 

To support its assertion that POWs were accorded special consideration, VA compared 

their compensation rates with that of other veterans. Although less than 10 percent of war veterans were on the disability compensation rolls, 43.6 percent of former POWs were being compensated. Korean War POWs ranked highest with 59 percent followed by 50.6 percent of Pacific theater POWs and 42.2 percent of European theater POWs (VA, 1980, pp. 78-93). 

Some 22.2 percent of non-POW veterans on the compensation roles had severe disabilities 

(rated 50 percent or more disabled) compared to 48.8 percent of Pacific theater, 20.1 percent 

European theater, and 34.7 percent Korean War POWs. Veterans on the disability compensation rolls who are rated at 60 percent or more are entitled to be paid at the total disability rate if 

they are determined to be individually unemployable. Of all veterans on the rolls, 5.3 percent 

were rated unemployable compared to 22 percent of World War II Pacific theater, 5.3 percent 

European theater, and 8.9 percent Korean War POWs (VA, 1980, pp. 78-93). 

On the question of lack of uniformity raised by VSOs in deciding POW claims among regional offices, VA’s response was that an inquiry had been initiated by the General Accounting 

Office (GAO) in 1974-1975. A sample of cases had been selected and examined at four regional offices. GAO found “occasional variances in disability percentages . . . but no differences as to granting service connection” (VA, 1980, p. 127). Following this initial review, VA 

reported that GAO decided against conducting a formal study. 

The literature review of health problems of former POWs, the fourth requirement of the 

study, included eyewitness accounts of disabilities during captivity, epidemiologic follow-up 

studies, analysis of concentration camp populations, and discussions of former POW family 

and social problems. VA said that its review showed that the higher rate of health problems experienced were “related to malnutrition, torture, climatic exposure, and other deprivations of 

internment.” The epidemiologic follow-up studies indicated that “residuals of these and other 

disabilities have persisted until the present time” (VA, 1980, p. 154). 

Particularly noteworthy, according to VA, was that the psychological problems of former 

POWs, especially those of World War II, “closely resemble[d]” those of concentration camp 

survivors of the same period. Known as K-Z syndrome—and discussed in Beebe’s 1975 

report—symptoms included 
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General anxiety and nervousness, “startle” reaction, insomnia and nightmares, phobias, 

psychosomatic complaints, memory lapses, moodiness, inferiority complex, obsession 

with the past, depression, apathy, and “survivor guilt.” 

(VA, 1980, p. 154) 

The psychological literature on K-Z syndrome and other forms of psychic stress revealed a 

“significantly higher amount of family and social maladjustment as evidenced by inadequate 

functioning in father/parent roles, and higher rates of unemployment and disability compensation” (VA, 1980, p. 154). 

VA concluded its literature review by observing that many important questions were left 

unanswered including whether deaths due to trauma and cirrhosis were directly related to the 

POW experience, and if the arteriosclerosis experienced by former POWs directly related to the 

stress of internment (VA, 1980). 

Two major legislative recommendations were contained in the study submitted to Congress. 

First, VA recommended that the law be amended to authorize eligibility for VA health care to 

former POWs for any disease or neuropsychiatric disability. VA observed that NRC/VA studies showed former POWs generally had higher mortality and morbidity rates and that this was 

reflected in their higher rates of service-connected disabilities. Yet, despite the special consideration given to POW claims, their adjudication was complicated by the frequent absence of 

medical information at the time of repatriation and by the fact that “medical science cannot, at 

this time, conclusively determine on an individual basis the origins of some disabilities particularly prevalent among former POWs.” Authorizing comprehensive VA inpatient and outpatient 

medical care for any disease or neuropsychiatric condition “would remove access barriers to 

VA medical care for those former POWs currently classified in a lower than 50 percent serviceconnected priority category” (VA, 1980, pp. 163-164). 

The second legislative recommendation was to modify the existing statutory presumption of 

service connection for psychosis. VA proposed to “eliminate the requirement that psychoses 

suffered by POWs must become manifest within 2 years following service separation before 

the rebuttable presumption of service connection arises.” VA said that its literature review indicated that psychosis related to the POW experience “frequently appears years after service, not 

just immediately after separation,” citing NRC/VA follow-up studies published between 1946 

and 1980 in support thereof (VA, 1980, p. 164). 

VA also reported that it was undertaking several administrative actions as a result of its 

study. First, forthcoming guidelines on “posttraumatic stress neurosis” would have “explicit 

reference to former POWs as well as other combat veterans.” (Posttraumatic stress neurosis

was a term scheduled on October 1, 1980, to become part of VA’s official diagnostic classification system to describe such anxiety neurosis.) The guidelines would “specifically be used to 

diagnose, treat, and rate former POWs with anxiety neurosis or similar neurotic disorders.” VA 

said this change was justified because former POWs had experienced a wide range of psychological problems, and “anxiety neurosis” had been the most prevalent disability of former 

POWs, according to NRC epidemiologic studies and VA compensation data. VA added that an 

analysis of anxiety neurosis with length of internment disclosed that it remained a “statistically 

significant service-connected disability among former POWs regardless of the amount of time 

in prison camp” (VA, 1980, pp. 165-166; emphasis added). 

VA also announced that it would adopt a standardized protocol for disability compensation 

examinations for all former POWs similar to that developed by the military for former Vietnam 
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APPENDIX I I-29 

POWs. Additional research into POW problems was promised as was the formation of a POW 

advisory committee (VA, 1980). 

Congressional hearings followed the receipt of VA’s study of POWs in both 1980 and 

1981. The VSOs concurred with the VA recommendations but criticized them for being inadequate to meet the needs of the POWs and “totally unresponsive to the facts presented” in the 

report. The VSOs recommended expanding the use of presumptions for POW disability compensation claims (VA, 1993, p. 52). 

Legislation was reported in June 1981 and enacted into law on August 14 as the Former 

Prisoner of War Benefits Act of 1981 (Public Law 97-37. 97th Cong., 1st Sess.). The existing 

presumptive provisions for POWs were amended to expand the definition of those considered 

to be prisoners of war and to modify the preconditions necessary for any presumption to attach 

to a former POW’s disability claim. First, the requirement that POWs had suffered dietary deficiencies, forced labor, or inhumane treatment in violation of the Geneva conventions was removed. Second, the minimum period of confinement was reduced from 6 months to 30 days. 

Third, the requirement that psychosis manifests itself within 2 years of separation of service in 

order to qualify for a service-connection presumption was deleted as recommended by VA. Finally, an additional presumption termed “any of the anxiety states” was added to the statute. 

The legislative history reveals that removing Geneva Convention violations was intended to 

“relieve to a certain extent the burden on the former POW to submit evidence . . . that certain 

disabilities are service connected” (VA, 1993, p. 54). Reducing confinement time from 6 

months to 30 days was justified on the grounds that 

Though dietary deficiencies are clearly a function of time and malnourishment, medical 

evidence reveals that a person can suffer from malnutrition in less than 6 months. 

 (VA, 1993, p. 54) 

The act (Former Prisoner of War Benefits Act of 1981. Public Law 97-37. 97th Cong., 1st 

Sess.) adopted the VA recommendation for unlimited access to health care for POWs. It also 

statutorily established an Advisory Committee on Former Prisoners of War which, among other 

things, was directed to submit an annual report to the VA Secretary containing an assessment of 

the needs of former POWs and any administrative or legislative recommendations the committee considered to be appropriate. The VA Secretary, in turn, was required to furnish his comments and intentions concerning these recommendations in an annual report to Congress (VA, 

1993). 

An additional presumption for mental disorders in POWs was added in the mid-1980s, the 

Veterans’ Compensation and Program Improvements Amendments of 1984 (Public Law 98-

223. 98th Cong., 2d Sess.). This legislation added “dysthymic disorder” to the list of disabilities 

developing anytime after a POW’s separation from service for which a presumption of service 

connection would attach. 

Senator Alan K. Simpson, chairman of the Senate Committee on Veterans Affairs, termed 

the inclusion a clarification of the original intent of the Former Prisoner of War Benefits Act of 

1981. Speaking on the floor of the Senate during consideration of the measure he said that 

The complexity of anxiety states, anxiety neuroses, posttraumatic stress disorder, 

and dysthymic disorders and their associated and sometimes interrelated diagnoses 
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I-30 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

inadvertently resulted in a lack of clarity regarding the granting of service connection for 

depression. 

 (VA, 1993, p. 55) 

Further explanation was contained in the committee’s report accompanying the measure 

which recites that at the time the Senate reached agreement with the House on the 1981 act: 

[The Senate] was not aware that there would be cases in which former POWS suffering 

from nonpsychotic depressive disorders would not be diagnosed as suffering from posttraumatic stress disorder and therefore not adjudged under VA guidelines to be serviceconnected disabled. . . . The committee intends that this addition would correct the inadvertent oversight in the original legislation and establish a presumption for a mental disorder which is linked in scientific literature to the POW experience. 

 (VA, 1993, pp. 55-56) 

Two years later, the Veterans Benefits Improvement and Health Care Authorization Act of 

1986 (Public Law 99-576. 99th Cong., 2d Sess.) added presumptions for “posttraumatic osteoarthritis” and “[o]rganic residuals of frostbite, if the VA Secretary determines that the veteran was detained or interned in climatic conditions consistent with the occurrence of frostbite.” Report language accompanying the legislation said that Congress expected VA “to give 

great weight to the veteran’s description of the circumstances of frostbite injury and to accept 

that description if it is possible that these circumstances occurred and the veteran suffers from 

residuals of frostbite” (U.S. Congress, Senate, Committee on Veterans’ Affairs, 1986, p. 30). 

As for traumatic arthritis, the report observed that there was “disagreement as to the adequacy of medical science to distinguish between arthritis resulting from earlier trauma and arthritis which is the result of other causes or which normally occurs during the aging process” 

(U.S. Congress, Senate, Committee on Veterans’ Affairs, 1986, p. 30). As reported to the Senate floor, the bill simply directed VA to provide a report of the effectiveness of procedures for 

evaluating such disability claims. During floor consideration, however, the Senate added the 

specific presumption of posttraumatic osteoarthritis based on unidentified “additional information” received by the committee after it had filed its report. 

In a letter to the Chairman of the Senate Committee on Veterans’ Affairs, VA administrator 

Thomas Turnage questioned the need for these presumptions, saying that if a POW had developed either condition it normally would have “manifested itself and required treatment upon 

repatriation or shortly thereafter.” But VA did not oppose the provisions, acknowledging that 

the presumption could serve as a safety net for those veterans whose repatriation processes 

were insufficient and for those “veterans who had a tendency to initially put aside traumatic 

experiences associated with captivity” (U.S. Congress, Senate, Committee on Veterans’ Affairs, 1986, pp. 128-129). 

Three additional POW presumptions were added with the enactment of the Veterans Benefits and Services Act of 1988 (Public Law 100-322. 100th Cong., 2d Sess.). They were peripheral neuropathy (except where directly related to infectious causes), irritable bowel syndrome, 

and peptic ulcer disease. Senator Cranston, who sponsored the presumptions, cited a 1986 VA 

study of former Pacific and European theater POWs as well as a 1985 Australian study which 

found higher incidence of duodenal ulcers among POWs than controls (VA, 1993, p. 58). The 

Senate report accompanying the legislation (U.S. Congress, Senate, Committee on Veterans’ 

Affairs, 1987) found that peripheral neuropathy is causally related to exposure to cold tempera-
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APPENDIX I I-31 

tures, exhausting physical activity, and vitamin deficiency resulting from extreme malnutrition. 

The report also found that stress and malnutrition were probable risk factors for irritable bowel 

syndrome and peptic and duodenal ulcers. 

VA again took the position that the conditions proposed to be added would ordinarily have 

become manifest and required treatment upon repatriation or shortly thereafter entitling the veterans to direct service connection without resort to a presumption. VA also maintained that irritable bowel syndrome was not a good candidate for a presumption because it was “a functional 

disorder of unknown etiology and pathogenesis” (VA, 1993, p. 59). 

Finally, the measure as enacted reduced the minimum confinement time to qualify for dental health-care benefits to 30 days. 

The 1990s 

Although there were no new POW presumptions during this decade, it was an active period 

for studies dealing with the health effects of POW internment. 

Several studies published in 1991 examined chronic depression among former POWs. The 

first, by Engdahl et al. (1991), found that long-term chronic depressive symptomatology persisted over 40 years and was elevated among POWs of all theaters when compared to control 

groups. The authors found that age, education, medical symptoms during captivity, and level of 

social support were related to later levels of adjustment. A second longitudinal study published 

the same year by Page et al. (1991) elaborated on previous research to show that not only was 

depressive symptomatology highly elevated in World War II and Korean War POWs, but it was 

elevated to the point where these populations closely resembled a clinical population of recovering depressives. Two major conclusions from this longitudinal study were that treatment during 

captivity is statistically linked with depressive symptoms, and that differences in these symptoms 

were attributable to captivity-related treatment, even when age at capture and education level 

were considered. 

Other variables were considered as well. Conducting a 40-year follow-up of U.S. World War 

II and Korean War former POWs, Engdahl and Page (1991) measured captivity trauma variables 

and individual protective variables (age, education, medical symptoms during captivity, social 

support) to current depressive symptoms. Although depressive symptoms persisted more than 40 

years with the knowledge that PTSD and generalized anxiety disorders are known to occur with 

elevated frequency in POW populations, the degrees of individual protective variables were related to levels of adjustment. This study made a case for the need to examine former POWs that 

adjusted well in order to understand both the role of specific protective variables and adjustment 

and resiliency following trauma. 

Page’s (1991) work continued with respect to the validity and reliability of some of the work 

cited above. Despite the heavy reliance on survey data, a noticeable shortage of reports on the 

effects of nonresponse bias on the measurement of depression existed. Longitudinal data presented opportunities for different types of nonresponse bias, but could also be useful in modeling 

for bias because of previously collected data. Page found that a predictive model shows nonresponse bias on the reporting of depressive symptoms among former World War II and Korean 

POWs to be small. 

In 1992, the IOM produced a report entitled The Health of Former Prisoners of War (IOM, 

1992). This longitudinal study, which focused on morbidity, was initiated in 1986 and built on 

the earlier work of Cohen and Cooper (1954), Nefzger (1970), Beebe (1975), and Keehn (1980). 

Veterans were invited to a medical center to undergo the VA protocol exam, which included a 
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I-32 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

comprehensive physical and psychiatric examination. A face-to-face psychiatric interview and a 

battery of psychological tests were also administered. A caution was provided at the outset of the 

report that due to low response rates there could be “no confidence . . . that the group of respondents accurately reflects the composition of all former POWs” (IOM, 1992, p. 4). Nevertheless, 

the study author noted that the results were presented as descriptive data for two reasons. First, 

the data, which constituted the largest national collection of POW examinations ever gathered 

and analyzed, contained a number of findings worthy of note. Some of the findings confirmed 

earlier studies while other findings were suggestive and served the purpose of generating more 

definitive research studies. 

The second reason to publish the data was not a scientific one, but rather a recognition that 

[T]he examination data will have uses beyond the scientific one—for example, in providing material for discussion of military service-connected disabilities among former 

POWs. Despite the fact that sound inferences about the group of all former POWs cannot 

be drawn from the exam data in this report, policymakers who must deal with such issues 

should be able to review this descriptive information. . . . Not to report the findings of the 

examinations would surely raise more questions than the report, with its careful documentation of the study’s limitations, would raise. The results of this examination study 

are thus discussed below, and we urge a maximum of reasonable caution in their 

interpretation. 

(IOM, 1992, p. 5; emphasis added) 

The report brought attention to the high prevalence of a number of medical conditions for 

POWs as compared to controls, especially with regard to psychiatric illness. Prevalence rates for 

over 20 different medical conditions were discussed, with key results including the following: 

• Percentage of weight loss was associated with higher prevalence of intermittent claudication and arterial vascular disease and lower prevalence of osteoarthritis. 

• Pacific POWs had higher prevalence of PTSD, ulcer, schizophrenia, and generalized 

anxiety than European and Korean POWs. 

• Vitamin A deficiency and ulcer prevalence was higher for all groups. 

• Edema (also significantly associated with higher prevalence of ischemic heart disease 

and peripheral nerve disease) and vitamin B1 deficiency was higher for all groups. 

• Visual symptoms were associated with higher prevalence rates of cerebrovascular 

disease, ulcers, asthma, and PTSD. 

• Neurologic symptoms were associated with beriberi. 

• Korean conflict POWs showed higher prevalence rates for schizophrenia. 

• Vitamin A deficiency helped to explain the prevalence of asthma and cerebrovascular 

disease in POWs with visual symptoms. 

(IOM, 1992, pp. 6-11) 

The report also said that many of the organ-specific findings were familiar and that the appreciably increased prevalence of depressive disorders, PTSD, and generalized anxiety were 

not unexpected. Similar findings regarding peripheral nerve disease, ulcer, and gastroenteritis 

were also not surprising (IOM, 1992). 

The report did state that the noteworthy association between current peripheral nerve disease and earlier edema “suggests . . . there may be persistent neurologic effects decades after 

the original nutritional disease may have been successfully treated and acute symptoms have 
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APPENDIX I I-33 

abated.” It added that the increased prevalence of schizophrenia among Korean War theater 

POWs and an “appreciable correlation with weight loss in this group offers further material for 

speculation” (IOM, 1992, p. 121). 

Perhaps the most striking finding was the association between ischemic heart disease and 

previous reporting of localized edema. It was observed that there was much interest in heart 

disease among former POWs, but cautioned that the “lack of a clear biologic mechanism linking nutritional deprivation and subsequent chronic heart disease” together with the study’s low 

response rate required that one “remain somewhat skeptical of this finding of association” 

(IOM, 1992, p. 122; emphasis added). Nevertheless, the report stated that 

Localized edema is a noteworthy risk factor for only two current medical conditions in 

these POW examinations—peripheral nerve disease and ischemic heart disease—both of 

which are acutely related to thiamin deficiency. . . . The specificity of association between localized edema and the only two medical conditions with well-established acute 

relationships to thiamin deficiency suggests that the association between earlier nutritional deprivation in prison camp and chronic ischemic heart disease is not an artifact. 

(IOM, 1992, p. 122) 

To better understand the characteristics that affect POWs’ reintegration into civilian life, 

Engdahl et al. published a report in 1993 that investigated long-term responses to captivity 

trauma in former POWs. The authors reported that symptoms at 20 years following release 

were related to those at 40 years following release. Many factors known to affect POWs’ longterm adjustment were not included in the study (e.g., combat exposure, postwar social support). 

This was due in part to their statistical infrequency or skewed nature (i.e., family history of 

mental illness, marital status at capture, military rank at capture). Trauma response was found 

to be determined by an interaction of characteristics of the individual and characteristics of the 

trauma, not primarily one over the other. The authors suggested that trauma response, from an 

evolutionary standpoint, may be better understood as adaptive due to its persistent nature (Engdahl et al., 1993). 

Research on POWs then turned to more specific disease outcomes in an attempt to ascertain 

if a relationship existed between POW status and increased mortality or morbidity. A 1994 study 

by Page and Ostfeld examined why a specific marker of malnutrition (lower limb edema related 

to vitamin B deficiency) in former POWs of World War II and the Korean War was associated 

with a three-fold increase in subsequent death attributed to ischemic heart disease. No medical 

basis for the link was found, but the confirmed findings emphasized the need for further research 

into links between severe malnutrition and subsequent chronic disease, both for former POWs 

and for other severely malnourished populations (Page and Ostfeld, 1994). 

Brass and Page (1996) examined health records of World War II POWs to see if severe or 

chronic stress increases risk of cerebrovascular disease. Compared to a control group, there appeared to be an association between stroke and being a former POW. There was no difference, 

however, in the prevalence of hypertension or diabetes. The results suggested that further research was needed to better define the risk factors for stroke and further understand the chronic 

effects of stress. 

PTSD continued to gain great attention. Page et al. (1997) examined the literature on PTSD 

in POWs and compared lifetime PTSD prevalence among POWs and control subjects. After a 

follow-up period of 40 years, differences in prevalence rates existed between POWs and control 

subjects for depressive disorders as well as generalized anxiety. All groups of POWs shared 
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nearly the same lifetime and current PTSD rates. Among World War II POWs, however, roughly 

half of the POWs who once suffered from PTSD were not currently diagnosed with that condition, suggesting the possible presence of chronic, stable PTSD in the other half of the POWs 

evaluated. However, the authors stated that this may be explained by the symptoms causing less 

stress on the first group of individuals. The authors suggested that those with higher distress levels should be evaluated for secondary symptoms of PTSD, such as depression. They concluded 

that 

Sensitivity toward older war veterans is vital. An awareness that their PTSD may have 

gone unnoticed by other health-care professionals for decades should encourage direct 

clinical inquiries about possible PTSD symptoms. We strongly recommend a structured 

interview. . . . PTSD symptoms have been all too common, yet undiagnosed among older 

war veterans, especially POWs. 

 (Page et al., 1997, p. 157; emphasis added) 

Recent Developments 

Work on PTSD continued into the new millennium when World War II and the Korean War 

POW interviews were examined for two separate index measures at two points in time—1965 

and 1990. Results from Gold et al. (2000) supported previous research highlighting the severe 

psychological consequences of POW status 40-50 years following captivity. Trauma severity 

during captivity was found to be the best predictor of current PTSD symptomatology. 

Other condition-specific research also continued. Page et al. (2000) examined data from 50 

years of follow-up for World War II former POWs in Pacific and European theaters to see 

whether location or POW status could be linked to death attributed to melanoma. Results showed 

that higher sun exposure in young adulthood (to the extent that POW status related to higher sun 

exposure) was associated with higher risk of melanoma mortality, with Pacific POWs at highest 

risk. A 50-year mortality follow-up by Page and Tanner, also in 2000, reported that Pacific theater POWs had twice the rate of death due to Parkinson’s disease and roughly one-sixth the rate of 

death from motoneuron disease compared to the control group. There was no difference, however, in the death rate due to Parkinson’s or other motoneuron disease in European theater 

POWs. 

Although the first 30 years after repatriation showed a survival advantage of World War II 

and Korean War former POWs for heart disease and stroke mortality, examination of death data 

at 50 years showed a significantly higher risk of heart disease deaths and slightly higher stroke 

mortality in POWs (aged 75 years and older) when compared to control groups. Page and Brass 

(2001) suggested that circulatory diseases from serious acute malnutrition and stresses from imprisonment may not appear until after many decades. 

A report that attracted much attention was a 2000 study of cirrhosis mortality among former 

World War II and Korean War POWs by Page and Miller. The authors conducted a 50-year 

follow-up study of World War II and Korean War former POWs to compare increased cirrhosis 

mortality found after a previous 30-year follow-up period with that of controls. World War II 

POWs were found to have a 32 percent higher risk of cirrhosis mortality compared to controls, 

while Korean conflict POWs had the same risk of cirrhosis mortality as controls. Lifetime prevalence rates for chronic liver disease, jaundice, helminthiasis, and nutritional deficiency were 

higher in Pacific and Korean POWs. But, the authors observed that 
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APPENDIX I I-35 

[T]here were no remarkable differences in levels of self-reported alcohol consumption 

among our POWs and controls, nor were their self-reported levels of consumption markedly different from those in the general population. The fact that cirrhosis mortality was 

not apparently associated with alcohol consumption may have implications for American 

POWs seeking disability compensation for cirrhosis. 

 (Page and Miller, 2000, p. 783)

The implications suggested by the authors soon became manifest. In April 2001, VA officials 

had prepared internal estimates of the budget impact of adding cirrhosis of the liver as a presumption of service connection for former POWs. Annual benefit costs were estimated to be 

$45,828 in 2002 and $624,106 through 2006 for an estimated caseload of “no more than 70 over 

5 years” (VA, 2001). 

On February 10, 2003, VA issued a proposed rule to add cirrhosis of the liver to the list of 

diseases for which entitlement to service connection would be presumed for former prisoners of 

war (VA, 2003). The proposed rule explained that its intended effect was to make it easier for 

former POWs to obtain compensation for cirrhosis “based on scientific and medical research 

showing a significantly higher risk of death from cirrhosis in former World War II POWs than in 

the general population” (VA, 2003, p. 1). Before discussing the rationale for adding cirrhosis of 

the liver as a presumptive service-connected condition, the notice observed that under 38 CFR § 

3.307(d) (Rebuttal of Service Incurrence of Aggravation) such presumptions may be rebutted by 

“competent evidence,” that is, “affirmative evidence that the disease was not incurred in service 

based on sound medical reasoning and consideration of all evidence of record” (VA, 2003, p. 2). 

In support of the presumption, the proposed rule (VA, 2003) cited the Page and Miller (2000) 

study that found the risk of cirrhosis mortality for Pacific and European theater former POWs 

was 1.5 times the rate for the control group. It also cited an Australian study that found World 

War II POW deaths from cirrhosis at twice the rate as expected. Observing that “it appears that 

alcohol consumption does not provide an explanation for the higher mortality rates identified in 

POWs,” the rule said that “[t]he VA Secretary believes that the research cited above constitutes 

sound scientific evidence supporting the conclusion that an association exists between cirrhosis 

and POW status” (VA, 2003, p. 3; emphasis added). 

Finally, the rule said that inasmuch as World War II POWs “comprise 93 percent” of all living ex-POWs, the “VA Secretary has therefore determined that it is appropriate to add cirrhosis 

of the liver . . . for which VA presumes service connection in all former POWs interned or detained for at least 30 days” (VA, 2003, p. 3). The proposed rule received no comments and became final on July 18, 2003. 

Later that same year, the Veterans Benefits Act of 2003 (Public Law 108-183. 108th Cong., 

1st Sess.) was signed into law. The measure contained two POW-specific provisions. First, it 

codified VA’s administrative decision concerning cirrhosis of the liver. Second, it removed the 

30-day minimum confinement requirement for 5 of the 16 POW presumptive conditions. Those 

5, for which no minimum confinement was required, were 

(a) Psychosis; (b) Any of the anxiety states; (c) Dysthymic disorder (or depressive neurosis); (d) Organic residuals of frostbite, if the VA Secretary determines that the veteran 

was detained or interned in climate conditions consistent with the occurrences of frostbite; and (e) Posttraumatic osteoarthritis. 

 
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I-36 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

In justifying the change, a Senate committee report on a similar bill observed that POWs 

were often treated brutally and, even if treated humanely, often suffered extreme mental anguish. 

Thus, the “30-day minimum internment requirement for purposes of presumptive service connection may be too restrictive for certain conditions” (U.S. Congress, Senate, Committee on Veterans’ Affairs, 2003, p. 10). In this connection, it should be noted that there was considerable public attention paid to Service members who were held as POWs for short periods of time shortly 

following the inception of Operation Iraqi Freedom in March 2003. 

Perhaps the most significant development concerning POW presumptions occurred on October 7, 2004, when VA issued an Interim Final Rule entitled Presumptions of Service Connection 

for Disease Associated with Service Involving Detention or Internment as a Prisoner of War 

(VA, 2004a). The rule established guidelines for establishing presumptions of service connection 

for diseases associated with service involving detention or internment as a prisoner of war. VA 

justified the rules as necessary because POW claims present unique medical issues and because 

factors including the lack of contemporaneous medical records during periods of captivity and 

the “relatively small body of available medical information” present obstacles to substantiating 

claims for service-connected benefits based on POW service. 

The guidelines were intended to help VA ensure that the claims are “decided fairly, consistently, and based on all available medical information concerning the diseases associated with 

detention or internment as a prisoner of war” (VA, 2004a, p. 60083). Finally, in utilizing the new 

guidelines, VA’s interim final rule also established presumptions of service connection for 

atherosclerotic and hypertensive heart disease and for stroke disease arising in former prisoners 

of war. 

The new guidelines found at 38 CFR 1.18 were as follows: 

§ 1.18—Guidelines for establishing presumptions of service connection for former 

prisoners of war. 

(a) Purpose. The Secretary of Veterans Affairs will establish presumptions of service 

connection for former prisoners of war when necessary to prevent denials of benefits 

in significant numbers of meritorious claims. 

(b) Standard. The Secretary may establish a presumption of service connection for a disease when the Secretary finds that there is at least limited/suggestive evidence that an 

increased risk of such disease is associated with service involving detention or internment as a prisoner of war and an association between such detention or internment and the disease is biologically plausible. 

(1) Definition. The phrase “limited/suggestive evidence” refers to evidence of a 

sound scientific or medical nature that is reasonably suggestive of an association 

between prisoner-of-war experience and the disease, even though the evidence 

may be limited because matters such as chance, bias, and confounding could not 

be ruled out with confidence or because the relatively small size of the affected 

population restricts the data available for study. 

(2) Examples. “Limited/suggestive evidence” may be found where one high-quality 

study detects a statistically significant association between the prisoner-of-war 

experience and disease, even though other studies may be inconclusive. It also 

may be satisfied where several smaller studies detect an association that is consistent in magnitude and direction. These examples are not exhaustive. 

(c) Duration of Detention or Internment. In establishing a presumption of service connection under paragraph (b) of this section, the Secretary may, based on sound scien-
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APPENDIX I I-37 

tific or medical evidence, specify a minimum duration of detention or internment 

necessary for application of the presumption. 

(d) Association. The requirement in paragraph (b) of this section that an increased risk of 

disease be “associated” with prisoner-of-war service may be satisfied by evidence 

that demonstrates either a statistical association or a causal association. 

(e) Evidence. In making determinations under paragraph (b) of this section, the Secretary 

will consider, to the extent feasible: 

(1) Evidence regarding the increased incidence of disease in former prisoners of war; 

(2) Evidence regarding the health effects of circumstances or hardships similar to 

those experienced by prisoners of war (such as malnutrition, torture, physical 

abuse, or psychological stress); 

(3) Evidence regarding the duration of exposure to circumstances or hardships experienced by prisoners of war that is associated with particular health effects; and 

(4) Any other sound scientific or medical evidence the Secretary considers relevant. 

(f) Evaluation of studies. In evaluating any study for the purposes of this section, the 

Secretary will consider: 

(1) The degree to which the study’s findings are statistically significant; 

(2) The degree to which any conclusions drawn from the study data have withstood 

peer review; 

(3) Whether the methodology used to obtain the data can be replicated; 

(4) The degree to which the data may be affected by chance, bias, or confounding 

factors; and 

(5) The degree to which the data may be relevant to the experience of prisoners 

of war in view of similarities or differences in the circumstances of the study 

population. 

(g) Contracts for Scientific Review and Analysis. To assist in making determinations under this section, the Secretary may contract with an appropriate expert body to review 

and summarize the scientific evidence, and assess the strength thereof, concerning the 

association between detention or internment as a prisoner of war and the occurrence 

of any disease, or for any other purpose relevant to the Secretary’s determinations. 

The interim final rule contained an extended discussion and explication of these guidelines. It 

first noted that statutory and regulatory standards currently existed to guide VA in identifying 

diseases associated with exposure to herbicide agents, hazards of service in the Gulf War, and 

ionizing radiation, and that it would be helpful to establish standards to guide VA in identifying 

diseases associated with service involving detention or internment as a POW. The POW guidelines were characterized as substantially similar to the existing guidelines noted above, with “minor differences necessary to reflect considerations unique to former POWs” (VA, 2004a, p. 

60084). 

The rule noted that evidentiary presumptions were to serve a number of purposes, including 

the promotion of efficient resolution of service-connection issues by codifying medical findings 

and principles that otherwise may not be familiar to VA adjudicators. Presumptions promote “fair 

and consistent decision making by establishing simple adjudicatory rules” as well as assisting 

claimants who might face substantial difficulties “due to the complexity of the factual issues, the 

lack of contemporaneous medical records during service, or other circumstances” (VA, 2004a, p. 

60084; emphasis added). 

Acknowledging that POW experiences have varied with time, place, and other factors, the 

rule stated that “certain hardships are so prevalent across the spectrum of POW experience as to 

support the presumption that POWs as a group have incurred similar health risks.” Evidentiary 
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I-38 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

presumptions were also strongly justified by the absence of “contemporaneous personnel and 

health records to document events, injuries, or diseases during periods of captivity.” Moreover, 

presumptions simplify and expedite the claims adjudication process, a “particularly significant 

consideration for former POWs, more than 90 percent of whom served in World War II and are 

now, on average, over 80 years old” (VA, 2004a, p. 60084). 

VA acknowledged that determining whether health effects may be associated with POW experience is “not a simple task.” The effects of the POW experience have been less extensively 

studied, because “there generally are not comparable civilian populations, and the number of 

former POWs available for study is comparatively small.” Accordingly, VA announced that it 

intended to establish presumptions of service connection when the medical evidence reasonably 

establishes an “association between the POW experience and particular diseases” (VA, 2004a, p. 

60084; emphasis added). 

Perhaps the most significant feature of the new POW guidelines was the explicit decision to 

establish POW presumptions utilizing the “limited/suggestive evidence of an association” classification. VA said this was essentially the same standard employed by IOM in reports it prepared 

for VA (IOM, 1994, 1996, 1999, 2000, 2001, 2003, 2005) analyzing the health effects of exposure to herbicide agents. “Limited/suggestive” evidence is one of four classifications employed 

by IOM in its Agent Orange reports and was a standard that had been utilized by VA in establishing presumptions of service connection. VA characterized the “limited/suggestive” evidence 

standard as a “useful analytical framework for assessing scientific evidence and determining 

whether a presumption of service connection may be warranted” (VA, 2004a, p. 60085). 

IOM’s use of the term “limited/suggestive evidence of an association” was explained as referring to circumstances in which evidence is suggestive of an association but is limited because 

matters of chance, bias, and confounding cannot be ruled out with confidence (IOM, 1994, 1996, 

1999, 2001, 2003, 2005). VA said its definition for POWs “adds that the evidence may be limited 

because the relatively small size of the affected population may restrict the data available for 

study.” This addition was significant, VA said, given the circumstances of the POW experience 

and the fact that “the population of surviving former POWs, most of whom served in World War 

II, is declining rapidly” (VA, 2004a, p. 60085). In the rule,VA added 

Although we intend that any presumptions VA establishes will be based on sound scientific and medical evidence, we believe . . . that fairness to former POWs requires that VA 

fully evaluate the available data and not accord undue significance to the fact that such 

data are comparatively limited by the small size of the affected population. 

 (VA, 2004a, p. 60085) 

Finally, the rule stated that 

The requirement that the association be biologically “plausible” does not require proof of 

a casual relationship . . . it requires only a determination that there is a possible biologic 

mechanism, consistent with sound scientific evidence, by which the suspected precipitating event (POW experience) could lead to the health outcome. IOM routinely applies the 

concept of biologic plausibility in its reviews of the literature concerning the health effects of herbicide exposure and hazards of Gulf War Service. . . . 

(VA, 2004a, p. 60085) 
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APPENDIX I I-39 

Having established the guidelines in the October 7, 2004, rule, VA then applied them in establishing new presumptions of service connection for (1) “stroke and its complications,” and (2) 

“atherosclerotic heart disease or hypertensive vascular disease (including hypertensive heart disease) and their complications (including myocardial infarction, congestive heart failure, arrhythmia” (VA, 2004a, p. 60090). 

With respect to the first presumption, VA admitted that there were very few studies investigating the possible relationship between POW experience and stroke. It referenced a 1996 Brass 

and Page study that found a seven-fold increase in the incidence of stroke among the POWs as 

compared to the control group. VA noted that the strength of those findings was limited by the 

small size of the study population. It also referenced a 2001 Brass and Page study that found a 

statistically significant increase in death from stroke among veterans who had experienced visual 

symptoms, such as night blindness, during their captivity. Because the presence of visual symptoms during captivity may be associated with vitamin A deficiency, this finding was regarded as 

consistent with the earlier study in suggesting an association between malnutrition during POW 

captivity and subsequent stroke (VA, 2004a). 

On the recommendation of the Expert Panel on Strokes in Former Prisoners of War, VA’s 

Environmental Epidemiology Service conducted a study in 2003 using medical and death data 

from VA and the Health Care Financing Administration (HCFA) records (Kang and Bullman, 

2003; as referenced in VA, 2004a). That study, which had not been published at the time the rule 

was issued, found that POWs had a significantly higher incidence of PTSD than the controls and 

further that POWs with PTSD had a higher incidence of stroke than POWs without PTSD. Although the study did not find a significantly increased risk of stroke among POWs as compared 

to non-POWs, the evidence for an association between PTSD and stroke among POWs was 

deemed consistent with findings stated in the 1996 Brass and Page study. 

Observing that several studies had provided evidence suggesting an association between 

stress and stroke, the rule reiterated that the VA Secretary would consider evidence concerning 

the effects of circumstances or hardships similar to those experienced by POWs, including stress, 

in assessing the evidence for establishing presumptions of service connection. 

Accordingly, based on the evidence discussed above, the VA Secretary determined that a presumption of service connection was warranted for stroke among former prisoners of war. The 

Brass and Page (1996) and Page and Brass (2001) POW studies both found an increased risk of 

stroke among former POWs. Although there was an absence of other directly corroborating studies, the lack of additional data was due in part to the small size of the POW population available 

for study and the limited number of studies generally undertaken in this field. Under those circumstances, VA concluded the lack of corroborating data did not imply the absence of an association (VA, 2004a). 

Because “VA consider[ed] stress and malnutrition to be among the hardships ordinarily associated with POW experience” and because “evidence suggest[ed] that the risk of stroke increases 

with the severity of those hardships” the VA Secretary found that 

[T]he available evidence is suggestive of an association between POW experience and 

stroke because sound scientific studies provide evidence of an association that is consistent in magnitude and direction, even though it is limited in some respects by the small 

size of the affected population and the correspondingly limited data available for study. 

 (VA, 2004a, p. 60086) 
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I-40 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

The VA Secretary further determined that an association between stroke and POW experience was biologically plausible, and for those reasons VA was establishing a presumption of service connection for stroke in former POWs.

Turning to the second presumption that was administratively added in 2004, VA again acknowledged that there were relatively few studies addressing the association between POW experience and heart disease (VA, 2004a). A series of older studies did not find consistent evidence 

of an association, as summarized in Page and Ostfeld’s 1994 study titled Malnutrition and Subsequent Ischemic Heart Disease in Former Prisoners of War of World War II and the Korean 

Conflict. 

VA stated that more recent studies had yielded “intriguing findings concerning the association between heart disease and POW experience.” The 1994 study by Page and Ostfeld found a 

statistically significant increase in deaths due to ischemic heart disease among former POWs who 

experienced edema in their lower limbs during captivity. As previously discussed, the authors 

theorized that the findings might suggest an association between malnutrition during captivity 

and subsequent ischemic heart disease. Current VA regulations provided for presumptive service 

connection of ischemic heart disease in former POWs who experienced localized edema during 

captivity (VA, 2004a). 

The 2001 study by Page and Brass found a trend of increased excess risk of heart disease with 

advanced age, with a statistically significant increased risk for former POWs aged 75 years or 

older. The authors suggested that the findings might indicate that the sequelae of serious, acute 

malnutrition may not appear until after many decades. 

The 2003 VA study (Kang and Bullman, 2003; as referenced in VA, 2004a) analyzed records 

of inpatient and outpatient treatment from VA and HCFA to determine whether POWs had an 

increased incidence of certain diseases in comparison to the non-POW controls. The study “detected small increases in the incidence of hypertension and myocardial infarction among some, 

but not all, of the subpopulations examined, and not all of the findings were statistically significant. However, the study did find a statistically significant increased incidence of hypertension 

and chronic heart disease among World War II veterans with PTSD” (VA, 2004a, p. 60087). The 

conclusion that PTSD may be associated with cardiovascular disorders was also supported by a 

1997 study (Boscarino, 1997) finding that Vietnam veterans diagnosed with PTSD had a significantly increased risk of circulatory disease many years after service. 

Based on the evidence discussed above, the VA Secretary determined that a presumption of 

service connection was warranted for atherosclerotic heart disease and hypertensive vascular disease among former POWs. As in the instance of stroke, the VA Secretary concluded that the evidence suggesting an association between heart disease and specific hardships of POW experience—malnutrition and stress—was significant. Notwithstanding limited data, the VA Secretary 

concluded that sound scientific studies provided “limited/suggestive” evidence of an association 

between POW experience and heart disease, and that it was “biologically plausible” (VA, 2004a). 

VA conceded that not all of the studies cited investigated the same range of heart diseases, 

and thus they did not clearly resolve the question of which types of heart disease may be associated with POW experience. For purposes of the presumption, however, all cardiovascular diseases were included by VA that were deemed consistent, in terms of biologic plausibility, with 

those findings because the diseases were potentially capable of being caused by the stress or malnutrition hardships of POW service. The presumption did not extend to diseases that arise from 

viral or bacterial causes, because the evidence concerning biologic plausibility did not support a 

finding that such heart diseases were associated with POW experience (VA, 2004a). 
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APPENDIX I I-41 

With respect to certain types of atherosclerotic heart disease or hypertensive vascular disease 

that were covered by these presumptions, VA acknowledged little available evidence upon which 

to rule in or rule out the possibility that the condition is capable of being caused by the hardships 

of POW service. In those cases, VA chose “to resolve the doubt in favor of veterans and include 

the condition within the scope of the presumption,” saying that 

Although the necessity of inclusion of some conditions may be uncertain from a purely 

scientific perspective, VA has decided as a policy matter to resolve this issue in favor of 

veterans because there is a reasonable basis for doing so. Presumptions of service connection for former POWs can be rebutted as provided in 38 U.S.C. 1113(a) and 38 CFR 

3.307(d). Accordingly, if evidence in a case supports a finding that a particular presumptive condition was not actually caused by a veteran’s POW experience, VA may consider 

the presumption to be rebutted. 

 (VA, 2004a, p. 60087; emphasis added) 

Finally, no minimum confinement time was required for either of the new presumptions: 

Because the evidence indicates that heart disease and stroke potentially may be associated either with malnutrition during prolonged captivity or with stress due to circumstances such as torture or abuse, which may occur during even brief periods of captivity, 

we do not believe a minimum period of detention or internment is warranted for these 

presumptions. 

(VA, 2004a, p. 60088)

The VA Secretary said that the rule was issued as an interim final rule without providing an 

opportunity for prior comment because he believed the rule was unlikely to generate any adverse public comment, “inasmuch as it confers a benefit on a deserving class of veterans based 

on sound scientific evidence.” Moreover, it was “impracticable to delay” inasmuch as 

. . . the class of veterans affected by this rule is elderly and rapidly dwindling. Delay in 

implementing these rules would have a significant adverse effect and frustrate the beneficial purpose of this rule in view of the high mortality rate among the POW population 

and the fact that the majority of former POWs are at an age where their medical and financial needs are likely to be at their greatest. 

(VA, 2004a, p. 60088) 

Only one written comment was received, and it primarily sought to have the presumptions 

further expanded. The interim rule, without changes, became final on June 28, 2005. 

Given the significance of VA guidelines for establishing presumptions of service connection 

for former POWs, the Committee sought material from VA concerning any information that may 

have been considered by VA in developing the guidelines and the two presumptions that was not 

referenced or discussed in the Federal Register notice. It also sought to ascertain what role, if 

any, the Advisory Committee on Former Prisoners of War had in the development of the rule. 

VA chose not to respond and stated in a letter to the Committee chair that statements made in the 

“context of robust deliberations” might be “misconstrued or misrepresented” and that to do so 

would “inhibit free discussion in future deliberations” (Dunne, 2006). 

VA estimated that the new presumptions would have a first-year cost of $26 million increasing to $33 million in the fourth year and then gradually declining to $21 million in the 
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I-42 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

tenth year due to increasing POW mortality. The 5- and 10-year cumulative costs were $152.3 

and $279.5 million, respectively (VA, 2004b, p. 4). 

No additional POW presumptions have been added since 2005 either administratively or 

statutorily. 

Lessons Learned 

Americans and their elected representatives have long been concerned with the welfare of 

those who protected, defended, and sacrificed for their country. The extensive system of veteran benefits and their liberalized rules for qualification is a manifestation of this concern. 

This concern is intensified if those veterans seeking assistance are viewed as having been 

subjected to extraordinary stresses and sacrifices. POWs are such a group. As VA declared in 

its 1980 study, the POW experience was an “extremely harsh and brutal experience” that was 

“characterized by starvation diet, poor quality or nonexistent medical care, ‘death marches,’ 

executions, and torture” (VA, 1980, p. 4). 

In this context, the creation of certain presumptions with respect to disabilities claimed to 

be connected with a veteran’s experience as a POW is a natural reflection of a long-established 

concern for their welfare. These presumptions simplify adjudication in what otherwise would 

be difficult cases to obtain evidence and resolve complex issues, thus relieving the burden on 

both the veteran and VA. Presumptions have been particularly helpful in assessing POW claims 

where information about individual conditions of internment and complete medical records 

were frequently unavailable. 

Finally, presumptions have enabled greater consistency in decision making, the absence of 

which generated much discontent by veterans who strongly communicated their concerns to 

their elected representatives. Indeed, it might reasonably be inferred that the subsequent modification of certain presumptions by reducing or eliminating preconditions for their applicability 

has been a further policy response to concerns registered by those former POWs who were not 

previously covered by presumptions. 

These policy considerations were obviously important factors that were weighed by Congress as it considered available epidemiologic and other scientific findings derived from various POW studies. These studies (Beebe, 1975; Brass and Page, 1996; Cohen and Cooper, 1954; 

IOM, 1992; Keehn, 1980; Nefzger, 1970; Page and Brass, 2001; Page et al., 1991, 1997; VA, 

1980) dating back to the early 1950s reveal a slow accretion of data and increased medical 

knowledge, particularly about malnutrition, stress, and the psychological effects of the POW 

experience. 

At the same time, available evidence for certain presumptions sometimes came from only a 

single study, and the data were often limited by the small size of the affected number of POWs. 

Consequently, authors of most studies acknowledged the tentative and inconclusive nature of 

their findings and urged caution at drawing unwarranted inferences. As one study author stated, 

the mixture and interdependence of various factors of the POW experience and the variation of 

their relative intensities “from time to time, from place to place, and from man to man,” has 

“limit[ed] the scope and specificity of the inferences that may be drawn statistically” (Nefzger, 

1970, p. 124).

Given the suggestive but scientifically uncertain results of many of the studies, it is not surprising that policy makers frequently decided to create service-connected presumptions when 

faced with the pressing claims of genuinely sick and disabled former POWs. As one author observed of the 1992 study of POWs, the descriptive data obtained had “uses beyond the scien-
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APPENDIX I I-43 

tific,” specifically in the discussion of military service-connected disabilities. The author added, 

“[d]espite the fact that sound inferences about the group of all former POWs cannot be drawn 

from the exam data in this report, policymakers who must deal with such issues should be able 

to review this descriptive information” (IOM, 1992, p. 5). 

It should also be noted that VA in its 2004 guidelines for POW presumptions, while expressing an intent to base its determinations on “sound scientific and medical evidence,” has 

adopted a standard of “limited/suggestive evidence” for former POWs and added the additional 

caveat that “fairness to former POWs requires VA to fully evaluate the available data and not 

accord undue significance to the fact that such data are comparatively limited by the small size 

of the affected population” (VA, 2004a, p. 60085). Given the forgoing, it is apparent that although various POW studies have often provided useful scientific information to Congress and 

the executive branch, there were other policy-relevant factors that had equal or greater weight 

in the presumptive decisions established for POWs. Over time, the requirement that a presumptive decision be based on sound scientific and medical evidence has increasingly been overshadowed by these other considerations. 

References 

Bard, M. G. 1994. Forgotten victims: The abandonment of Americans in Hitler’s camps. Boulder, CO: 

Westview Press. 

Beebe, G. W. 1975. Follow-up studies of World War II and Korean War prisoners. II. Morbidity, disability, and maladjustments. American Journal of Epidemiology 101(5):400-422.

Boscarino, J. A. 1997. Diseases among men 20 years after exposure to severe stress: Implications for 

clinical research and medical care. Psychosomatic Medicine 59(6):605-614. 

Brass, L. M., and W. F. Page. 1996. Stroke in former prisoners of war. Journal of Stroke and Cerebrovascular Diseases 6(2):72-78. 

Cohen, B. M., and M. Z. Cooper. 1954. A follow-up study of World War II prisoners of war. Washington, 

DC: Government Printing Office. 

Dunne, P. W. 2006 (December). Department of Veterans Affairs responses: Questions following from the 

Veteran’s Disability Benefits Commission’s charge. Letter to Jonathan M. Samet. 

Engdahl, B. E., and W. F. Page. 1991. Psychological effects of military captivity. In Epidemiology in 

military and veteran populations. Proceedings of the Second Biennial Conference. Washington, DC: 

National Academy Press. Pp. 49-66. 

Engdahl, B. E., W. F. Page, and T. W. Miller. 1991. Age, education, maltreatment, and social support as 

predictors of chronic depression in former prisoners of war. Social Psychiatry and Psychiatric Epidemiology 26(2):63-67. 

Engdahl, B. E., A. R. Harkness, R. E. Eberly, W. F. Page, and J. Bielinski. 1993. Structural models of captivity trauma, resilience, and trauma response among former prisoners of war 20 to 40 years after release. Social Psychiatry and Psychiatric Epidemiology 28(3):109-115. 

Gold, P. B., B. E. Engdahl, R. E. Eberly, R. J. Blake, W. F. Page, and B. C. Frueh. 2000. Trauma exposure, 

resilience, social support, and PTSD construct validity among former prisoners of war. Social Psychiatry and Psychiatric Epidemiology 35(1):36-42. 

HEW (U.S. Department of Health Education and Welfare). 1956. Effects of malnutrition and other hardships on the mortality and morbidity of former United States prisoners of war and civilian internees 

of World War II: An appraisal of current information. H.R. Doc. No. 296. 84th Cong., 2nd Sess. 

IOM (Institute of Medicine). 1992. The health of former prisoners of war. Washington, DC: National Academy Press. 

IOM. 1994. Veterans and Agent Orange: Health effects of herbicides used in Vietnam. Washington, DC: 

National Academy Press. 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy Press. 
Copyright © National Academy of Sciences. All rights reserved.

Improving the Presumptive Disability Decision-Making Process for Veterans 

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I-44 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

IOM. 1999. Veterans and Agent Orange: Update 1998. Washington, DC: National Academy Press. 

IOM. 2000. Veterans and Agent Orange: Herbicide/dioxin exposure and type 2 diabetes. Washington, 

DC: National Academy Press. 

IOM. 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy Press. 

IOM. 2003. Veterans and Agent Orange: Update 2002. Washington, DC: The National Academies Press. 

IOM. 2005. Veterans and Agent Orange: Update 2004. Washington, DC: The National Academies Press. 

Kang, H. K., and T. A. Bullman. 2003 (unpublished). Ten year mortality and morbidity follow-up of former World War II and Korean War prisoners of war. 

Keehn, R. J. 1980. Follow-up studies of World War II and Korean Conflict prisoners. III. Mortality to 1 

January 1976. American Journal of Epidemiology 111(2):194-211. 

Nefzger, M. D. 1970. Follow-up studies of World War II and Korean war prisoners. I. Study plan and mortality findings. American Journal of Epidemiology 91(2):123-138. 

Page, W. F. 1991. Using longitudinal data to estimate non-response bias. Social Psychiatry and Psychiatric Epidemiology 26:127-131. 

Page, W. F., and L. M. Brass. 2001. Long-term heart disease and stroke mortality among former American prisoners of war of World War II and the Korean Conflict: Results of a 50-year follow-up. Military Medicine 166(9):803-808. 

Page, W. F., and R. N. Miller. 2000. Cirrhosis mortality among former American prisoners of war of World 

War II and the Korean Conflict: Results of a 50-year follow-up. Military Medicine 165(10):781-785. 

Page, W. F., and A. M. Ostfeld. 1994. Malnutrition and subsequent ischemic heart disease in former prisoners of World War II and the Korean Conflict. Journal of Clinical Epidemiology 47(12):1437-1441. 

Page, W. F., and C. M. Tanner. 2000. Parkinson’s disease and motor-neuron disease in former prisoners of 

war (Letter). Lancet 355(9206):843. 

Page, W. F., B. E. Engdahl, and R. E. Eberly. 1991. Prevalence and correlates of depressive symptoms 

among former prisoners of war. Journal of Nervous and Mental Disease 179(11):670-677. 

Page, W. F., B. E. Engdahl, R. E. Eberly, C. S. Fullerton, and R. J. Ursano. 1997. Persistence of PTSD in 

former prisoners of war. In Posttraumatic stress disorder: Acute and long-term responses to trauma 

and disaster, edited by C. S. Fullerton and R. J. Ursano. Washington, DC: American Psychiatric 

Press. Pp. 147-158. 

Page, W. F., D. Whiteman, and M. Murphy. 2000. A comparison of melanoma mortality among WWII veterans of the Pacific and European theaters. Annals of Epidemiology 10(3):192-195. 

President’s Commission on Veterans’ Pensions. 1956. A report to the president: Veterans benefits in the 

United States, Parts I and II: Findings and recommendations. Washington, DC: Government Printing 

Office. 

U.S. Congress, Senate, Committee on Finance. 1970. Increase in veterans disability compensation. Senate Report Number 91-784. 91st Cong., 2nd Sess. April 23. 

U.S. Congress, Senate, Committee on Veterans’ Affairs. 1986. Omnibus Veterans’ Benefits Improvement and Health Care Authorization Act of 1986. Senate Report Number 99-444. 99th 

Cong., 2nd Sess. September 16. 

U.S. Congress, Senate, Committee on Veterans’ Affairs. 1987. Omnibus Veterans’ Benefits and Services 

Act of 1987. Senate Report Number 100-215. 100th Cong., 1st Sess. November 6. 

U.S. Congress, Senate, Committee on Veterans’ Affairs. 2003. Veterans’ Benefits Enhancements Act. 

Senate Report Number 108-169. 108th Cong., 1st Sess. October 21. 

VA (Department of Veterans Affairs). 1980. Study of former prisoners of war. Washington, DC: Government Printing Office. 

VA. 1993. Analysis of presumptions of service connection. Washington, DC: Department of Veterans Affairs. 

VA. 2001. Costing of regulation RIN 2900-AK83—Presumption of service connection for cirrhosis of the 

liver in former prisoners of war. 

VA. 2003. Presumption of service connection for cirrhosis of the liver in former prisoners of war. Proposed Rule. February 10, 2003. Federal Register 68(27):6679. 
Copyright © National Academy of Sciences. All rights reserved.

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APPENDIX I I-45 

VA. 2004a. Presumptions of service connection for disease associated with service involving detention or 

internment as a prisoner of war. Interim Final Rule. October 7, 2004. Federal Register

69(194):60083-60090. 

VA. 2004b. Additional presumptions for former POWs: Methodology (cost estimates). RIN 2900-AM09. 

108th Cong., 2nd Sess. 

VA. 2005. Former American prisoners of war. Washington, DC: Department of Veterans Affairs. 

VA. 2006. Fact sheet: VA benefits for former prisoners of war. http://www1.va.gov/opa/fact/powmia.asp 

(accessed March 23, 2007). 

CASE STUDY 4: AMPUTEES AND CARDIOVASCULAR 

DISEASE PRESUMPTION 

This case study examines the 1979 presumption of service connection for cardiovascular disease (CVD) that develops in veterans with certain types of service-related amputations. By exploring the scientific basis for this decision, as well as the implications of this decision for the 

VA, this analysis seeks to illustrate the challenges and implications of establishing a service connection for a common chronic condition with multiple contributing causal risk factors.

Background on Cardiovascular Disease 

This presumption establishes service connection for CVD in veterans with certain types of 

lower extremity amputations. The literature on which this presumption is based examines the 

broad category of CVD, with specific attention to atherosclerotic (or ischemic) heart disease, the 

most common of the cardiovascular conditions. Two features of CVD in general and atherosclerotic disease in particular are important for evaluating the scientific evidence and events surrounding this presumption. First, CVDs are common in the general population, and their prevalence increases with advancing age (Figure I-3). 

The high prevalence of CVD among the general adult population may pose challenges for determining whether, among veterans, CVD can be attributed to military service. The high prevalence may also translate into a large constituency advocating for a presumption, as well as determine the cost implications of such a presumption for VA. Second, there are multiple 

established risk factors for CVD, particularly atherosclerotic disease, that are common in the 

general population. Many of these are lifestyle factors, including smoking, obesity, and physical 

inactivity. Determining the relationship between risk factors that develop during military service 

and the additional risk factors that may develop after service is challenging, as is estimating the 

incremental risk of CVD attributable to military service. 

The Need for a Presumption 

Veterans with amputations resulting from trauma sustained during military service automatically receive compensation for this service-related condition and may also receive compensation 

for amputation-related complications. The presumption service connecting CVD among veterans 

with service-connected amputations (38 CFR § 3.310[b], Cardiovascular disease) was created 

after a comprehensive review of the prior literature and analysis of data from World War II veterans suggested a link might exist between certain types of amputation and CVD. In contrast 

with many presumptions that exist because of an evidence gap in exposure assessment (e.g., presumptions related to Agent Orange), this presumption was created because of gaps in the evidence linking amputations to CVD. 
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FIGURE I-3 Prevalence of cardiovascular disease by age and sex. 

SOURCE: Thom et al., 2006, p. 91. 

Scientific and Legislative History of the Presumption for Cardiovascular 

Disease Among Amputees 

The following is a brief review of the scientific and legislative events of relevance to this 

presumption. 

Prior to 1976

In a study conducted by MFUA/NRC, Hrubec and Ryder (1979) reviewed the scientific literature published prior to 1976 on the relationship between amputation and mortality from CVD, 

the findings of which appeared to be mixed. The evidence for higher cardiovascular mortality 

rates stemmed primarily from one large Finnish study (Bakalim, 1969) of 4,738 World War II 

amputees that reported 63.1 percent greater cardiovascular death rates among amputees than 

among the general population (Hrubec and Ryder, 1979, p. 31). In their review, Hrubec and Ryder noted two major limitations of this study. The first limitation was that mortality among amputees participating in the study was compared with that of the general population, rather than 

veterans who had also sustained combat-related injuries. The second limitation was that the time 

period of comparison for the study group included the acute hospitalization for the amputation, a 

period in which risk of mortality may be higher. 

Hrubec and Ryder noted several other studies conducted prior to 1976 that found no increased mortality among amputees. The Advisory Committee on Cardiovascular Disorders and 

Mortality Rate in Amputees (1954), for example, compared incidence of cardiovascular disorders among 27,000 British amputees from the 1914 war with that of both the general population 

and veterans with wounds to the lower extremities (not necessarily amputations). They concluded that limb amputation does not appear to “initiate or aggravate cardiovascular disorders to 

any significant extent” (Hrubec and Ryder, 1979, pp. 30-31). 

In an effort to clarify the possible association between amputations and cardiovascular disorders, the Veterans Disability Compensation and Survivor Benefits Act of 1976 (Public Law 94-

433. 94th Cong., 2d Sess.) mandated that, in addition to reviewing the existing literature on this 

topic, “an analysis of statistically valid samples of disability claims of veterans having service-
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APPENDIX I I-47 

connected extremity amputation matched by age, sex and war period with nonamputee veterans” 

be conducted. 

The 1979 Medical Follow-Up Agency Report on Service-Connected Traumatic Limb 

Amputations and Subsequent Mortality from Cardiovascular Diseases 

In 1979 Hrubec and Ryder delivered their report conducted by MFUA/NRC as a part of its 

contract with VA. MFUA had access to summary information from all Army hospitalizations 

from 1944 and 1945 and used this information to identify three comparison groups based on the 

type of injury—3,890 Service members with proximal limb amputations (at or above the knee or 

elbow), 2,918 with distal amputations (loss of part of foot or hand), and 3,890 with disfigurement 

(disfigurement other than head, face, or skull, and disfiguring scars). The authors compared the 

observed death rates in each of these three groups to the expected rates based on age and timespecific rates for U.S. males in the general population. Veterans in the three comparison groups 

were followed from January 1946 to April 1977, and their mortality from a variety of different 

causes was evaluated. 

During more than 30 years of follow-up, 922 proximal amputees died; 714.1 deaths would 

have been expected based on the general U.S. male death rate (Hrubec and Ryder, 1979, p. 47). 

Compared with distal amputees and those with disfigurement, proximal amputees had a higher 

risk of all-cause mortality and mortality related to diabetes and CVD, particularly atherosclerotic 

(ischemic) heart disease. Mortality from CVD was similar between proximal amputees and the 

general population during the period immediately following amputation, but increased dramatically among the proximal amputees over later time periods. This greater than expected cardiovascular mortality among the proximal amputees was not affected by their age at amputation. 

The same pattern of increasing cardiovascular mortality was not observed among those with distal amputations or disfigurement; they continued to have the same or lower than expected death 

rates. In matched pair comparisons with disfigured veterans, the highest risk of CVD was observed among those with bilateral lower extremity amputations of any degree and unilateral amputations at the knee or above (Hrubec and Ryder, 1979). 

Hrubec and Ryder noted that strict time constraints imposed by Congress prevented them 

from conducting detailed individual analyses to explore the potential mediators of the increased 

risk of cardiovascular mortality among proximal amputees. Their discussion on this topic included a brief review of the existing literature on other cardiovascular risk factors, and they proposed the following potential explanations for the association: (1) CVD may be a risk factor for 

amputation, as Service members with CVD at the time of injury may have been more likely to 

undergo amputation (versus procedures to salvage the limb) because of concerns for peri- and 

postoperative risk, (2) amputation may itself be a direct risk factor for CVD, and (3) amputation 

may be a risk factor for other factors (e.g., physiologic factors such as hypertension, as well as 

lifestyle factors such as inactivity, psychosocial stress, and smoking) known to place individuals 

at greater risk for CVD. 

The authors explored wound infection as a potential mediator and found no increased risk of 

CVD by the presence of infection at the time of amputation. They also commented that smoking 

was unlikely to mediate the increased risk since the rates of lung cancer mortality are not higher 

among proximal amputees (although it is intriguing that increased risk of buccal cavity and pharynx cancer among proximal amputees is noted in this study but not commented on further). 

Hrubec and Ryder concluded from their analysis that proximal traumatic amputation of the 

lower limbs was a risk for subsequent cardiovascular mortality and commented that, based on 
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I-48 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

their review of the existing risk factor literature, “the most likely factors of importance (for mediating this increased risk) include increased sedentary lifestyle among amputees and increased 

emotional stress caused by amputation” (Hrubec and Ryder, 1979, p. 43). 

The results of this MFUA study led to 38 CFR § 3.310(b) (Cardiovascular disease) granting a 

service connection “for ischemic heart disease or other cardiovascular disease developing in a 

veteran who has a service-connected amputation of one lower extremity at or above the knee or 

service-connected amputations of both lower extremities at or above the ankles.” 

The Scientific Literature Since the 1979 Presumption 

The literature on CVD and amputation since the 1979 Hrubec and Ryder study is limited and 

has focused on exploring the mechanisms whereby amputation might lead to cardiovascular 

morbidity and mortality. A small study (Rose et al., 1986) of 31 Vietnam veterans comparing 

veterans with proximal lower extremity amputations to those with upper extremity amputations 

noted higher blood pressure, higher body mass index, and impaired glucose metabolism among 

the lower extremity amputees. Another study (Modan et al., 1998) followed 201 veterans of the 

Israeli army with proximal amputations for over 24 years and compared their risk factor profile 

and mortality with 1,832 controls (matched based on age and ethnic origin) from the general 

population. The authors found an increase in the risk of cardiovascular mortality among traumatic lower limb amputees. Surviving amputees did not have higher rates of obesity, physical 

inactivity, or hypertension compared with controls from the general population, but were more 

likely to have hyperinsulinemia and be in a hypercoagulable state. The authors suggested that 

hypercoagulability and hyperinsulinemia (independent of body mass index or inactivity) may be 

a consequence of amputation and may be a mechanism leading to higher rates of CVD. 

Studies of cardiovascular risk in amputees have had limited ability to explore the mechanism 

of disease and the nature of the increased cardiovascular risk because (1) baseline data on risk 

factors and comorbid conditions at the time of amputation are either not available or not analyzed, and (2) longitudinal follow-up studies exploring the interim development of cardiovascular risk factors among amputees who died or developed CVD do not exist. 

The presumption of service connection for CVD among amputees has not been reexamined 

since it was put into place in 1979. No studies have been commissioned to provide any further 

information regarding association of CVD with amputation in a more contemporary cohort. 

Costs to VA Associated with This Presumption 

No cost estimates were available for this analysis. However, the long-term cost implications 

of this legislation are likely to continue to rise as veterans of contemporary conflicts in Iraq and 

Afghanistan have experienced higher rates of amputations than those of veterans of previous 

wars (Bilmes, 2007). 

Lessons Learned 

This case study reveals several important lessons that are relevant when considering strategies for improving the current system of presumptions. These lessons center around the type of 

evidence necessary to put a presumption in place, specifically what level of evidence should be 

required for a presumption, how the scientific base of evidence is updated based on new studies, 

how to evaluate evidence regarding exposures, outcomes, and potential mediators, and what 

types of evidence might make the scientific basis for a presumption more robust. 
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APPENDIX I I-49 

The scientific basis for this presumption was a single retrospective study of World War II 

veterans conducted by MFUA (Hrubec and Ryder, 1979). Although this study was large and apparently scientifically sound, confirmation of these findings with additional studies was warranted. Particularly since this presumption was put in place via legislative action (and not the 

more easily malleable administrative action on the part of VA), the highest standard of scientific 

evidence should have been employed, including replicating these findings in additional cohorts 

and exploring potential mechanisms for the observed association. 

Understanding the mechanisms whereby an exposure leads to an outcome has important scientific implications for establishing a causal relationship and certainly has clinical relevance. 

However, understanding the mediators of an association between exposure and outcomes should 

not have bearing on policy considerations inherent in presumptions. Whether amputation leads to 

CVD via sedentary lifestyle or derangements in the coagulation cascade are irrelevant from a 

policy perspective. Both pathways are ultimately initiated by exposure that occurred during military service (i.e., amputation). Only knowledge of exposure (that a veteran was amputated during 

military service) and the association between exposure and outcome (that amputations lead to 

higher rates of CVD) are necessary for a valid presumption; knowing which of the multiple, possible pathways might mediate this association is not required. 

Cardiovascular mortality rates for men have decreased dramatically over the last 30 years 

(Figure I-4) because of improved prevention and more aggressive treatment of modifiable risk 

factors for CVD. Given the decreasing mortality rates because of improved treatment, it is reasonable to question whether the association between amputations and cardiovascular mortality 

observed in the original MFUA study would be observed among contemporary amputees. Unfortunately, standard procedures are not in place for incorporating new studies of amputations and 

CVD. The ability to incorporate new evidence is additionally limited because this presumption 

was issued by Congress and not administratively by VA. 

Certain populations of veterans, such as amputees, may be at high risk for complications as a 

result of military service and in particular need of compensation for these complications. Certain 

exposures, such as amputations, are particularly challenging to study except in cohort studies of 

exposed Service members and veterans. Both of these factors argue strongly for ongoing surveillance of high-risk Service member populations by the Department of Defense (DoD) and veteran 

380

400

420

440

460

480

500

520

79

81

83

85

87

899193

95

97

9901

Years

Deaths in Thousands

Males Females 

FIGURE I-4 Trends in cardiovascular mortality rates from 1979 to 2003. 

SOURCE: Thom et al., 2006, p. 95. 
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I-50 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

populations by VA. Such ongoing surveillance could have provided important confirmatory evidence to support the basis for this presumption, as well as a natural mechanism to update the scientific evidence with contemporary exposed Service members and veterans. 

 References 

Advisory Committee on Cardiovascular Disorders and Mortality Rate in Amputees. 1954. Ultimate conclusions. London, England: Ministry of Pensions. 

Bakalim, G. 1969. Causes of death in a series of 4738 Finnish war amputees. Artificial Limbs 13(1): 

27-36. 

Bilmes, L. 2007. Soldiers returning from Iraq and Afghanistan: The long-term costs of providing veterans 

medical care and disability benefits. RWP07-001. Paper prepared for the Allied Social Sciences Association Meeting, Chicago, IL, January 2007. 

http://www.epsusa.org/events/aea2007papers/bilmes.htm (accessed April 24, 2007). 

Hrubec, Z., and R. A. Ryder. 1979. Report to the Veterans’ Administration Department of Medicine and 

Surgery on service-connected traumatic limb amputations and subsequent mortality from cardiovascular disease and other causes of death. Bulletin of Prosthetic Research 16(2):29-53. 

Modan, M., E. Peles, H. Halkin, H. Nitzan, M. Azaria, S. Gitel, D. Dolfin, and B. Modan. 1998. Increased 

cardiovascular disease mortality rates in traumatic lower limb amputees. American Journal of Cardiology 82(10):1242-1247. 

Rose, H. G., R. S. Yalow, P. Schweitzer, and E. Schwartz. 1986. Insulin as a potential factor influencing 

blood pressure in amputees. Hypertension 8(9):793-800. 

Thom, T., N. Haase, W. Rosamond, V. J. Howard, J. Rumsfeld, T. Manolio, Z.-J. Zheng, K. Flegal, C. 

O’Donnell, S. Kittner, D. Lloyd-Jones, D. C. Goff, Jr., Y. Hong, R. Adams, G. Friday, K. Furie, P. 

Gorelick, B. Kissela, J. Marler, J. Meigs, V. Roger, S. Sidney, P. Sorlie, J. Steinberger, S. 

Wasserthiel-Smoller, M. Wilson, and P. Wolf. 2006. Heart disease and stroke statistics—2006 update: A report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation 113(6):e85-e151. http://circ.ahajournals.org/cgi/content/short/113/6/ 

e85#SEC3 (accessed March 9, 2007). 

CASE STUDY 5: RADIATION PRESUMPTIONS 

This case study examines decisions related to radiation made over several decades for various groups of individuals involved in different military efforts. The case study describes the scientific basis and uncertainties for assessing exposure and risk to ionizing radiation. 

The Scientific Basis of Risk Assessment for Ionizing Radiation 

From the late 1940s to the early 1960s, about 200,000 American servicemen and 

women⎯along with civilians and groups from other countries⎯participated in above-ground 

tests of nuclear weapons (IOM, 2000, p. 1). U.S. testing was conducted primarily at the Nevada 

Test Site and the Marshall Islands in the Pacific Ocean. Many of the people at the test sites may 

have received substantial doses of ionizing radiation, and, as might be expected in any comparable population, many have developed cancer and other chronic diseases over the ensuing years. 

These “atomic veterans” are understandably concerned that their diseases could be service connected and have been quite vocal in seeking compensation. To provide compensation, it must be 

determined how likely it is that any particular cancer among the atomic veterans might be service 

related. 

There is no doubt that radiation can cause cancer. Evidence in support of this claim comes 

from a vast literature of human epidemiologic studies, experimental animal studies, and basic 
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APPENDIX I I-51 

radiobiology research on cell cultures (ACHRE, 1995; Caldwell et al., 1980, 1983; Dalager et al., 

2000; Darby et al., 1988, 1991, 1993; Doll et al., 1998; IOM, 1995, 2000; Johnson et al., 1997; 

Muirhead and Kendall, 2003; Muirhead et al., 2003, 2004; Pearce et al., 1997; Raman et al., 

1987; Robinette et al., 1985; Watanabe et al., 1995). All major national and international advisory committees concerned with radiation risk assessment agree on this point (IARC, 2000; 

NRC, 2006; UNSCEAR, 2000). There is thus a prima facie case for causation for any individual 

with cancer and a history of radiation exposure. However, the magnitude of the risk and hence 

the probability of a causal connection in any individual is highly variable, depending upon such 

factors as the type of cancer, the radiation dose, age at exposure, time interval between exposure 

and cancer, and individual characteristics that determine response to radiation. Risk estimates are 

also inherently uncertain, both the estimates of population dose-response relationships and estimates based on an individual’s estimated dose and other modifying factors. The rarer the cancer, 

the more unstable the risk estimates will be, based on epidemiologic data, unless data for rarer 

sites are combined with other similar cancers (thereby introducing additional uncertainty about 

the appropriateness of that combination). Thus, it is certainly not the case that every cancer in a 

radiation-exposed individual is caused by that exposure, and therein lies the difficulty in establishing presumptions of causation or other criteria for compensation. 

Although this case study will be focused on cancer, certain other endpoints have been definitely linked to ionizing radiation⎯notably severe mental retardation in those exposed during 

pregnancy and cataracts⎯and evidence for certain other diseases, such as CVD following high 

doses and nonmalignant tumors, is still evolving (NRC, 2006). There is also the potential for genetic effects that would be transmissible from one generation to the next; although genetic 

transmission has been demonstrated in animal experiments, there is so far no convincing evidence in humans, and the risk is generally thought to be low (NRC, 2006). 

The mechanism by which radiation causes cancer is the physical interaction of a quantum of 

energy (e.g., an X ray or a particle such as a neutron or alpha particle) with a cell, leading to mutation of its DNA. Although such mutations can take several forms, the most serious come from 

double-strand breaks. There are several biological pathways for repair of such lesions, but some 

of these processes are error prone, and if not repaired or repaired incorrectly, a mutation can be 

fixed into the affected cell and passed on to its daughter cells. Depending upon the specific part 

of the chromosome affected, a mutation can lead to a chain of subsequent events and the growth 

of a clone of mutated daughter cells that can ultimately develop into a fully malignant tumor. 

Thus, radiation most frequently acts as one of the initiating steps in this complex process, although it is also possible that it can promote some of the later steps in an already initiated precancerous lesion. The probability of such an initial mutational event happening thus depends 

primarily on the probability of a damaging interaction between energy and DNA; the probability 

of such interaction depends on dose. The resulting cancer risk, however, can be modified by numerous other factors involved in the subsequent stages of malignant transformation or by the 

sensitivity of the target tissue (NRC, 2006). 

The nature of this dose-response relationship and its modification by other factors has been 

extensively studied, both observationally in humans and in various experimental systems. Although experimental studies can be very useful for exploring the basic mechanisms of radiation 

carcinogenesis, quantitative risk estimates in humans have been derived from epidemiologic 

studies that have data on exposure. Numerous radiation-exposed populations have been studied, 

including the atomic bomb survivors, patients treated with diagnostic and therapeutic radiation, 

occupationally exposed nuclear workers and uranium miners, and groups exposed environmen-
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I-52 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

tally to emissions from nuclear accidents, nuclear weapons production and testing, or other 

sources. An overall conclusion that can be reached based on this body of evidence is that cancer 

rates roughly increase linearly with dose, with no evidence of an absolutely “safe” dose (a 

threshold below which there is no increase in risk). The slope of this dose-response relationship, 

which varies with cancer type, type of radiation, age, latency, and other factors is basically what 

determines an individual’s risk given their exposure, and hence the probability of causation (PC) 

if that person develops cancer. Various expert groups such as the NAS (NRC, 2006), the United 

Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 2000), and the 

International Agency for Research on Cancer (IARC, 2000) have compiled the full body of evidence on dose-response relationships and performed extensive joint analyses of the raw data 

from the major studies in order to develop these risk estimates and evaluate their uncertainties. 

Veterans’ Studies 

Among the sources of human risk estimates uniquely relevant to compensation policy for 

veterans are direct studies of radiation-exposed military personnel, specifically the atomic veterans. Several hundred thousand such veterans in total, mostly Americans but also substantial 

numbers of British veterans and other nationalities, have been included in several epidemiologic 

studies (ACHRE, 1995; Caldwell et al., 1980, 1983; Dalager et al., 2000; Darby et al., 1988, 

1991, 1993; IOM, 1995, 2000; Johnson et al., 1997; Muirhead and Kendall, 2003; Muirhead et 

al., 2003, 2004; Pearce et al., 1997; Raman et al., 1987; Robinette et al., 1985; Watanabe et al., 

1995). One of the first of these tests involved about 40,000 participants at the first hydrogen 

bomb tests at Bikini in 1946 (Operation CROSSROADS), later studied by the MFUA of the 

IOM (Johnson et al., 1997). A summary of these various studies is provided in the Appendix 

found at the end of this case study. Unfortunately, results from these studies are somewhat inconsistent, largely because most of these veterans’ doses were relatively low, and hence any elevation of cancer risks would be expected to be close to the limits of detection even in large epidemiologic studies. 

Uncertainties in doses and the potential for confounding further add to the difficulty of establishing definitive dose-response relationships from such studies. (For example, the majority of 

participants in the CROSSROADS study had no dose estimates available.) The epidemiologic 

studies of radiation-exposed veterans are therefore more useful for establishing the plausibility of 

a population-level causal connection between veterans’ radiation exposures and subsequent cancer risks rather than for estimating these risks directly. Indeed, all of the point estimates found in 

Table I-1 and even most of the upper 95 percent confidence limits are substantially lower than 

the relative risk of 2, which translates to a 50 percent probability of causation for exposed veterans. Given these uncertainties of the data on veterans, a negative or inconsistent finding cannot 

be taken as definitive evidence against a causal connection, in the face of the wealth of positive 

evidence from other epidemiologic studies. But a positive finding could help bolster the evidence 

from other sources and can suggest specific cancer types that might be plausibly connected to 

radiation in the absence of compelling evidence against such an association. 

For comparison, a graphical presentation of the relative risks from the atomic bomb survivors 

(Preston et al., 2003) is reproduced in Figure I-5. The specific cancers listed are those with sufficient numbers of cases available to support separate analysis and that show a clear radiation effect. The category “other solid cancers” may be quite heterogeneous in terms of radiosensitivity, 

but in general, convincing evidence to show that any specific cancer in this group is not radiosensitive would be elusive. 
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APPENDIX I I-53 

TABLE I-1 Summary of Standardized Mortality Rates (95% Confidence Limits) from U.S. Veterans’ Studies of Cancer Conducted by the Institute of Medicine (IOM) in Participants in the 

CROSSROADS and Five Series of Nuclear Weapons Testing Exercises 

Study Population All Deaths Cancer Mortality 

Leukemia 

Mortalitya

CROSSROADSb 

 All Navy 1.05 (1.02-1.07) 1.01 (0.96-1.07) 1.02 (0.75-1.39) 

 Boarded target ships 1.06 (1.01-1.10) 1.03 (0.94-1.12) 1.01 (0.61-1.66) 

 Did not board target ships 1.04 (1.02-1.07) 1.01 (0.95-1.07) 1.02 (0.74-1.42) 

Five Series Studyc 

 All participants vs. all nonparticipants 1.00 (0.98-1.02) 1.02 (0.98-1.06) 1.14 (0.90-1.44) 

 Land only 0.96 (0.93-0.99) 1.00 (0.95-1.06) 1.49 (1.04-2.13) 

 Sea only 1.03 (1.00-1.06) 1.04 (0.98-1.10) 0.92 (0.67-1.27) a

 Excluding chronic lymphocytic leukemia (CLL). 

b

 IOM, 1996, p. 65. 

c

 IOM, 2002, pp. 63, 71. 

FIGURE I-5 Estimates of excess relative risk per Sv for site-specific cancers among the atomic bomb 

survivors. 

SOURCE: Preston et al., 2003. 

The National Institutes of Health Radioepidemiologic Tables and 

Interactive Radiation Epidemiology Program 

Because the risks vary by such factors as dose, type of radiation, age, gender, and latency, it 

is not particularly useful to settle upon a single summary number for risk. Instead, some algorithm is needed to predict an individual’s risk or related PC given the specifics of his or her situa-
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I-54 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

tion. In 1985, a provision of the Orphan Drug Act (Orphan Drug Act of 1983. Public Law 97-

414. 97th Cong., 2d Sess.) directed the National Institutes of Health (NIH) to assemble a set of 

“radioepidemiologic tables,” which were to provide estimates of the PC for 12 types of cancer as

a function of dose, age, gender, latency, and other factors (NIH, 1985, p. 65). Some examples of 

the calculations provided in the resulting report (NIH, 1985) are illustrated in Table I-2. The report also listed 14 specific cancer sites for which there was either no evidence of radiosensitivity 

or risk estimates were too uncertain to support PC calculations (NIH, 1985, p. 262). The estimates in the NIH report were derived mainly from risk estimates by earlier expert committees, 

principally the Biological Effects of Ionizing Radiation (BEIR) III report (NRC, 1980), and the 

methodology was carefully evaluated by a separate expert committee convened by the NAS 

(Lagakos and Mosteller, 1986; NRC, 1984). A summary of their conclusions is discussed in 

Chapter 9 of this report.

The act that created the 1985 radioepidemiologic tables (Orphan Drug Act of 1983. Public 

Law 97-414. 97th Cong., 2d Sess.) also included a provision calling for the tables to be periodically updated, but more than 15 years passed before this occurred. At that point, a new committee created a computer program, the Interactive Radiation Epidemiology Program (IREP), which 

could be used by individuals or compensation bodies to compute individualized PC estimates, 

given the specifics (dose, age, cancer type, etc.) of their experience. In addition to making the 

calculator accessible interactively on the Internet (https://www.niosh-irep.com/irep%5Fniosh/), 

an important advance was the inclusion of uncertainty estimates for each PC, based both on uncertainties in the epidemiologic data and the individual’s history (see the last two columns of Table I-2 for the previous illustrative examples). The interpretation of these uncertainties will be 

discussed later in this case study. 

History of Radiation Compensation Criteria for Veterans 

Congress has enacted three major pieces of legislation addressing compensation standards relating to the exposure of various populations to ionizing radiation from government programs, as 

reviewed in detail in Chapter 4 and earlier NAS reports (NRC, 2003, 2005). The first of these, 

the Veterans’ Dioxin and Radiation Exposure Compensation Standards Act of 1984 (Public Law 

98-542. 98th Cong., 2d Sess.), did not establish any presumptions, but directed VA to establish a 

TABLE I-2 Illustrative Calculations of the Probability of Causation (PC) Provided in the Original 

Radioepidemiological Tables and the Revised Interactive Radiation Epidemiology Program 

Cancer Site Gender 

Age(s) at 

Exposure 

Dose 

(Gy) RR PC 

PC 

(1985) 

PC 

(IREP) 

95% CI 

(IREP) 

Breast Female 25 45 0.1 (X-ray) 1.03 3% 9% 4-26%

Bone Male 15 20 0.7 (alpha) 15.2 93% 51% 8-92%

Thyroid Male 17 25 0.3 (X-ray) 12.5 92% 66% 29-90%

Lung Male 

(nonsmoker)

28 55 0.4 (gamma) 1.23 19% 20% 7-41%

Acute 

leukemia

Female 20-35 44 0.14 (total) 1.10 9% 16% 4-36%

SOURCE: IREP (https://www.niosh-irep.com/irep%5Fniosh/); NIH, 1985. 
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APPENDIX I I-55 

system for compensating veterans that eventually formed the basis for nonpresumptive compensation (Claims Based on Exposure to Ionizing Radiation. 2006. 38 CFR § 3.311), requiring evidence of sufficient exposure in the form of a quantitative dose reconstruction. These regulations 

permit claims for 24 “radiogenic diseases,” mainly specific cancers, plus certain cataracts and 

nonmalignant thyroid disease, as well as “any other cancer” not specifically enumerated. 

In response to “concerns about the possible health effects of exposure to radiation” (Podgor, 

2007, p. 522), Congress later enacted the Radiation-Exposed Veterans Compensation Act of 

1988 (REVCA) (Public Law 100-321. 100th Cong., 2d Sess.) which established presumptions 

for 13 cancers. Congress later codified these presumptions (Disease Subject to Presumptive Service Connection. 2006. 38 CFR § 3.309) which includes 21 cancer types. The scientific basis for 

this selection appears to have been based at least in part on a report of the Science Panel of the 

Committee on Interagency Radiation Research and Policy Coordination (CIRRPC, 1988). This 

report explicitly avoids addressing any policy implications of their conclusions, but mentions a 

concurrent policy panel that intended to conduct such a review (CIRRPC, 1988, pp. iii-iv); no 

such report has been located by the Committee, and VA has not responded to queries from this 

Committee about how the criteria provided in REVCA (Public Law 100-321. 100th Cong., 2d 

Sess.) were developed. The list first promulgated in REVCA (Public Law 100-321. 100th Cong., 

2d Sess.) has been amended several times subsequently in response to developing scientific evidence, but arguably the list did not fully reflect the available scientific evidence at the time. It 

excluded some clearly radiation-related cancers (e.g., lung, ovarian, and prostate) while including others (e.g., pharynx, small intestine, and bile ducts) with only tenuous scientific evidence to 

support an association of risk with radiation exposure. Nevertheless, recognizing the general carcinogenic potential of ionizing radiation, some of these rarer cancers, for which site-specific risk 

has not been convincingly demonstrated, could nevertheless be linked to radiation, as are other 

more common cancers. 

The Radiation Exposure Compensation Act of 1990 (Public Law 101-426. 101st Cong., 2d 

Sess.) did not directly relate to veterans, but instead focused on two other exposed populations, 

the Colorado plateau miners and other uranium miners and residents downwind of the Nevada 

Test Site. The act is relevant to consider here because of how some presumptions that were established for these groups differ from those for veterans. Uranium miners are exposed to radon 

gas and its radioactive decay products (“radon daughters” or “radon progeny”), which deliver 

substantial doses to the lung epithelium, leading to lung cancer. The miners could claim compensation only for lung cancer, by criteria that involved their dose and smoking history. Because few 

if any veterans would have experienced similar types of exposure, this comparison is not particularly relevant here. The downwinders, on the other hand, received qualitatively similar exposures 

to those of many of the atomic veterans, albeit usually at generally low doses. The Radiation Exposure Compensation Act of 1990 did not require any individualized dose estimates for the 

downwinders, but rather based presumptions on county of residence and cancer type. As one 

might expect, the cancers for which these presumptions were established were similar to those of 

the Radiation-Exposed Veterans Compensation Act of 1988 (Public Law 100-321. 100th Cong., 

2d Sess.). 

The adjustment for smoking for uranium miners who developed lung cancer deserves further 

comment. There were relatively few studies of the interaction between smoking and ionizing radiation effects on lung cancer risk, but some of the earlier studies indicated a joint effect that was 

either approximately additive (or the atomic bomb survivors [Prentice et al., 1983]) or somewhat 

less than multiplicative (for underground uranium miners [Lubin and Steindorf, 1995]). On this 
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I-56 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

basis, the relative risk (RR) per unit of radiation would indeed be lower for smokers than for 

nonsmokers and the corresponding “doubling dose”⎯the dose required to attain an RR of 

2⎯would be higher. More extensive reanalyses of all the miner data, however, subsequently indicated that a multiplicative model, or one intermediate between additive and multiplicative, was 

more appropriate (NRC, 1988). Under the multiplicative model, the RR for radiation would be 

the same for smokers and nonsmokers, and there would be no need to take smoking into account 

in deciding about compensation, even though the absolute risk is much higher in smokers. The 

reason for this is that both the background risk and the excess risk due to radiation are raised by 

the same factor, so the proportion of the risk attributable to radiation is the same. In addition, of 

course, there is the practical difficulty of establishing a smoking history in the face of an obvious 

incentive for a claimant to deny it. 

Many of the subsequent amendments to these three acts, detailed in the footnotes to Table I-3 

under the column heading “Other,” were in response to pressure from veterans groups seeking 

parity with the provisions of the Radiation Exposure Compensation Act of 1990. 

Recommendations of the Advisory Committee on Human Radiation Experiments (1995) 

and the Human Radiation Interagency Working Group 

In 1994, President Clinton established the Advisory Committee on Human Radiation Experiments (ACHRE), primarily to consider compensation policy for participants of certain medical experiments on human subjects with ionizing radiation and for people exposed to certain intentional releases of radiation into the environment for research purposes (ACHRE, 1995). 

However, the advisory committee interpreted its charge to encompass a number of other radiation-exposed groups, including the atomic veterans and the uranium miners. The advisory committee made a number of recommendations regarding compensation policy for these groups, noting the failure to update the radioepidemiological tables and calling for a review of the 

presumptions for the atomic veterans (ACHRE, 1995, ch. 18). These recommendations were in 

turn considered by the Radiation Exposure Compensation Act Committee (a committee established by the Human Radiation Interagency Working Group) which concluded that “the latest 

epidemiologic data suggest that the current exposure criteria do not accurately distinguish among 

lung cancer cases on a ‘more likely than not’ basis, and, therefore, do not effectively implement 

congressional intent” (RECAC, 1996, executive summary). They recommended revised criteria 

based either on dose or duration of exposure. 

Dealing with Uncertainties 

Uncertainties arise at both the population and individual level. At the population level, there 

can be uncertainty about whether a causal relationship between radiation and cancer has been 

established at all, as discussed in Chapter 9. If there is convincing evidence of a causal relationship, the estimate of risk attributable to exposure will be subject to statistical variation, since 

these estimates are based on a finite sample. The risk for particular categories of individuals 

(e.g., categories defined by dose, age, and time since exposure) will inevitably be even more uncertain than the average risk, since such estimates will be based on smaller sample sizes than for 

the overall risk. Epidemiologic risk estimates can also be distorted by selection bias, uncontrolled confounding, exposure measurement error, or a host of other potential biases. At the individual level, there are additional uncertainties about the specifics of an individual’s history (as 

discussed in Chapters 7 and 9). These might include the estimate of an individual’s dose (or 
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APPENDIX I I-57 

TABLE I-3 Selected Cancers and Diseases for Which Presumptive Service Connection Has Been Established Under Various Acts of Congress or Regulations 

Disease 

Veterans Dioxin 

and Radiation 

Exposure 

Compensation 

Standards Act 

of 1984 

RadiationExposed 

Veterans 

Compensation 

Act of 1988 

Radiation 

Exposure 

Compensation 

Act of 1990 Other BEIR VII 

Leukemia (excluding CLL) x x x x 

Cancer: 

Thyroid x x x x 

Urinary bladder f x 

Kidney k 

Lung x h, j x 

Bronchiolo-alveolar g 

Bone x h, j 

Female breast x x x x 

Male breast f 

Pharynx x x 

Esophagus x x 

Stomach x x x 

Colon f, h, j x 

Small intestine x x 

Pancreas x x 

Bile ducts x x 

Gall bladder x x 

Skin x 

Liver x x x x 

Salivary f 

Ovarian b, f, h, j x 

Brain and CNS c, f, h, j 

Rectum d 

Prostate e x 

Uterus x 

Any other cancer e x 

Multiple myeloma x x 

Lymphomas (excl. 

Hodgkin’s) 

 x x d 

Nonmalignant thyroid 

nodules 

 a 

Cataracts (posterior 

subcapsulary) 

 a 

Parathyroid adenoma b, k 

Polycythemia vera x i 

SOURCES: aVA, 1989; bVA, 1993; cVA, 1994; dVA, 1995; eVA, 1998; fRadiation Exposure Compensation Act Amendments of 2000 (Public Law 106-245. 106th Cong., 2d Sess.); g

VA, 2000; hVA, 2002b; 

i

VA, 2002a; jVeterans Benefits Improvement Act of 2004 (Public Law 108-454. 108th Cong., 2d Sess.); 

k

Claims Based on Exposure to Ionizing Radiation. 2006. 38 CFR § 3.311. 
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I-58 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

even, in the case of a presumptive causation case, whether the individual met the minimum exposure criterion to qualify for the class at all), as well as other specific criteria (e.g., latency). 

IREP, described above, makes an attempt to incorporate both types of uncertainty into a “credibility interval” for each PC estimate it computes. 

Other Considerations 

Costs 

The only information on the costs of existing radiation presumptions available to the Committee came from a single memo prepared by the Office of Resource Management concerning 

the proposal to add bronchiolo-aveolar carcinoma of the lung to the list of presumptions. This 

document estimated a caseload of 120 veterans and 338 survivors during fiscal year 2000, at a 

cost of $5.9 million, cumulative cost through 2004 of $33.3 million, with administrative costs of 

$308,000 (VA, 1999, p. 1). 

Sensitivity and Specificity 

As there is no unique marker for the cause of any given cancer and because cancers can be 

caused by any of a number of different factors (separately or acting in combination), any compensation scheme must necessarily lead to both false positives (compensation of cases not caused 

by radiation) and false negatives (failure to compensate a case that in fact was caused by radiation). Current VA policy is to err on the side of false positives. Thus, the aim of the current policy is to achieve high sensitivity, necessarily at the expense of low specificity. Given the probabilistic nature of radiation carcinogenesis, no compensation policy can hope to be both highly 

sensitive and highly specific. 

Secrecy 

Arguably a unique feature of much of the radiation story concerns the national security elements that pervaded the entire Cold War culture in which nuclear weapons testing exercises were 

conducted. This secrecy element has been addressed in detail in the ACHRE report (1995) and 

Chapter 11 of this report. Although much of the information about the veterans’ participation in 

nuclear weapons testing has now been declassified, access to records and even in some instances 

the simple fact of a veteran’s participation in particular exercises has undeniably been a barrier to 

establishing a credible claim in the past. 

Lessons Learned 

This case study illustrates a situation quite different from many of those in other case study 

chapters; for radiation, there is an abundant literature of solid science⎯some relating to doseresponse relationships in general populations, some specific to veterans⎯upon which to base 

compensation policy. Despite this, there remain numerous uncertainties, particularly with respect 

to estimation of an individual’s exposures and with respect to the risk for specific rare cancers. 

These uncertainties in large part are responsible for the shift in emphasis from individual PCbased criteria for compensation in the 1984 Act (Veterans’ Dioxin and Radiation Exposure 

Compensation Standards Act of 1984. Public Law 98-542. 98th Cong., 2d Sess.) to the estab-
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APPENDIX I I-59 

lishment of presumptions in the 1988 act (Radiation-Exposed Veterans Compensation Act of 

1988. Public Law 100-321. 100th Cong., 2d Sess.). This evolution reflects the growing recognition of the difficulty of establishing criteria for individual compensation in the face of such uncertainties and the need for presumptions. 

In general, studies of the effects of radiation in veteran populations have been of limited utility, in part because of the relatively small number of excess cancers expected in the available cohorts and, importantly, because of the failure to track individual exposures systematically or accurately. For this reason, these direct observations in the population of greatest relevance should 

not negate the wealth of more informative data from other populations. Nevertheless, the availability of informative epidemiologic data from other populations has made it possible to construct quantitative models to guide compensation policy for radiation-exposed veterans, which 

has often not been possible for other exposures. These studies also illustrate the difficulty of 

dealing with other causal risk factors for cancer, such as smoking. Yet even in that case, this case 

study has demonstrated that it is possible to develop scientifically based policies using strong 

epidemiologic evidence about their joint effects. 

Ultimately, much of the force behind the movement for compensation for the atomic veterans 

derived from a sense of outrage that their government deliberately exposed them to radiation 

with at least some knowledge of risks involved at the time (Podgor, 2007). Furthermore, these 

risks were often denied by government officials, both at the time of exposure when they were not 

properly informed and later when diseases were manifest and their attempts at redress were rebuffed. On this basis, the veterans feel their claims for compensation are enhanced by the culpability of the government (ACHRE, 1995). 

Appendix: Epidemiologic Studies of Radiation-Exposed Veterans 

The first study of cancer in the atomic veterans was published by investigators from the CDC 

in 1980 (Caldwell et al., 1980, p. 1577), describing nine cases of all types of leukemia among the 

3,224 participants of nuclear test explosion “Smoky” conducted in 1957, compared with 3.5 expected, a statistically significant excess. A subsequent report (Caldwell et al., 1983, p. 622) 

raised the toll to 10 leukemias compared with 4.0 expected, but found no statistically significant 

excess of any other cancers. The mean dose for the entire cohort was 0.5 cGy (ranging from 0-

3.0 cGy for the leukemia cases, with a mean of 1.0 cGy) (Caldwell et al., 1980, p. 1577). The 

above-ground test conducted at the Nevada Test Site, “Smoky,” produced substantial fallout exposures to Utah downwinders in addition to the onsite military participants. However, the original investigators declared that the measured doses were inadequate to account for all of the observed leukemia excess (Caldwell et al., 1983). 

Largely in response to the CDC study, NAS undertook a more extensive epidemiologic study 

of 46,186 participants in five series of tests at the Nevada Test Site (Robinette et al., 1985, as 

referenced in IOM, 2000, p. 29). This report confirmed the previous excess of leukemia among 

Smoky participants, but found no excesses among the other participants or any consistent patterns for other cancers. This study was later found to be flawed by the inclusion of 4,500 individuals who had not participated, the exclusion of 15,000 others who had, and inadequacies in 

the dosimetry (Gelband, 1992, as referenced in IOM, 2000, p. 29). A separate IOM committee 

concluded that the film badge dosimetry was unsuitable for epidemiologic purposes and recommended that dose reconstruction methods be used instead to impute dose estimates to study participants (IOM, 1995, p. 14). This formed the basis for a revised report on this cohort, now including 70,000 participants and 65,000 comparable nonparticipants (IOM, 2000, p. 1). This 
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I-60 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

report found no significant differences between the two groups for overall or site-specific cancer 

mortality, although a nonsignificant 14 percent increase in leukemia was noted. 

A cohort of 40,000 participants at the first hydrogen bomb tests at Bikini in 1946 (Operation 

CROSSROADS) was compared with a similar cohort of nonparticipants in a study by IOM’s 

MFUA (Johnson et al., 1997). A significant 5 percent increase in all cause mortality (P < .001) 

was seen, but there were no significant excesses for all cancers (1.4 percent) or for leukemia (2 

percent). The authors concluded that this pattern did not support a radiation hypothesis. 

Another study was conducted on 8,554 Navy participants in a series of 35 tests conducted at 

the Pacific Proving Grounds in the Marshall Islands in 1958 (Operation HARDTACK) compared 

with 14,625 Navy veterans who did not participate in any tests (Watanabe et al., 1995, pp. 524-

525). Overall, the exposed cohort received an average of 0.4 cGy and experienced a nonsignificant 14 percent increase in total cancer (95% confidence interval [CI], −2 to 33%) and a significant 47 percent increase in digestive cancers (6-104%). Among the 1,064 participants who received over 1 cGy, a significant 42 percent excess (95% CI, 4-96%) of total cancer was seen 

relative to nonparticipants, but no single site was noteworthy, and there were no significant doseresponse trends. In comparison with general population rates, the excess of total cancer was only 

12 percent (−1 to 27 percent) and 24 percent for digestive cancers (−4 to 57 percent) (Watanabe 

et al., 1995, pp. 524-525). 

A subsequent analysis (Dalager et al., 2000) expanded the high-dose cohort to include 1,010 

participants who received at least 5 cGy (374 Navy participants at the Pacific Proving Grounds, 

636 from other services, mainly from the Nevada Test Site). In this group, the overall mortality 

was increased by 22 percent (RR = 1.22; 95% CI 1.04-1.44%); mortality from all lymphopoietic 

cancers increased by 272 percent (RR = 3.72; 95% CI 1.28-10.83); and there was a nonsignificant 41 percent increase in respiratory cancers (RR = 1.41; 95% CI 0.91-2.18), but there was no 

excess of digestive cancers or all other cancers. The comparison of all high-dose participants 

with Navy-only controls found that the numbers of cancers in the 374 Navy participants was inadequate to establish significant excesses, except for lymphopoietic cancers and all causes combined (Dalager et al., 2000). 

In addition to U.S. military participants, veterans from other countries have also been studied, and it is reasonable to expect that their experience would be broadly comparable. A small 

Canadian study (Raman et al., 1987) of 954 participants and twice as many controls found no 

differences, but another small cohort of 528 New Zealand participants compared to 1,504 controls (Pearce et al., 1997, p. 139) found a significant 5.6-fold excess mortality from leukemia (n 

= 4) and 3.8-fold excess of deaths from hematologic malignancies (n = 8) (Pearce et al., 1997, 

p. 142). 

A much larger study of British participants of nuclear tests conducted in Australia (Darby et 

al., 1988, p. 335) found higher rates of leukemia and multiple myeloma than in matched controls 

(28 compared with 6). Compared with national rates, however, it appeared that the excess was 

driven more by unusually low rates in controls than by high rates in cases. Various updates of 

the UK studies have been reported (Darby et al., 1991, 1993; Muirhead and Kendall, 2003; 

Muirhead et al., 2003, 2004), which have generally confirmed the original findings, except for 

eliminating the excess of multiple myeloma. The most recent publication (Muirhead et al., 2004, 

p. 227) shows an 83 percent excess (15-193 percent) of all leukemia excluding CLL, rising to a 

199 percent excess (26-641 percent) for the period 2 to 25 years after exposure. As before, however, the rate relative to the general population was only slightly elevated in the exposed cohort 

(RR of 1.06 [n = 40] overall or of 1.23 [n = 18] 2 to 25 years after exposure), compared with 
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APPENDIX I I-61 

considerably lower rates in the control cohort (RR of 0.58 [n = 23] overall or relative risk of 0.36 

[n = 6] 2 to 25 years after exposure) (Muirhead et al., 2004, p. 227). 

This literature up to 1995 was reviewed by ACHRE (1995, ch. 10), who attempted to put 

these results in perspective by noting that among the roughly 220,000 U.S. participants, current 

risk estimates would predict about 100 excess lifetime cancers, a small number in comparison 

with the 48,000 that would be expected from natural causes, an excess whose magnitude is not 

only uncertain, but would be virtually undetectable by even the best designed epidemiologic 

study. They also estimated that among the 1,200 veterans who received more than 5 cGy, about 8 

excess cancers would be expected. Nevertheless, the committee was highly critical of the government’s culture of secrecy that made it very difficult for veterans to learn about their experiences, their failure to protect participants against any but acute effects from high-dose exposures, 

and their failure to maintain adequate records about either the individuals’ participation or their 

policy-making process. 

References 

ACHRE (Advisory Committee on Human Radiation Experiments). 1995. The human radiation experiments: Final report. http://www.hss.energy.gov/HealthSafety/ohre/roadmap/achre/report.html (accessed June 24, 2007). 

Caldwell, G. G., D. B. Kelley, and C. W. Heath, Jr. 1980. Leukemia among participants in military maneuvers at a nuclear bomb test. A preliminary report. Journal of the American Medical Association

244(14):1575-1578. 

Caldwell, G. G., D. Kelley, M. Zack, H. Falk, and C. W. Heath, Jr. 1983. Mortality and cancer frequency 

among military nuclear test (Smoky) participants, 1957 through 1979. Journal of the American Medical Association 250(5):620-624. 

CIRRPC (Committee on Interagency Radiation Research and Policy Coordination). 1988. Use of probability of causation by the Veterans Administration in the adjudication of claims of injury due to exposure to ionizing radiation. Science Panel Report Number 6. Washington, DC: Office of Science 

and Technology Policy. http://www.cdc.gov/niosh/ocas/pdfs/irep/cirrpc.pdf (accessed March 25, 

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atmospheric nuclear test participants. Journal of Occupational and Environmental Medicine

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Kingdom who participated in the United Kingdom’s atmospheric nuclear weapon tests and experimental programmes. British Medical Journal 296(6618):332-338. 

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programmes. British Medical Journal 307(6918):1530-1535. 

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nuclear weapons test programme. Journal of Radiological Protection 18(3):209-210. 

Gelband, H. 1992. A discussion of questions about the 1985 NAS report “Mortality of nuclear weapons 

test participants.” Washington, DC: Office of Technology Assessment. 
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IARC (International Agency for Research on Cancer). 2000. Ionizing radiation, part 1: X- and gamma 

(g)-radiation, and neutrons. Lyon, France: International Agency for Research on Cancer. 

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IOM. 1996. Mortality of veteran participants in the CROSSROADS nuclear test. Washington, DC: National Academy Press. 

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Washington, DC: National Academy Press. 

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CROSSROADS nuclear test. Health Physics 73(1):187-189. 

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Lubin, J. H., and K. Steindorf. 1995. Cigarette use and the estimation of lung cancer attributable to radon 

in the United States. Radiation Research 141(1):79-85. 

Muirhead, C. R., and G. M. Kendall. 2003. UK nuclear-test veterans. Lancet 362(9380):331-332. 

Muirhead, C. R., D. Bingham, R. G. Haylock, J. A. O’Hagan, A. A. Goodill, G. L. Berridge, 

M. A. English, N. Hunter, and G. M. Kendall. 2003. Follow up of mortality and incidence of cancer 

1952-98 in men from the UK who participated in the UK’s atmospheric nuclear weapon tests and experimental programmes. Occupational and Environmental Medicine 60(3):165-172. 

Muirhead, C. R., G. M. Kendall, S. C. Darby, R. Doll, R. G. Haylock, J. A. O’Hagan, G. L. Berridge, 

M. A. Phillipson, and N. Hunter. 2004. Epidemiological studies of UK test veterans: II. Mortality and 

cancer incidence. Journal of Radiological Protection 24(3):219-241. 

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group to develop radioepidemiologic tables. NIH Publication No. 85-2748. Washington, DC: U.S. 

Department of Health and Human Services. 

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radiation. Washington, DC: National Academy Press. 

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assigning probability of causation. Washington, DC: National Academy Press. 

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DC: National Academy Press. 

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program. Washington, DC: The National Academies Press. 

NRC. 2006. Health risks from exposure to low levels of ionizing radiation: BEIR VII - Phase 2. Washington, DC: The National Academies Press. 

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the Pacific. Cancer Causes and Control 8(2):139-145. 

Podgor, M. F. 2007. The inability of World War II atomic veterans to obtain disability benefits: Time is 

running out on our chance to fix the system. Elder Law Journal 13(2):519-552. 

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exposure to cancer mortality in Hiroshima and Nagasaki. Journal of the National Cancer Institute

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atomic bomb survivors. Report 13: Solid cancer and noncancer disease mortality: 1950-1997. Radiation Research 160(4):381-407. 
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Raman, S., C. S. Dulberg, R. A. Spasoff, and T. Scott. 1987. Mortality among Canadian military personnel exposed to low-dose radiation. Canadian Medical Association Journal 136(10):1051-1056. 

RECAC (Radiation Exposure Compensation Act Committee). 1996. Final report of the Radiation Exposure Compensation Act Committee. Washington, DC: Human Radiation Interagency Working Group. 

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Robinette, C. D., S. Jablon, and T. L. Preston. 1985. Studies of participants in nuclear tests. Washington, 

DC: National Academy Press. 

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2000 report: Sources and effects of ionizing radiation. Vol. 2. New York: United Nations. 

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VA (Department of Veterans Affairs). 1989. Claims based on exposure to ionizing radiation. Final regulations. Federal Register 54(200):42802-42803. 

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16359. 

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6871. 

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3616. 

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of a 1958 atmospheric nuclear weapons test. American Journal of Public Health 85(4):523-527. 

CASE STUDY 6: MUSTARD GAS AND LEWISITE PRESUMPTIONS 

This case study examines the 1992 and 1994 decisions by the VA to establish presumptive 

service connection for health outcomes related to mustard gas and lewisite exposures among 

World War II veterans. It outlines several issues critical to protecting and treating those in military service: secrecy and classification of exposures, the latency period to adverse health outcome following exposures, lack of medical records, the involvement of “volunteers” in chemical 

experiments, the classification of scientific evidence and the use of scientific evidence, and the 

impact of policy considerations in making compensation decisions. 

Background 

In 1992, VA recognized that some World War II veterans had been exposed to mustard gas 

during laboratory experiments that involved full-body, field, or chamber tests of protective 

equipment. A presumption was proposed that covered several diseases associated with exposure 

to mustard gas. VA justified this presumptive service connection based on several factors: (1) the 

studies were classified; (2) participants were directed not to discuss their participation in the 

studies; (3) their medical records were sparse; and (4) no long-term follow-up was conducted or 

provided for the participants (VA, 1992a). After public comment on this proposed regulation, 

VA issued a final rule in July 1992 (VA, 1992b). In early 1994, VA revised the presumption 
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based on a study conducted by the IOM on the health effects of exposure to mustard gas and 

lewisite and issued a proposed rule (VA, 1994a). The second presumptive service-connection 

rule was issued in August 1994 and amended the original proposal by (1) adding more diseases 

to the original list of diseases; (2) adding the compound lewisite to the rule; (3) adding veterans 

who might have been exposed during World War I and in studies after the end of World War II; 

and (4) clarifying the extent of exposure. Again the presumptive decision was based on the same 

factors stated in the original proposed rule (VA, 1994b). In August 2006, the VA Under Secretary for Health issued an information letter intended to inform health-care providers about the 

diseases resulting from exposure to mustard gas, lewisite, and some 250 different agents used in 

studies conducted at Edgewood-Aberdeen during the period of 1955 to 1975 (VA, 2006a). However, this letter specifically states that VA does not presumptively recognize any long-term 

health effects from agents other than mustard agents and lewisite. Any health effects from exposure to the 250 chemical agents used during chemical warfare testing studies are to be addressed 

on an individual basis (VA, 2006a). 

Although chemical warfare has its roots in antiquity, World War I was the beginning of modern day chemical agent usage. The German army released tens of thousands of pounds of chlorine gas in April 1915 near Ypres, Belgium, as an offensive weapon (Joy, 1997). In July 1917 the 

blistering agent sulfur mustard, called mustard gas, was released for the first time in the same 

general area (Joy, 1997). This agent caused the most casualties during World War I, but not the 

most fatalities. Some 400,000 troops were injured by sulfur mustard during World War I 

(Gilchrist, 1928, as referenced in IOM, 1993, p. 9). This began the trend of concern regarding 

mustard gas and other chemical agents. Further concern was forthcoming with the December 

1943 Bari Harbor, Italy, incident and the initiation and continued laboratory testing begun during 

World War II (Alexander, 1947; Harris and Paxman, 1982; Reminick, 2001; Tucker, 2006). The 

alleged use of mustard agents offensively by other countries since World War II has been documented: Egypt against Yemen in the 1960s (Shoham, 1998) and Iraq against Iran in the 1980s 

(Balali-Mood et al., 2005; IOM, 1993; Sidell et al., 1997; Tucker, 2006). 

Although there was no chemical warfare during World War II, the lingering memories of 

World War I chemical usage by the German army remained foremost in the minds of the U.S. 

military. Chemical and biological warfare agent use and testing against the Chinese by the notorious Japanese Unit 731, commanded by General Shiro Ishii, spurred the United States to develop protective clothing and respirators, better termed gas masks (Harris, 1994). Sulfur mustard 

use was a major concern (IOM, 1993). Consequently, history reveals that the U.S. government 

began preparing for chemical agent usage prior to the attack on Pearl Harbor by the Japanese in 

December 1941. Under President Franklin D. Roosevelt, war-related research units were established and placed under the control of the White House Office of Scientific Research and Development (IOM, 1993). Two groups were established to investigate different aspects of the mustard agents and lewisite. The Committee on Medical Research studied protective ointments and 

alternative treatments through the NRC’s Committee on Treatment of Gas Casualties. The second group, the National Defense Research Committee, studied protective clothing and gas masks 

through different military units. Both these groups were involved in secret testing programs involving mustard agents and lewisite. Because of a lack of animal models of human injury, researchers in these programs decided in 1942 to use human subjects (IOM 1993). In total these 

two testing programs involved approximately 60,000 military personnel as human experimental 

subjects deemed by the government to be “volunteers” (IOM, 1993, pp. vii, 1). Some 4,000 volunteers participated in gas chamber or field exercises (IOM, 1993, p. 1). The gas chamber tests 
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involved high concentrations of mustard agents or lewisite. The field exercises were conducted 

over heavily contaminated soils. Exposure concentrations ranged from mild, such as a drop of 

agent on the arm in patch tests, to severe, repeated gas chamber trials with and without protective 

clothing. All human experimental subjects were sworn to secrecy regarding their involvement in 

these tests (IOM, 1993). 

However, concerns regarding health consequences of sulfur mustard and lewisite exposures 

were not entertained by VA until the early 1990s. Concern by VA at this time was brought about 

by some of the former human subjects as they attempted to obtain medical help for diseases 

thought to be associated with exposure to mustard gas or lewisite. VA was unable to resolve 

these cases for two reasons: (1) the absence of records or documentation regarding the individual’s participation in exposure testing, and (2) the uncertainty of health effects linked to the two 

agents of concern, sulfur mustard and lewisite (VA, 1992a,b). On January 15, 1992, VA announced guidelines for the handling and subsequent adjudication of these cases (VA, 1992a). 

These guidelines included a lessening of normal requirements for documenting an individual’s 

participation in exposure testing and awarding of compensation based upon disease presentation. 

VA at this time was proposing to adjudicate compensation claims for disabilities or deaths 

resulting from the chronic effects of exposure to mustard gas while in service. Supplementary 

information provided in the proposed rule states that 

Some Naval personnel were experimentally exposed to mustard gas during full-body, 

field or chamber tests of protective equipment and clothing conducted at the Naval Research Laboratory, located at Edgewood Arsenal, Washington, DC, between 1943 and 

1945. Similar testing may have been conducted at other locations during World War II. 

These World War II tests were classified, participants were instructed not to discuss their 

involvement, and medical records associated with the tests are generally unavailable. No 

long-term follow-up examinations were conducted. For these reasons, some participants 

may not have filed claims with VA for disabilities resulting from mustard gas poisoning, 

or, if they did file claims, may have experienced difficulty in establishing entitlement to 

benefits. 

VA believes that the special circumstances surrounding these World War II testing programs have placed veterans who participated in them at a disadvantage when attempting 

to establish entitlement to compensation for disability or death resulting from experimental exposure. The proposed rule specifies that, if exposure occurred under the described 

circumstances, disabilities or deaths resulting from certain diseases are to be recognized 

as connected to a veteran’s exposure in-service. 

A review of the available medical literature by Veterans Health Administration (VHA) 

personnel indicates that the chronic, long-term effects of acute mustard gas poisoning 

may include laryngitis, bronchitis, emphysema, asthma, conjunctivitis, keratitis, and corneal opacities. Chronic forms of these conditions which developed subsequent to experimental exposure during World War II will be service-connected. 

 (VA, 1992a, pp. 1-2)

After public comment regarding the proposed rule, VA published the final rule with an effective date of July 31, 1992 (VA, 1992b). The proposed rule was modified to include World War I 

veterans who could claim residual disability from sulfur mustard exposure. These individuals 

would be able to show service medical record entries regarding acute sulfur mustard exposure 
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and that the long-term chronic effects from exposure have existed continually since the acute exposure episode. 

The use of long-term chronic effects of exposure was retained in the final rule by the following VA rationale: 

Veterans who were exposed to mustard gas during experimental tests of protective clothing and equipment during World War II, however, face a potentially insurmountable disadvantage when attempting to establish entitlement to compensation. Those tests were 

conducted behind a strictly enforced veil of secrecy, medical records associated with the 

tests are generally unavailable, and no long-term follow-up examinations were conducted. As a result, service medical records for individuals who participated in those tests 

may not show evidence of the acute effects of mustard gas exposure. Furthermore, it is 

likely that participants who developed chronic effects of exposure did not previously file 

compensation claims with VA solely because they had been instructed not to discuss their 

involvement in the tests. Physicians who may have treated these veterans for chronic effects more than 40 years ago have almost certainly retired from private practice, making 

it impossible for a veteran to establish that a chronic form of one of the specified disabilities has existed continually since exposure to mustard gas. 

 (VA, 1992b, p. 2) 

The VA indicated in the final rule that it would not have a significant financial impact: (1) 

the annual effect on the economy would be less than $100 million; (2) there would be no major 

increase in costs or prices; and (3) it would not “have significant adverse effects on competition, 

employment, investment, productivity, innovation, or on the ability of United States-based enterprises to compete with foreign-based enterprises in domestic or export markets” (VA, 1992b, p. 

2). Additionally, VA would contract with the NAS to address questions raised during the public 

comment period for which they did not have sufficient information to answer and issue a subsequent rule if necessary (VA, 1992b). 

IOM Report Entitled Veterans at Risk: The Health Effects of Mustard Gas 

and Lewisite

As a result of public comment to the proposed rule, VA stated in the final rule that they 

would contract with NAS to conduct a review of the published literature worldwide, medical and 

scientific, to include languages other than English, covering the long-term health effects of mustard gas exposure. NAS, through IOM, established a committee to address this issue and to publish a report. The committee (Committee to Survey the Health Effects of Mustard Gas and 

Lewisite) included experts in the disciplines of toxicology, chemistry, epidemiology, psychology, oncology, dermatology, ophthalmology, occupational medicine, and environmental medicine. The task delivered to this committee was to “survey the medical and scientific literature on 

mustard agents and lewisite, assess the strength of association between exposure to these agents 

and the development of specific diseases, identify the gaps in the literature, and recommend 

strategies and approaches to deal with any gaps found” (IOM, 1993, p. vi). 

IOM Report General Conclusions 

The lack of follow-up health assessments of the human subjects in the WWII gas chamber and field tests severely diminished the amount and quality of information that could 
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APPENDIX I I-67 

be applied in the assessment of long-term health consequences of exposure to mustard 

agents and Lewisite. 

The levels of exposure to mustard agents or Lewisite experienced by the human subjects 

may have been much higher than inferred in the summaries of the gas chamber and field 

tests. 

The committee was additionally dismayed that there were no epidemiological studies 

done of mustard agent-exposed, U.S. chemical weapons production workers, war gas 

handlers and trainers, or combat casualties from WWII. 

 (IOM, 1993, p. 3) 

IOM Report Specific Findings 

The data found generally fell into three categories of causal relationships: indicated, suggested, or insufficient evidence of a relationship. The committee emphasized that “no condition 

evaluated could be removed from consideration as a health consequence of exposure to these 

agents. Thus, for many diseases there remains significant doubt” (IOM, 1993, p. 4). 

The evidence found indicated a causal relationship between exposure and the following 

health conditions: 

• Respiratory cancers 

—Nasopharyngeal 

—Laryngeal 

—Lung 

• Skin cancer 

• Pigmentation abnormalities of the skin 

• Chronic skin ulceration and scar formation 

• Leukemia (typically acute nonlymphocytic type, nitrogen mustard) 

• Chronic respiratory diseases (also Lewisite) 

—Asthma 

—Chronic bronchitis 

—Emphysema 

—Chronic obstructive pulmonary disease 

—Chronic laryngitis 

• Recurrent corneal ulcerative disease (includes corneal opacities; acute severe injuries to 

eye from Lewisite will also persist) 

• Delayed recurrent keratitis of the eye 

• Chronic conjunctivitis 

• Bone marrow depression and (resulting) immunosuppression (an acute effect that may 

result in greater susceptibility to serious infections with secondary permanent damage 

to vital organ systems) 

• Psychological disorders 

—Mood disorders 

—Anxiety disorders (including post-traumatic stress disorder [PTSD]) 

—Other traumatic stress disorder responses (These may result from traumatic or stressful features of the exposure experience, not a toxic effect of the agents themselves.) 

• Sexual dysfunction (Scrotal and penile scarring may prevent or inhibit normal sexual 

performance or activity.) 
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I-68 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

The evidence found suggested a causal relationship between exposure and the following 

health conditions: 

• Leukemia (acute nonlymphocytic type, sulfur mustard) 

• Reproductive dysfunction (genotoxicity, mutagenicity, etc.; mustard agents) 

There was insufficient evidence found to demonstrate a causal relationship between exposure and the following health conditions: 

• Gastrointestinal diseases 

• Hematologic diseases 

• Neurological diseases 

• Reproductive dysfunction (Lewisite) 

• Cardiovascular diseases (Except for those that may result from serious infections shortly following exposure—heart disease resulting from rheumatic fever, for 

example.) 

 (IOM, 1993, pp. 4-5) 

IOM Report Recommendations

The committee recommends that the Department of Veterans Affairs (VA) institute a 

program to identify each human subject in the WWII testing programs (chamber and field 

tests, and to the degree possible, patch tests), so that these individuals can be notified of 

their exposures and the likely health risks associated with those exposures. Further, all 

subjects so identified, if still living, should be medically evaluated and followed by the 

VA as to their health status in the future. These individuals should also, if they request it, 

be treated by the VA for any exposure-related health problems discovered. Morbidity and 

mortality studies should be performed by the VA, comparing chamber, field, and patch 

test cohorts to appropriate control groups, in order to resolve some of the remaining questions about the health risks associated with exposure to these agents. 

 (IOM, 1993, p. 5) 

The committee recommends that careful attention be paid by health care providers to the 

special problems and concerns of the affected veterans and their families. This attention 

may include the convening of a special task force of experts in stress disorders and risk 

perception to aid the VA, further than this committee is able, in the establishment of 

comprehensive guidelines for handling of these cases. 

 (IOM, 1993, pp. 6-7) 

The committee additionally recommends that the Department of Defense (DoD) should 

use all means at its disposal, including public channels, to identify former chemical warfare production workers (military or civilian) and individuals exposed to mustard agents 

or Lewisite from gas handling, training, the Bari Harbor disaster, or other circumstances. 

Records of former military personnel could be turned over to the VA for notification, inclusion in morbidity and mortality studies, and health status evaluation. Records of the 

civilian personnel should be used by the DoD to advise former workers as to their health 

risks and options for seeking appropriate compensation for any illnesses that resulted 

from their exposures. 

 (IOM, 1993, p. 7) 
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The committee recommends that the VA and DoD publicly announce and widely advertise that personnel exposed to mustard agents or Lewisite during their service are released 

from any oath of secrecy taken at the time. In addition, professional educational materials 

should be prepared by the VA or DoD, or both, and made available for physicians who 

may be treating affected individuals. These materials should incorporate the latest information regarding the long-term health effects of exposure to mustard agents and 

Lewisite. 

 (IOM, 1993, p. 8) 

 

 After review of the IOM report, VA issued a proposed rule on January 24, 1994 (VA, 

1994a). The proposed amendment to VA adjudication regulations was based on the NAS study 

of the long-term health effects of exposure to mustard agents and lewisite. The NAS study, 

commissioned by VA, indicated that there is a relationship between mustard agent and lewisite 

exposure and subsequent development of certain medical conditions. The intended effect of the 

proposed rule was to expand compensation eligibility. 

The NAS study (IOM, 1993) substantiated VA’s prior determination that a casual relationship existed between mustard gas exposure and the resultant disease development. Further, the 

original seven diseases associated with this exposure were confirmed. However, the NAS study 

revealed numerous other medical effects as indicated above. VA accepted the additional medical 

conditions indicated by the NAS and included them in the proposed rule. A few minor exceptions were noted. Mesothelioma was excluded from the lung cancer grouping because it has only 

been associated with asbestos exposure. The term skin cancer was considered to be too broad a 

designation, and VA chose to include only squamous cell carcinomas of the skin. Likewise, VA 

indicated that, in their opinion, 

. . . there is no reason to establish presumptive service connection for “pigmentation abnormalities of the skin” because these abnormalities would be obvious from the time of 

the exposure to vesicant agents rather than occurring many years after exposure, as in the 

case of cancer. Also, because the usual places for mustard gas burns are areas of the body 

which are not visible, i.e., moist areas of the body such as the groin and axilla, rather than 

exposed areas as in the case of sunburn, most pigmentation abnormalities resulting from 

these burns would not be considered disabling, unless they interfered with the veteran’s 

ability to function. . . . Since compensation is only payable for a disability resulting from 

an injury suffered or disease contracted in line of duty or from aggravation of a preexisting injury or disease contracted in line of duty [Basic Entitlement. 2006. 38 USC 1110; 

Basic Entitlement. 2005. 38 USC 1121; Basic Entitlement. 2005. 38 USC 1131; Deaths 

Entitling Survivors to Dependency and Indemnity Compensation. 2005. 38 USC 1310.], 

and since exposure to vesicant agents does not cause a type of pigmentation abnormality 

which is disabling, we do not propose to include pigmentation abnormalities of the skin 

in the regulation. However, we propose to include scar formation in the regulation. 

 (VA, 1994a, p. 3) 

Because the NAS study reported that data demonstrated a “suggestive” causal or “insufficient” causal relationship for certain health outcomes, VA stated the following in its proposed 

rule: 

NAS found that the evidence was “suggestive” of a causal relationship between exposure 

to mustard gas and reproductive dysfunction (genotoxicity, mutagenicity, etc.) and expo-
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I-70 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

sure to sulfur mustard and leukemia. NAS found insufficient evidence of a causal relationship between exposure to mustard gas and gastrointestinal diseases, hematologic diseases, neurological diseases, cardiovascular diseases, and for reproductive dysfunction as 

a result of exposure to Lewisite. As NAS itself indicates, further study in these areas is 

necessary and in our judgment, the scientific and medical evidence on the whole does not 

support the establishment of presumptions for these conditions. 

(VA, 1994a, p. 4) 

 

The NAS report further did not address any condition of exposure other than whole-body exposure conditions. Therefore, VA did not include any veterans who were engaged in patch or 

drop testing of vesicants in the proposed rule. VA’s rationale was that since the NAS report did 

not address the issue of patch or drop testing, then the only conclusion that can be drawn is that 

NAS findings regarding specific diseases are linked only to full-body exposure (VA, 1994a). 

Lastly, the proposed rule addressed lewisite as well as mustard gas. Lewisite exposure was 

not included in the final rule issued July 31, 1992: 

The current regulation applies only to those veterans exposed while participating in secret 

tests of protective equipment during World War II; we propose to expand it to cover any 

verified full-body exposure during military service, which will allow veterans exposed to 

mustard gas under battlefield conditions in World War I, those present at the German air 

raid on the harbor of Bari, Italy, in World War II, and those engaged in manufacturing 

and handling vesicant agents during their military service to be eligible for consideration 

under this regulation. 

 (VA, 1994a, p. 4) 

After public comment on the proposed rule, VA issued the final rule on August 18, 1994: 

The regulation published on July 31, 1992, applied only to those veterans who experienced full-body exposure to mustard gas while participating in secret tests of protective 

equipment during World War II. This amendment expands that regulation to cover any 

full-body exposure to mustard gas or Lewisite during military service, and it now applies 

to veterans exposed under battlefield conditions in World War I, those present at the 

German air raid on the harbor of Bari, Italy, in World War II, those engaged in manufacturing and handling vesicant agents during their military service, etc. By expanding the 

number of conditions, vesicant agents, and veterans covered, this amendment clearly 

represents a significant liberalization of the previous criteria. 

 (VA, 1994b, p. 4) 

 

VA again expressed a concern about the secrecy issue covering the government’s work on 

mustard gas and lewisite: 

It is unquestionably beyond VA’s ability to modify historical events by regulation; however, we believe that this regulation is an appropriate government response to these issues. VA recognizes that because the tests were secret and no follow-up examinations 

were conducted, veterans who took part in them are at a disadvantage when attempting to 
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APPENDIX I I-71 

establish entitlement to compensation. This regulation addresses that situation by establishing a regulatory framework which recognizes that specific conditions are likely to result from exposure to vesicant agents and relieves veterans of the burden of submitting 

evidence to establish those associations in individual claims. 

 (VA, 1994b, p. 5) 

As a result of the issuance of the final rule, 38 CFR § 3.316 (Claims Based on Chronic Effects of Exposure to Mustard Gas. 2006), currently reads as follows: 

 

(a) Except as provided in paragraph (b) of this section, exposure to the specified vesicant 

agents during active military service under the circumstances described below together with the subsequent development of any of the indicated conditions is sufficient to establish service-connection for that condition: 

 (1) Full-body exposure to nitrogen or sulfur mustard during active military service 

together with the subsequent development of chronic conjunctivitis, keratitis, 

corneal opacities, scar formation, or the following cancers: Nasopharyngeal; laryngeal; lung (except mesothelioma); or squamous cell carcinoma of the skin. 

 (2) Full-body exposure to nitrogen or sulfur mustard or Lewisite during active military service together with the subsequent development of a chronic form of laryngitis, bronchitis, emphysema, asthma or chronic obstructive pulmonary disease. 

 (3) Full-body exposure to nitrogen mustard during active military service together 

with the subsequent development of acute nonlymphocytic leukemia. (b) Service 

connection will not be established under this section if the claimed condition is 

due to the veteran’s own willful misconduct (See Sec. 3.301[c]) or there is affirmative evidence that establishes a nonservice-related supervening condition or 

event as the cause of the claimed condition (See Sec. 3.303). 

 (Claims Based on Chronic Effects of Exposure to Mustard Gas. 

2006. 38 CFR 3.316) 

Analysis of Presumptive Decisions 

The final rule published in 1992 (VA, 1992b) was too restrictive, both from a standpoint of 

the personnel covered by the rule and the health effects considered by the rule. VA addressed 

only World War II veterans who were experimentally exposed to mustard gas during full-body, 

field, or chamber tests of protective equipment. The seven health effects and the restricted personnel inclusion were based on a VA review process only. The presumptions used were based on 

the fact that the World War II tests were classified (minimally Secret), the “volunteers” were directed not to discuss their involvement with any of the studies, medical service records were not 

maintained or were not available because of the secret classification, and consequently no longterm medical examinations were conducted. Because of these stated reasons some of the human 

volunteers who experienced adverse health effects probably did not file for any VA assistance, 

and those who did file would have experienced great difficulty in establishing service 

connection. 

The final rule published in August 1994 (VA, 1994b) greatly expanded the scope of effects 

and the population of workers covered. Based on the NAS report (IOM, 1993), the regulation 

was amended to cover any verified full-body exposure to mustard gas or lewisite during military 

service and included veterans from World War I exposed during battlefield conditions. This rule 
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I-72 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

also significantly increased the number of adverse health effects which would be covered as a 

result of full-body exposure to mustard gas or lewisite. 

The significantly higher number of medical conditions to be covered and the increased number of Service members to be included for disability coverage indicated that VA was sensitive to 

veterans’ attempts to obtain VA assistance. Because of the secrecy classification applied to the 

veterans who worked on the projects, and subsequently to their medical service records, the usual 

methods of establishing eligibility were deemed to be too great a burden for the veteran. Consequently, the presumptions used were to the benefit of the veteran. VA was attempting to be extremely sensitive to the needs of the veteran in lieu of the strict classification assignment. A fine 

line must be addressed for national security measures and the health needs of the personnel assigned to work on these national security measures. As indicated in the IOM report, there is still 

hesitancy in declassifying many of the study results (IOM, 1993). The IOM committee addressing this issue was not given full cooperation in retrieving documents from these studies while the 

DoD stated that they were not declassified. 

Costs could not be fully addressed in this case study because no financial information was 

received from VA. In the July 1992 rule (VA, 1992b) VA did indicate that there would be no 

significant financial impact on the amended regulation for compensation. The cost of the 

amendment would not have an annual effect on the economy of $100 million or more, it would 

not cause a major increase in costs or prices, and it would not have significant adverse effects on 

other economic parameters. The August 1994 amendment (VA, 1994b) also indicated no adversity in economic impact. However, VA has not presented IOM with any dollar values for either 

amendment period. 

In view of the current classification scheme based upon national security concerns, those individuals working in classified studies remain potentially at risk. Only after a few individuals 

involved in the World War II studies attempted to obtain VA assistance was VA able to implement disability assistance. Failure to declassify study results up to 50 years after exposure puts 

our veterans at considerable risk of disease manifestation and progression without possible warranted screening and therapy. Although project classification may be necessary for DoD, a 

method should be developed and implemented to account for medical intervention in such cases. 

The absence of medical service records, no long-term medical or epidemiologic follow-up, and 

the enforced requirement for secrecy hampered veterans and VA from providing the necessary 

assistance to the veteran or the beneficiary. Future projects must include a means to ensure medical care is afforded to the participants if needed. A thorough communication path and cooperative working arrangements need to be explored and developed between DoD and VA to ensure 

that such a lack of medical attention does not occur in the future. If secrecy is mandatory to the 

level exhibited by the current mustard gas and lewisite rule, then future study participants will be 

hindered as much as past participants. This issue was examined in great detail in the report, Veterans at Risk, and recommendations were provided (IOM, 1993). The committee found that the 

secrecy coverage still existed some 50 years after the World War II programs were initiated. 

Even though some documents were declassified, many of them remained “restricted” and consequently are not releasable to the public. Additionally, not all facilities freely cooperated with 

IOM in releasing documents. Some did not release documents until the committee work had essentially been completed. 
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APPENDIX I I-73 

Classification and Secrecy Requirements 

The oath of secrecy is still held inviolate by many of the veterans involved in the World War 

II mustard gas and lewisite studies. These military and civilian workers took an oath to keep all 

information involving these studies secret, and they have maintained that oath to this day. Even 

though this oath has prevented possibly thousands of individuals from obtaining necessary medical care, the oath has not been violated. They took a secrecy oath and legally and ethically then 

maintained their oath. However, the government that they are protecting has not reciprocated in 

protecting them. The lack of medical records and long-term medical care for past exposures to 

mustard gas and/or lewisite has not been provided to all military and civilian workers, ostensibly 

due to the secrecy clause. Classification is mandatory to preserve national security. Consequences of this same classification can be paramount as is evidenced in the mustard gas and 

lewisite exposure issue. An appropriate resolution between DoD and VA needs to be made to 

protect both the nation and the nation’s governmental workers. 

There are three entities involved in the secrecy issue: DoD scientific and military organizations, VA disability/compensation programs, and the individual Service member. At times, DoD 

must undertake secret studies to obtain results that will be used to provide the best security possible for our country. To provide the maximum protection, these studies may require a classification level. Many of the studies being conducted today are appropriately under this mantle of classification. On the other hand, VA must provide assistance to the veterans who have provided a 

necessary service to the government and the country. VA cannot provide this assistance if the 

necessary information is not given to them to ensure that entitled individuals are tracked, medically treated, and compensated appropriately. Furthermore, the exposures and agents must be 

identified so that health consequences can be linked. The individual workers must be given the 

ability to seek VA assistance as the need arises. Using the mantle of secrecy to protect the country is a dire hindrance to the veteran in seeking the necessary medical assistance. Policy considerations may be involved in both the roles played by DoD and VA. Both agencies have requirements and responsibilities that must be met. 

The IOM report Veterans at Risk (1993) provided three recommendations addressing this 

issue: 

The committee additionally recommends that the Department of Defense (DoD) should 

use all means at its disposal, including public channels, to identify former chemical warfare production workers (military or civilian) and individuals exposed to mustard agents 

or Lewisite from gas handling, training, the Bari harbor disaster, or other circumstances. 

Records of former military personnel could be turned over to the VA for notification, inclusion in morbidity and mortality studies, and health status evaluation. Records of the 

civilian personnel should be used by the DoD to advise former workers as to their health 

risks and options for seeking appropriate compensation for any illnesses that resulted 

from their exposures. 

 (IOM, 1993, p. 7) 

The IOM committee additionally recommended that the secrecy requirement for workers involved in the World War I and World War II mustard gas and lewisite studies be deleted so that 

the individuals may seek medical assistance without the threat of punishment for violating the 

secrecy oath: 
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The committee recommends that the VA and DoD publicly announce and widely advertise that personnel exposed to mustard agents or Lewisite during their service are released 

from any oath of secrecy taken at the time. In addition, professional educational materials 

should be prepared by the DoD or VA, or both, and made available for physicians who 

may be treating affected individuals. These materials should incorporate the latest information regarding the long-term health effects of exposure to mustard agents and 

Lewisite. 

 (IOM, 1993, p. 8) 

The VA final rule issued in August 1994 (VA, 1994b) addressed the disease and eligibility 

issues for veterans. DoD’s response to the IOM committee recommendations has not been fully 

ascertained. 

VHA Under Secretary for Health’s Information Letters 

Since the IOM report was issued in 1993, three information letters have been released by the 

VHA Under Secretary for Health as well as a veteran health initiative. The Under Secretary for 

Health’s information letter IL 10-2002-016 (VA, 2002) provided information to clinicians who 

might encounter and treat veterans involved in Project Shipboard Hazard and Defense. While 

this letter primarily addressed biological agents, there is a section addressing chemical agents as 

well. Reference is made to reports produced by IOM. The Under Secretary for Health’s information letter IL 10-2005-004 (VA, 2005) provided information to clinicians who might treat veterans who had been exposed to mustard or lewisite chemical warfare agents as part of human experimentation conducted by DoD through World War II. Extensive reference is made to the IOM 

report (1993). This letter indicates that because of the secrecy issue related to these studies, VA 

health-care providers were not aware of the history of these chemicals being used. Guidance was 

presented for the health-care providers to consider the diseases covered by the presumptive decision rule and emphasized that medical care should focus on the current health status of the veteran. Further, direction was given, emphasizing that there is no test available to confirm exposure to these compounds that occurred decades ago. The Under Secretary for Health’s 

information letter IL 10-2006-010 (VA, 2006a) again provided information to clinicians on this 

issue. This letter stated that the Veterans Benefits Administration released notification letters on 

June 30, 2006, to DoD-identified veterans who were test subjects in military experiments and 

advised the veteran of benefits they might be entitled to because of their participatory exposures. 

Again the diseases identified in the final rule for mustard and lewisite agent exposure as causative were discussed and references to websites for additional information were provided. Chemical Warfare Agent Experiments Among U.S. Service Members is a report that describes more 

chemicals evaluated at Edgewood-Aberdeen than the mustard and lewisite agents (VA, 2006b). 

In October 2003, a veterans health initiative was released as an independent study course 

(VA, 2003). The veterans health initiative, titled Health Effects from Chemical, Biological and 

Radiological Weapons, contained a forwarding message from the VA Under Secretary for 

Health, Robert H. Roswell, M.D., stating “greater general awareness of the specialized health 

issues facing persons with [Chemical, Biological and Radiological] injuries is needed to assure 

therapeutically appropriate clinical processes” (VA, 2003, p. ii). Dr. Roswell emphasized that 

every clinician must complete the study course in order to better serve the health needs of the 

veteran. 
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APPENDIX I I-75 

Lessons Learned 

A number of concerns are raised by this presumptive decision. Foremost is the issue of secrecy surrounding military and governmental studies involving warfare agents. Classifying warfare studies based on national security is necessary in many cases. However, this classification 

can lead to concerns about health that might not be resolved for decades. In the case of mustard 

and lewisite agents national security took precedence over identifying the long-term health consequences of exposure. Volunteers who participated in these studies maintained their secrecy 

oaths for decades even though health issues arose. When these issues were brought to the attention of VA a second problem arose: the lack of definitive medical records for these individuals. 

Medical records that did exist did not contain any information relating to potential mustard gas 

or lewisite exposures. Consequently, health-care providers were unaware of these health-related 

issues. Long-term medical follow-up therefore was not provided to the study participants. A third 

area of concern is that this classification precluded health-care providers from being aware that 

symptoms of mustard gas or lewisite exposure might be exhibited by patients. As a result, the 

health-care providers did not look for these occupationally related symptoms. 

Several Under Secretary for Health information letters have been issued by VA to address 

this gap. As indicated in the presidential task force 2003 report (President’s Task Force to Improve Health Care Delivery for Our Nation’s Veterans, 2003) and a recent GAO report (GAO, 

2006a), the health of our veterans must be considered for the entire time of an individual’s military service. The presidential task force specifically cited the lack of exposure data to a known 

environmental hazard as a root cause for not being able to determine compensatory issues for our 

veterans (GAO, 2006a,b). While DoD apparently is addressing the tracking and recording of the 

Service members’ movements to link with exposure data collected, both areas remain concerns 

for the veteran. Inadequate exposure data are collected, and the ability to vector these data to location and troop movement has limited attribution of disease to exposure agents for individual 

veterans. Exposure assessment is the key to disability benefits for veterans. A recent report 

(GAO, 2004) indicates that force health protection and surveillance policy are not as good as 

they could be, but are improving, especially with more current deployments. The final rule for 

mustard gas and lewisite (VA, 1994b), based upon the 1993 IOM report, outlined three categories of causal relationships for health consequences of exposure: indicated, suggested, and insufficient evidence of a relationship. VA acknowledged in the final rule that certain health consequences could be linked directly to mustard gas or lewisite exposure and that a second grouping 

of health consequences had a suggestive linkage based upon the 1993 IOM report. Although the 

IOM report recommended many diseases that could be associated with exposure to these agents, 

VA specifically eliminated several of the diseases as not being related to mustard gas or lewisite 

exposure. Consequently, a precedent was established by VA for causal health consequences associated with specific chemical agents as recommended by IOM. Lastly, this case study indicates 

an apparent lack of communication and coordination between DoD and VA regarding individual 

Service members and government workers involved in studies, chemical agents used in these 

studies, and any actual or potential exposure data for the individuals involved. This lack of coordination was emphatically pointed out in the IOM 1993 report Veterans at Risk. 

References 

Alexander, S. F. 1947. Medical report of the Bari Harbor mustard casualties. The Military Surgeon

101(1):2-17. 
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Balali-Mood, M., M. Hefazi, M. Mahmoudi, I. Jalali, D. Attaran, M. Maleki, M.-R. E. Razavi, G. Zare, 

M.-R. Jaafari, and A. Tabatabaee. 2005. Evaluation of delayed toxic effects of sulfur mustard poisoning in severely intoxicated Iranian veterans: A cross-sectional study. Journal of Medical, Chemical, 

Biological, and Radiological Defense 3:1-32. 

GAO (Government Accountability Office). 2004. Report to Congressional requesters. Defense health 

care: Force health protection and surveillance policy compliance was mixed, but appears better for 

recent deployments. GAO-05-120. Washington, DC: Government Accountability Office. 

http://www.gao.gov/new.items/d05120.pdf (accessed March 19, 2007).

GAO. 2006a. Military disability evaluation: Ensuring consistent and timely outcomes for reserve and 

active duty members. Testimony before the Subcommittee on Military Personnel, Committee on 

Armed Services, House of Representatives. GAO-06-561T. Washington, DC: United States Government Accountability Office. http://www.gao.gov/new.items/d06561t.pdf (accessed February 28, 

2007). 

GAO. 2006b. VA and DOD health care: Efforts to provide seamless transition of care for OEF and OIF 

servicemembers and veterans. GAO-06-794R. Washington, DC: United States Government Accountability Office. http://www.gao.gov/htext/d06794r.html (accessed July 9, 2007). 

Gilchrist, H. L. 1928. A comparative study of World War casualties from gas and other weapons. Washington, DC: U.S. Government Printing Office. 

Harris, R., and J. Paxman. 1982. A higher form of killing: The secret story of chemical and biological 

warfare. New York: Hill and Wang. 

Harris, S. H. 1994. Factories of death: Japanese biological warfare, 1932-45, and the American coverup. New York: Routledge. 

IOM (Institution of Medicine). 1993. Veterans at risk: The health effects of mustard gas and lewisite. 

Washington, DC: National Academy Press. 

Joy, R. J. T. 1997. Historical aspects of medical defense against chemical warfare. In Textbook of military 

medicine: Medical aspects of chemical and biological warfare, edited by F. R. Sidell, E. T. Takafuji, 

and D. R. Franz. Washington, DC: Surgeon General United States Army. Pp. 87-109. 

http://www.bordeninstitute.army.mil/published_volumes/chemBio/Ch3.pdf (accessed June 29, 2007). 

President’s Task Force to Improve Health Care Delivery for our Nation’s Veterans. 2003. A brief guide to 

the final report. Arlington, VA: President’s Task Force to Improve Health Care Delivery for our Nation’s Veterans. http://veterans.house.gov/spotlight/ShortTaskForceReport.pdf (accessed July 11, 

2007). 

Reminick, G. 2001. Nightmare in Bari. The World War II Liberty Ship poison gas disaster and cover-up. 

El Cerrito, CA: Glencannon Press. 

Shoham, D. 1998. Chemical and biological weapons in Egypt. The Nonproliferation Review (SpringSummer):48-58. http://cns.miis.edu/pubs/npr/vol05/53/shoham53.pdf (accessed March 20, 2007). 

Sidell, F. R., J. S. Urbanetti, W. J. Smith, and C. G. Hurst. 1997. Vesicants. In Textbook of military medicine: Medical aspects of chemical and biological warfare, edited by F. R. Sidell, E. T. Takafuji, and 

D. R. Franz. Washington, DC: Surgeon General United States Army. Pp. 197-228. 

http://www.bordeninstitute.army.mil/published_volumes/chemBio/Ch7.pdf (accessed July 2, 2007). 

Tucker, J. B. 2006. War of nerves. Chemical warfare from World War I to Al-Qaeda. New York: Pantheon Books. 

VA (Department of Veterans Affairs). 1992a. Claims based on chronic effects of exposure to mustard gas. 

Proposed rule. January 15, 1992. Federal Register 57(10):1699-1700. 

VA. 1992b. Claims based on chronic effects of exposure to mustard gas. Final rule. Federal Register

57(148):33875-33877. 

VA. 1994a. Claims based on chronic effects of exposure to vesicant agents. Proposed rule. Federal Register 59(15):3532-3534. 

VA. 1994b. Claims based on chronic effects of exposure to mustard gas or lewisite. Final rule. Federal 

Register 59(159):42497-42500. 
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VA. 2002. Possible occupational health exposures of veterans involved in Project SHAD tests. Veterans 

Health Administration and Under Secretary for Health information letter. Il-10-2002-016. Washington, DC: Department of Veterans Affairs. http://www1.va.gov/shad/docs/IL_10-2002-016.pdf (accessed February 28, 2007). 

VA. 2003. Veterans Health Initiative: Health effects from chemical, biological, and radiological weapons. Washington, DC: Department of Veterans Affairs. http://www1.va.gov/vhi/docs/CBR_www.pdf 

(accessed March 19, 2007). 

VA. 2005. Health effects among veterans exposed to mustard and lewisite chemical warfare agents. Under Secretary for Health information letter, IL 10-2005-004. 

http://www1.va.gov/environagents/docs/USHInfoLetterIL10-2005-004_March_14_2005.pdf (accessed July 2, 2007). 

VA. 2006a. Potential health effects among veterans involved in military chemical warfare agent experiments conducted from 1955 to 1975. Under Secretary for Health information letter, Il 10-2006-010. 

Washington, DC: Department of Veterans Affairs. 

http://www1.va.gov/environagents/docs/USHInfoLetterIL10-2006-010.pdf (accessed February 28, 

2007). 

VA. 2006b. Chemical warfare agent experiments among U.S. service members. 

http://www.va.gov/EnvironAgents/docs/Fact_Sheet_Edgewoodaberdeen_Chemical_Agent_Experiments_Information_paper.pdf (accessed March 20, 2007). 

CASE STUDY 7: GULF WAR PRESUMPTIONS 

Introduction 

This case study examines the legislative and scientific history for Gulf War presumptions. 

This analysis illustrates the challenges and implications of establishing service-connected presumptions for health outcomes when exposure data are limited (or unavailable) but environmental agents present in theater may pose potential health concerns. The case study also addresses a syndrome defined by symptoms, rather than a specific illness linked to a specific 

etiological factor. 

Background 

Although the duration of combat engagement during the first Gulf War was measured only in 

days, it also included a protracted aerial campaign of many weeks and ultimately involved nearly 

700,000 U.S. troops (IOM, 2006b, p. 11). As a result, while the first Gulf War’s time span may 

have been relatively brief, its scope and scale affected many U.S. military personnel. It also created a long list of health concerns in Gulf War veterans who believed they had been exposed to 

biological and chemical agents during Gulf War service that might have adversely affected their 

health. Veterans from the first Gulf War returned home with a constellation of symptoms that 

were initially termed Gulf War syndrome. However, the diversity of symptoms did not cluster 

into a specific group such that it could be defined as a syndrome and has been modified to the 

descriptions of “unexplained illnesses” or “undiagnosed illnesses.” 

The Gulf War presumption process was heavily influenced by the Agent Orange presumption 

history. The Agent Orange Act of 1991 (Public Law 102-4. 102d Cong., 1st Sess.) represented 

the culmination of repeated efforts to create a comprehensive presumption decision-making 

process. This process proposed an integration of the VA policy response to complaints of veterans being made to Congress and to a scientific evidence review performed by the IOM. In many 

ways, the Agent Orange Act of 1991 (Public Law 102-4. 102d Cong., 1st Sess.) was the example 
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for the Gulf War legislation which provided the guidance for a review process examining agents 

of interest in light of Gulf War illnesses. The history of the government’s sluggish response to 

radiation and herbicide exposure concerns played a role in the establishment of Congress’ Gulf 

War presumptions for undiagnosed illnesses and chronic multisymptom illness. Following Congress’ experiences with establishing radiation and Agent Orange legislation in the 1980s and 

early 1990s, Congress did not want to wait to lend aid to the first Gulf War veterans. 

A Review of the Scientific and Legislative Landmarks Related 

to Gulf War Presumptions 

Almost immediately following the first Gulf War, veterans began to complain of numerous 

adverse health effects that they attributed to service in the Persian Gulf. It became evident that 

the Persian Gulf veterans’ health complaints differed significantly from those voiced by Vietnam 

veterans. Vietnam veterans ascribed many of their medical woes to one agent—Agent Orange—

and claimed that the numerous well-defined illnesses from which they suffered, ranging from 

skin and liver illnesses to a variety of cancers, could be attributed to exposure to Agent Orange. 

Persian Gulf War veterans, on the other hand, appeared to be suffering from syndromes and 

symptoms rather than established illnesses. They were concerned about exposures to a host of 

toxic environmental agents that were present during the Persian Gulf War. VA claimed that 

many of the exposures experienced by Persian Gulf War veterans were no different from those 

experienced by civilians in the United States and for the great majority of veterans, the magnitude of the exposures was small and limited to a short period of time (Brown, 2005). 

Congress responded by authorizing VA to provide health-care services on a priority basis 

(Priority VA Health Care for Persian Gulf Veterans. 1993. Public Law 103-210. 103d Cong., 1st 

Sess.). An effort to gather data about the nature of the illnesses and symptoms that veterans 

claimed to have, as well as to conduct research on environmental exposures that occurred during 

the war was started. In 1994, Congress passed the Veterans’ Benefits Improvements Act of 1994 

(Public Law 103-446. 103d Cong., 2d Sess., codified as 38 USC § 1117) which authorized VA to 

compensate veterans for certain chronic disabilities and illnesses that cannot be attributed to any 

known clinical diagnosis. Originally, these adverse health effects had to manifest within 2 years 

of service in the Persian Gulf for a veteran to receive compensation. This presumptive interval 

has, however, been extended a number of times, most recently in December 2006, so that compensation is provided to the veteran if the disability manifests itself by December 31, 2011 (VA, 

2006). 

In 1998, Congress passed the Persian Gulf War Veterans Act of 1998 (Public Law 105-277, 

105th Cong., 2d Sess., codified, in part, as Presumptions of Service Connection for Illnesses Associated with Service in the Persian Gulf during the Persian Gulf War. 2006. 38 USC § 1118) 

and the Veterans Programs Enhancement Act of 1998 (Public Law 105-368. 105th Cong., 2d 

Sess.). These acts, which used the Vietnam War Agent Orange legislation as a starting point, set 

up procedures for establishing presumptions of service connection for diseases incurred by Gulf 

War Veterans. As in the Agent Orange legislation, “a positive association” is required between 

an environmental exposure associated with service in the Persian Gulf War and “the occurrence 

of a diagnosed or undiagnosed illness in humans or animals” (Presumptions of Service Connection for Illnesses Associated with Service in the Persian Gulf During the Persian Gulf War. 2006. 

38 USC § 1118[b][1][B][ii]). In addition, the Gulf War Act stated that an association “shall be 

considered to be positive . . . if the credible evidence for the association is equal to or outweighs 

the credible evidence against the association” (Presumptions of Service Connection for Illnesses 
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APPENDIX I I-79 

Associated with Service in the Persian Gulf During the Persian Gulf War. 2006. 38 USC § 1118 

[b][3]). The same scientific review process was established as for Agent Orange; an agreement 

was made with the NAS to set up a committee that was charged with answering the same three 

questions previously asked with regard to Agent Orange (Persian Gulf War Veterans Act of 

1998. Public Law 105-277. 105th Cong., 2d Sess. § 1603). However, as discussed later in this 

case study, the charges for the Gulf War committees were not identical and addressed many different potential etiological agents of interest. As with the Agent Orange reports, each IOM committee was to provide a report to VA, and the VA Secretary was to determine whether a presumption should be made for specific health outcomes and then publish the decision(s) in the 

Federal Register. IOM has issued several volumes of Gulf War reports (IOM, 2000, 2003, 2005, 

2006b, 2007). VA published a Federal Register notice (VA, 2001a) following receipt of IOM’s 

report for Gulf War Volume 1 (IOM, 2000). However, Federal Register notices and determination of presumptions for the Gulf War have yet to be published by VA following the receipt of 

the remaining IOM Gulf War reports. 

In 2001, the VA Secretary “determined that there [was] no basis to establish a presumption of 

service connection for any disease based on service in the Persian Gulf during the Persian Gulf 

War” (VA, 2001b, p. 35702). This determination was based, in part, on review of the first Gulf 

War and Health report (IOM, 2000) which reviewed the evidence regarding associations between 

health outcomes and exposures experienced during the Persian Gulf War, including depleted 

uranium, pyridostigmine bromide (PB), sarin, and vaccines (anthrax, botulinum toxoid, and multiple vaccines) (IOM, 2000). The VA Secretary determined that “neither the acute and transient 

symptoms resulting from possible sarin exposure, nor any long-term health consequences associated with possible sarin exposure, warrant a presumption of service-connection” (VA, 2001b, p. 

35708). For PB, the VA Secretary concluded that “these acute effects [of PB, as reported in 

IOM, 2000] were not in the nature of an illness within the contemplation of the governing statute” and that “such effects failed to meet the standards for establishment of presumptive service 

connection based on exposure to PB” (VA, 2001b, p. 35708). Regarding long-term adverse 

health effects based on exposure to PB, the VA Secretary determined that “the credible evidence 

against an association between long-term adverse health effects and PB outweighs the credible 

evidence for such an association” (VA, 2001b, p. 35708). A similar conclusion was reached for 

exposure to vaccines and transient acute local and systemic effects. The VA Secretary concluded 

that “such [acute] effects failed to meet the standards for establishment of presumptive service 

connection based on anthrax vaccination, botulinum toxoid vaccination or multiple vaccinations” 

(VA, 2001b, p. 35710). 

The Presumption for “Undiagnosed Illnesses” in 1995 

The initial presumptive legislation for the Gulf War was in response to numerous symptoms 

experienced by returning Gulf War veterans. The symptoms were not related to a single or even 

a few organ systems and were not easily explained by a unifying mechanism, such as being attributed to an infectious cause or the result of drinking tainted water, for example. The legislation 

arose primarily from the concerns expressed by veterans and without the interaction between VA 

and IOM that occurred previous to the passage of the Agent Orange legislation.

The list of “signs or symptoms which may be manifestations of undiagnosed illness or medically unexplained chronic multisymptom illness” that were considered as associated with undiagnosed illnesses during the Persian Gulf War and that were ultimately presumptively linked by 

Congress to service in the Persian Gulf via legislation in 1995 “include, but are not limited to 
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I-80 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

• Fatigue 

• Signs or symptoms involving skin 

• Headache 

• Muscle pain 

• Joint pain 

• Neurologic signs or symptoms 

• Neuropsychological signs or symptoms 

• Signs or symptoms involving the respiratory system (upper or lower) 

• Sleep disturbances 

• Gastrointestinal signs or symptoms 

• Cardiovascular signs or symptoms 

• Abnormal weight loss 

• Menstrual disorders” (VA, 1995, pp. 6665-6666) 

The Presumption of Chronic Multisymptom Illness in 2001 

In 2001, chronic multisymptom illness was added by Congress to the unexplained illness 

provision for presumption of disability acquired during Gulf War service (Veterans Education 

and Benefits Expansion Act of 2001. Public Law 107-103. 107th Cong., 1st Sess.). Several additional health outcomes were included under this grouping. The list of symptom complexes that 

were considered as associated with chronic multisymptom illness included: chronic fatigue syndrome, fibromyalgia, and irritable bowel syndrome. Although some of these symptoms overlap 

with the list included in the undiagnosed illness provision, these symptoms were not specifically 

designated under one or the other grouping but may exist under either. This new terminology 

added confusion to an already nonspecific nomenclature for the symptoms or conditions qualifying for presumptive coverage of Gulf War veterans. 

Additional Legislative Actions for Gulf War Veterans 

Between the time of the initial Gulf War presumption legislation of 1995 (VA, 1995) and the 

addition of the chronic multisymptom illness provision in 2001 (Veterans Education and Benefits 

Expansion Act of 2001. Public Law 107-103. 107th Cong., 1st Sess.), there were several other 

legislative actions to address Gulf War veterans’ needs. These legislative actions did not enlarge 

the domain of diseases or symptoms being considered as presumptively linked to Gulf War service, but rather addressed administrative aspects of the existing legislation, such as the timeframe 

of the presumptive period. Extension of the presumptive time period has occurred several times. 

Originally, it was required that a disease manifest itself within 2 years following military service. 

At the close of 2001, the presumptive time period was extended to 5 years following military 

service (VA, 2001a). In December 2006, the presumptive time period was again extended so that 

compensation would be provided if the disability manifested by December 31, 2011 (VA, 2006). 

VA stated in this Federal Register notice that “this amendment is necessary to extend the presumptive period for qualifying chronic disabilities resulting from undiagnosed illnesses that must 

become manifest to a compensable degree in order that entitlement for compensation be established. The intended effect of this amendment is to provide consistency in VA adjudication policy and preserve certain rights afforded to Persian Gulf War veterans and ensure fairness for current and future Persian Gulf War veterans” (VA, 2006, p. 75670). VA also stated in this Federal 
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APPENDIX I I-81 

Register notice that it had extended the presumptive period for undiagnosed illnesses from December 31, 2001, to December 31, 2006, “based upon ongoing research that would require review by the Secretary” (VA, 2006, p. 75670). 

Exposures of Concern 

A number of candidate toxicants were mentioned as potential causes for undiagnosed illnesses in the initial legislation of 1994-1995 (Veterans’ Benefits Improvements Act of 1994. 

Public Law 103-446. 103d Cong., 2d Sess. § 102, codified as 38 USC § 1117). Congress found 

that U.S. troops in the Gulf War were exposed to “fumes and smoke from military operations, oil 

well fires, diesel exhaust, paints, pesticides, depleted uranium, infectious agents, investigational 

drugs and vaccines, and indigenous diseases, and were also given multiple immunizations” (Veterans’ Benefits Improvements Act of 1994. Public Law 103-446. 103d Cong., 2d Sess. § 102). 

However, these nominated toxicants were not well linked to specific types of symptoms nor was 

a retrospective exposure assessment performed to estimate exposure intensities or likelihood of 

exposure potential. Instead several descriptive scenarios were suggested as plausibly leading to 

opportunities for exposure, at least to some Service members. 

In the Persian Gulf War Veterans Act of 1998 (Public Law 105-277. 105th Cong., 2d Sess. § 

1602), diseases related to a presumed exposure to “a biological, chemical, or other toxic agent, 

environmental or wartime hazard, or preventive medicine or vaccine” were added to the description of illnesses presumed to be service connected. This change in the legislative focus moved 

the presumption from one based upon an outcome (i.e., unexplained illnesses) to one based on an 

exposure agent (e.g., depleted uranium or PB). This important change resulted in adding potential adverse health outcomes to the presumptions list that might be linked to the action or toxicity 

of the now “presumed” agent of exposure. 

This change in focus was likely influenced by maturation of hypotheses regarding environmental exposures in the Persian Gulf that had only been alluded to in the first presumptive legislation of 1995 (VA, 1995). In addition, the Presidential Advisory Committee on Gulf War Veterans’ Illnesses commissioned by President Clinton issued their report in December of 1996 

regarding the nature and risk factors for Gulf War illness. While not specifically focused on presumptions of service connection, the report did raise inadequately characterized environmental 

exposures and poor troop tracking as areas in need of improvement to avoid future postconflict 

health concerns (Presidential Advisory Committee on Gulf War Veterans’ Illnesses, 1996). The 

controversies about such hazards had motivated VA to commission reports by IOM on possible 

health effects associated with exposures during the Persian Gulf War (IOM, 1999, 2000, 2003, 

2005, 2006b, 2007). 

IOM Gulf War Reports 

IOM reports were initially requested by VA that focused on the group of toxicants that had 

emerged as possible candidates for causing unexplained illnesses (IOM, 2000, 2003, 2005). Review of the first grouping of toxicants began in late 1998, and a report was published in 2000 

(IOM, 2000). This first report reviewed depleted uranium (a modestly radioactive heavy metal 

used in projectiles and armament), PB (a chemical antidote for cholinergic “nerve” agent weapons), sarin (a chemical nerve agent with cholinergic properties), and vaccines, including that for 

anthrax (IOM, 2000). 
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A second Gulf War report by IOM was completed in 2003 that reviewed insecticides and 

solvents used by U.S. troops during the Gulf War. The committee was charged by VA “to assess 

the scientific evidence regarding long-term health effects associated with exposure to specific 

agents that were potentially present during the Gulf War” (IOM, 2003, p. 2). 

The third major Gulf War review by IOM included fuels, combustion products, and propellants as its focus (IOM, 2005). Although driven by a toxicological literature review, it appears 

that this study was also commissioned by VA to think more broadly about exposures and to inform VA about illnesses (among veterans) that might not be fully appreciated. This committee 

was to look not only at specific hazards that may have been encountered in the Persian Gulf, but 

also asked to comment on “the increased risk of illness among people exposed to the putative 

agents during service in the Persian Gulf” (IOM, 2005, p. 2). This committee’s report was issued 

in 2005 and was also hoped to offer some prevention strategies for troops deployed to Iraq for 

the current conflict. 

A fourth Gulf War review by IOM, which was commissioned by VA, did not focus on toxicants but rather was directed at determining what peer-reviewed medical literature, taken together, can tell us about the health status of Gulf War veterans (IOM, 2006b). In this instance, 

VA was interested in an integrated review and asked for the committee’s insight about deployment-related illnesses that might not be fully appreciated. Their report was issued in 2006. 

A fifth Gulf War review by IOM was commissioned by VA in 2004 to examine the infectious agent exposures that may have contributed to illness in the deployed Gulf War cohort. The 

report of the committee was issued in 2007 (IOM, 2007) and identified nine pathogenic agents 

endemic to the Gulf War theater and capable of causing illnesses with long-term adverse health 

effects. These agents were listed regardless of whether or not their related illnesses were acutely 

diagnosed in Gulf War troops. Further refinement of this list would require that the likelihood of 

infection with a candidate agent during deployment be equal to or greater than the likelihood of 

infection when not deployed. 

Interspersed among these major review activities by IOM were several smaller projects 

commissioned by VA that addressed more limited topics, such as updated literature reviews for 

sarin (IOM, 2004) or a review for a specific disease or complaint (IOM, 2006a,c). Two additional studies are in progress—one dealing with PTSD and one with deployment-related stress. 

Work continues at IOM to provide VA with the most up-to-date research and published studies 

related to the Gulf War. 

A summary of the statements of task as well as the conclusions from each of the IOM Gulf 

War reports can be found in Appendix H. 

The VA Response to IOM Gulf War Reports 

Typically, VA responds to IOM reports with policy decisions that it publishes in the Federal 

Register. To date, only one Federal Register notice (VA, 2001a) has been published by VA following receipt of an IOM Gulf War report (IOM, 2000). Federal Register notices have not yet 

been published in response to IOM Gulf War reports, volumes 2-5 (IOM, 2003, 2005, 2006b, 

2007). To date, presumptions have not been granted by VA for Persian Gulf veterans pursuant to 

38 USC § 1118 (Compensation for Service-Connected Disability or Death. 2006. 38 USC § 

1118), although the machinery for establishing presumptions is in place. In February 2006, the 

VA Secretary wrote to leaders of the House and Senate Veterans’ Affairs Committees advising 

them that the evidence currently available did not warrant the establishment of Persian Gulf presumptions, and that VA would publish notices of its decision in the Federal Register “explaining 
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APPENDIX I I-83 

the basis for that determination” (Nicholson, 2006a,b,c,d). As of the writing of this report, no 

statement appears in the Federal Register, although such statements are required to be filed 

within 60 days of the receipt of an IOM report (Persian Gulf War Veterans Act of 1998. Public 

Law 105-277, 105th Cong., 2d Sess. § 1602). Although the presumptive service-connection 

mechanism has not been a major pathway for service connection of Persian Gulf veterans, it has 

been reported that a comparatively large percentage of Persian Gulf veterans have been able to 

collect compensation through the direct service-connection route (as stated by Pamperin, 2006). 

As of now, the Persian Gulf statutes would govern any presumptions dealing with current 

service in Iraq or any other area in the Persian Gulf. (As defined in 38 USC § 101, the term “Persian Gulf War” means “ the period beginning on August 2, 1990, and ending on the date thereafter prescribed by Presidential proclamation or by law” [Definitions. 2006. 38 USC § 101(33)]). 

Cost Implications of Gulf War Presumptions 

No cost estimates were made available by VA or published in the Federal Register for this 

analysis. However, the long-term cost implications of Gulf War legislation are likely to continue 

to rise as veterans of contemporary conflicts in the Persian Gulf continue to return from Iraq and 

Afghanistan. During the Committee’s first open session meeting, Mr. Tom Pamperin, a VA representative, stated that 3,259 veterans had been presumptively service-connected for undiagnosed 

illnesses and that these individuals had typically been rated at 10 percent (Pamperin, 2006). Mr. 

Pamperin stated that most of the Gulf War veterans who have secured service connection did so 

via the direct service-connection route (as stated during Pamperin, 2006). In VA’s Federal Register notice that extended the presumptive period for compensation of Gulf War veterans to 

2011, VA stated that “VA continues to receive claims for qualifying chronic disabilities. In 2005 

for example, VA received 2,241 new claims with diagnostic codes that would be affected by this 

final rule, and we continue to receive such claims during 2006” (VA, 2006, p. 75671). 

Lessons Learned 

This case study offers several lessons that are relevant when considering strategies for improving the current presumptive disability decision-making process. These lessons relate to the 

role of Congress in issuing Gulf War legislation and establishing presumptions, VA in responding to the receipt of IOM reports, and IOM in evaluating and presenting the body of evidence 

relating to potential Gulf War exposures. In addition, the case study makes clear that closer coordination and collaboration between the DoD and VA are needed with regard to health monitoring and tracking of military personnel and veterans as well as exposure assessment efforts. 

The principal participants in the current framework of the presumptive disability decisionmaking process include veterans and VSOs, VA, Congress, and IOM. Although each of these 

entities is motivated to assure the well-being of the veteran, there is also a need to balance the 

granting of benefits against resource constraints. Comparative fairness needs to be maintained by 

Congress and VA in its handling of each group of veterans. The current presumptive framework 

for Gulf War illnesses appears to have been strongly driven by time pressures on Congress and 

VA to respond to the concerns of Gulf War veterans, and to do so more rapidly than took place 

with radiation and Agent Orange. When a presumption of service connection for a disease or 

health condition is legislated by Congress (e.g., unexplained illnesses) rather than through the 

accrual and evaluation of scientific evidence, there is the potential to diminish the credibility of a 

presumptive decision-making process that is evidence based. A misperception then may arise 

that the decision was evidence based, even though it was actually driven by other considerations. 
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I-84 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Congress 

 In the politically charged and time-pressured context of responding to Gulf War veterans in 

the 1990s, it was clear that Congress believed that action needed to be taken quickly. However, 

the response was not grounded in specific diagnostic tests or in a validated pattern of symptoms 

that could be linked to exposures in the Gulf War. Rather, a presumption was made for the entity, 

undiagnosed illnesses, that was based largely around features of numerous individual cases. The 

affected veterans, many previously robust in their health, experienced inexplicable symptomatology and deterioration of health. Thus, a decision was made by Congress to endorse the veteran’s 

self-reported symptom complaints as sufficient evidence for documenting the occurrence of a 

Gulf War service-connected illness. 

In establishing undiagnosed illnesses and chronic multisymptom illness, Congress defined 

medical conditions and health outcomes for the presumptive disability decision-making process 

for the first time. 

There seems to have been little application of exposure assessment in determining eligibility 

for a service-connected Gulf War condition. This approach to handling affected veterans was 

largely authored outside of VA by Congress and then handed to VA to administer. The decision 

to not consider exposure history in determining eligibility for a presumption is similar to the exposure presumption made for Agent Orange, meaning if a Service member set foot in the Vietnam theater they were considered “exposed,” and thus any illnesses linked to that exposure can 

be presumed to be service connected. In the example of the Gulf War, Congress directed VA to 

apply an approach with high sensitivity (i.e., toward including all possible claims, but thereby 

risking a high false positive rate). 

Congress used two legislative approaches for veterans of the Gulf War in the absence of exposure data or a unifying case definition of Gulf War illness. The 1995 decision (VA, 1995) to 

term a list of conditions as presumptive signs or symptoms clustered under the rubric of undiagnosed illnesses permitted medical care and other benefits to be provided to affected veterans by 

VA. The second approach departed from the initial symptom-based presumption model and in 

the 1998 Act (Persian Gulf War Veterans Act of 1998. Public Law 105-277. 105th Cong., 2d 

Sess. § 1602) mandated any additional conditions or symptoms as presumptive that could be 

linked to “a biological, chemical, or other toxic agent, environmental or wartime hazard, or preventive medicine or vaccine.” This decision added to the menu of potential illnesses that could 

be considered presumptively linked to service in the Gulf that had not yet been so deemed. 

VA 

The Gulf War example makes clear the critical need for improved collaboration and cooperation between DoD and VA with respect to health monitoring and tracking of military personnel 

and veterans as well as improved exposure assessment efforts. Attempts at retrospective reconstruction of troop exposures during military service have identified the gaps in exposure information available to inform decisions about veterans’ health. Indeed, lack of these data has been 

noted by many IOM committees and by stakeholders grappling with service-connected disability 

determinations (IOM, 2000, 2003, 2005). There are many barriers, both historical and contemporary, to eliminating such information gaps through research and data collection. Certainly, the 

most obvious is the potential conflict of mission in collecting exposure data during wartime deployments. On the other hand, since the Gulf War began and perhaps taking into consideration 

the Agent Orange experience, there has been increased understanding of the need for exposure 
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APPENDIX I I-85 

assessment as an element of force health protection and readiness (DoD, 1997, 2006). The 

Committee fully understands that exposure assessment and troop tracking are challenging in a 

fixed environment; the Committee also recognizes the considerable efforts that both DoD and 

VA will need to make to improve exposure assessment and troop tracking during the chaotic and 

immediately hazardous environment of a wartime deployment. Nevertheless, talented professionals with technical knowledge, trained in scientific disciplines including engineering, toxicology, industrial hygiene, and epidemiology, regularly perform such assessments in other complex 

work environments and can be more fully engaged in troop exposure assessment. Indeed, substantial effort is needed before deployment to anticipate and evaluate potential hazards and the 

fielding of monitoring equipment and control measures that will be needed. The plans of DoD to 

develop and link health and environmental surveillance data will be an important element in attaining a longitudinal database for such information on every Service member. Applied research 

in the areas of large surveillance database development and real-time exposure assessment for 

candidate toxicants is to be encouraged. The commitment of DoD and VA to work more closely 

in harmonizing the medical records of all Service members to allow a truly seamless transition 

from DoD to VA health care and follow-up is strongly endorsed by the Committee and should be 

well resourced by the leadership of both DoD and VA. 

VA has now received several IOM reports; however, Federal Register notices have not been 

published to explain how VA has evaluated the IOM reports and if VA will or will not establish 

presumptive connections as a result of the IOM reports. 

VA continues to extend the presumptive time period for undiagnosed illnesses, and will 

likely continue to do so because of the current conflict in Iraq. 

VA had an apparently limited role in the initial approach to Gulf War presumptions; its role 

primarily consisted of implementing a policy assigned by Congress in the absence of scientific 

evidence, a contrast to VA’s actions in subsequent Gulf War-related presumptive decisionmaking actions. In latter examples, VA has asked IOM to examine adverse health effects rather 

than the existing “undiagnosed illness” or “chronic diseases” provisions established by Congress 

with relation to Gulf War service. These reviews have been the basis for subsequent decisionmaking by VA, which has not yet established any presumptions for the Gulf War. 

The Committee was provided with an example of how VA was considering exposure potential to Gulf War veterans in a presentation made by a VA official. The VA official discussed 

VA’s consideration of an IOM review regarding leukemia and its links to benzene exposure. VA 

took the position that leukemia developing in a Gulf War veteran was not presumptively service 

connected. VA explained to the Committee that because benzene is widely encountered in the 

environment generally, such a presumption of exposure occurring exclusively or primarily in the 

Persian Gulf could not be made. VA also pointed out that the individual exposure opportunity of 

the veteran during military service, which could be examined for service-connected benefits on a 

case-by-case basis, was a reasonable remedy for the veteran for whom exposure during Gulf War 

service and leukemia development were linked. This would occur via direct service-connection 

methods. 

IOM 

The Committee agrees with the inclusion of a category for evidence sufficient to infer causality, “Sufficient Evidence of a Causal Relationship,” in IOM evaluations for the Gulf War and 

Health series. 
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I-86 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

The lack of exposure information for Gulf War veterans was emphasized in the Gulf War and 

Health series by IOM (2000, 2003, 2005). The inclusion of a specific substance, such as benzene, 

on a list of candidate toxicants that a veteran may have encountered in the Persian Gulf was 

based on one of the following qualitative assessments—a listing of solvents potentially used or 

obtained locally or known constituents of a product used—and not necessarily on actual supply 

lists or industrial hygiene measurements. Indeed, for just this reason, the vast majority of evidence considered in the IOM Gulf War reports does not come from studies of veterans but of 

other exposed cohorts described in the published scientific literature (IOM, 2000, 2003, 2005). 

This lack of exposure and health information from studies on veterans points to the need for exposure estimation and surveillance for health risks. 

References 

Brown, M. 2005. The role of science in Department of Veterans Affairs disability compensation policies 

for environmental and occupational illnesses and injuries. Paper presented at the first meeting of the 

IOM’s Committee on the Evaluation of the Presumptive Disability Decision-Making Process for Veterans, Washington, DC. 

DoD (Department of Defense). 1997. Implementation and application of joint medical surveillance for 

deployments. Instruction number 6490.3. Washington, DC: Department of Defense. 

DoD. 2006. Deployment health. Instruction number 6490.03. Washington, DC: Department of Defense. 

IOM (Institute of Medicine). 1999. Gulf War veterans: Measuring health. Washington, DC: National 

Academy Press. 

IOM. 2000. Gulf War and health, volume 1: Depleted uranium, pyridostigmine bromide, sarin, vaccines. 

Washington, DC: National Academy Press. 

IOM. 2003. Gulf War and health, volume 2: Insecticides and solvents. Washington, DC: The National 

Academies Press. 

IOM. 2004. Gulf War and health: Updated literature review of sarin. Washington, DC: The National 

Academies Press. 

IOM. 2005. Gulf War and health, volume 3: Fuels, combustion products, and propellants. Washington, 

DC: The National Academies Press. 

IOM. 2006a. Amyotrophic lateral sclerosis in veterans: Review of the scientific literature. Washington, 

DC: The National Academies Press. 

IOM. 2006b. Gulf War and health, volume 4: Health effects of serving in the Gulf War. Washington, DC: 

The National Academies Press. 

IOM. 2006c. Posttraumatic stress disorder: Diagnosis and assessment. Washington, DC: The National 

Academies Press. 

IOM. 2007. Gulf War and health, volume 5: Infectious diseases. Washington, DC: The National Academies Press. 

Nicholson, R. J. 2006a. Letter to Larry E. Craig, Chairman, Committee on Veterans’ Affairs, United 

States Senate. February 24, 2006. 

Nicholson, R. J. 2006b. Letter to Steve Buyer, Chairman, Committee on Veterans’ Affairs, U.S. House of 

Representatives. February 24, 2006. 

Nicholson, R. J. 2006c. Letter to Congressman Lane Evans. February 24, 2006. 

Nicholson, R. J. 2006d. Letter to Senator Daniel K. Akaka. February 24, 2006. 

Pamperin, T. 2006. Presumptions in VA’s disability program—The effect. Paper presented at the first 

meeting of the IOM’s Committee on the Evaluation of the Presumptive Disability Decision-Making 

Process for Veterans, Washington, DC. 

Presidential Advisory Committee on Gulf War Veterans’ Illnesses. 1996. Final report. Washington, DC: 

U.S. Government Printing Office. 
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APPENDIX I I-87 

VA (Department of Veterans Affairs). 1995. Compensation for certain undiagnosed illnesses. Final rule. 

Federal Register 60(23):6660-6666. 

VA. 2001a. Compensation for certain undiagnosed illnesses. Interim rule with requests for comments. 

Federal Register 62(82):23138-23139. 

VA. 2001b. Illnesses not associated with service in the gulf during the Gulf War. Notice. Federal Register

66(130):35702-35710. 

VA. 2006. Extension of the presumptive period for compensation for Gulf War veterans. Interim Final 

Rule. Federal Register 71(242):75669-75672.

CASE STUDY 8: AGENT ORANGE AND PROSTATE CANCER 

PRESUMPTION 

This case study examines the 1996 decision by the VA to establish presumptive service connection for prostate cancer based on herbicide exposure among Vietnam veterans. VA’s presumption followed IOM’s Agent Orange committee’s report which assigned a classification of 

“limited/suggestive evidence” for the association of exposure to Agent Orange and prostate cancer. This case study explores aspects of the development of a presumption for Vietnam veterans. 

It illustrates the challenges and implications of establishing a service connection for a common 

chronic condition when exposure data are unavailable and evidence of association is limited. 

Background Information on Prostate Cancer 

 Prostate cancer is among the most common cancers in men. In fact, it is the second highest 

cause of cancer deaths in U.S. males. Overall prostate cancer age-adjusted death rates for all U.S. 

males are reasonably stable (27.9/100,000 in 2004) (see 

http://seer.cancer.gov/csr/1975_2004/results_merged/topic_mor_trends.pdf). There is a marked 

difference between Caucasians and African Americans—the 2004 death rate for African Americans is more than twice that of Caucasians (62.3 vs. 25.6 per 100,000). Prostate cancer is primarily a disease of older males; the comparable Surveillance, Epidemiology, and End Results data 

for annual death rates from prostate cancer for men over age 65 is 188.7 per 100,000 while the 

rate for men younger than 65 is 1.8 per 100,000 (see 

http://seer.cancer.gov/csr/1975_2004/results_merged/topic_annualrates.pdf). The steep increase 

in age incidence has led the medical community to the conclusion that if a man lives long 

enough, he will develop prostate cancer. The prevalence of prostate cancer in the United States is 

increasing, possibly reflecting earlier diagnosis and better treatment modalities. 

The Need for a Presumption 

The history of the Agent Orange Act of 1991 (Public Law 102-4. 102d Cong., 1st Sess.), establishing a presumption of service connection for diseases associated with herbicide exposure 

during the Vietnam conflict, as well as the procedure of adding additional diseases to this presumption, has been reviewed elsewhere in this report (see Chapter 2, Chapter 4, and Appendix 

D). The need for an exposure presumption for Agent Orange-associated diseases is based in part 

on the difficulty of establishing with certainty the degree of exposure to herbicides among Vietnam veterans (IOM, 1994). The Agent Orange Act eliminates the need for an individual Vietnam 

veteran to provide evidence of herbicide exposure; exposure is presumed for all Vietnam 

veterans. 

Although the need for a presumption is based primarily on the difficulty of establishing exposure, presumptions also address gaps in the evidence for association. An examination of the 
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I-88 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

exact charge to IOM for determining the diseases that are linked to herbicides is instructive. For 

each disease, IOM has been asked to determine, to the extent that available data permit meaningful determinations, 

1. whether a statistical association with herbicide exposure exists, taking into account the 

strength of the scientific evidence and the appropriateness of the statistical and epidemiologic methods used to detect the association; 

2. the increased risk of the disease among those exposed to herbicides during Vietnam service; and 

3. whether there is a plausible biological mechanism or other evidence of a causal relationship between herbicide exposure and the disease. 

Each of the IOM reports that examined herbicides and prostate cancer risk (IOM, 1994, 

1996, 1999, 2001, 2003, 2005) focused almost exclusively on addressing the task described in 

charge 1, and each report included additional discussions of the more limited data to address 

charge 3. Each of the IOM reports address charge 2 but acknowledge the difficulty of providing 

risk estimates because of the lack of exposure data. IOM (2005) notes that 

Although there are data to suggest an association between exposure to the chemicals of 

interest and prostate cancer, the lack of exposure information on Vietnam veterans precludes quantification of any possible increase in their risk. 

 (IOM, 2005, p. 282) 

The presumption of service connection for prostate cancer in Vietnam veterans therefore 

serves more than just to address the gap in evidence of exposure. As the lack of exposure data 

makes quantification of the magnitude of the association between military service and prostate 

cancer difficult, this presumption also implicitly serves to address a gap in the evidence for association between herbicides and prostate cancer among Vietnam veterans. 

Development of the Prostate Cancer Presumption 

As a result of Public Law 102-4 (Agent Orange Act of 1991. Public Law 102-4. 102d Cong., 

1st Sess.), IOM signed an agreement with VA to review and summarize the strength of the scientific evidence concerning the association between herbicide exposure during Vietnam service 

and diseases or conditions that may be associated with this exposure. The first report was issued 

in 1994 (IOM, 1994) and has been updated on a biennial basis since that time. This section reviews the scientific evidence contained in the IOM reports and the legislative events that resulted 

from the conclusions of these reports. It is not meant to be a comprehensive analysis of the entire 

body of scientific literature on this topic, but rather to highlight those events and data that inform 

the conclusions in the reports and changes in legislation. 

Each of the IOM Agent Orange committees’ reviews of prostate cancer has categorized the 

evidence between Agent Orange and prostate cancer as “limited/suggestive evidence of an association.” The IOM Agent Orange committees’ definition of the category “limited/suggestive evidence of an association” includes an example that “at least one high-quality study shows a positive association, but the results of other studies are inconsistent” (IOM, 1994, 1996, 1999, 2001, 

2003, 2005). Each of the IOM Agent Orange committees reviewing prostate cancer found at least 

one study of agricultural workers exposed to herbicides, in particular phenoxy herbicides, that 
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APPENDIX I I-89 

had statistically significant findings and was deemed to be of high quality. Each IOM report also 

cites other studies with some supporting evidence of an association between Agent Orange and 

prostate cancer, although the results of some of the studies are not statistically significant (IOM, 

1994, 1996, 1999, 2001, 2003, 2005). The 1994 IOM report states that 

One large well-done study in farmers showed an increased risk, and subanalyses in this 

study indicate that the increased risk is specifically associated with herbicide exposure 

(OR = 2.2, confidence interval [CI] 1.3-3.8; Morrison et al., 1993). 

 (IOM, 1994, p. 519) 

The IOM Agent Orange committees have tended to rely largely on epidemiologic findings 

for the evidentiary classifications. For example, the Conclusions section of the 2003 report states 

that 

Strength of Evidence from Epidemiologic Studies 

On the basis of its evaluation of the epidemiologic evidence reviewed in this and previous 

Veterans and Agent Orange reports, the committee finds that there is limited or suggestive evidence of an association between exposure to at least one of the chemicals of interest (2,4-D, 2,4,5-T or its contaminant TCDD, picloram, or cacodylic acid) and prostate 

cancer. Although the associations are not large, a number of studies provide evidence 

suggestive of a small increase in morbidity or mortality from prostate cancer. The evidence regarding association is drawn from occupational studies in which subjects were 

exposed to a variety of pesticides, herbicides, and herbicide components and from studies 

of Vietnam veterans. 

(IOM, 2003, p. 323) 

The Extent of Association Reported by the IOM Agent Orange Committees and the 

Presumptive Decision for Prostate Cancer by VA 

The Agent Orange Act of 1991 (Public Law 102-4. 102d Cong., 1st Sess.) specifies two 

categories of diseases that may be presumptively service connected. For one group of specified 

diseases, a presumption is to be given “unless there is affirmative evidence to establish that the 

veteran was not exposed to any such agent during that service” (Agent Orange Act of 1991. Public Law 102-4. 102d Cong., 1st Sess. § 2[a][3]). The act then specifies a second group: “each additional disease (if any) that the VA Secretary determines in regulations prescribed under this 

section warrants a presumption of service connection by reason of having positive association 

with exposure to an herbicide agent” (Agent Orange Act of 1991. Public Law 102-4. 102d 

Cong., 1st Sess. § 2[a][1][B]; emphasis added). Prostate cancer falls into the second group. The 

language in the act defines a positive association as one in which “the credible evidence of the 

association is equal to or outweighs the credible evidence against the association” (Agent Orange 

Act of 1991. Public Law 102-4. 102d Cong., 1st Sess., § 2[b][3]). Each of the IOM Agent Orange committees was charged with determining 

1. whether a statistical association with herbicide exposure exists, taking into account 

the strength of the scientific evidence and the appropriateness of the statistical and 

epidemiologic methods used to detect the association; 

2. the increased risk of the disease among those exposed to herbicides during Vietnam 

service; and 
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3. whether there is a plausible biological mechanism or other evidence of a causal relationship between herbicide exposure and the disease. 

In 2007, the Committee has no way to assess how the congressional language (“equal to 

or outweighs”) and the three points of the charge to the IOM Agent Orange committees were 

viewed by VA and the IOM Agent Orange committees. We could not specifically determine how 

these points were considered by the 1994 IOM Agent Orange committee, and the subsequent 

committees, in their deliberations and their design of the evidence categories chosen by the 1994 

committee. We could also not judge the rationale for VA’s translation of the Agent Orange 

committee’s category of “limited/suggestive” and its evaluation of biological plausibility in response to charge 3 into a 1996 presumptive decision for prostate cancer based upon the congressional language of “equal to or outweighs.” 

In 1994, after review of the first IOM Agent Orange report (IOM, 1994), the VA Secretary determined that “the credible evidence against an association between prostate cancer and 

herbicide exposure outweighs the credible evidence for such an association, and he has determined that a positive association does not exist” (VA, 1994, p. 342). At this time, no presumption of service connection based on exposure to herbicides used in the Republic of Vietnam during the Vietnam era was issued for prostate cancer. Two years later, after the release of the 

second IOM Agent Orange report (IOM, 1996), the VA Secretary determined that, although 

prostate cancer remained in the “limited/suggestive” category of evidence, there was “a positive 

association between herbicide exposure and prostate cancer” (VA, 1996c, p. 41369). VA’s determination was based, in part, on the review of several new occupational studies and veteran 

studies as reported in the 1996 IOM report (IOM, 1996) and presumptive service connection for 

prostate cancer was established (VA, 1996d). 

Biological Plausibility 

The relationship between prostate cancer and endocrine hormones has long been posited, as 

having the “endocrine-disruptive” effects of dioxins. This hormonal hypothesis implies toxicological mechanisms that might contribute to understanding the plausibility of a causal association. The lack of integration with epidemiological evidence of animal toxicology and dose issues 

related to biological plausibility to make an overall conclusion regarding the causal evidence for 

effect distinguishes the IOM approach from those of other national and international agencies 

considering the causal relationship between dioxins and cancer. 

It is usual in assessing the evidence of a causal relationship between an environmental agent 

and cancer to evaluate its biological plausibility. For example, issues related to potential mechanisms of carcinogenesis are prominently discussed in reviews of possible adverse health consequences of dioxins by the International Agency for Research on Cancer (IARC, 1997), the National Toxicology Program (NTP, 2006), the Agency for Toxic Substances and Disease Registry 

(ATSDR, 1998), the U.S. Environmental Protection Agency (EPA, 2003), and the NAS (NRC, 

2006a). The integration of basic mechanistic considerations, experimentation in laboratory animals, and findings in exposed humans are central to the weight-of-evidence approaches used by 

these organizations in considering the potential consequences of environmental agents. National 

Academy committees using this holistic process include those responsible for the various BEIR 

reports (NRC, 1972, 1979, 1980, 1988, 1990, 1998, 1999b, 2006b) and such documents as Arsenic in Drinking Water (NRC, 1999a). 
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APPENDIX I I-91 

As previously stated, the congressional language of “[w]hether there exists a plausible biological mechanism or other evidence of a causal relationship between herbicide exposure and the 

disease” directs the review of the issue of biological plausibility for each disease evaluated 

(Agent Orange Act of 1991. Public Law 102-4. 102d Cong., 1st Sess. § 3[d][C]). The first IOM 

Agent Orange committee noted the paucity of data on chlorophenoxy herbicides and most of its 

emphasis was on dioxin in its discussions of biological plausibility. The first IOM Agent Orange 

committee summarized their review of the carcinogenicity data as follows: 

TCDD has been shown to have a wide range of effects in laboratory animals on growth 

regulation, hormone systems, and other factors associated with the regulation of activities 

in normal cells. In addition, TCDD has been shown to cause cancer in laboratory animals 

at a variety of sites. If TCDD has similar effects on cell regulation in humans, it is plausible that it could have an effect on human cancer incidence. 

 (IOM, 1994, pp. 521-522) 

This conclusion that TCDD is a plausible carcinogen was subsequently supported by IARC 

(IARC, 1997). It should be noted that the epidemiologic data used by the IOM Agent Orange 

committees to categorize prostate cancer as “limited/suggestive” was due to the evaluation of a 

study of agricultural workers using phenoxy herbicides contaminated with dioxins. It could be 

hypothesized that phenoxy herbicides, irrespective of contamination with dioxins, may cause 

prostate cancer. This hypothesis might explain why studies of industrial workers and the Seveso 

population which have been heavily exposed to dioxins, but not phenoxy herbicides, have not 

shown evidence that exposure to dioxins is causally related to prostate cancer. If this hypothesis 

were correct, then the paragraph quoted above from the 1994 report as well as below from the 

1996 report would not provide a biological basis for this association. 

The second IOM Agent Orange committee provided more in-depth information about dioxins, in general, as well as a rationale for not considering specific cancers as requested by Congress (IOM, 1996). Based on its review of an extensive toxicological database, the committee 

stated 

Given these data, which establish biological plausibility for cancer in general but not for 

all specific sites, the committee chose not to summarize biologic plausibility for each 

cancer reviewed in this chapter. Toxicological data are provided only for a small number 

of cancer types that have specific, relevant experimental data. 

(IOM, 1996, p. 176) 

 The most recent IOM Agent Orange committee provided a much more detailed review of the 

toxicological mechanisms underlying the effects of dioxins, including a brief discussion of potential mechanisms related to prostate cancer (IOM, 2005). However, the Committee could not 

determine how this information was generally considered when classifying the extent of an association between Agent Orange and prostate cancer—which was still based upon review of individual epidemiologic studies (IOM, 2005). 

Dose Issues 

A common epidemiologic approach to exploring whether there is a causal relationship between chemicals and a specific cancer has been to focus on cohorts with particularly high levels 

of exposure, usually in an occupational setting. There are a number of such cohorts that have 
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I-92 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

been heavily exposed to dioxins and related compounds. As a corollary, biological markers of 

effect (when available) can serve as useful indicators of high levels of exposure. For dioxins and 

related compounds, chloracne is a common health outcome in those most heavily exposed and 

has been used as an exposure surrogate. 

Consideration of comparative doses among published studies does not appear to have played 

a major role in the deliberations of the IOM Agent Orange committees. For example, the findings of the studies were not arranged by likelihood of high-dose exposures, such as in IARC reviews. The IOM Agent Orange committees give consideration to dose issues within a cohort. For 

example, evidence in a study shows that a higher risk for prostate cancer is observed in those 

who estimated to have the largest number of acres sprayed with pesticides. 

Congruency of the IOM Process with That of IARC and Other Organizations

The process used by the IOM Agent Orange committees in developing the categorization of 

the strength of scientific evidence appears to have been adapted from the IARC process. The 

overall approach differs in that the IOM Agent Orange committees developed findings separately 

for epidemiological evidence (using criteria adapted from IARC) and biological plausibility 

based on toxicological and mechanistic studies but do not integrate these, like IARC and other 

organizations, to make an overall evaluation regarding causality. During the time period in which 

the IOM Agent Orange committees have conducted their biennial reviews, IARC has also reviewed the evidence concerning dioxins and cancer, as have other organizations including NTP, 

EPA, and ATSDR. IARC’s 1997 review focused extensively on the experimental literature and 

an understanding of dose issues (IARC, 1997). Further, the findings in these areas were determinative of the IARC classification of TCDD as a Group 1 carcinogen which is defined as “[t]he 

agent (mixture) is carcinogenic to humans. The exposure circumstance entails exposures that are 

carcinogenic to humans” (see http://www.inchem.org/documents/iarc/monoeval/eval.html). 

 In reaching the determination that TCDD should be classified as a Group 1 carcinogen, 

IARC particularly relied on mechanistic data and on findings in heavily exposed workgroups. 

IARC found limited evidence in humans and sufficient evidence in experimental animals for the 

carcinogenicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin. This normally would lead to categorizing 

a compound as a Group 2 carcinogen rather than a Group 1 carcinogen. However, the IARC 

document explained that 

In making the overall evaluation, the Working Group took into consideration the following supporting evidence: (i) 2,3,7,8-TCDD is a multisite carcinogen in experimental animals that has been shown by several lines of evidence to act through a mechanism involving the Ah receptor; (ii) this receptor is highly conserved in an evolutionary sense 

and functions the same way in humans as in experimental animals; (iii) tissue concentrations are similar both in heavily exposed human populations in which an increased overall cancer risk was observed and in rats exposed to carcinogenic dosage regimens in 

bioassays. 

 (IARC, 1997, pp. 8-9) 

The approach used by IARC, as well as its focus on dose, lead to cautionary language in considering the epidemiologic evidence: 

Overall, the strongest evidence for the carcinogenicity of 2,3,7,8-TCDD is for all cancers 

combined, rather than for any specific site. The relative risk for all cancers combined in 
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APPENDIX I I-93 

the most highly exposed and longer-latency subcohorts is 1.4. While this relative risk 

does not appear likely to be explained by confounding, this possibility cannot be excluded. There are few examples of agents which cause an increase in cancers at many 

sites; examples are smoking and ionizing radiation in the atomic bombing survivors (for 

which, however, there are clearly elevated risks for certain specific cancer sites). This 

lack of precedent for a multisite carcinogen without particular sites predominating means 

that the epidemiologic findings must be treated with caution; on the other hand, the lack 

of precedent cannot preclude the possibility that in fact 2,3,7,8-TCDD, at high doses does 

act as a multisite carcinogen. It should be borne in mind that the general population is exposed to levels far lower than those experienced by the industrial populations. 

 (IARC, 1997, p. 4) 

Emphasis on the toxicological database and on dose-response issues is also common to other 

agencies (e.g., NTP, ATSDR, EPA) reviewing the evidence of adverse health consequences resulting from exposure to dioxins or Agent Orange. The focus by IARC on mechanistic considerations and on cohorts with high levels of exposure as determinative of a cause-and-effect relationship has also been carried through in subsequent reviews. Steenland et al. reviewed the 

evidence that had accumulated since the 1997 IARC report and summarized additional analyses 

of the four industrial cohorts whose high-level TCDD exposures had been the focus of the IARC 

review (Steenland et al., 2004). Steenland et al. also reviewed additional findings in the Seveso 

cohort and discussed recent toxicological findings supportive of the potential for TCDD carcinogenesis. In the section on new studies they described the Ranch Hand studies of Air Force personnel involved in herbicide spraying, including the increased incidence of malignant melanoma. 

The authors stated the following regarding elevated prostate cancer findings in these studies: 

Akhtar et al. (2004) also found excesses of prostate cancer incidence, but these occurred 

in both exposed and nonexposed Air Force personnel and may have been due to increased 

cancer surveillance in both groups; both are subject to intense medical follow-up. 

 (Steenland et al., 2004, pp. 1266-1267) 

Cost Implications of the Presumption for Prostate Cancer

There are limited data regarding the costs to VA associated with the prostate cancer presumption. The commentary on 38 CFR Part 3 includes a brief discussion of the cost of this prostate 

cancer presumption. It states that 

The 6-year benefit cost for prostate cancer based on herbicide exposure is $65.3 million, 

with an administrative cost of $959,000. Additionally, the medical care cost over 6 years 

is $38 million. Prostate cancer is a male genitourinary cancer that shows marked increased prevalence with age. Accordingly, costs beyond the 6-year period would likely be 

substantially higher. 

 (VA, 1996c, p. 41370) 

VA provided the Committee two summary cost estimate documents relating to prostate cancer (VA, 1996a,b). These documents, entitled Cost Estimate for Regulation on Claims Based on 

Exposure to Herbicides (dated June 10, 1996, and November 6, 1996) summarize the anticipated 

benefit (i.e., veterans and survivors) and administrative costs for the prostate cancer presumption. 

Both documents state the “methodology was developed in collaboration with the Office of Man-
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I-94 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

agement and Budget (OMB).” Caseload was projected by applying DoD mortality rates in military retirees to the estimated number of gross separations of veterans who had service in the 

Vietnam theater from 1965 through 1981. Age-specific incident and mortality rates for prostate 

cancer, as found in the Cancer Statistics Review of 1973-1986, were applied to the base population. On June 10, 1996, the total benefit costs estimated for years 1997-2001 were $56.4 million 

while the administrative costs were estimated at $787,000. On November 6, 1996, the total benefit costs estimated for years 1997-2002 were $65.3 million. The Committee was not provided 

recent cost estimates with regard to the prostate cancer presumption nor could the Committee 

confirm the actual costs following the 1996 estimates through year 2002. Taking into account the 

number of surviving Vietnam veterans who will soon enter into the age range for which there is a 

steep increase in age-related incidence of prostate cancer, it can be anticipated that a marked rise 

of prostate cancer in the Vietnam veteran population is virtually certain. 

Lessons Learned 

This case study offers several lessons that are relevant when considering strategies for improving the current system of presumptions. These lessons relate to the role of Congress in issuing the Agent Orange Act of 1991 (Public Law 102-4. 102d Cong., 1st Sess.), VA in its use of 

scientific evidence and issuance of a presumption related to prostate cancer, and IOM in its 

evaluation and presentation of the body of evidence on the relationship between Agent Orange 

and prostate cancer. 

Congress 

In describing the type of relationship between dioxin and health outcomes necessary for a 

presumption, Congress used the language both of “association” as well as “causation” in the 

Agent Orange Act of 1991 (Public Law 102-4. 102d Cong., 1st Sess.) (see Chapter 4). Association appears to be the standard set for VA: 

An association between the occurrence of a disease in humans and exposure to an herbicide agent shall be considered to be positive for the purposes of this section if the credible 

evidence for the association is equal to or outweighs the credible evidence against the association. 

(Agent Orange Act of 1991. Public Law 102-4. 

102d Cong., 1st Sess. § 2[b][3]) 

 

However, the congressional language regarding “Scientific Determinations Concerning Diseases” includes evidence related to causation (Public Law 102-4): 

1. whether a statistical association with herbicide exposure exists, taking into account 

the strength of the scientific evidence and the appropriateness of the statistical and 

epidemiologic methods used to detect the association; 

2. the increased risk of the disease among those exposed to herbicides during service in 

the Republic of Vietnam during the Vietnam era; and 

3. whether there exists a plausible biological mechanism or other evidence of a causal 

relationship between herbicide exposure and disease. 

(Agent Orange Act of 1991. Public Law 102-4. 

102d Cong., 1st Sess. § 3[d]; emphasis added) 
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APPENDIX I I-95 

This inconsistency around “causation” and “association” in the congressional language may 

have allowed differing interpretations of whether sufficient scientific evidence exists for establishing a presumption. The difficulties that result from this lack of clarity in the Agent Orange 

Act of 1991 (Public Law 102-4. 102d Cong., 1st Sess.) may have been problematic for prostate 

cancer for which some evidence for association is present from epidemiological data, but limited 

by chance, bias, or confounding while the current toxicological evidence for causation (particularly evidence from animal studies and on plausible biological mechanisms) differs from that of 

the epidemiologic data and was not integrated to make an overall conclusion regarding causality. 

In addition to the more general confusion between “association” and “causation” in the 

Agent Orange Act described above, the second charge set for IOM by this act—evaluating evidence for the increased risk of disease among those exposed to herbicides during service in the 

Republic of Vietnam during the Vietnam era—is particularly difficult to address. Nearly all of 

the Agent Orange reports issued by IOM (1994, 1996, 1999, 2001, 2003, 2005) comment on the 

challenge of addressing this second charge noting that the lack of exposure data on Vietnam veterans made the task difficult to fulfill. The intent of Congress in this second charge is unclear, 

particularly as the lack of exposure data for Vietnam veterans was well known at the time of the 

Agent Orange Act. 

VA 

Overall, VA’s process for using the IOM reports to inform presumptive decisions is not 

transparent. The prostate cancer presumption was based on a “limited/suggestive” classification 

of the levels of evidence, rather than the highest standard of “sufficient” evidence of an association. This decision was most likely influenced by a variety of considerations (i.e., political, economic, and administrative factors) and not just by the scientific evidence. The interplay of these 

multiple factors and their relative weighting by VA are not easily characterized because of lack 

of transparency in the VA process for using scientific evidence to arrive at the final decision of 

issuing a presumption. This attempt at a balanced critique of the various parties in the Agent Orange and prostate cancer presumption is limited by the nonspecific information provided by VA 

on this subject, in particular the use of the “limited/suggestive” classification of an association. 

VA’s cost projections for the prostate cancer presumption are likely underestimates and did 

not consider the very large cohort of aging Vietnam veterans past year 2002. Taking into account 

the number of surviving Vietnam veterans who will soon enter into the age range for which there 

is a steep increase in age-related incidence of prostate cancer, it can be anticipated that a marked 

rise of prostate cancer in the Vietnam veteran population is virtually certain. 

IOM 

There were some questions regarding the responsiveness of the IOM process (via VA) to 

congressional intent. The Agent Orange Act of 1991 (Public Law 102-4. 102d Cong., 1st Sess. § 

2[b][3]) states that a positive association is one for which “the credible evidence of the association is equal to or outweighs the credible evidence against the association.” This statement is not 

necessarily equivalent to the category of “limited/suggestive” evidence for association used by 

IOM Agent Orange committees. The IOM “limited/suggestive” category covers a potential range 

of epidemiologic evidence from relatively weak to strongly suggestive. In the instance of Agent 

Orange and prostate cancer, VA established a presumption based on the IOM’s 1996 classification of “limited/suggestive” evidence of an association. The evidence at the time was relatively 
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I-96 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

limited, but it did include one study showing a statistically significant excess and a number of 

other studies showing positive, but weak and nonsignificant associations. 

Biological Plausibility The IOM Agent Orange committees did not appear to have an explicit 

and formal methodological protocol for synthesizing evidence and updating the classification of 

evidence based on new studies. The IOM Agent Orange committees appear to have developed a 

process which differs somewhat from that used by other Academies’ committees and national 

and international organizations in their review of the level of evidence between an environmental 

agent and adverse consequences. In reviewing evidence on Agent Orange, the 2005 review considered biological and toxicological evidence when evaluating the biological plausibility of the 

association between prostate cancer and exposure to Agent Orange but did not integrate these 

other lines of evidence with epidemiologic findings to develop an overall evaluation. In seeking 

to classify the strength of evidence with regard to association only, prior IOM committees have 

relied almost entirely on epidemiologic findings in classifying the strength of evidence. 

Approach to Dose-Response The criterion for reaching “limited/suggestive” evidence for association of Agent Orange used by the IOM committees is that the “(e)vidence is suggestive of an 

association between herbicides and the outcome but is limited because chance, bias, and confounding could not be ruled out with confidence. For example, at least one high-quality study 

shows a positive association, but the results of other studies are inconsistent” (IOM, 2005, p. 8). 

The Agent Orange committees’ evaluations for prostate cancer considered the totality of epidemiologic evidence, but did not take into account the very much higher exposures in certain exposed worker groups and in the population exposed during the Seveso incident. Several studies 

were of worker groups and measures of exposure to either the chlorophenoxy compounds or dioxin but were not available to enable comparisons across studies. Dose-response relationships 

could be considered for a few studies; for example, the RR “of prostate cancer in the Ranch 

Hands study correlated with putative exposure to Agent Orange (high 6.04 versus low 2.17 versus background 1.5; P = 0.01)” (IOM, 2005, p. 282). The lack of accurate estimates of exposure 

from the military experience has limited the study of the association between prostate cancer and 

exposure to Agent Orange in veterans. 

The IOM reports did not attempt to address the fraction of prostate cancer risk that might be 

attributed to military service. It nonetheless notes that “(p)rostatic cancer is a common condition 

in older men, so it is likely that multiple factors are responsible and unlikely that herbicide exposure is a major cause” (IOM, 2005, p. 282) An explicit evaluation of attributable fraction might 

have been useful to policy makers considering this presumption by placing the scientific evidence on the link between Agent Orange exposure and prostate cancer in context of overall prostate cancer risks, although determining the magnitude of this attributable fraction would remain 

difficult in the absence of accurate exposure data. 

General 

The Agent Orange and prostate case study illustrates the challenge—both for scientists and 

policy makers—of evaluating evidence for an association between exposure and subsequent disease when accurate exposure data are lacking. This challenge is particularly striking for a disease 

like prostate cancer where multiple factors often contribute to the onset of disease, and the other 

known risk factors (e.g., race, age, family history of the disease, and a diet high in fats) are 

common in the general population. In this context, the contribution of exposures incurred during 
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APPENDIX I I-97 

prior military service to overall disease risk is likely to be small as acknowledged in the IOM 

reports. In the absence of accurate exposure data, determining whether this small increased risk 

of disease is present and further quantifying the magnitude of this risk is difficult. 

Faced with this challenge of identifying a possible small increased risk of disease without accurate exposure data, it appears that policy makers have adopted an approach in the prostate cancer presumption that minimizes the possibility of denying service connection to a veteran whose 

prostate cancer may have been caused by Agent Orange (maximizing sensitivity). The implicit 

assumption in the prostate cancer presumption is that if any possibility exists, no matter how 

small, that a veteran may have been exposed to any amount of Agent Orange (presumption of 

exposure), and any possibility exists, no matter how small, that Agent Orange may have contributed even the smallest incremental increased risk of prostate cancer (presumption of association), 

service connection should be granted. 

High-quality data for a cohort of veterans are essential for improving this process; ideally 

such data would include more accurate assessments of exposure during service, evaluation of 

other risk factors that may have been present during service or have developed after service before the onset of disease, and longitudinal assessments for evaluation of diseases that may have 

long latency periods. The prostate cancer case study highlights the potential value of such an ongoing cohort study and the missed opportunities when such studies are not continued. 

References 

Akhtar, F. Z., D. H. Garabrant, N. S. Ketchum, and J. E. Michalek. 2004. Cancer in U.S. Air Force veterans of the Vietnam war. Journal of Occupational and Environmental Medicine 46(2):123-136. 

ATSDR (Agency for Toxic Substances and Disease Registry). 1998. Toxicological profile for chlorinated 

dibenzo-p-dioxins (CDDs). Atlanta, GA: U.S. Public Health Service. 

EPA (U.S. Environmental Protection Agency). 2003. Exposure and human health reassessment of 2,3,7,8-

tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. Part II: Health assessment of 2,3,7,8-

tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. NAS review draft. Washington, DC: 

National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency. http://www.epa.gov/ncea/pdfs/dioxin/nas-review/#part2 (accessed June 9, 

2007). 

IARC (International Agency for Research on Cancer). 1997. Polychlorinated dibenzo-para-dioxins and 

polychlorinated dibenzofurans. Summaries of data reported and evaluation. Vol. 69. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. 

http://monographs.iarc.fr/ENG/Monographs/vol69/volume69.pdf (accessed March 8, 2007). 

IOM (Institute of Medicine). 1994. Veterans and Agent Orange: Health effects of herbicides used in Vietnam. Washington, DC: National Academy Press. 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy Press. 

IOM. 1999. Veterans and Agent Orange: Update 1998. Washington, DC: National Academy Press. 

IOM. 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy Press. 

IOM. 2003. Veterans and Agent Orange: Update 2002. Washington, DC: The National Academies Press. 

IOM. 2005. Veterans and Agent Orange: Update 2004. Washington, DC: The National Academies Press. 

Morrison, H., D. Savitz, R. Sernenciw, B. Hulka, Y. Mao, D. Morison, and D. Wigle. 1993. Farming and 

prostate cancer mortality. American Journal of Epidemiology 137(3):270, 280. 

NRC (National Research Council). 1972. The effects on populations of exposure to low levels of ionizing 

radiation (BEIR I). Washington, DC: National Academy Press. 

NRC. 1979. The effects on populations of exposure to low levels of ionizing radiation (BEIR II). Washington, DC: National Academy Press. 

NRC. 1980. The effects on populations of exposure to low levels of ionizing radiation (BEIR III). Washington, DC: National Academy Press. 
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NRC. 1988. Health effects of radon and other internally deposited alpha-emitters (BEIR IV). Washington, 

DC: National Academy Press. 

NRC. 1990. Health effects of exposure to low levels of ionizing radiation (BEIR V). Washington, DC: National Academy Press. 

NRC. 1998. Health risks from exposure to low levels of ionizing radiation (BEIR VII - Phase 1, Letter 

Report). Washington, DC: National Academy Press. 

NRC. 1999a. Arsenic in drinking water. Washington, DC: National Academy Press. 

NRC. 1999b. Health effects of exposure to radon (BEIR VI). Washington, DC: National Academy Press. 

NRC. 2006a. Health risks from dioxin and related compounds: Evaluation of the EPA reassessment. 

Washington, DC: The National Academies Press. 

NRC. 2006b. Health risks from exposure to low levels of ionizing radiation (BEIR VII - Phase 2). Washington, DC: The National Academies Press. 

NTP (National Toxicology Program). 2006. Toxicology and carcinogenesis studies of 2,3,7,8-

tetrachlorodibenzo-p-dioxin (TCDD) (CAS No. 1746-01-6) in female Harlan Sprague-Dawley rats 

(Gavage Study). Technical Report Series No. 521. NIH Publication No. 06-4468. Research Triangle 

Park, NC: National Toxicology Program. 

Steenland, K. L., P. Bertazzi, A. Baccarelli, and K. Manolis. 2004. Dioxin revisited: Developments since 

the 1997 IARC classification of dioxin as a human carcinogen. Environmental Health Perspectives 

112(13):1265-1268. 

VA (Department of Veterans Affairs). 1994. Disease Not Associated with Exposure to Certain Herbicide 

Agents. Notice. Federal Register 59(2):341-346. 

VA. 1996a. Cost estimate for regulation on claims based on exposure to herbicides. Washington, DC: Office of Resource Management, Department of Veterans Affairs. 

VA. 1996b. Cost estimate for regulation on claims based on exposure to herbicides. Washington, DC: 

Office of Resource Management, Department of Veterans Affairs. 

VA. 1996c. Diseases associated with exposure to certain herbicide agents (prostate cancer and acute and 

subacute peripheral neuropathy). Proposed rule. Federal Register 61(154):41368-41371. 

VA. 1996d. Diseases associated with exposure to certain herbicide agents (prostate cancer and acute and 

subacute peripheral neuropathy). Final rule. Federal Register 61(217):57586-57589. 

CASE STUDY 9: AGENT ORANGE AND TYPE 2 DIABETES 

PRESUMPTION 

This case study examines the 2001 decision by the VA to establish presumptive service connection for type 2 diabetes based on herbicide exposure among Vietnam veterans. By exploring 

the scientific and legislative history of this decision, as well as the consequences of this decision 

for VA, this analysis seeks to illustrate the challenges and implications of establishing a service 

connection for a common chronic condition when exposure data are unavailable and evidence for 

association with the putative causal agent is limited. 

Type 2 Diabetes 

This presumption establishes service connection for type 2 diabetes developing in veterans of 

the Vietnam era. Several clinical and epidemiological features of type 2 diabetes are noted as 

they inform some of the challenges in the epidemiologic investigations of type 2 diabetes, particularly with regard to characterizing the effect of Agent Orange. First, type 2 diabetes is common in the general population, and its prevalence increases with advancing age (Figure I-6). This 

high background prevalence may pose challenges for determining additional risk attributable to 

military service in many studies. The high prevalence of type 2 diabetes may also translate into a 
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APPENDIX I I-99 

FIGURE I-6 Prevalence and incidence of type 2 diabetes in the United States. 

SOURCE: CDC, 2005, pp. 4, 6. 

 

0

2

4

6

8

10

12

NHANES I

('71-75)

NHANES II

('76-'80)

NHANES III

('88-'94)

NHANES 

<25 kg/m2

25.0-29.9 kg/m2

Prevalence

≥30 kg/m2

Body Mass Index 

(BMI)

1999-2000

FIGURE I-7 Age- and sex-adjusted trends in type 2 diabetes prevalence. 

SOURCE: Adapted, with permission, from Gregg et al., 2005, p. 1871. 

larger constituency advocating for this presumption and affect the financial implications of a 

decision. 

Second, there are multiple established risk factors for type 2 diabetes that are common in the 

general population. These contributors to type 2 diabetes risk include family history and lifestyle 

factors such as obesity and physical inactivity (Figure I-7). Because these risk factors are common, estimating the incremental risk of type 2 diabetes attributable to herbicide exposure among 

Vietnam veterans is challenging. 

The known link between obesity and type 2 diabetes has particularly important implications 

for evaluating the observational studies exploring the risk of type 2 diabetes associated with 

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) levels. Adipose tissue is a primary site of distribution for TCDD, and percentage of body fat appears to correlate with serum TCDD levels (IOM, 

1994). Increasing body fat may also decrease the rate of TCDD elimination (IOM, 1994). The 

relationship between body fat and TCDD pharmacokinetics suggests that body mass index and 

other measures of body fat are important covariates that must be considered in observational 

studies of dioxins and risk for type 2 diabetes. 
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Third, type 2 diabetes is a disorder of carbohydrate metabolism that is characterized by hyperglycemia. Many individuals with type 2 diabetes initially exhibit few or no symptoms, making the exact onset of this disease difficult to establish. The diagnostic criteria for type 2 diabetes 

are based primarily on blood glucose levels, and the level of hyperglycemia that is diagnostic of 

type 2 diabetes has been adjusted downward over time. The current criteria are fasting blood glucose ≥126 mg/dL or a random blood glucose ≥200 mg/dL in the presence of symptoms (often 

polyuria or polydipsia) (ADA, 2007). The World Health Organization and American Diabetes 

Association definitions recognize a state of impaired glucose tolerance (fasting blood glucose of 

100-125 mg/dL) that is not diagnostic of type 2 diabetes, but places individuals at high risk for 

subsequent development of this disease (ADA, 1997, 2003, 2007; Alberti and Zimmet, 1998). 

These changing definitions of type 2 diabetes make comparisons of studies across time potentially difficult. In addition, many studies evaluate both type 2 diabetes and blood glucose levels 

as outcomes; although hyperglycemia not meeting diagnostic criteria for type 2 diabetes may 

signal an important increased risk of type 2 diabetes, the significance of small increases in mean 

glucose concentrations within the range of normal glucose levels (<100 mg/dL) (ADA, 2007) 

may be less clear. 

Finally, type 2 diabetes is an extraordinarily morbid condition that affects virtually every organ system. Heart disease and stroke account for nearly 65 percent of deaths among individuals 

with type 2 diabetes (CDC, 2005, p. 6). Type 2 diabetes is also associated with significantly 

higher rates of nontraumatic amputations, kidney disease, neuropathies, and blindness (CDC, 

2005). There are two important implications of this high rate of morbidity associated with type 2 

diabetes. First, mortality studies of this disease are limited because complications of type 2 diabetes (i.e., heart disease) are often listed as the underlying cause of death, resulting in an underestimate of type 2 diabetes-related mortality from use of death certificate diagnoses. Second, the 

multiple complications of type 2 diabetes could have significant consequences for the true costs 

associated with a service connection for this common and highly morbid chronic condition. 

The Need for a Presumption 

The history of the Agent Orange Act of 1991 (Public Law.102-4. 102nd Cong., 1st Sess.) establishing a presumption of service connection for diseases associated with herbicide exposure 

during the Vietnam conflict as well as the procedure of adding additional diseases to this presumption has been reviewed elsewhere in this report (see Chapter 2, Chapter 4, Appendix D). 

The need for a presumption for Agent Orange-associated diseases generally is based in part on 

the difficulty of establishing with certainty the degree of exposure to herbicides among Vietnam 

veterans (IOM, 1994). The Agent Orange Act eliminates the need for an individual Vietnam veteran to provide evidence of herbicide exposure; exposure is presumed for all Vietnam veterans. 

Although the need for a presumption is based primarily on the difficulty of establishing exposure, presumptions also address gaps in the evidence for association. An examination of the 

exact charge to the IOM for determining the diseases that are linked to herbicides is instructive. 

For each disease, IOM has been asked to determine, to the extent that available data permit 

meaningful determinations, 

1. whether a statistical association with herbicide exposure exists, taking into account the 

strength of the scientific evidence and the appropriateness of the statistical and epidemiological methods used to detect the association; 

2. the increased risk of the disease among those exposed to herbicides during Vietnam service; 

and 
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APPENDIX I I-101 

3. whether there is a plausible biological mechanism or other evidence of a causal relationship 

between herbicide exposure and the disease. 

Each of the IOM reports that examined herbicides and type 2 diabetes risk (IOM, 1994, 1996, 

1999, 2000, 2001, 2003, 2005) has focused almost exclusively on addressing the task described 

in charge 1 and have included additional discussions of the more limited data to address charge 

3. Each of the IOM reports address charge 2 but acknowledge the difficulty of providing risk 

estimates because of the lack of exposure data: 

Although there are data to suggest an association between exposure to the chemicals of 

interest and type 2 diabetes, the lack of exposure information on Vietnam veterans precludes quantification of any possible increase in their risk. 

 (IOM, 2005, p. 446) 

Some committees additionally note, in response to charge 2, that the epidemiological evidence on known risk factors for type 2 diabetes would suggest that the contribution of exposures 

during military to overall diabetes risk is likely to be small: 

Available data allow for the possibility of an increased risk of type 2 diabetes in Vietnam 

veterans. It must be noted, however, that studies indicate that the increased risk, if any, 

posed by herbicide or TCDD exposure appears to be small. The known predictors of diabetes risk—family history, physical inactivity, and obesity—continue to greatly outweigh 

any suggested increased risk posed by wartime exposure to herbicides. 

 (IOM, 2003, p. 492)

 

The presumption of service connection for type 2 diabetes in Vietnam veterans therefore 

serves more than just to address the gap in evidence of exposure. As the lack of exposure data 

makes quantification of the magnitude of the association between military service and diabetes 

difficult, this presumption also implicitly serves to address a gap in the evidence for association 

between herbicides and type 2 diabetes among Vietnam veterans. 

A Review of the Scientific and Legislative Landmarks Leading to 

the Agent Orange and Type 2 Diabetes Presumption by VA 

As a result of Public Law 102-4 (Agent Orange Act of 1991. Public Law 102-4. 102nd 

Cong., 1st Sess.), the NAS signed an agreement with VA to review and summarize the strength 

of the scientific evidence concerning the association between herbicide exposure during Vietnam 

service and diseases or conditions that may be associated with this exposure. The first report 

from NAS was issued in 1994 (IOM, 1994) and has been updated on a biennial basis since that 

time. Additionally, a special report on Agent Orange and type 2 diabetes was published in 2000 

(IOM, 2000). This section reviews the scientific evidence contained in the IOM Agent Orange 

reports of 1994-2005 and the legislative events that resulted from the conclusions of these reports. It is not meant to be a comprehensive analysis of the entire body of scientific literature on 

this topic, but rather to highlight those events and data that inform the conclusions in the reports 

and changes in legislation. 
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1994-1999 

The earliest publication reviewed by IOM that suggested a link between the herbicides and 

type 2 diabetes was a report of the 10-year follow-up of 55 workers who had become acutely ill 

after exposure to TCDD. Eight percent of these workers developed type 2 diabetes immediately 

following exposure; after 10 years, 11 of the 55 had developed type 2 diabetes (PazderovaVejlupkova et al., 1981, pp. 6, 7). Several small epidemiologic and occupational studies that followed the report of these cases failed to show a statistically significant association between exposure to these compounds and type 2 diabetes risk or type 2 diabetes mortality (Bertazzi et al., 

1998; Cook et al., 1987, as referenced in IOM, 1999; Henneberger et al., 1989, as referenced in 

IOM, 1999; Moses et al., 1984, as referenced in IOM, 1999; May, 1982, as referenced in IOM, 

1999; von Benner et al., 1994, as referenced in IOM, 1996; Zober et al., 1994, as referenced in 

IOM, 1996). 

The National Institute for Occupational Safety and Health (NIOSH) studied 281 workers at 

dioxin plants in New Jersey and Missouri and compared them with 260 unexposed workers. 

Sweeney et al. found that increasing concentrations of TCDD were associated with a slight, but 

statistically significant increased risk of type 2 diabetes [odds ratio (OR) 1.1, P < .003] and elevated fasting glucose (≥ 140 mg/dL) (P < .001) (Sweeney et al., 1996, p. 245; Sweeney et al., 

1997, as referenced in IOM, 2000, pp. 16, 54). An earlier study of this cohort found that exposed 

workers had a type 2 diabetes prevalence of 9.2 percent compared with 5.8 percent among unexposed workers, a difference that did not reach statistical significance (Sweeney et al., 1992, as 

referenced in IOM, 1999, p. 500). The authors of these studies concluded that more analyses 

were necessary to eliminate the possibility of confounding from other established risk factors for 

type 2 diabetes, including age and weight, and the IOM Agent Orange 1998 update (IOM, 1999) 

called for a more detailed analysis of this cohort.

A study of Air Force veterans involved in herbicide spraying—the Air Force Health Study 

(AFHS)—suggested that serum concentration of TCDD was associated with glucose intolerance 

or type 2 diabetes in a dose-dependent manner. In this 1997 study (Henriksen et al., 1997, pp. 

253-256), 989 Air Force veterans involved in Agent Orange spraying (Operation Ranch Hand) 

were categorized based on their TCDD levels; initial TCDD levels at the time of wartime exposure were estimated based on their current serum TCDD. In addition to comparing disease outcomes between veterans involved in Agent Orange spraying in different categories of TCDD 

levels, these subjects were also compared with 1,276 Air Force veterans that were not involved 

in spraying. Those with the highest level of TCDD had a significantly increased risk of elevated 

blood glucose (RR 1.4, 95% CI 1.1-1.8) and type 2 diabetes (RR 1.5, 95% CI 1.2-2.0) and a decreased time to onset of disease after adjusting for age and body mass index, compared to those 

with the lowest level of TCDD. Veterans involved in Agent Orange spraying with intermediate 

levels of TCDD exhibited an intermediate risk for these outcomes. This study was commended 

in the IOM Agent Orange 1998 update (IOM, 1999), but two concerns were also noted. First, 

there were no differences in type 2 diabetes rates overall between veterans involved in Agent Orange spraying and the designated comparison group that was not involved in spraying, despite 

significant differences in their serum TCDD levels (median 12.2 ppt versus 4.0 ppt [Henriksen et 

al., 1997]) (IOM, 1999, p. 499). Second, the dose-dependent association with TCDD concentration was also observed within the comparison group that was not involved with spraying (IOM, 

1999, p. 500). Taken together these additional observations are concerning for residual confounding by a third factor such as weight or body fat that may be related to both TCDD levels 
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APPENDIX I I-103 

and type 2 diabetes. The IOM Agent Orange 1998 Update (IOM, 1999) called for a more detailed analysis of the AFHS. 

One omission from the otherwise comprehensive review of scientific literature in the IOM 

reports of this period is an analysis of the Vietnam Experience Study of the CDC. CDC used a 

random sample of military records to identify a cohort of U.S. enlisted men who had served a 

single tour in Vietnam between 1965 and 1971 and a comparison cohort of U.S. Army enlisted 

men who had served elsewhere during this period. TCDD levels were not assessed in this study; 

rather Vietnam service was used as a proxy for exposure to herbicides. A total of 7,924 Vietnam 

and 7,364 Vietnam-era veterans completed telephone health surveys in 1985 and 1986 (CDC, 

1989b, p. 1). Vietnam veterans did not have an increased risk of self-reported type 2 diabetes 

compared with the Vietnam-era veterans (adjusted OR = 1.2, P > 0.05) (CDC, 1989b, pp. 109, 

114). A random subsample of these individuals (2,490 Vietnam veterans and 1,972 Vietnam-era 

veterans) underwent complete physical examinations in 1985 and 1986 (CDC, 1989a). The crude 

geometric mean of fasting serum glucose was slightly higher for Vietnam veterans (93.4 mg/dL) 

than for Vietnam-era veterans (92.4 mg/dL), a difference that was found to be significant even 

after adjustment for a variety of factors including age, race, military specialty, body mass index, 

and medications known to affect glucose metabolism (CDC, 1989c, p. 174). Despite this difference in mean glucose levels, there was no significant difference between the two groups in the 

number of veterans with abnormal blood glucose levels (> 140 mg/dL in this study) (CDC, 

1989c, pp. 172, 175). 

Although the Vietnam Experience Study is directly relevant to the IOM charge of determining whether herbicide exposure during the Vietnam era resulted in an increased risk of type 2 

diabetes among Vietnam veterans, the IOM reports do not comment on the type 2 diabetes results found in the Vietnam Experience Study. The finding of no association between military 

service in Vietnam and type 2 diabetes in this study is not included in the summary analyses presented in the various tables of these reports. As participants in the Vietnam Experience Study 

were not followed beyond this assessment in the 1980s, it is impossible to determine whether the 

very small but significant increases in blood glucose concentration observed in this younger cohort might have been an indicator of subsequent type 2 diabetes risk. 

In reviewing the studies of this period, the IOM Agent Orange reports of 1994, 1996, and 

1998 (IOM, 1994, 1996, 1999) all concluded that there was inadequate or insufficient evidence 

to determine whether an association existed between herbicide exposure and type 2 diabetes. No 

presumption of service connection for type 2 diabetes among Vietnam veterans exists for this 

time period.

1999-2001 

In 1999 VA asked IOM to convene a special committee to conduct a focused review of the 

scientific evidence regarding the association between Agent Orange and type 2 diabetes in advance of the regularly scheduled biennial IOM reports (IOM, 2000). VA’s reason for convening 

this special committee out of the scheduled sequence of IOM reports on Agent Orange is outlined in the Federal Register (VA, 2001a) and reviewed here. 

In 1999, NIOSH published a further analysis of exposed and unexposed workers in the New 

Jersey and Missouri dioxin plants (Calvert et al., 1999). The authors of this study summarize 

their findings in this way: 
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Overall, the prevalence of diabetes mellitus was not significantly different between the 

workers and referents. Also, there was not a significant positive trend between prevalence 

of diabetes and increasing serum TCDD concentration. However, diabetes was found in 

six of 10 workers with current serum TCDD concentrations >1500 pg/g lipid. 

 (Calvert et al., 1999, p. 270) 

In the Federal Register outlining the rationale for the special diabetes report, the NIOSH 

study is summarized in the following way: 

. . . a report that detects an association, though not a strong association, between type 2 

diabetes and dioxin exposure. The study does suggest a dose response relationship because of excess cases of type 2 diabetes found in workers having the highest serum-lipid 

levels of dioxin. 

 (VA, 2001a, p. 2378) 

 

The VA Secretary viewed this study as potentially important enough to warrant a full review 

of the scientific literature on Agent Orange and type 2 diabetes and commissioned a special report (IOM, 2000) on this topic from IOM. As with the prior Agent Orange committees, the 

charge of the Agent Orange and type 2 diabetes committee was to review evidence from epidemiologic studies, evidence for increased risk among Vietnam veterans, and evidence for biologic 

plausibility; the majority of this report focused on the epidemiologic evidence (as was the case 

with prior and subsequent reports). In their summary, the Agent Orange and type 2 diabetes 

committee (IOM, 2000) commented on two trends that they noted in the literature on this topic 

published since the IOM Agent Orange 1998 Update (IOM, 1999). 

The report stated “[p]ositive associations are reported in many mortality studies, which may 

underestimate the incidence of diabetes” (IOM, 2000, pp. 2, 36). This statement was based on the 

data from four mortality studies that had not been reviewed in previous IOM reports: 

 

• A 1998 report of the 5-year follow-up of individuals living near a 1976 industrial 

accident site involving dioxin (Pesatori et al., 1998). Individuals were grouped 

into three categories based on their distance from the site of the accident and 

compared with an unexposed reference group. Women with substantial exposure 

(41,391 person-years of follow-up) had significantly higher rates of type 2 diabetes mortality (RR 1.9, 95% CI 1.1-3.2); the same effect was observed among men 

with substantial exposure (42,219 person-years of follow-up), although the results 

did not reach significance (RR 1.3, 95% CI 0.6-2.9) (Pesatori et al., 1998, pp. 

127-128). Only age and calendar period were included as covariates in this study. 

• A study of 5,172 workers exposed to TCDD at 12 U.S. plants did not find an increase in the standardized mortality ratio (SMR) for type 2 diabetes as the primary 

cause of death (SMR 1.18, 95% CI 0.77-1.73) or type 2 diabetes as the primary or 

secondary cause of death (SMR 1.08, 0.87-1.33) (Steenland et al., 1999, p. 782). 

In fact, analysis of this cohort categorized by septiles of TCDD exposure revealed 

a statistically significant inverse trend between cumulative exposure and type 2 

diabetes risk (those with the highest exposure had the lowest type 2 diabetes risk; 

p = 0.02), though the trend was not statistically significant when the logarithm of 

cumulative exposure was considered (p = 0.12) (Steenland et al., 1999). An analysis of the 608 individuals who developed chloracne after the exposure (a condition 
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APPENDIX I I-105 

that may indicate high exposure) failed to reveal an increased risk of type 2 diabetes (Steenland et al., 1999, p. 781). These studies accounted for age and calendar 

year. 

• A 1998 study that combined data from multiple exposed cohorts internationally 

(including the U.S. cohort analyzed in the study by Steenland et al. referenced 

above) found that exposure was associated with an RR of type 2 diabetes of 2.25 

(0.53-9.50), although these results did not reach the level of statistical significance 

(Vena et al., 1998, p. 649). Age, gender, country, employment status, and calendar period were included as covariates in this analysis. 

The results of these studies are mixed with a nonsignificant trend toward association between 

exposure and type 2 diabetes observed in some studies and a significant inverse association between TCDD and type 2 diabetes noted in another study. Additionally, the relevance of the 

committee’s concern that mortality studies may underestimate the risk of type 2 diabetes is not 

entirely clear. The report (IOM, 2000, pp. 2, 36), as quoted extensively in the Federal Register

(VA, 2001a, p. 2378), notes that (1) type 2 diabetes is not typically fatal, (2) complications of 

type 2 diabetes are more likely to be listed as a cause of death rather than type 2 diabetes itself, 

and (3) contributory factors (such as type 2 diabetes) are not routinely listed on death certificates. 

Although these features are likely all true and would be expected to underestimate type 2 diabetes-associated mortality generally, there is no reason to suspect that this underreporting of type 2 

diabetes as a cause of death should differ based on exposure status. The strength of association 

between dioxin exposure and type 2 diabetes, therefore, would likely be unaffected by overall 

underreporting of type 2 diabetes on death certificates. However, the IOM report (IOM, 2000) 

and its summary by VA in the Federal Register (VA, 2001a) appear to suggest that the associations observed in these mortality studies be given additional weight because the type 2 diabetes 

mortality is underestimated. 

The report stated “[p]ositive associations are reported in most of the morbidity studies identified by the committee” (IOM, 2000, pp. 3, 37). Studies of three cohorts are described to support 

this statement: 

• A survey of male Australian veterans of Vietnam found a statistically significant 

excess of self-reported type 2 diabetes (2,391 reported cases; 1,780 expected 

cases with an expected range of 1,558-2,003 (CDVA, 1998, as referenced in IOM, 

2000, pp. 32, 37). 

• A further analysis of the NIOSH cohort (the impetus for convening the special 

Agent Orange type 2 diabetes committee) of 281 workers (exposed to TCDD in 

chemical plants more than 15 years prior) and 260 controls (from the same residential neighborhood as the exposed individuals and matched on age, race, and 

sex) found no significantly increased risk of type 2 diabetes among exposed individuals compared with reference individuals (OR 1.49, 95% CI 0.77-2.91) (Calvert et al., 1999, pp. 270-271, 273). Additionally, there was no trend observed between increasing TCDD concentration and type 2 diabetes risk. However, when 

individuals with type 2 diabetes were excluded from the analysis, individuals in 

the highest TCDD group had significantly higher glucose concentrations than the 

unexposed group (geometric mean 5.45 mmol/L [1.02] vs. 5.21 mmol/L [1.01]). 
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These analyses were all adjusted for age, gender, race, body mass index, and 

medications that affect glucose metabolism. 

• The AFHS again provided important, though perhaps conflicting, evidence related 

to TCDD and type 2 diabetes. Updated analysis of veterans of Operation Ranch 

Hand estimated TCDD concentration at the time of exposure based on the elimination kinetics observed in a sample of Ranch Hand veterans with multiple TCDD 

measures over time. Among Ranch Hand veterans, both measured TCDD concentrations from the start of the study (1987) and estimated time-of-exposure TCDD 

concentrations were associated with the risk of diabetes. Those Ranch Hand veterans with the highest estimated time-of-exposure TCDD concentration also had 

higher rates of diabetes compared with the unexposed comparison cohort that had 

not been involved in Agent Orange spraying, although overall diabetes rates did 

not differ between Ranch Hand veterans and the unexposed comparison cohort

(AFHS, 2000). Among the comparison cohort that had not been involved in Agent 

Orange spraying, a significant dose-dependent relationship between TCDD concentration and type 2 diabetes prevalence was also observed, with an RR of 1.71 

(95% CI 1.00-2.91) for the highest quartile concentration compared with the lowest (Longnecker and Michalek, 2000, p. 46). Veterans in this comparison cohort 

had very low serum TCDD concentrations, within the range of background exposure typically seen in the United States (≤10 ng/kg lipid) (Longnecker and 

Michalek, 2000, p. 45). The committee noted that the observations from AFHS, 

including a graded risk of diabetes associated with very low levels of TCDD, continued to leave open the possibility that residual confounding related to body fat 

or correlated factors such as triglyceride concentration may interfere with accurate 

evaluation of the relationship between TCDD and type 2 diabetes (IOM, 2000). 

Because of the trends that the committee found in the newly published mortality and morbidity literature, the IOM report on type 2 diabetes concluded that evidence for the association between herbicides and type 2 diabetes had reached the level of limited/suggestive—that is, evidence is suggestive of an association between herbicides and the outcome, but limited because 

chance, bias, and confounding could not be ruled out with confidence (IOM, 2000). 

This “limited/suggestive” finding of the IOM report was submitted to the VA Secretary. In 

accordance with Title 38 USC 1116(b)(1) (Compensation for Service-Connected Disability or 

Death. 2006. 38 USC § 1116[b][1]), the VA Secretary was required to review this report and determine whether a presumption was warranted. The VA Secretary determined that evidence of a 

“positive association” between Agent Orange and type 2 diabetes existed, noting that an association is considered “positive” if the credible evidence for the association is equal to or outweighs 

the credible evidence against the association. Additional information regarding how data from 

the IOM report and the IOM summary finding of “limited/suggestive” figured into VA’s recommendation is unavailable. The VA Secretary’s determination of a positive association between 

herbicide and type 2 diabetes resulted in the May 8, 2001, 38 CFR Part 3 (VA, 2001b) finding of 

presumptive service connection for type 2 diabetes based on herbicide exposure during Vietnam. 

In the Federal Register commentary, the increasing rates of type 2 diabetes associated with 

the obesity prevalence was noted, and the suggestion was made that more studies be undertaken 

that control for the background high rates of obesity before the type 2 diabetes presumption be 

considered. In response to these comments, the VA Secretary noted that IOM “adequately took 
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APPENDIX I I-107 

into consideration the recognized relationship between obesity and type 2 diabetes” (VA, 2001b, 

p. 23167). This statement appears to conflict with the IOM reports, as the 2000 IOM type 2 diabetes report stated that “the known predictors of diabetes risk—family history, physical inactivity, and obesity—continue to greatly outweigh any suggested increased risk from wartime exposure to herbicides” (IOM, 2000, pp. 3, 37). In the Federal Register commentary, the VA 

Secretary also notes that the time requirements imposed by section 1116(c)(2) limited the capacity of VA to wait for additional studies on this topic (VA, 2001b). 

Title 38 USC 1116(c)(1) (Compensation for Service-Connected Disability or Death. 

2006. 38 USC § 1116[c][1]) requires that the Secretary, not later than 60 days after the 

date on which he receives a report from NAS, determine whether a presumption of service connection is warranted for each disease covered by the report, and if the Secretary 

determines that a presumption is warranted, issue proposed regulations within 60 days 

thereafter. . . . We believe that NAS adequately took into consideration the recognized relationship between obesity and type 2 diabetes, and the existence of additional studies 

concerning this risk factor does not warrant ignoring the time requirements of section 

1116(c)(2). 

(VA, 2001b, p. 23167) 

2002-2004 

IOM reports over this time period (IOM, 2003, 2005) continued to find limited/suggestive 

evidence for the association between herbicides and type 2 diabetes. One important study of this 

period includes an attempt to pool the data on participants from the NIOSH study with those 

from AFHS (Steenland et al., 2001). To match the criteria in AFHS, the cut-off values defining 

type 2 diabetes in the NIOSH study were adjusted downward (from > 140 mg/dL to > 126 

mg/dL) and 55 individuals included in the NIOSH study were excluded from the joint analysis. 

As a result of these changes, the OR for the NIOSH data was reduced from 1.49 to 1.22 and the 

dose-dependent association was no longer observed (OR = 0.84, 95% CI 0.4-1.8 for the highest 

TCDD concentration compared with the lowest). The significant association between serum concentration of TCDD and type 2 diabetes observed in the AFHS cohort was unchanged. Another 

study explored one possible mechanism for residual confounding in the AFHS studies and found 

that the significant association between TCDD concentration and type 2 diabetes risk noted in 

AFHS was not attributable to a third factor that both caused type 2 diabetes and slowed elimination of TCDD (Michalek et al., 2003). The 2002 and 2004 reports again rated the evidence for an 

association between herbicides and type 2 diabetes as “limited/suggestive.” 

Cost Implications of the Presumption for Type 2 Diabetes 

There are limited data regarding the costs to VA associated with the type 2 diabetes presumption. The commentary on 38 CFR Part 3 (VA, 2001b, p. 23168) includes a brief discussion of the 

cost of this type 2 diabetes presumption. Cost projections were estimated by applying a type 2 

diabetes prevalence rate of 9 percent to the 2.3 million estimated living Vietnam veterans (VA, 

2000). National survey data suggest that 9 percent may be an underestimate, particularly as the 

population of Vietnam veterans ages and national trends continue to demonstrate increasing rates 

of incident type 2 diabetes across all age groups (Figure I-8). 

The discussion in 38 CFR Part 3 also estimates the average monthly award for type 2 diabetes or its ancillary conditions at $462 (for original claims) (VA, 2001b, p. 23168). Although the 
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I-108 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

bases for this estimate are not described, the multiple possible complications associated with type 

2 diabetes suggests that this average payment would likely increase over time for a given veteran 

with type 2 diabetes. Estimated administrative costs for type 2 diabetes from 2001 through 2005 

were $62 million with estimated benefit costs of $3.3 billion during that same time period. VA 

estimated that there would be 20,399 new type 2 diabetes awards in the first year and 179,000 

over the next 5 years. The estimates did not include retroactive payments (McLenachen, 2005). 

Today, the most frequent service-connected disability for which Vietnam veterans are receiving 

compensation is type 2 diabetes (VBA, 2006). “At the end of fiscal year 2006, nearly 248,000 

veterans were service connected for diabetes. More than 215,000 of these awards were based 

upon herbicide exposure in Vietnam. As veterans with diabetes reach and move past the 10-year 

point since initial diagnosis, additional secondary conditions tend to manifest. VA has started to 

see increasingly complex medical cases resulting in neuropathies, vision problems, cardiovascular problems, and other issues directly related to diabetes” (VA, 2007, pp. 6B-13). 

Lessons Learned 

This case study offers several lessons that are relevant when considering strategies for improving the current system of presumptions. These lessons relate to the role of Congress in issuing the Agent Orange Act of 1991 (Public Law 102-4. 102nd Cong., 1st Sess.), VA in their use 

of scientific evidence to both convene the special IOM committee on type 2 diabetes (IOM, 

2000) and eventually issue a presumption related to type 2 diabetes, and IOM in its evaluation 

and presentation of the body of evidence for the relationship between Agent Orange and type 2 

diabetes. 

18–44 45–64 65–79

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Rate (per 1,000 Population)

1997 1998 1999 2000 2001 2002 20

Year

FIGURE I-8 Annual incidence of diagnosed type 2 diabetes per 1,000 population aged 18-79 years, by 

age, United States, 1997-2004. 

SOURCE: See http://www.cdc.gov/diabetes/statistics/incidence/fig3.htm. 
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APPENDIX I I-109 

Congress 

In describing the type of relationship between dioxin and health outcomes necessary for a 

presumption, Congress used the language both of “association” as well as “causation” in the 

Agent Orange Act of 1991 (Public Law 102-4. 102nd Cong., 1st Sess., Sec. 2[b][3]) (see Chapter 

4). Association appears to be the standard set for VA: 

An association between the occurrence of a disease in humans and exposure to an herbicide agent shall be considered to be positive for the purposes of this section if the credible 

evidence for the association is equal to or outweighs the credible evidence against the association. 

 (Agent Orange Act of 1991. Public Law 102-4. 102nd Cong., 1st Sess.) 

However, the congressional language regarding “Scientific Determinations Concerning Diseases” includes evidence related to causation (Agent Orange Act of 1991. Public Law 102-4. 

102nd Cong., 1st Sess., Sec. 3[d]): 

1. whether a statistical association with herbicide exposure exists, taking into account 

the strength of the scientific evidence and the appropriateness of the statistical and 

epidemiologic methods used to detect the association; 

2. the increased risk of disease among those exposed to herbicides during service in the 

Republic of Vietnam during the Vietnam era; and 

3. whether there exists a plausible biological mechanism or other evidence of a causal 

relationship between herbicide exposure and disease. (emphasis added) 

This inconsistency in the congressional language may have allowed considerable differences 

in interpretation of whether scientific evidence exists for the basis for a presumption. The difficulties that result from this lack of clarity in the Agent Orange Act of 1991 (Public Law 102-4. 

102nd Cong., 1st Sess.) may have been particularly problematic for type 2 diabetes for which 

some evidence for association is present, but limited by chance, bias, or confounding. 

In addition to the more general confusion between “association” and “causation” in the 

Agent Orange Act described above, the second standard set for IOM by this act—evaluating evidence for the increased risk of disease among those exposed to herbicides during service in the 

Republic of Vietnam during the Vietnam era—is particularly vague. Nearly all of the Agent Orange reports issued by IOM (1994, 1996, 1999, 2000, 2001, 2003, 2005) comment on the challenge of addressing this second charge, noting that the lack of exposure data on Vietnam veterans 

made the task difficult to fulfill. The intent of Congress in this second charge is unclear, particularly as the lack of exposure data for Vietnam veterans was well known at the time of the Agent 

Orange Act. 

VA 

In justifying its decision to convene a special IOM panel to evaluate the evidence related to 

Agent Orange and type 2 diabetes, VA may have overstated the findings of the report that 

prompted this action. Based on the Federal Register, VA summarized the report by NIOSH on 

occupational exposure to dioxin as 
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. . . a report that detects an association, though not a strong association, between type 2 

diabetes and dioxin exposure. The study does suggest a dose-response relationship because of excess cases of type 2 diabetes found in workers having the highest serum-lipid 

levels of dioxin. 

 (VA, 2001a, p. 2378) 

 

 By contrast, the authors of the NIOSH report summarized their findings in this way: 

Overall, the prevalence of diabetes mellitus was not significantly different between the 

workers and referents. Also, there was not a significant positive trend between prevalence 

of diabetes and increasing serum TCDD concentration. However, diabetes was found in 

six of 10 (60%) workers with current serum TCDD concentrations > 1500 pg/g lipid. 

 (Calvert et al., 1999, p. 270) 

Because this study was the primary justification for the special IOM committee, an understanding of VA’s interpretation of the study results is essential. No additional information regarding how new studies come to the attention of VA or the criteria for evaluating new studies 

and using these to inform the charge to IOM were made available to the Committee. 

In the debate regarding this presumption, VA dismissed the link between national increases 

in type 2 diabetes rates related to obesity and the calls for more studies that control for the background high rates of obesity, noting that the IOM “adequately took into consideration the relationship between obesity and type 2 diabetes” (VA, 2001b, p. 23167). This statement appears to 

conflict with the IOM reports, as the IOM type 2 diabetes report stated that “the known predictors of diabetes risk—family history, physical inactivity, and obesity—continue to greatly outweigh any suggested increased risk from wartime exposure to herbicides” (IOM, 2000, pp. 3, 

37). VA noted that the requirement of timely action on the part of VA imposed by the Agent Orange Act prevented consideration of additional studies; although action is required within 60 

days of the finding of a “positive association” on the part of the VA Secretary, it is notable that 

this VA finding was based on the lesser “limited/suggestive” categorization of evidence in the 

IOM report. 

VA’s cost projections for the type 2 diabetes presumption were likely underestimates. VA 

failed to consider the likely rise in type 2 diabetes prevalence in the aging veteran population and 

national trends suggesting increasing rates of type 2 diabetes in all age groups. Furthermore, as 

type 2 diabetes has many known complications that are also highly morbid, it is likely that the 

average percentage of service-connected disability for veterans with type 2 diabetes will continue 

to increase over time. 

Overall, the Committee found that VA’s process for using IOM reports to inform presumptive decisions has not been transparent. The diabetes presumption signaled an important trend on 

the part of VA to assign presumption on the basis of “limited/suggestive” classification of the 

levels of evidence. This decision could have been influenced by a variety of considerations beyond scientific ones, such as political, economic, and administrative factors. The interplay of 

these multiple factors and their relative weighting by VA are not easily characterized because of 

the lack of transparency in the VA process for using scientific evidence to arrive at the final decision of issuing a presumption. 

This attempt by the Committee to carry out at a balanced critique of the various parties in the 

Agent Orange and type 2 diabetes presumption is limited by the availability of information from 

VA on this subject. 
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APPENDIX I I-111 

IOM 

All of the IOM committees reviewing the type 2 diabetes evidence did not consider the results of the Vietnam Experience Study. This CDC study is one of the few large studies comparing the health of Vietnam veterans to other veterans of the same age who did not serve in Vietnam. The Vietnam-enlisted veterans surveyed in the Vietnam Experience Study did not have an 

increased risk of self-reported type 2 diabetes compared with other Vietnam-era veterans. In the 

subsample of participants that underwent blood test evaluation, Vietnam veterans also did not 

show higher rates of abnormal blood glucose concentrations compared with their Vietnam-era 

counterparts, although the geometric mean of their fasting serum glucose was slightly (and significantly) higher. 

The IOM committee did not appear to have an explicit and formal methodological protocol 

for synthesizing evidence and for updating the classification of evidence based on new studies. 

The IOM type 2 diabetes committee “upgraded” their assessment of the existing literature from 

“inadequate/insufficient” (studies of insufficient quality, consistency, or statistical power to permit conclusion) to “limited/suggestive” (studies limited because chance, bias, and confounding 

could not be ruled out with confidence; for example, at least one high-quality study shows a 

positive association, but the results of other studies are inconsistent). The committee’s conclusion was not reached because of a single high-quality study that provided evidence of a conclusive association between Agent Orange and type 2 diabetes. Rather, the reclassification resulted 

from the committee’s view of the cumulative weight of the evidence from several smaller studies, each limited in varying ways so that overall chance, bias, and confounding could not be ruled 

out with confidence and some studies differed in the direction of the association found (i.e., positive or negative). 

The IOM report emphasized a particular feature of outcome ascertainment in type 2 diabetes 

research that may have led to overinterpretation of the conclusions of their report. The IOM 

committee concluded that “[p]ositive associations are reported in many mortality studies, which 

may underestimate the incidence of diabetes” (IOM, 2000, pp. 2, 36; emphasis added). The 

committee correctly pointed out that death certificates routinely underestimate death rates attributable to type 2 diabetes. Because type 2 diabetes is not typically fatal, complications of type 2 

diabetes are more likely to be listed as a cause of death rather than type 2 diabetes itself, and contributory factors (such as type 2 diabetes) are not routinely listed on death certificates. However, 

these features would only be expected to underestimate type 2 diabetes mortality generally and 

should not lead to differential outcome ascertainment based on exposure status. Although the 

strength of association between dioxin exposure and type 2 diabetes would likely be unaffected 

by overall underreporting of type 2 diabetes on death certificates, the VA summary of the IOM 

findings appeared to suggest that the associations observed in these mortality studies be given 

additional weight because the type 2 diabetes mortality associated with dioxin exposure is underestimated. 

Although determining the extent of type 2 diabetes risk that might be attributable to military 

service was not explicitly part of their charge, several of the committee reports address this issue 

and implicitly suggest that this fraction is likely to be small: 

It must be noted, however, that these studies indicate that the increased risk, if any, posed 

by herbicide or TCDD exposure appears to be small. The known predictors of diabetes 
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risk—family history, physical inactivity, and obesity—continue to greatly outweigh any 

suggested increased risk from wartime exposure to herbicides. 

(IOM, 2000, pp. 3, 37) 

A more explicit evaluation of attributable fraction might have been useful to policy makers 

considering this presumption by placing the scientific evidence on the link between TCDD and 

diabetes in context of overall diabetes risks, although determining the magnitude of this attributable fraction would remain difficult in the absence of accurate exposure data. 

General 

The Agent Orange and type 2 diabetes case study illustrates the challenge—both for scientists and policy makers—of evaluating evidence for an association between exposure and subsequent disease when accurate exposure data are lacking. This challenge is particularly striking for 

a disease like diabetes where multiple factors often contribute to the onset of disease, and the 

other known risk factors (e.g., genetics, obesity) are common in the general population. In this 

context, the contribution of exposures incurred during prior military service to overall disease 

risk is likely to be small as acknowledged in the IOM reports. In the absence of accurate exposure data, determining whether this small increased risk of disease is present and further quantifying the magnitude of this risk is difficult. 

Faced with this challenge of identifying a possible small increased risk of disease without accurate exposure data, it appears that policy makers have adopted an approach in the diabetes presumption that minimizes the possibility of denying service connection to a veteran whose type 2 

diabetes may have been caused by Agent Orange (maximizing sensitivity). The implicit assumption in the type 2 diabetes presumption is if any possibility exists, no matter how small, that a 

veteran may have been exposed to any amount of Agent Orange (presumption of exposure), and 

any possibility exists, no matter how small, that Agent Orange may have contributed even the 

smallest incremental increased risk of type 2 diabetes (presumption of association), service connection should be granted. 

High-quality data for a cohort of veterans are essential for improving this process. Ideally 

such data would include (1) more accurate assessments of exposure during service; (2) evaluation of other risk factors that may have been present during service or have developed after service before the onset of disease; and (3) longitudinal assessments for evaluation of diseases that 

may have long latency periods. The type 2 diabetes case study highlights the potential value of 

such an ongoing cohort study and the missed opportunities when such studies are not continued. 

The VES was the largest study of a representative group of Vietnam veterans exploring whether 

Vietnam service was associated with a variety of disease outcomes. Although this study did not 

include an assessment of exposures, the variety of measurements included after military service 

did provide some ability to address multiple other risk factors that might confound the association observed between military service and type 2 diabetes. Extension of the VES as a cohort 

study might have provided an opportunity to determine whether the observed increase in mean 

glucose levels signaled future type 2 diabetes risk, whether this risk was independent of other 

risk factors present among Vietnam veterans, and what fraction of type 2 diabetes risk is attributable to military service. 
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APPENDIX I I-113 

References 

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Classification of Diabetes Mellitus. Diabetes Care 20(7):1183-1197. 

ADA. 2003. Follow-up report on the diagnosis of diabetes mellitus. Diabetes Care 26(11):3160-3167. 

ADA. 2007. Diagnosis and classification of diabetes mellitus. Diabetes Care 30(Suppl 1):S42-S47. 

AFHS (Air Force Health Study). 2000. An epidemiologic investigation of health effects in Air Force personnel following exposure to herbicides. 1997 follow-up examination results. Reston, VA: Science 

Application International Corporation. Doc. F41624-96-C1012. 

Alberti, K. G., and P. Z. Zimmet. 1998. Definition, diagnosis and classification of diabetes mellitus and 

its complications. Part 1: Diagnosis and classification of diabetes mellitus provisional report of a 

WHO consultation. Diabetic Medicine 15(7):539-553. 

Bertazzi, P. A., I. Bernucci, G. Brambilla, D. Consonni, and A. C. Pesatori. 1998. The Seveso studies on 

early and long-term effects of dioxin exposure: A review. Environmental Health Perspectives

106(Suppl 2):625-633. 

Calvert, G. M., M. H. Sweeney, J. Deddens, and D. K. Wall. 1999. Evaluation of diabetes mellitus, serum 

glucose, and thyroid function among United States workers exposed to 2,3,7,8-tetrachlorodibenzo-pdioxin. Occupational and Environmental Medicine 56(4):270-276. 

CDC (Centers for Disease Control and Prevention). 1989a. Health status of Vietnam veterans. Synopsis. 

Vol. 1. Atlanta, GA: CDC. http://www.cdc.gov/nceh/veterans/default1c.htm (accessed June 7, 2007). 

CDC. 1989b. Health status of Vietnam veterans. Telephone interview. Vol. 2. Atlanta, GA: CDC. 

http://www.cdc.gov/nceh/veterans/default1c.htm (accessed June 7, 2007). 

CDC. 1989c. Health status of Vietnam veterans. Medical examination. Vol. 3. Atlanta, GA: CDC. 

http://www.cdc.gov/nceh/veterans/default1c.htm (accessed June 7, 2007). 

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CDVA (Commonwealth Department of Veterans’ Affairs). 1998. Morbidity of Vietnam veterans: A study 

of the health of Australia’s Vietnam veteran community. Male Vietnam veterans survey and community comparison outcomes. Vol. 1. Canberra, Australia: Department of Veterans’ Affairs. 

Cook, R. R., G. G. Bond, R. A. Olson, and M. G. Ott. 1987. Update of the mortality experience of workers exposed to chlorinated dioxins. Chemosphere 16(8-9):2111-2116. 

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D. F. Williamson. 2005. Secular trends in cardiovascular disease risk factors according to body mass index in 

U.S. adults. Journal of the American Medical Association 293(15):1868-1874. 

Henneberger, P. K., B. G. Ferris, Jr., and R. R. Monson. 1989. Mortality among pulp and paper workers 

in Berlin, New Hampshire. British Journal of Industrial Medicine 46(9):658-664. 

Henriksen, G. L., N. S. Ketchum, J. E. Michalek, and J. A. Swaby. 1997. Serum dioxin and diabetes mellitus in veterans of Operation Ranch Hand. Epidemiology 8(3):252-258. 

IOM (Institute of Medicine). 1994. Veterans and Agent Orange: Health effects of herbicides used in Vietnam. Washington, DC: National Academy Press. 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy Press. 

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IOM. 2000. Veterans and Agent Orange: Herbicide/dioxin exposure and type 2 diabetes. Washington, 

DC: National Academy Press. 

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Longnecker, M. P., and J. E. Michalek. 2000. Serum dioxin levels in relation to diabetes mellitus among 

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McLenachen, D. 2005. Presumptive service connection in the VBA. Paper presented to Veterans Disability Benefits Commission. Washington, DC. 

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tetrachlorodibenzo-p-dioxin elimination in veterans of Operation Ranch Hand. Journal of Toxicology 

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of 2,4,5-trichlorophenoxyacetic acid: Comparison of findings with and without chloracne. American 

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prognosis of chronic intoxication by tetrachlorodibenzo-p-dioxin in men. Archives of Environmental 

Health 36(1):5-11. 

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exposure and nonmalignant health effects: A mortality study. Occupational and Environmental Medicine 55(2):126-131. 

Steenland, K., L. Piacitelli, J. Deddens, M. Fingerhut, and L. I. Chang. 1999. Cancer, heart disease, and 

diabetes in workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin. Journal of the National Cancer 

Institute 91(9):779-786. 

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of combined NIOSH and Ranch Hand data. Occupational and Environmental Medicine 58(10):641-

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serum glucose levels in TCDD-exposed workers. Abstract of a paper presented at the 12th International Symposium on Chlorinated Dioxins (Dioxin ‘92), Tampere, Finland, August 24-28. 

Sweeney, M. H., G. Calvert, G. A. Egeland, M. A. Fingerhut, W. E. Halperin, and L. A. Piacitelli. 1996. 

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and Human Health—An Update, Berlin, Germany, June 17. 

Sweeney, M. H., G. Calvert, G. A. Egeland, M. A. Fingerhut, W. E. Halperin, and L. A. Piacitelli. 1997. 

Review and update of the results of the NIOSH medical study of workers exposed to chemicals contaminated with 2,3,7,8-tetrachlorodibenzodioxin. Teratogenesis, Carcinogenesis, and Mutagenesis

17(4-5):241-247. 

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with exposure to certain herbicide agents: Type 2 diabetes. Washington, DC: Office of Resource 

Management, Department of Veterans Affairs. 

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Federal Register 66(8):2376-2380. 

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regulations. Federal Register 66(89):23166-23169. 

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DepartmentalAdmin.pdf (accessed June 6, 2007). 

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DC: VBA. 

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Pesatori, R. Saracci, K. Steenland, and M. Kogevinas. 1998. Exposure to dioxin and nonneoplastic 

mortality in the expanded IARC international cohort study of phenoxy herbicide and chlorophenol 

production workers and sprayers. Environmental Health Perspectives 106(Suppl 2):645-653. 
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Von Benner, A., L. Edler, K. Mayer, and A. Zober. 1994. Dioxin investigation program of the chemical 

industry professional association. Arbeitsmedizin Sozialmedizin Praventivmedizin 29(1):11-16. 

Zober, A., M. G. Ott, and P. Messerer. 1994. Morbidity follow up study of BASF employees exposed to 

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) after a 1953 chemical reactor incident. Occupational 

and Environmental Medicine 51:479-486. 

CASE STUDY 10: SPINA BIFIDA PROGRAM 

This case study examines the 1996 and 2003 decisions to grant monetary compensation and 

health benefits to children of Vietnam and Korean War veterans with spina bifida, respectively. 

These decisions were based on scientific evidence for an association between Agent Orange and 

this developmental abnormality. This case study illustrates the issues surrounding compensation 

for reproductive health effects related to exposures incurred during military service. As spina bifida is a condition that affects the children of veterans, it is not a presumptive decision for veterans; however, the children of Vietnam and Korean War veterans are covered by a VA program. 

Reproductive Effects of Military Service 

Two categories of reproductive effects for exposures to toxic agents have been considered by 

the IOM committees charged with evaluating the evidence for adverse health effects associated 

with Agent Orange. The first category relates to the reproductive health of the exposed men and 

women and includes conditions that affect fertility and impaired ability to conceive and/or to 

bear live children. The second category relates to developmental effects in the offspring of exposed individuals, including birth defects, growth retardation, and childhood cancers. Exposure 

to certain toxic agents has long been accepted as leading to developmental abnormalities in the 

offspring of women. However, the role of paternal exposures in the etiology of developmental 

outcomes has been more challenging to understand. The Agent Orange reports review the biological plausibility for paternal exposure leading to developmental abnormalities and generally 

find evidence from both animal and human studies to support the potential for male-mediated 

developmental toxicity (IOM, 1994, 1996). 

The Need for a Spina Bifida Program 

The preceding case studies examine presumptions which serve to fill important evidentiary 

gaps (either gaps for exposure or gaps for association). The program related to spina bifida departs from this pattern in important ways. Strictly speaking, the program for spina bifida is not 

based on a presumption; however, the program operates in a similar manner as those based on 

presumptions in the type of evidence that a veteran (and their offspring) is required to produce to 

claim compensation. The reason for the program for spina bifida is that the existing compensation structure within the Department of Veterans Affairs (VA) does not provide a mechanism for 

compensating an individual other than the veteran; that is, children with developmental consequences of toxic exposures incurred by the veteran cannot be compensated by existing VA 

mechanisms for presumptions. This program creates a specific exception, allowing for compensation for one type of developmental effect (i.e., spina bifida) in specific populations (i.e., children of Vietnam and Korea veterans). Therefore, this program exists to fill a gap in legal authority and policy rather than a gap in evidence. 

It is important to note that this narrowly tailored program for spina bifida does not address 

the more general ongoing policy concern that VA is not able to compensate the adverse health 
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consequences to offspring of veterans due to exposures they may have incurred during military 

service. Through the presumptive process, VA can only compensate a veteran. 

A Brief History of the Spina Bifida Program 

Reproductive health effects were evaluated by the first IOM Agent Orange committee (IOM, 

1994). The Committee concluded that male exposure to toxins could plausibly be linked to adverse developmental consequences in their offspring, stating that 

The animal and human data indicate that the exposure of the male to various toxic agents 

may increase the risk of the full spectrum of adverse developmental endpoints from fetal 

loss to cancer. 

 (IOM, 1994, p. 595) 

However, the committee found the evidence in support of an association between Agent Orange 

and a range of birth defects to be “inadequate/insufficient” (IOM, 1994, p. 6). In VA’s Federal 

Register response to the consideration of developmental toxicities associated with Agent Orange 

exposure, VA noted that there was no mechanism within the existing VA compensation structure 

to award benefits to any party other than the veteran; providing compensation to children of veterans with developmental effects attributable to Agent Orange exposure would require additional 

legislative action (VA, 1994, p. 346). 

In the 1996 Agent Orange report (IOM, 1996), the committee included a specific evaluation 

of the evidence for the association between Agent Orange and spina bifida as “limited/suggestive.” This classification of the strength of evidence was based on the review of three 

studies in Vietnam veterans that, although limited in their ability to completely control the effects of bias, were deemed by the committee to be of high quality and demonstrate a consistent 

pattern of results (IOM, 1996). The three studies are summarized as follows. 

The CDC VES surveyed Vietnam and non-Vietnam veterans and found that Vietnam veterans were more likely to report central nervous system defects in their offspring than nonVietnam veterans (OR 2.3; 95% CI 1.2-4.5) (CDC, 1989, p. 23). A substudy that attempted to 

validate these findings with birth records failed to confirm the results, but the substudy was limited by differential participation between Vietnam and non-Vietnam veterans and by the difficulty in validating negative responses (CDC, 1988). 

The CDC Birth Defects Study was a case-control study utilizing a population-based birth defects registry in the Atlanta, Georgia area (Erickson et al., 1984a,b). Service in Vietnam was not 

associated with risk of spina bifida among the offspring of veterans; however, when an exposure 

opportunity index was used (based on interviews that evaluated which types of activities the veteran engaged in during military service), those veterans with the highest estimated level of exposure to Agent Orange had the highest risk of having children with spina bifida (OR 2.7; 95% CI 

1.2-6.2) (Erickson et al., 1984a,b, as referenced in IOM, 1996, p. 9). This study was limited by 

the low response rates among both cases and controls and the lag between the birth of the offspring and exposure assessment. 

The Ranch Hand study of Air Force personnel involved in herbicide spraying found excess 

cases of neural tube defects among offspring of the Ranch Hands, with two cases of spina bifida 

occurring among those with the highest level of exposure, and one case of spina bifida and one 

of anencephaly occurring among the low-exposure group. No cases of neural tube defects were 

observed in the nonexposed group (P = .04) (IOM, 1996, p. 9; Wolfe et al., 1995). 
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APPENDIX I I-117 

In 1996, VA noted the findings in the IOM report and again stated that providing compensation to anyone other than the veteran would require enabling legislation by Congress (VA, 1996). 

Public Law 104-204 (Departments of Veterans Affairs and Housing and Urban Development, 

and Independent Agencies Appropriation Act, 1997. 104th Cong., 2d Sess.) was passed in 1996 

and authorized benefits for children born to Vietnam veterans with spina bifida. Additional legislation in 2000 established benefits for “children of women Vietnam veterans with certain birth 

defects” (Veterans Benefits and Healthcare Improvement Act of 2000. Public Law 106-419 § 

401. 106th Cong., 2d Sess.). This law provided benefits to children of female veterans that covered a broad range of defects potentially attributable to maternal exposure during Vietnam service; however, the law excluded defects that were the result of familial predisposition or of injury suffered at birth. In 2003, these benefits were extended to children of veterans of the Korean 

War (Veterans Benefits Act of 2003. Public Law 108-103. 108th Cong., 2d Sess.). 

Lessons Learned 

With the exceptions of the legislative actions to establish the spina bifida program as well as 

the program for the children of female Vietnam veterans, there continues to be no overall 

mechanism for compensating the offspring of veterans for health consequences attributable to 

maternal and paternal exposures incurred during military service. Toxic exposures that occur 

during military service have the potential to cause adverse developmental effects, and each of the 

IOM Agent Orange reports (IOM, 1994, 1996, 1999, 2001, 2003, 2005) has described biologically plausible mechanisms for these effects in the offspring of both exposed female and male 

veterans. Given VA’s interest in compensating veterans for adverse health effects incurred as a 

result of military service and the possibility that such effects may extend to the health of veterans’ offspring, the absence of a clear and consistent mechanism and policy on compensating potentially affected offspring is notable. The need for a clear policy statement will continue to grow 

as VA considers the health effects of military service in the large population of reproductiveaged female and male veterans, especially with the growing number of women who serve in the 

military. 

Although the public laws providing compensation for particular categories of offspring with 

birth defects may have been expedient for these affected individuals, the approach of addressing 

the more general policy gap described above with these VA programs runs counter to principles 

of consistency and equity that should inform the approach for presumptions. Any new adverse 

reproductive consequences of Agent Orange exposure identified in the IOM reports would again 

require legislative action for these specific effects in order for compensation to be granted to the 

offspring of veterans; the administrative route that has applied to all other Agent Orange presumptions is not available for reproductive consequences of exposure at present. 

It is worthy of note that the evidence standard for establishing the program for spina bifida 

was “limited/suggestive evidence of an association” not the more rigorous “sufficient” classification. The challenges in using this lower evidence classification as the basis for VA’s presumptions have been described in case studies related to Agent Orange and prostate cancer and type 2 

diabetes. 

References 

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CDC. 1989. Health status of Vietnam veterans: Reproductive outcomes and child health. Vol. 5. Atlanta, 

GA: Centers for Disease Control. http://www.cdc.gov/nceh/veterans/default1c.htm (accessed July 1, 

2007). 

Erickson, J. D., J. Mulinare, P. W. McClain, T. G. Fitch, L. M. James, A. B. McClearn, and M. J. Adams, 

Jr. 1984a. Vietnam veterans’ risks for fathering babies with birth defects. Atlanta, GA: Centers for 

Disease Control. 

Erickson, J. D., J. Mulinare, P. W. McClain, T. G. Fitch, L. M. James, A. B. McClearn, and M. J. Adams, 

Jr. 1984b. Vietnam veterans’ risks for fathering babies with birth defects. Journal of the American 

Medical Association 252(7):903-912. 

IOM (Institute of Medicine). 1994. Veterans and Agent Orange: Health effects of herbicides used in Vietnam. Washington, DC: National Academy Press. 

IOM. 1996. Veterans and Agent Orange: Update 1996. Washington, DC: National Academy Press. 

IOM. 1999. Veterans and Agent Orange: Update 1998. Washington, DC: National Academy Press. 

IOM. 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy Press. 

IOM. 2003. Veterans and Agent Orange: Update 2002. Washington, DC: The National Academies Press. 

IOM. 2005. Veterans and Agent Orange: Update 2004. Washington, DC: The National Academies Press. 

VA (Department of Veterans Affairs). 1994. Disease not associated with exposure to certain herbicide 

agents. Notice. Federal Register 59(2):341-346. 

VA. 1996. Disease not associated with exposure to certain herbicide agents. Federal Register

61(154):41442-41449. 

Wolfe, W. H., J. E. Michalek, J. C. Miner, A. J. Rahe, C. A. Moore, L. L. Needham, and D. G. Patterson, 

Jr. 1995. Paternal serum dioxin and reproductive outcomes among veterans of Operation Ranch 

Hand. Epidemiology 6(1):17-22. 
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J-1 

Appendix J 

Causation and Statistical Causal Methods 

In this appendix we provide more detail about the meaning of general causal claims, and how 

the qualitative aspects of causal claims can be precisely modeled. Substantial progress has been 

made on this front in the last two decades (see Pearl, 2000; Spirtes et al., 2000). 

INDIVIDUAL- VERSUS POPULATION-LEVEL CAUSAL CLAIMS 

First, consider the difference between individual- and population-level causal claims. In legal 

contexts, the goal is often to establish whether one particular event was the cause of another particular event. For example, if a child who lives near a chemical factory contracts a rare cancer, a 

court might seek to establish whether or not a chemical spill adjacent to the child’s property was 

the “cause” of his or her particular cancer. By saying that the chemical spill caused the disease, 

we mean that the cancer would not have occurred had the spill not happened (“but for exposure” 

in legal terms). This is an individual-level causal claim. For cases in which a particular veteran 

seeks to service connect a particular disease or disability he or she has contracted after separation 

from the service is, if causation is the standard, an instance of establishing an individual-level 

causal claim. 

In epidemiologic or scientific contexts, however, the goal is often to establish whether, in a 

population of individuals, generic sorts of exposures result in a change in the frequency or average severity of a disease. For example, an epidemiologist might ask whether the frequency of 

abnormal births among American women who were exposed to polychlorinated biphenyls 

(PCBs) during pregnancy is higher than the frequency among those who were not. If so, then 

epidemiologists might assert that exposure to PCBs during pregnancy is capable of causing birth 

defects. The causal claim about the population does not entail that every fetus whose mother is 

exposed to PCBs during pregnancy will develop birth defects, and it does not entail that every 

birth defect would not have happened but for PCB exposure. On the population level, causal 

claims typically involve how the probability distribution of the disease changes in response to 

exposure. When either Congress or the Department of Veterans Affairs seeks to presumptively 

service-connect a particular health condition or disability to a particular population of veterans, 

establishing a population-level causal claim is required. 
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J-2 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

CAUSATION AND COUNTERFACTUALS 

Beginning in the 1970s, Rubin (1974) and many after him developed a formal theory of 

causal inference based on counterfactuals, which play an essential role in both individual- and 

population-level causal claims. On the individual level, for example, we might observe that a 

particular person was exposed to a chemical and later contracted a disease. The question we 

would like to answer is counterfactual: What would have happened had the same individual not

been exposed to the chemical? Likewise, for other individuals who were not exposed, we might 

like to know what would have happened had they been exposed. 

On the population level the questions are similar. We observe that a population of individuals, such as Gulf War veterans, were exposed to a variety of conditions and substances in their 

tour of duty in the Mideast and then exhibited a certain frequency of illness years later. The 

population question we would like to answer is counterfactual: What would the frequency of illnesses have been had the same population not been exposed to the conditions and substances 

they were exposed to in the Gulf War? 

In Rubin’s framework, analyzing randomized clinical trials that involve assigning one group 

to treatment and another to control is a counterfactual missing data problem. For all the people in 

the treatment group, we are missing data on their response had they been assigned to the control 

group, and symmetrically for the control group. 

INTERVENTION 

Underneath these counterfactuals, however, is a subtle but crucial assumption about how the 

world should be imagined to have been different. Recall that “exposure to excessive radiation 

caused Mary to get leukemia” means that “had Mary not been exposed to excessive radiation she 

would not have gotten leukemia.” This makes sense if we envision a world identical to the one 

Mary did experience, but change it minimally by intervening to prevent her from being exposed 

to excessive radiation. 

Consider a slightly different example, however. Suppose John smoked 30 roll-your-own 

cigarettes a day from age 25 to 50, had intensely tar-stained fingers during this period, and got 

lung cancer at the age of 51. 

Sticking with common sense, we will assume that smoking caused John to have both tarstained fingers and lung cancer, but that having tar-stained fingers has no causal influence on 

getting lung cancer (Figure J-1). By the counterfactual theory, the following ought then to be 

true: “Had John not had tar-stained fingers, he would have gotten lung cancer anyway.” To 

make sense of this counterfactual, we might envision a world in which John still smoked, but either smoked packaged cigarettes that produced no finger stains or washed his hands with tarFIGURE J-1 Causal structure for smoking, tar-stained fingers, and lung cancer. 
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APPENDIX J J-3 

FIGURE J-2 Hypothetical intervention on finger tar stains.

solvent soap every night. Some might object and say: “What I think of when I hear ‘Had John

not had tar-stained fingers’ is a situation in which he didn’t smoke—and in that case he wouldn’t

have gotten lung cancer!” Again, to make sense of the counterfactual: “Had John not had tarstained fingers, he would have gotten lung cancer anyway,” we must imagine a world in which 

we directly change only whether John had tar-stained fingers and leave the rest of the story intact 

(Figure J-2).

Further, in such a world our hypothetical intervention destroys any influence smoking might 

have had on whether John had tar-stained fingers in the real world. If it didn’t, we could not 

make sense of the hypothetical. 

These points apply directly to the same population claims we used above to illustrate presumptive service connection. When we ask the question, “What would the frequency of illnesses 

have been among Gulf War veterans had they not been exposed to the conditions and substances 

they were exposed to in the Gulf War?” we don’t mean to imagine a world in which these veterans never signed up for the armed forces because they were medically unfit for duty. Instead, we 

mean to imagine a world in which everything about them was the same, but they were prevented 

from being exposed to the conditions and substances they were exposed to in the Gulf War. This 

is the counterfactual that bears on presumptive service connection. 

So a theory of causation must model hypothetical interventions that are tightly targeted, and, 

most importantly, describe how the world would react to any sort of ideal, hypothetical intervention or treatment we can imagine. Further, the theory ought to make the connection with statistical evidence clear. Over the last two decades, epidemiologists,1

 computer scientists,2 philosophers,3

 and statisticians4 have developed a theory of statistical causal inference that incorporates 

the virtues of Rubin’s counterfactual account but also models interventions and provides a clear 

connection to statistical evidence as it bears on causal claims. Below we present the briefest possible introduction to this theory. More detail is available in Robins (1986, 1988), Pearl (2000), 

Spirtes et al. (2000), Dawid (2004), Cox and Wermuth (2004), and many other sources. 

 1 Sander Greenland, Jamie Robins, and others. 

2 Judea Pearl, David Heckerman, Greg Cooper, and many others. 

3 Peter Spirtes, Clark Glymour, Richard Scheines, Jim Woodward, Dan Hausmann, and many others. 

4 David Cox, Nanny Wermuth, Phil Dawid, Paul Rosenbaum, Thomas Richardson, Larry Wasserman, and many 

others. 
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J-4 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

CAUSAL STATISTICAL MODELS 

The kind of causal theories and statistical evidence relevant to presumptive serviceconnection decisions involve a population and a set of variables, or factors. A population denotes 

a (potentially infinite) group of individuals, such as Vietnam War veterans, or American men 

over the age of 60, or all possible offspring of a heterozygous and homozygous pea plant. A set 

of variables describe properties of such individuals that might cause each other, such as exposed 

to Agent Orange (yes, no), smoked (no, lightly, heavily), lung cancer (yes, no), yearly income (in 

dollars), and so on. 

The qualitative part of a causal theory, that is, which variables are causes of which other 

variables and which are not, can be represented with a causal graph, that is, a diagram involving 

arrows that connect the variables. See Neapolitan (2004), Pearl (2000), Spirtes et al. (2000), and 

Glymour and Cooper (1999). For example, consider the causal graph in Figure J-3. 

To be concrete, let us assume that this model is meant to apply to a population of 4-year-old 

American children. Further, suppose the variables are the following: 

• Exposure (yes, no)—Yes, if exposed to another child who was within 2 days of symptomatic chicken pox. 

• Infection (yes, no)—Yes, if chicken pox virus was active in bloodstream. 

• Rash (yes, no)—Yes, if rash appeared. 

Then each arrow in the causal diagram depicts a claim about direct causation relative to this set 

of variables and this population. In this case, the diagram claims that 

• exposure is a direct cause of infection, and 

• infection is a direct cause of rash, and 

• that no other direct causal claims hold among these variables in this population, including 

the claim that exposure is a direct cause of rash. 

DEFINITION OF DIRECT CAUSATION 

The presence of an arrow from one variable, such as exposure, to another, such as infection, 

means that, holding all the other variables in the system fixed, changing the assignment of exposure will result in some change in the probability of infection.5

 The absence of an arrow, for example the absence of an arrow from exposure to rash, means that, holding the other variables (infection) fixed, changing the assignment of exposure will not result in any change in the 

probability of rash. 

FIGURE J-3 Chicken pox. 

 5 More fully, X Æ Y just in case there exists any set of assignments for the variables besides X and Y such that 

there exists some change of assignments for X such that the probability distribution for Y changes. 
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APPENDIX J J-5 

Notice the role of possibly counterfactual interventions. When we say “holding fixed,” or 

“changing the assignment,” we are referring to hypothetical interventions in which we set or assign the value of a variable. 

The quantitative part of a causal theory involves specifying a probability model that accords 

with the qualitative model. The full model with both graph and probability distribution is called a 

Causal Bayes Network. See Pearl (2000), Spirtes et al. (2000), and Neopolitan (2004). For each 

variable in the system, we express its probability distribution as a function of its direct causes. 

That is, we specify the way in which each effect responds to any set of values its direct causes 

might take on, and, since it is a population we are talking about, we need to express this response 

probabilistically. For example, in the chicken pox case, we might give the whole causal model—

both its qualitative and quantitative parts—with a causal diagram and a table expressing the response structure for each variable (Figure J-4). 

Because exposure has no immediate causes in our model, the hypothetical quantitative table 

just gives how probable it is for a 4-year-old American child to be exposed to another child who 

is infected and within 2 days of exhibiting chicken pox symptoms. Note that the numbers in this 

table are purely for illustration and do not reflect actual data. The probability of infection is 

given as a function of its immediate causes—in this case exposure. It claims that if a child is exposed to another child with chicken pox, then they have an 80 percent chance of becoming infected themselves, but if they are not exposed to another child with chicken pox, they have just a 

3 percent chance of becoming infected. 

We compute the joint probability distribution over the variables V as the product of the conditional probability of each variable on its direct causes: 

∏∈

=

V V

P( VP direct |()V V ) of causes

Having the joint distribution allows us to compute the probability of any variable conditional on 

an observation for any other variable or set of variables. For example, in the chicken pox model, 

we can compute the probability of exposure conditional on observing that a child is infected or 

conditional on having a rash, or the probability of rash conditional on observing exposure, and 

so on. 

Most importantly, these models allow us to explicitly represent hypothetical interventions. 

The rule is simple: add an “intervention” variable to the system and draw an arrow to the variables targeted by the intervention. If the intervention determines the probability of its targets⎯for example, a randomizer that assigns subjects to treatment or control⎯erase the other 

arrows that previously went into these targets, and change the quantitative model accordingly. 

For example, suppose we wanted to model an intervention in which we assigned everyone in 

our population of 4-year-old children to be infected with the chicken pox virus (by injection). 

Then the resulting “intervened upon” system would be as shown in Figure J-5. 

Computing the joint distribution after an intervention goes the same way as for preintervention systems, but the results will sometimes differ, and it is this difference that captures the 

causal part of the model. For example, in the chicken pox model prior to our intervention (Figure 

J-4), the probability of exposure given infection is higher than 0.1, as in P(Exposure = yes | Infection = yes) > 0.1, but in the intervened-upon version of the system (Figure J-5), P(Exposure = 

yes | Infection set = yes) = 0.1 = P(Exposure). This is because the intervention on infection eliminated the causal connection between exposure and infection, and thus changed their informational relationship as well. 
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J-6 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Exposure Infection Rash 

P(Exposure = yes) = 0.1

P(Infection = yes | Exposure = yes) = 0.8 

P(Infection = yes | Exposure = no) = 0.03 

P(Rash = yes | Infection = yes) = 0.2 

P(Rash = yes | Infection = no) = 0 

Qualitative Model 

Quantitative Model

FIGURE J-4 Hypothetical statistical causal model for chicken pox. 

Exposure Infection Rash 

P(Exposure = yes) = 0.1

P(Infection = yes | Intervention) = 1 

P(Rash = yes | Infection = yes) = 0.2

P(Rash = yes | Infection = no) = 0 

Qualitative Model 

Quantitative Model 

Intervention 

FIGURE J-5 Hypothetical intervention in the chicken pox system. 

As this point cannot be emphasized enough, and as it underlies the difference between association and causation, consider another case in which two models agree about things prior to an 

intervention but differ about things after an intervention. Consider two distinct causal models of 

the relationship between a child’s exposure to environmental lead and their cognitive function 

measured by IQ (Figure J-6). 
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APPENDIX J J-7 

FIGURE J-6 Two hypothetical models of lead exposure and cognitive function.

 In model 1 (M1), lead and IQ are effects of a common cause, parental resources, but have 

no influence on each other. We assume that parents with more resources will choose environments with less lead, and provide the stimulation necessary to increase their child’s measured IQ. 

In model 2 (M2), lead is a direct negative cause of IQ. Supposing that the level of parental resources remains unmeasured, it is easy to attach quantitative values for both models such that the 

probability distributions over the measured variables lead and IQ are identical. In that case, 

P(IQ | Lead)M1 = P(IQ | Lead)M2. That is, predictions about IQ from observations of lead exposure are implied to be identical in both models. Put another way, the association between lead 

and IQ implied by M1 can just as well be implied by M2 and vice versa. 

It is not possible, however, for the models to agree about the relationship after a hypothetical 

intervention that sets the value of lead exposure: P(IQ | Leadset by intervention)M1 ≠ P(IQ | Leadset by 

intervention)M2. That is because a hypothetical intervention, or treatment, on lead, changes M1 in a 

way that makes lead and IQ independent, but leaves the causal dependence of lead and IQ unperturbed in M2 (Figure J-7). 

So M1 and M2 can agree completely on the population we observe, but differ on the sorts of 

counterfactuals that underlie presumptive service connections. M2 supports counterfactuals of 

the sort: “Had Jonathan not been exposed to lead, he wouldn’t have scored below average on the 

IQ test,” but M1 does not. If M1 is true (and clearly that is a big if), then hypothetically changing 

the amount of lead Jonathan was exposed to leaves his IQ the same, for in M1 it is not lead that 

FIGURE J-7 Hypothetical postintervention models of lead and IQ. 
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J-8 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

causes IQ but parental resources. In all likelihood the “correct” model is a combination of M1 

and M2: one in which any observed negative association between lead exposure and IQ is due to 

both a common cause and a direct causal influence. 

Equipped with the correct causal model connecting military service (or a particular exposure 

in service) for an identified group and a health outcome, both qualitatively and quantitatively, we 

can compute the probability of this outcome in the counterfactual world in which the group was

not exposed to the conditions and substances of military service and compare this to the probability of the outcome that we actually observed. This computation, of course, depends crucially 

on the model we consider “correct.” 

For example, consider the three hypothetical causal models shown in Figure J-8. Suppose 

that we didn’t know which of these models was an accurate representation of the world. Suppose 

further that we collected a sample of 255 subjects, and for each recorded whether they had been 

exposed to some substance (Exposure), whether they had the disease in question (Health Outcome), and whether or not they showed evidence of some covariate, for example low income. 

We show purely hypothetical data table in Table J-1. The analysis of this dataset under the three 

models in Figure J-8 would yield three quite different estimates of the relative risk (RR) and any 

of the other epidemiologic parameters derived from it, for example, the population attributable 

risk (PAR). Under model M1, which asserts that Exposure causes Health Outcome and that the 

relationship is not confounded, we would ignore the covariate and estimate the RR from the 

crude odds ratio between exposure and disease, [(155/45) / (100/100)] = 3.44 (95% confidence 

interval [CI] 2.23-5.31). Under model M2, on the other hand, which asserts that Exposure is not 

a cause of Health Outcome at all, and that any observed association is due entirely to confounding, we would ignore the apparent association in the data and conclude based solely on the model 

that there was no causal association between exposure and disease (i.e., OR = 1.0). Finally, under model M3, which asserts that Exposure causes Health Outcome but that the two are also confounded, we would have to adjust for the confounder and obtain the adjusted OR = 3.03 (95% CI 

1.93-4.73). 

For these data, neither model M1 nor M2 fits the observed data very well, so we would need 

very compelling prior knowledge to accept them over M3. If, however, we had no recorded data 

on the covariate, then we could not distinguish between the three models. 

TABLE J-1 Hypothetical Exposure and Health Outcome Data 

Exposure Covariate 

Health Outcome = 

No Disease Health Outcome = Disease 

No 60 19 

Yes 40 26 

No 

Total 100 45 

No 40 39 

Yes 60 116 

Yes 

Total 100 155 
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APPENDIX J J-9 

Confounder/Covariate 

Exposure to 

Substance 

Health 

Outcome 

Exposure to 

Substance 

Health 

Outcome 

M1 M2

Confounder/Covariate 

Exposure to 

Substance 

Health 

Outcome 

M3

FIGURE J-8 Three hypothetical causal models connecting exposure/disease. 

So given the correct causal model, and the knowledge that it is the right causal model, we can 

compute the quantities we need to entertain questions about service connection and presumptive 

service connection. 

REFERENCES 

Cox, D. R., and N. Wermuth. 2004. Causality: A statistical view. International Statistical Review 72:285-

305. 

Dawid, A. P. 2004. Probability, causality and the empirical world: A Bayes-de Dinetti-Popper-Borel synthesis. Statistical Science 19:44-57. 

Glymour, C., and G. F. Cooper, eds. 1999. Computation, causation, and discovery. Menlo Park, CA: 

AAAI Press/Cambridge, MA: MIT Press. 

Neapolitan, R. E. 2004. Learning Bayesian networks. Upper Saddle River, NJ: Pearson Prentice Hall. 

Pearl, J. 2000. Causality: Models, reasoning, and inference. New York: Cambridge University Press. 

Robins, J. M. 1986. A new approach to causal inference in mortality studies with sustained exposure 

periods—application to control of the healthy worker survivor effect. Mathematical Modelling

1986(7):1393-512 (errata appeared in Computers and Mathematics with Applications 1987(14): 

917-921). 

Robins, J. M. 1988. Confidence intervals for causal parameters. Statistics in Medicine 7:773-85. 

Rubin, D. B. 1974. Estimating causal effects of treatments in randomized and nonrandomized studies. 

Journal of Educational Psychology 56:688-701. 

Spirtes, P., C. Glymour, and R. Scheines. 2000. Causation, prediction, and search. 2nd ed. Boston, MA: 

MIT Press. 
Copyright © National Academy of Sciences. All rights reserved.

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K-1 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Appendix K 

Sources of Health and Exposure 

Data for Veterans 

APPENDIX K-1 

BIBLIOGRAPHY OF DEPARTMENT OF VETERANS AFFAIRS EPIDEMIOLOGIC 

STUDIES OF VETERANS

Publication/VHA Environmental Epidemiology Service1

Gulf War Veterans 

Blanchard, M. S., S. A. Eisen, R. Alpern, J. Karlinsky, R. Toomey, D. J. Reda, F. M. Murphy, L. W. 

Jackson, and H. K. Kang. 2006. Chronic multisymptom illness complex in Gulf War I veterans 10 

years later. American Journal of Epidemiology 163(1):66-75. 

Bullman, T. A., C. M. Mahan, H. K. Kang, and W. F. Page. 2005. Mortality in U.S. Army Gulf War 

veterans exposed to 1991 Khamisiyah chemical munitions destruction. American Journal of Public 

Health 95(8):1382-1388. 

Davis, L. E., S. A. Eisen, F. M. Murphy, R. Alpern, B. J. Parks, M. Blanchard, D. J. Reda, M. K. King, 

F. A. Mithen, and H. K. Kang. 2004. Clinical and laboratory assessment of distal peripheral nerves in 

Gulf War veterans and spouses. Neurology 63(6):1070-1077. 

Eisen, S. A., H. K. Kang, F. M. Murphy, M. S. Blanchard, D. J. Reda, W. G. Henderson, R. Toomey, 

L. W. Jackson, R. Alpern, B. J. Parks, N. Klimas, C. Hall, H. S. Pak, J. Hunter, J. Karlinsky, M. J. 

Battistone, M. J. Lyons, and the Gulf War Study Participating Investigators. 2005. Gulf War veterans’ 

health: Medical evaluation of a U.S. cohort. Annals of Internal Medicine 142(11):881-890. 

Eisen, S. A., J. Karlinsky, L. W. Jackson, M. Blanchard, H. K. Kang, F. M. Murphy, R. Alpern, R. J. 

Domenic, R. Toomey, M. J. Battistone, B. J. Parks, N. Klimas, H. S. Pak, J. Hunter, M. J. Lyons, and 

W. G. Henderson. 2006. Spouses of Gulf War I veterans: Medical evaluation of a U.S. cohort. 

Military Medicine 171(7):613-618. 

Gackstetter, G. D., T. I. Hooper, S. F. DeBakey, A. Johnson, B. E. Nagaraj, J. M. Heller, and H. K. Kang. 

2006. Fatal motor vehicle crashes among veterans of the 1991 Gulf War and exposure to munitions 

 

1

List provided by Kang, H. K. 2006. Publication/VA Environmental Epidemiology Service. Presented at 

the second committee meeting of the Institute of Medicine’s Committee on the Evaluation of the 

Presumptive Disability Decision-Making Process for Veterans. July 27. Washington, DC. 
Copyright © National Academy of Sciences. All rights reserved.

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K-2 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

demolitions at Khamisiyah: A nested case control study. American Journal of Industrial Medicine

49(4):261-270. 

Gray, G. C., and H. K. Kang. 2006. Healthcare utilization and mortality among veterans of the Gulf War. 

Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences

361(1468):553-569. 

Gray, G. C., B. D. Coates, C. M. Anderson, H. K. Kang, S. W. Berg, F. S. Wignall, J. D. Knoke, and E. 

Barrett-Connor. 1996. The postwar hospitalization experience of U.S. veterans of the Persian Gulf 

War. New England Journal of Medicine 335(20):1505-1513. 

Gray, G. C., A. W. Hawksworth, T. C. Smith, H. K. Kang, J. D. Knoke, and G. D. Gackstetter. 1998. Gulf 

War veterans’ health registries. Who is most likely to seek evaluation? American Journal of 

Epidemiology 148(4):343-349. 

Gray, G. C., T. C. Smith, H. K. Kang, and J. D. Knoke. 2000. Are Gulf War veterans suffering warrelated illnesses? Federal and civilian hospitalizations examined, June 1991 to December 1994. 

American Journal of Epidemiology 151(1):63-71. 

Gray, G. C., G. D. Gackstetter, H. K. Kang, J. T. Graham, and K. C. Scott. 2004. After more than 10 

years of Gulf War veteran medical evaluation, what have we learned? American Journal of 

Preventive Medicine 26(5):443-452. 

Hallman, W. K., H. M. Kipen, M. Diefenbach, K. Boyd, H. Kang, H. Leventhal, and D. Wartenberg. 

2003. Symptom patterns among Gulf War Registry veterans. American Journal of Public Health

93(4):624-630. 

Hooper, T. I., S. F. DeBakey, A. Lincoln, H. K. Kang, D. N. Cowan, and G. D. Gackstetter. 2005. 

Leveraging existing databases to study vehicle crashes in combat occupational cohort: Epidemiologic 

methods. American Journal of Industrial Medicine 48(2):118-127. 

Hooper, T. I., S. F. DeBakey, K. S. Bellis, H. K. Kang, D. N. Cowan, A. Lincoln, and G. D. Gackstetter. 

2006. Understanding the effect of deployment on the risk of fatal motor vehicle crashes: A nested 

case-control study of fatalities in Gulf War era veterans, 1991-1995. Accident; Analysis and 

Prevention 38(3):518-525. 

Kang, H. K., and T. A. Bullman. 1996. Mortality among U.S. veterans of the Persian Gulf War. New 

England Journal of Medicine 335(20):1498-1504. 

Kang, H. K., and T. A. Bullman. 1998. Counterpoint: Negligible “healthy-warrior effect” on Gulf War 

veterans’ mortality. American Journal of Epidemiology 148(4):324-325. 

Kang, H. K., and T. A. Bullman. 2001. Mortality among U.S. veterans of the Persian Gulf War: 7-year 

follow-up. American Journal of Epidemiology 154(5):399-405. 

Kang, H. K., and K. C. Hyams. 2005. Mental health care needs among recent war veterans. New England 

Journal of Medicine 352(13):1289. 

Kang, H. K., C. M. Mahan, K. Y. Lee, C. A. Magee, and F. M. Murphy. 2000. Illnesses among United 

States veterans of Gulf War: A population-based survey of 30,000 veterans. Journal of Occupational 

and Environmental Medicine 42(5):491-501. 

Kang, H. K., C. M. Mahan, K. Y. Lee, F. M. Murphy, S. J. Simmens, H. A. Young, and P. H. Levine. 

2002a. Evidence for a deployment related Gulf War syndrome by factor analysis. Archives of 

Environmental Health 57(1):61-68. 

Kang, H. K., T. A. Bullman, G. J. Macfarlane, and G. C. Gray. 2002b. Mortality among U.S. and UK 

veterans of the Persian Gulf War: A review. Occupational and Environmental Medicine 59(12): 

794-799. 

Kang, H. K., B. H. Natelson, C. M. Mahan, K. Y. Lee, and F. M. Murphy. 2003. Post-traumatic stress 

disorder and chronic fatigue syndrome-like illness among Gulf War veterans: A population based 

survey of 30,000 veterans. American Journal of Epidemiology 157(2):141-148. 

Karlinsky, J. B., M. Blanchard, R. Alpern, S. A. Eisen, H. K. Kang, F. M. Murphy, and D. Reda. 2004. 

Late prevalence of respiratory symptoms and pulmonary function abnormalities in Gulf War 1 

veterans. Archives of Internal Medicine 164(22):2488-2491. 
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APPENDIX K K-3 

Kipen, H. M., W. Hallman, H. K. Kang, N. Fiedler, and B. H. Natelson. 1999. Prevalence of chronic 

fatigue and chemical sensitivities in Gulf Registry veterans. Archives of Environmental Health

54(5):313-318. 

Levine, P. H., H. A. Young, S. J. Simmens, D. Rentz, V. E. Kofie, C. M. Mahan, and H. K. Kang. 2004. 

Is testicular cancer related to Gulf War deployment? Evidence from a pilot population-based study of 

Gulf War era veterans and cancer registries. Military Medicine 170(2):149-153. 

Lincoln, A. E., T. I. Hooper, H. K. Kang, S. F. Debakey, D. N. Cowan, and G. D. Gackstetter. 2006. 

Motor vehicle fatalities among Gulf War era veterans: Characteristics, mechanisms and 

circumstances. Traffic Injury Prevention 7(1):31-37. 

Mahan, C. M., H. K. Kang, N. A. Dalager, and J. M. Heller. 2004. Anthrax vaccination and self-reported 

symptoms, functional status, and medical conditions in the National Health Survey of Gulf War Era 

Veterans and Their Families. Annals of Epidemiology 14(2):81-88. 

Miller, R. N., D. J. Costigan, H. A. Young, H. K. Kang, N. Dalager, R. W. Mathes, H. C. Crawford, W. F. 

Page, and S. Thaul. 2006. Patterns of health care seeking of Persian Gulf War Registry members prior 

to deployment. Military Medicine 171(5):370-375. 

Murphy, F. M., H. K. Kang, N. A. Dalager, K. Y. Lee, R. E. Allen, S. H. Mather, and K. W. Kizer. 1999. 

The health status of Gulf War veterans: Lessons learned from the Department of Veterans Affairs 

Health Registry. Military Medicine 164(5):327-331. 

Page, W. F., C. M. Mahan, H. K. Kang, and T. A. Bullman. 2005a. Health effects in Army Gulf War 

veterans possibly exposed to chemical munitions destruction at Khamisiyah, Iraq: Part II. Morbidity 

associated with notification of potential exposure. Military Medicine 170(11):945-951. 

Page, W. F., C. M. Mahan, T. A. Bullman, and H. K. Kang. 2005b. Health effects in Army Gulf War 

veterans possibly exposed to chemical munitions destruction at Khamisiyah, Iraq: Part I. Morbidity 

associated with potential exposure. Military Medicine 170(11):935-944. 

Persian Gulf Veterans Coordinating Board. 1995. Unexplained illnesses among Desert Storm veterans: A 

search for causes, treatment, and cooperation. Archives of Internal Medicine 155(3):262-268. 

Smith, T. C., B. Smith, M. A. Ryan, G. C. Gray, T. I. Hooper, J. M. Heller, N. A. Dalager, H. K. Kang, 

and G. D. Gackstetter. 2002. Ten years and 100,000 participants later: Occupational and other factors 

influencing participation in U.S. Gulf War health registries. Journal of Occupational and 

Environmental Medicine 44(8):758-768. 

Smith, T. C., D. L. Jimenez, B. Smith, G. C. Gray, T. I. Hooper, G. D. Gackstetter, J. M. Heller, N. A. 

Dalager, H. K. Kang, K. C. Hyams, and M. A. Ryan. 2004. The postwar hospitalization experience of 

Gulf War veterans participating in U.S. health registries. Journal of Occupational and Environmental 

Medicine 46(4):386-397. 

Young, H. A., S. J. Simmens, H. K. Kang, C. M. Mahan, and P. H. Levine. 2003. Factor analysis of 

fatiguing syndrome in Gulf War era veterans: Implications for etiology and pathogenesis. Journal of 

Occupational and Environmental Medicine 45(12):1268-1273. 

Women Veterans 

Dalager, N. A., H. K. Kang, and T. L. Thomas. 1995. Cancer mortality patterns among women who 

served in the military: The Vietnam experience. Journal of Occupational Medicine 37(3):298-305. 

Kang, H. K., C. M. Mahan, K. Y. Lee, C. A. Magee, and S. Selvin. 2000a. Prevalence of gynecological 

cancers among women Vietnam veterans. Journal of Occupational and Environmental Medicine

42(11):1121-1127. 

Kang, H. K., C. M. Mahan, K. Y. Lee, C. A. Magee, S. H. Mather, and G. Matanoski. 2000b. Pregnancy 

outcomes among U.S. women Vietnam veterans. American Journal of Industrial Medicine 38(4):447-

454. 

Kang, H. K., C. Magee, C. Mahan, K. Lee, F. Murphy, L. Jackson, and G. Matanoski. 2001. Pregnancy 

outcomes among U.S. Gulf War veterans: A population-based survey of 30,000 veterans. Annals of 

Epidemiology 11(7):504-511. 
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K-4 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Kang, H. K., N. A. Dalager, C. M. Mahan, and E. Ishii. 2005. The role of sexual assault on the risk of 

PTSD among Gulf War veterans. Annals of Epidemiology 15(3):191-195. 

Thomas, T. L., H. K. Kang, and N. A. Dalager. 1991. Mortality among women Vietnam veterans, 1973-

1987. American Journal of Epidemiology 134(9):973-980. 

Atomic Veterans and Radiation Exposure 

Dalager, N. A., H. K. Kang, and C. M. Mahan. 2000. Cancer mortality among the highest exposed U.S. 

atmospheric nuclear test participants. Journal of Occupational and Environmental Medicine

42(8):798-805. 

Kang, H. K. 1996. Feasibility of an epidemiologic study of submariners who received radium irradiation 

treatment. Otolaryngology-Head and Neck Surgery 115(5):433-437. 

Kang, H. K., T. A. Bullman, and C. M. Mahan. 2000. A mortality follow-up study of WWII submariners 

who received nasopharyngeal radium irradiation treatment. American Journal of Industrial Medicine

38(4):441-446. 

Watanabe, K. K., H. K. Kang, and N. A. Dalager. Cancer mortality risk among military participants of a 

1958 atmospheric nuclear weapons test. American Journal of Public Health 85(4):523-527. 

Others (POWs, Mustard Gas) 

Bullman, T. A., and H. K. Kang. 1994. The effects of mustard gas, ionizing radiation, herbicides, trauma, 

and oil smoke on U.S. military personnel: The results of veterans studies. Annual Review of Public 

Health 15:69-90. 

Bullman, T. A., and H. K. Kang. 2000. A fifty year mortality follow-up study of veterans exposed to low 

level chemical warfare agent, mustard gas. Annals of Epidemiology 10(5):333-338. 

Kang, H. K. 1991. Resources for epidemiologic research in Vietnam era veteran populations within the 

Department of Veterans Affairs. in Epidemiology in military and veteran populations: Proceedings of 

the second biennial conference, March 7, 1990, edited by W. F. Page. Washington, DC: National 

Academy Press. Pp. 97-103. 

Kang, H. K., and P. P. Breslin. 1986. Effects of military draft on mortality. New England Journal of 

Medicine 315:454. 

Kang, H. K., and T. L. Thomas. 1990. Comment. National sources of vital status information: Extent of 

coverage and possible selectivity in reporting. American Journal of Epidemiology 132(6):1196-1197. 

Kang, H. K., T. A. Bullman, and J. W. Taylor. 2006. Risk of selected cardiovascular diseases and 

posttraumatic stress disorder among former World War II prisoners of war. Annals of Epidemiology

16(5):381-386. 

Page, W. F., C. M. Mahan, and H. K. Kang. 1996. Vital status ascertainment through the files of the 

Department of Veterans Affairs and the Social Security Administration. Annals of Epidemiology

6(2):102-109. 

Schneiderman, A. I., A. E. Lincoln, B. A. Curbow, and H. K. Kang. 2004. Racial variations in health 

communication needs of combat veterans. American Journal of Public Health 94(12):2074-2076. 

Vietnam Veterans 

Breslin, P., H. K. Kang, Y. Lee, V. Burt, and B. M. Shepard. 1988. Proportionate mortality study of Army 

and Marine Corps veterans of the Vietnam War. Journal of Occupational Medicine 30(5):412-419. 

Bullman, T. A., and H. K. Kang. 1994. Posttraumatic stress disorder and the risk of traumatic deaths 

among Vietnam veterans. Journal of Nervous and Mental Disorder 182(11):604-610. 

Bullman, T. A., and H. K. Kang. 1995. A study of suicide among Vietnam veterans. Federal Practitioner

12:9-13. 
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APPENDIX K K-5 

Bullman, T. A., and H. K. Kang. 1996. Risk of suicide among wounded Vietnam veterans. American 

Journal of Public Health 86(5):662-667. 

Bullman, T. A., and H. K. Kang. 1997. Posttraumatic stress disorder and the risk of traumatic death 

among Vietnam veterans. In Posttraumatic stress disorder: Acute and long-term responses to trauma 

and disaster, edited by C. S. Fullerton and R. J. Ursano. Washington, DC: American Psychiatric 

Press, Inc. Pp. 175-190. 

Bullman, T. A., H. K. Kang, and K. K. Watanabe. 1990. Proportionate mortality among U.S. Army 

Vietnam veterans who served in military region I. American Journal of Epidemiology 132(4): 

670-674. 

Bullman, T. A., H. K. Kang, and T. L. Thomas. 1991. Posttraumatic stress disorder among Vietnam 

veterans on the Agent Orange Registry: A case-control analysis. Annals of Epidemiology 1(6): 

505-512. 

Bullman, T. A., K. K. Watanabe, and H. K. Kang. 1994. Risk of testicular cancer associated with 

surrogate measures of Agent Orange exposure among Vietnam veterans on the Agent Orange 

Registry. Annals of Epidemiology 4(1):11-16. 

Dalager, N. A., H. K. Kang, V. L. Burt, and L. Weatherbee. 1991. Non-Hodgkin’s lymphoma among 

Vietnam veterans. Journal of Occupational Medicine 33(7):774-779. 

Dalager, N. A., H. K. Kang, V. L. Burt, and L. Weatherbee. 1995. Hodgkin’s disease and Vietnam 

service. Annals of Epidemiology 5(5):400-406. 

Dalager, N. A., and H. K. Kang. 1997. Mortality among Army Chemical Corps Vietnam Veterans. 

American Journal of Industrial Medicine 31(6):719-726. 

Farberow, N. L., H. K. Kang, and T. A. Bullman. 1990. Combat experience and postservice psychosocial 

status as predictor of suicide in Vietnam veterans. Journal of Nervous and Mental Disease 178:32-37. 

Kang, H. K., L. Weatherbee, P. P. Breslin, Y. Lee, and B. M. Shepard. 1986. Soft tissue sarcoma and 

military service in Vietnam: A case comparison group analysis of hospital patients. Journal of 

Occupational Medicine 28(12):1215-1218. 

Kang, H. K., F. Enzinger, P. Breslin, M. Feil, Y. Lee, and B. Shepard. 1987. Soft tissue sarcoma and 

military service in Vietnam: A case-control study. Journal of the National Cancer Institute 79(4): 

693-699. 

Kang, H. K., K. K. Watanabe, J. Breen, J. Remmers, M. G. Conomos, J. Stanley, and M. Flicker. 1991. 

Dioxins and dibenzofurans in adipose tissue of U.S. Vietnam veterans and controls. American 

Journal of Public Health 81(3):344-349. 

Kang, H. K., N. A. Dalager, L. L. Needham, D. G. Patterson, G. M. Matanoski, S. Kanchanaraksa, and 

P. S. Lees. 2001. U.S. Army Chemical Corps Vietnam veterans health study: Preliminary results. 

Chemosphere 43(4-7):943-949. 

Kang, H. K., N. A. Dalager, L. L. Needham, D. G. Patterson, P. S. Lees, K. Yates, and G. M. Matanoski. 

2006. Health status of Army Chemical Corps Vietnam veterans who sprayed defoliant in Vietnam. 

American Journal of Industrial Medicine 49(11):975-884. 

Mahan, C. M., T. A. Bullman, H. K. Kang, and S. Selvin. 1997. A case-control study of lung cancer 

among Vietnam veterans. Journal of Occupational and Environmental Medicine 39(8):740-747. 

Thomas, T. L., and H. K. Kang. Mortality and morbidity among Army Chemical Corps Vietnam veterans: 

A preliminary report. American Journal of Industrial Medicine 18(6):665-673. 

Watanabe, K. K., and H. K. Kang. 1995. Military service in Vietnam and the risk of death from trauma 

and selected cancer. Annals of Epidemiology 5(5):407-412. 

Watanabe, K. K., and H. K. Kang. 1996. Mortality patterns among Vietnam veterans: 24-year 

retrospective analysis. Journal of Occupational and Environmental Medicine 38(3):272-278. 

Watanabe, K. K., H. K. Kang, and T. L. Thomas. 1991. Mortality among Vietnam veterans: With 

methodological considerations. Journal of Occupational Medicine 33(7):780-785. 

Young, A. L., H. K. Kang, and A. L. Shepard. 1983. Chlorinated dioxins as herbicide contaminants. 

Environmental Science and Technology 17:530A-540A. 
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K-6 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

APPENDIX K-2 

SELECTED NATIONAL ACADEMIES REPORTS ON U.S. VETERANS’ 

HEALTH2 (IN CHRONOLOGICAL ORDER)

NRC (National Research Council). 1982. Possible long-term health effects of short-term exposure to 

chemical agents: Anticholinesterases and anticholingergics. Vol. 1. Washington, DC: National 

Academy Press. 

NRC. 1984. Possible long-term health effects of short-term exposure to chemical agents: Cholinesterase 

reactivators, psychochemicals and irritants and vesicants. Vol. 2. Washington, DC: National 

Academy Press. 

NRC. 1985. Possible long-term health effects of short-term exposure to chemical agents. Volume 3. Final 

report. Current health status of test subjects. Washington, DC: National Academy Press. 

IOM (Institute of Medicine). 1991. Epidemiology in military and veteran populations: Proceedings of the 

2nd biennial conference, March 7, 1990. Washington, DC: National Academy Press.

IOM. 1995. Recommendations for research on the health of military women: Bibliographies. 

Washington, DC: National Academy Press.

IOM. 1996. Interactions of drugs, biologics, and chemicals in U.S. military forces. Washington, DC: 

National Academy Press.

IOM. 1996. Military nursing research: Bibliographies. Washington, DC: National Academy Press. 

IOM. 1997. Adequacy of the Comprehensive Clinical Evaluation Program: A focused assessment. 

Washington, DC: National Academy Press.

IOM. 1997. An evaluation of radiation exposure guidance for military operations: Interim report. 

Washington, DC: National Academy Press.

IOM. 1998. Assessing readiness in military women: The relationship of body, composition, nutrition, and 

health. Washington, DC: National Academy Press.

IOM. 1999. National Center for Military Deployment Health Research. Washington, DC: National 

Academy Press.

IOM. 1999. Potential radiation exposure in military operations: Protecting the soldier before, during, 

and after. Washington, DC: National Academy Press. 

IOM. 2000. Protecting those who serve: Strategies to protect the health of deployed U.S. forces. 

Washington, DC: National Academy Press.

IOM. 2005. Noise and military service: Implications for hearing loss and tinnitus. Washington, DC: The 

National Academies Press.

IOM. 2006. Amyotrophic lateral sclerosis in veterans: Review of the scientific literature. Washington, 

DC: The National Academies Press.

IOM. 2006. Disposition of the Air Force Health Study. Washington, DC: The National Academies Press.

APPENDIX K-3 

VIETNAM EXPERIENCE STUDY AND OTHER CDC STUDIES ON 

VIETNAM VETERANS AND GULF WAR VETERANS 

Vietnam Experience Study 

Background 

Conducted by the Centers for Disease Control and Prevention (CDC), the Vietnam 

Experience Study compared the morbidity and mortality among Vietnam veterans and nonVietnam veterans. 

 

2 Not intended to be a comprehensive list. See www.nap.edu for additional reports.
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APPENDIX K K-7 

Vietnam veterans were concerned that their service in Vietnam adversely affected their 

health, and the health of their families. However, data did not exist comparing those who served 

in Vietnam and those who served during the Vietnam War in other countries. In 1979 President 

Jimmy Carter signed the Veterans Health Programs Extension and Improvement Act of 1979 that 

called for the Veterans Administration (VA) to “conduct an epidemiological study of persons 

who, while serving in the Armed Forces of the United States during the period of the Vietnam 

conflict, were exposed to any of the class of chemicals known as ‘the dioxins’ produced during 

the manufacture of the various phenoxy herbicides (including the herbicide known as ‘Agent 

Orange’) to determine if there may be long-term adverse health effects in such persons from such 

experiences” (Veterans Health Programs Extension and Improvement Act of 1979. Public Law 

96-151. 96th Cong., 1st Sess.; as referenced in CDC VES, 1989b, pp. 4-5). 

In 1981 an amendment was passed to the law above to include “an evaluation of any longterm adverse health effects in humans of such [military] service as such health effects may result 

from other factors involved in such [military] service, including exposure to other herbicides, 

chemicals, medications, or environmental hazards or conditions” (Veterans’ Health Care, 

Training, and Small Business Loan Act of 1981. Public Law 97-72. 97th Cong., 1st Sess.; as 

referenced in CDC VES, 1989b, p. 5). 

The responsibility of designing, conducting, and analyzing such an investigation was 

originally bestowed upon VA and then transferred, by an Interagency Agreement, to the CDC. 

The CDC was then authorized to conduct three studies: the Agent Orange Exposure Study, the 

Selected Cancers Study, and the Vietnam Experience Study (CDC VES, 1989a, p. 3). This 

section will focus on the Vietnam Experience Study (VES). 

VES Main Objectives 

Is there an excess risk of postservice mortality for the Vietnam group? (If so, due to what 

causes?) 

1. Is there an excess risk of specific illnesses (including psychological) or groups of 

postservice illnesses for the Vietnam group? 

2. Is there an excess of adverse reproductive outcomes or childhood illnesses among 

children of the Vietnam group?

 (CDC VES, 1989a, p. 4)

VES Cohort 

The VES cohort included a random sample of male Vietnam and non-Vietnam veterans 

(limited to those who served in the United States, Germany, or Korea). The random selection 

process was based on “a computerized list of accession numbers taken from military personnel 

files of Army veterans discharged during the relevant time period” (CDC VES, 1987a). Sample 

sizes are given in Figure K-1. The inclusion criteria for this study were 

• Army veterans (Marine, Air Force, and Navy personnel were not included); 

• military occupational specialty (MOS) other than “duty soldier” and “trainee”; 

• single term of enlistment; 

• minimum of 16 weeks of active duty time; 

• pay grade E-1 (Private) to E-5 (Sergeant-Specialist 5); 
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K-8 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

• entered military service for the first time during 1965-1971; and 

• discharged alive (CDC VES, 1989a, pp. 5, 7). 

FIGURE K-1 Sample sizes for each component of the VES.

SOURCE: Adapted from CDC VES, 1989a. 
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APPENDIX K K-9 

Demographics3

• Vietnam veterans were more likely than non-Vietnam veterans to have 

o lower General Technical (GT) test scores; 

o entered the Army before 1969; 

o been volunteers; 

o had a tactical operation primary MOS; 

o been in a combat unit; 

o honorable discharges; 

o been discharged at pay grades >E3; 

o lower educational attainment at time of interview; 

o more unemployment at time of interview; 

o lower income in year immediately preceding the interview; 

o used drugs (marijuana only, or hard drugs) at least once/week in past year; 

o received therapy for drug, alcohol, or emotional problems in past year; and 

o drank, on average, ≥90 drinks per month (CDC VES, 1989a, Tables 2-4). 

• Vietnam veterans were significantly less likely than non-Vietnam veterans to have 

an executive/managerial professional specialty (OR = 0.9, 95% CI 0.8-0.9) (CDC 

VES, 1989b, p. 44). 

• There were no significant differences between the Vietnam veterans and the nonVietnam veterans with respect to 

o region of birth, region of residence at time of interview; 

o year of birth, age at interview; 

o race; 

o mean age at enlistment; 

o percent with some AWOL or confinement time; 

o current martial status; and 

o cigarette smoking. 

Components of the VES 

 The VES included a mortality study, a telephone interview, an examination (medical, 

psychological, and laboratory), and a reproductive outcomes and child health component. 

Primary potential confounders The primary potential confounders adjusted for in all 

analyses listed below are as follows: 

• Race = white (referent), black, other 

• Age at entry into the Army = <20 years (referent), ≥20 years 

• Year of entry into Army = 1965-1966 (referent), 1967-1969, 1970-1971 

• Primary MOS = tactical, other (referent) 

 

3

 These results are from the telephone interview only. However, the demographic results did not 

significantly differ between the telephone interview and the medical history questionnaire (as part of the 

examination). 
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K-10 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

• Enlistment status = drafted (referent), volunteered 

• GT test score = 40-89, 90-109 (referent), 110-129, 130-160 (CDC VES, 1989b, p. 23, 

Table 4) 

For this summary on the VES analytical results, if the significance levels are not reported 

here, they were not reported in the documentation obtained from the CDC. Also, the VES full 

documentation presents both models: (1) the model only adjusting for the primary potential 

confounds listed above and (2) a multivariable model that adjusts for further potential 

confounders as appropriate. However, since the two models offer similar results, this summary 

only lists the results from the first model. 

The Mortality Study: Postservice mortality among Vietnam veterans Mortality among the 

Vietnam veterans (n = 9,324) was compared to that of the non-Vietnam veterans (n = 8,989), 

based on information from personal physicians as well as hospital records, autopsy reports, and 

coroner and law enforcement files. The data showed that, over the entire follow-up period, total 

mortality in the Vietnam veterans was 17 percent higher than for the non-Vietnam veterans 

(http://www.cdc.gov/nceh/veterans/default1a.htm; CDC VES, 1987a,b). “The excess in 

postservice mortality due to external causes among Vietnam veterans is similar to that found 

among men returning from combat areas after World War II and the Korean War” (CDC VES, 

1987b). Selected findings on mortality are given in Table K-1. Other findings on mortality 

included the following: 

• When all drug-related deaths were analyzed together, “the rate ratio between 

Vietnam and non-Vietnam veterans appeared to increase with the number of years 

since discharge.” This difference was found “almost exclusively among draftees; 

those assigned to tactical military occupational specialties; and those serving in 

Vietnam during 1968 or 1969, the years of heaviest combat activity.” 

• Alcohol did not seem to account for the difference in motor vehicle crashes 

between the Vietnam veterans and the non-Vietnam veterans. 

• Vietnam veterans were significantly less likely than non-Vietnam veterans to die 

from circulatory system diseases (OR = 0.5, 95% CI 0.25-0.99). 

TABLE K-1 Vietnam Veterans Were Significantly More Likely Than Non-Vietnam 

Veterans to Die from the Following Conditions 

Condition 

Risk Ratio 

(RR) 

95% Confidence 

Interval (CI) 

Mortalitya within 5 years of 

discharge 

1.45 1.08-1.96 

Suicides within 5 years of 

discharge 

2.56 1.11-5.87 

Motor vehicle crashes 1.48 1.04-2.09 a

Mortality mostly due to motor vehicle accidents, suicide, homicide, and accidental 

poisonings. 

SOURCE: CDC VES, 1987a,b. 
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APPENDIX K K-11 

• There were no significant differences between the Vietnam veterans and the nonVietnam veterans with respect to mortality from unintentional poisonings, most of 

which were due to the use of illicit drugs. 

• After the initial 5 years after discharge, there were no significant differences in 

mortality among the Vietnam veterans and the non-Vietnam veterans, except that 

drug-related deaths continued to be elevated in the Vietnam veterans. 

The telephone interview Under contract with the CDC, Research Triangle Institute (RTI) 

located, contacted, and interviewed the veterans with the help of Equifax, Inc. which provided 

multilevel locating and contacting services. To locate veterans these companies used the 

permanent addresses provided by the veterans at the time of discharge, the names and addresses 

of family members provided by the veterans upon entry into the service, the address on the 

veterans’ most recent tax return, and the address provided by the veterans when filing for 

benefits (CDC VES, 1989a, pp. 7-8; CDC VES, 1989b, p. 9). 

Eventually, 9,078 Vietnam veterans and 8,789 non-Vietnam veterans were found to be 

eligible for the interview (i.e., those not known to have died before December 31, 1983). Of 

these, veterans were not interviewed if they could not be located, refused to be interviewed, were 

unable to contact, were incarcerated, died after December 31, 1983, or were mentally or 

physically incapable of being interviewed. Thus, 7,924 Vietnam veterans and 7,364 non-Vietnam 

veterans were ultimately interviewed (CDC VES, 1989a, p. 7, Figure 1; CDC VES, 1989b, p. 31, 

Table 6). 

It is important to note that there were differences between those interviewed and those not 

interviewed. On average, compared to those interviewed (Vietnam and non-Vietnam veterans 

combined, unless otherwise stated), those not interviewed (Vietnam and non-Vietnam veterans 

combined, unless otherwise stated) were more often nonwhite (21.5 percent vs. 11.6 percent), 

younger at enlistment (56.2 percent <20 years vs. 48.8 percent <20 years), volunteers (41.0 

percent vs. 34.2 percent), having lower scores on the GT test (mean score about 100.0 vs. 105.2), 

and more likely received non-honorable discharges (8.0 percent for Vietnam veterans and 21.2 

percent for non-Vietnam veterans vs. 1.8 percent for Vietnam veterans and 6.2 percent for nonVietnam veterans) and discharged at lower pay grades (23.7 percent for Vietnam veterans and 

40.1 percent for non-Vietnam veterans vs. 9.3 percent for Vietnam veterans and 15.9 percent for 

non-Vietnam veterans) (CDC VES, 1989b, pp. 31-33, Table 8). However, significance levels for 

these differences were not reported in the documents. 

 

Although the unlocatable subset of the non-respondent group appears to be very different 

from respondents with respect to demographic and military characteristics, about the 

same degree of divergence is seen for both Vietnam and non-Vietnam veterans. Thus, 

absence of interview data from the lost-to-follow-up group should not adversely affect 

the findings presented here. 

(CDC VES, 1989b, p. 33) 

Selected findings from the telephone interviews are shown in Tables K-2, K-3, K-4, and K-5. 
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K-12 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

TABLE K-2 Current Health Status: Vietnam Veterans Were Significantly More Likely 

Than Non-Vietnam Veterans to Have the Following Conditions 

Condition Odds Ratio (OR) 

95% Confidence 

Interval (CI) 

Perceived fair/poor health 1.8 1.7-2.0 

Higher mean BMI BMI = 

geometric mean 

25.7 vs. 25.5 

p = 0.004 

Limitations in activities 1.3 1.2-1.4 

≥3 prescribed medications 1.3 1.1-1.6 

General symptoms 2.5 1.7-3.6 

SOURCE: CDC VES, 1989b, Tables 18, 19, 20, 22, 102. 

TABLE K-3 Health Status Between Discharge and Time of Interview: Vietnam Veterans 

Were Significantly More Likely Than Non-Vietnam Veterans to Have Experienced/Suffered 

from the Following Conditions 

Condition Odds Ratio (OR) 

95% Confidence 

Interval (CI) 

≥1 hospitalization 1.1 p <0.05 

Hypertension 1.3 1.2-1.4 

Benign growths 1.2 1.1-1.3 

Chloracne 3.9 2.5-6.2 

Excessive hair growth 1.9 1.6-2.3 

Other skin conditions 1.8 1.7-2.0 

Gastrointestinal ulcers 1.2 1.1-1.3 

≥4 Neurologic symptoms 2.0 1.8-2.3 

Hepatitis B 1.5 1.3-1.8 

Other liver conditions 1.4 1.1-1.8 

Urinary tract problems 1.2 1.1-1.3 

Fertility difficulties 1.3 1.2-1.5 

SOURCE: CDC VES, 1989a, p. 18, Table 5; 1989b, pp. 100, 371-373, Table 73, Table I-I. 

TABLE K-4 Reported Medical Care: Vietnam Veterans Were Significantly More Likely 

Than Non-Vietnam Veterans to Report Medical Care While in the Army for the Following 

Conditions 

Condition 

Odds Ratio 

(OR) 

95% Confidence 

Interval (CI) 

Intestinal infections 2.7 2.1-3.5 

Malaria 104.0 33.3-324.4 

Sexually transmitted disease 2.0 1.7-2.4 

Mycoses 6.5 4.8-9.0 

Ear disorders 1.7 1.4-2.0 

Hepatitis B 1.8 1.3-2.5 

Skin infections 2.1 1.7-2.7 

Other skin disease 1.3 1.1-1.6 

Rash 3.3 2.5-4.3 

Fever 2.3 1.7-3.0 
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APPENDIX K K-13 

SOURCE: CDC VES, 1989b, pp. 37-39, Table 12. 

TABLE K-5 Vietnam Veterans Were Significantly Less Likely Than Non-Vietnam 

Veterans to Report Medical Care While in the Army for the Following Conditions 

Condition 

Odds Ratio 

(OR) 

95% Confidence 

Interval (CI) 

Strep infections 0.6 0.5-0.8 

Acute respiratory infection 0.8 0.7-0.9 

Other upper respiratory disease 0.6 0.4-0.8 

Influenza 0.8 0.7-0.9 

Osteopathy 0.7 0.5-0.9 

SOURCE: CDC VES, 1989b, pp. 37-39, Table 12. 

There were no significant differences between the Vietnam veterans and the non-Vietnam 

veterans with respect to postdischarge cancer, diabetes, and cirrhosis (CDC VES, 1989a, p. 18, 

Table 5). 

 There were no significant differences between the Vietnam veterans and the non-Vietnam 

veterans with respect to viral exanthemas; neoplasms; endocrine, nutritional, and metabolic 

disease; mental disorders; disease of the nervous system; eye disorders; circulatory disease; 

pneumonia; digestive diseases (except for hepatitis B); genitourinary disease; dermatitis; 

musculoskeletal disease (except for osteopathy); head and neck symptoms; cardiorespiratory 

symptoms; fractures, dislocations, sprains and strains, intracranial injuries, contusions, other and 

unspecified injuries; and poisoning (CDC VES, 1989b). 

The examination At the end of the telephone interview, veterans were told if they were 

preselected by RTI to be examined. The preselection process was done randomly by RTI and 

names and information were then transferred to the Lovelace Medical Foundation (LMF) in 

Albuquerque, New Mexico. LMF was under contract with the CDC to schedule the examination 

appointments which were conducted at LMF, arrange the veterans’ round-trip travel to 

Albuquerque, and provide food and lodging during the examination period (CDC VES, 1989c, p. 

16). Over 3,300 Vietnam veterans and over 3,100 non-Vietnam veterans were invited for the 

examination. However, veterans were not examined if they could not be contacted, refused to be 

examined, were incarcerated, died after December 31, 1983, were mentally or physically 

incapable of being examined, or were in a mental institution. Ultimately 2,490 Vietnam veterans 

and 1,972 non-Vietnam veterans were examined (CDC VES, 1989c, pp. 31, 32). See the 

demographics section above for differences between the Vietnam and non-Vietnam veterans. 

It is important to note that there were also some differences between those examined and 

those not examined. Higher participation rates were observed among blacks compared to whites, 

those in the youngest age group compared to those in the older age groups, those with higher 

levels of education, those in the lowest income category, and those not married compared to 

those currently married. However, the documentation did not present significance levels (CDC 

VES, 1989c, pp. 33-34). 

Open wounds 3.5 3.1-4.0 

Superficial injuries 1.6 1.1-2.1 

Burns 1.8 1.2-2.5 
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K-14 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

For the 3 days before the examination, the veterans were instructed not to eat red meat, pork, 

or sweets; drink any alcohol or use any mouthwash; take any multivitamins or vitamin C 

supplements; take any nonprescription drugs; or start a new exercise program. However, 

participants could continue current prescription medications and exercise programs. From 7pm 

the night before the first day of examinations, the participants were asked to fast, permitting only 

water, and during the night they began a 12-hour urine sample (CDC VES, 1989c, p. 17). 

Participants were in Albuquerque for 4 days. The first day included an orientation session. 

The next day started with a morning blood draw, followed by a medical examination (including a 

medical history questionnaire and general physical, dermatologic and neurological clinical tests), 

special medical tests (chest roentgenogram, electrocardiogram, pulmonary function, Doppler 

evaluation of peripheral vasculature, hypersensitivity skin test, nerve conduction velocities, 

vibratory sensation, audiometry, visual acuity), and laboratory tests (hematologic assays, serum 

analytes, hepatitis B, endocrine, immunology, urinalysis, 12-hour urine, semen analysis, 

erythrocyte sedimentation rate, prothrombin time, rapid plasma regain test, stool occult blood, 

melioidosis antibody titer, breath alcohol level). The third day focused on psychological and 

neurological tests conducted in a special center at their hotel. On the fourth day the veterans met 

with an internist and a psychologist to discuss their individual results (CDC VES, 1989c, p. 17). 

Selected results from the examinations are shown in Tables K-6, K-7, K-8, K-9, and K-10. 

TABLE K-6 Current Health Status: Vietnam Veterans Were Significantly More 

Likely Than Non-Vietnam Veterans to Currently Have the Following Conditions 

Condition 

Odds Ratio 

(OR) p-value 

Perceived fair/poor health 1.9 p <0.05 

Somatic symptoms 1.7 p <0.05 

SOURCE: CDC VES, 1988a,b; 1989a, p. 18, Table 5. 

TABLE K-7 Postdischarge Health Status: Vietnam Veterans Were Significantly 

More Likely Than Non-Vietnam Veterans to Have Experienced/Suffered from the 

Following Conditions Postdischarge 

Condition 

Odds Ratio 

(OR) p-Value 

Hypertension 1.2 p <0.05 

Chloracne 7.3 p <0.05 

Other skin conditions 1.7 p <0.05 

Other liver conditions 1.7 p <0.05 

Fertility difficulties 1.5 p <0.05 

SOURCE: CDC VES, 1989a, p. 18, Table 5. 

TABLE K-8 Vietnam Veterans Were Significantly More Likely Than Non-Vietnam 

Veterans to Have Experienced the Following Conditions 

Conditiona

Odds Ratio 

(OR) 

95% Confidence 

Interval (CI) 

Alcohol abuse or dependence 1.5 1.2-1.8 

Generalized anxiety 1.5 1.1-2.1 
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APPENDIX K K-15 

Depression 2.0 1.4-2.9 

≥1 of the above conditions 1.5 1.3-1.8 

≥2 of the above conditions 1.9 1.2-2.8 a

Based on the Diagnostic Interview Schedule. 

SOURCE: CDC VES, 1989a, pp. 24-26, Tables 13-15. 

TABLE K-9 Vietnam Veterans Were Significantly More Likely Than Non-Vietnam 

Veterans to Have Elevated Levels on the Minnesota Multiphasic Personality 

Inventory Clinical Scales 

Condition 

Odds Ratio 

(OR) 

95% Confidence 

Interval (CI) 

Scale 1 (Hypocondriasis) 1.7 1.4-2.1 

Scale 2 (Depression) 1.6 1.3-1.8 

Scale 3 (Hysteria) 1.5 1.2-2.0 

Scale 7 (Obsessive-compulsive 

syndrome) 

1.6 1.3-1.9 

Scale 8 (Schizophrenia) 2.0 1.6-2.4 

≥1 or more scales elevated 1.3 1.2-1.5 

≥2 or more scales elevated 1.5 1.2-1.7 

TABLE K-10 Vietnam Veterans Were Significantly More Likely Than NonVietnam Veterans to Experience the Following Conditions 

Condition 

Odds Ratio 

(OR) 

95% Confidence 

Interval (CI) 

High-frequency hearing loss 

 Right ear 

 Left ear 

 Both ears 

1.4 

1.4 

1.4 

1.2-1.7 

1.2-1.6 

1.1-1.8 

Peripheral nervous system 

abnormalities—leg absent 

pinprick (distal dorsal) 

1.6 1.1-2.4 

SOURCE: CDC VES, 1989a, pp. 20-21, Tables 8-9; 1989c, pp. 110, 113, Tables 7.9, 

7.12. 

Medical history questionnaire 

• These results are somewhat different than those from the telephone interview. 

• Vietnam veterans reported more current health problems than non-Vietnam veterans, 

particularly for mental disorders; diseases of the nervous system; diseases of the skin; 

symptoms, signs, and ill-defined conditions. However, significance levels were not 

reported in the document. 

• Vietnam veterans reported more physician-diagnosed alcohol-related liver damage, 

hepatitis B, gastritis, and stomach or duodenal ulcer, and less physician-diagnosed 

cirrhosis than non-Vietnam veterans. However, significance levels were not reported in 

the document. 
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• There were no significant differences between Vietnam veterans and non-Vietnam 

veterans with respect to current limitation in activities or prescribed medications. These 

results are different than those from the telephone interview listed above.

• There were no significant differences between Vietnam veterans and non-Vietnam 

veterans with respect to post-discharge hospitalization, cancer, benign growth, diabetes, 

gastrointestinal ulcers, hepatitis B, cirrhosis, and urinary tract problems. These results are 

somewhat different than those from the telephone interview listed above. 

Cardiac tests There were no significant differences between the Vietnam and non-Vietnam 

veterans with respect to hypertension, altered peripheral arterial hemodynamics, 

electrocardiogram findings (ischemia, left ventricular hypertrophy, any finding), chest 

roentgenogram findings (pulmonary, cardiac, any finding), or pulmonary function parameters 

(CDC VES, 1989a, p. 19, Table 7). 

Dermatologic examinations There were no significant differences between the Vietnam and 

non-Vietnam veterans with respect to chloracne-like lesions, acneiform lesions, 

hyperpigmentation, skin cancer, infections, and postinflammatory scars. These results are 

somewhat difference than those from the telephone interview (CDC VES, 1989a, p. 19, Table 6; 

CDC VES, 1989b, pp. 56-58). 

Psychiatric examinations 

• There was no significant difference between the Vietnam veterans and the non-Vietnam 

veterans with respect to drug abuse or dependence. 

• Combat-related PTSD analysis was restricted to Vietnam veterans since non-Vietnam 

veterans had a low likelihood of experiencing combat. Almost 15 percent Vietnam 

veteran had experienced PTSD prior to examination while over 2 percent experienced 

PTSD the month before the examination. 

• There were no significant differences between the Vietnam veterans and non-Vietnam 

veterans with respect to MMPI scale 4 (psychopathic personality disorders), scale 5 (male 

sexual inversion), scale 6 (Paranoia), scale 9 (hypomania), or scale 0 (uneasiness in social 

situations or dealing with others). 

Neurological examinations/tests 

• Vietnam veterans had a significantly lower mean score on the Army Classification 

Battery (ACB) General Technical Test at examination, Rey-Osterreith Test (RO) 

Complex Figure-Copy, Wechsler Adult Intelligence Scale-Revised (WAIS-R) block 

design subset (p <0.05), and a significantly higher average number of cards per sort on 

the Wisconsin Card Sorting Test (p <0.05). 

• There were no significant differences between the Vietnam veterans and the non-Vietnam 

veterans with respect to peripheral neuropathy. 

• There were no significant differences between the Vietnam veterans and non-Vietnam 

veterans with respect to a mean score on the California Verbal Learning Tests, Grooved 

Pegboard, Paced Auditory Serial Addition Test, short-delay recall and long-delay recall 
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APPENDIX K K-17 

on the RO Complex Figure, the information subset of the WAIS-R, and Word List 

Generation. 

Hematological/laboratory tests (CDC VES, 1989c, pp. 174, 176, 187, 190, Tables 11.5, 11.8, 

12.6, 12.8) 

• Vietnam veterans had significantly higher fasting serum glucose (difference = 0.9mg/dl, 

95% CI 0.2-1.6) and thyroid-stimulating hormone (difference = 4.3mIU/L, 95% CI 0.5-

8.2). 

• There were no significant differences between the Vietnam veterans and the non-Vietnam 

veterans with respect to 

o mean red cell count, hemoglobin, hematocrit, mean corpuscular volume, mean 

corpuscular hemoglobin, mean corpuscular hemoglobin concentration, white cell 

count, segmented neutrophil, band neutrophil, lymphocyte, monocyte, eosinophil, 

basophil, platelet count and prothrombin time; 

o free thyroxine index, cortisol, dehydroepiandrosterone, testosterone, folliclestimulating hormone, or luteinizing hormone; 

o blood urea nitrogen or serum creatinine; and

o diabetes or hypothyroidism. 

Semen tests (CDC VES, 1989c, pp. 208-209, Tables 13.5, 13.6) 

• Vietnam veterans had significantly lower sperm concentrations (mean difference = 

–20.2 million cells/mL, 95% CI –34.5 to –2.8) and a lower percent of normal cell 

morphology (mean difference = –3.8 percent, 95% CI –6.6 to –0.9) compared to nonVietnam veterans. 

• There were no significant differences between the Vietnam veterans and the non-Vietnam 

veterans with respect to movement characteristics (percent motile cells, mean linear 

velocity, mean straight line velocity, mean linearity, mean amplitude lateral head 

displacement, mean beat/cross frequency). 

Reproductive outcomes and child health During the interview, data on the following topics 

were collected: 

• Basic data for all veterans’ biological children, including month and year of birth, sex 

of child, live-born or stillborn status 

• Birth defects of malformations diagnosed by a physicians—up to two per child 

• Physician-diagnosed major health problems or impairments occurring in the first 5 

years of life, not including normal childhood diseases and injuries—up to three per 

child 

• Leukemia and other types of cancer 

• Infant and child mortality 

• Pregnancies fathered by the veteran that ended early, including miscarrages, induces 

abortions, and tubal pregnancies 

 (CDC VES, 1989d, p. 9) 

Selected results from the interview are as follows are shown in Tables K-11, K-12, and K-13. 
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K-18 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

TABLE K-11 The Offspring of Vietnam Veterans Were Significantly More Likely 

Than Those of Non-Vietnam Veterans to Have the Following Conditions 

Condition 

Odds Ratio 

(OR) 

95% Confidence 

Interval (CI) 

Been miscarried 1.3 1.2-1.4 

Anomalies (total) 1.3 1.2-1.4 

Anemia 1.9 1.1-3.2 

Diseases of the ear 1.3 1.1-1.6 

Diseases of the skin 1.5 1.1-2.0 

Symptoms and signs 1.5 1.2-1.8 

Injuries and poisoningsa

 1.6 1.2-2.1 a

Standardized for race. 

SOURCE: CDC VES, 1989d, pp. 22-28, Tables 10, 11, 14, 15, 16, 17, 19, 21, 23. 

TABLE K-12 Vietnam Veterans Were Significantly More Likely Than Non-Vietnam 

Veterans to Father Children with Birth Defects of These Organ Systems 

No. of Children 

Organ System Vietnam Non-Vietnam 

Odds Ratio 

(OR)a

95% Confidence 

Interval (CI) 

Total anomalies 826 590 1.3 1.2-1.4 

Nervous 33 13 2.3 1.2-4.5 

Hydrocephalus 11 2 5.1b

 1.1-23.1 

Musculoskeletal 426 309 1.2 1.1-1.5 

Integument 41 17 2.2 1.2-4.0 a

Adjusted for primary potential confounders listed above, as well as years between entry into Army 

and birth of the child. 

b

Crude OR because the number of cases is not sufficient for multivariable modeling. 

SOURCE: CDC VES, 1989d, pp. 22-28, Tables 10, 11, 14, 15, 16, 17, 19, 21, 23. 

 

TABLE K-13 Vietnam Veterans Were Significantly More Likely Than NonVietnam Veterans to Report the Following Birth Defects 

Birth Defect 

Odds Ratio 

(OR) 

95% Confidence 

Interval (CI) 

Children with 1 birth defect 1.3 1.1-1.4 

Children with >1 birth defect 1.6 1.1-2.5 

1 child with 1 birth defect 1.2 1.1-1.4 

SOURCE: CDC VES, 1989d, pp. 22-28, Tables 10, 11, 14, 15, 16, 17, 19, 21, 23. 

• There were no significant differences between the Vietnam veterans and the non-Vietnam 

veterans with respect to induced abortions, and tubal pregnancies, stillbirths, and 

childhood cancer among the offspring. 

• There were no significant differences between the offspring of the Vietnam veterans and 

the non-Vietnam veterans with respect to infectious and parasitic diseases, benign and 

unspecified neoplasms, endocrine diseases, mental disorders, nervous system diseases 

(except for diseases of the ear), circulatory system diseases, respiratory system diseases, 
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APPENDIX K K-19 

digestive system diseases, genitourinary system diseases, urinary tract infection, 

musculoskeletal disease, perinatal conditions, and supplementary classifications. 

• There were no significant differences between the offspring of the Vietnam veterans and 

those of the non-Vietnam veterans with respect to total serious health problems, infant 

mortality or child mortality. 

• There were no significant differences between the offspring of the Vietnam veterans and 

those of the non-Vietnam veterans with respect to birth defects of the eye; ear, face, and 

neck; circulatory system; respiratory system; digestive system; genitals; urinary system; 

or other unspecified systems. 

• There were no significant differences between the offspring of the Vietnam veterans and 

those of the non-Vietnam veterans with respect to veterans reporting more than one child 

with a birth defect. 

The General Birth Defects Sub-Study 

The General Birth Defects (GBD) Sub-Study was designed to compare the rates of birth 

defects, as presented in hospital birth records, among offspring of Vietnam veterans and those 

among non-Vietnam veterans. This comparison was also used to validate the data from the 

telephone interview (see data above). Selected results from this substudy are as follows: 

• There were no significant differences between the offspring of the Vietnam veterans and 

those of the non-Vietnam veterans with respect to major, minor, or suspected birth 

defects. 

• There were no significant differences between the offspring of the Vietnam veterans and 

those of the non-Vietnam veterans with respect to defects of the ear, face, and neck; 

digestive system; genitals; musculoskeletal system; or integument system. 

• There were no significant differences between the offspring of the Vietnam veterans and 

those of the non-Vietnam veterans with respect to having a child with low birth weight or 

perinatal deaths. (CDC VES, 1989d, p. 46, Tables 16, 19, 21, 23, 24) 

The Cerebrospinal Malformations Sub-Study 

The Cerebrospinal Malformations (CSMs) Sub-Study also used hospital birth records to 

identify all children with possible cerebrospinal malformations (i.e., a reported CSM, a reported 

condition that suggested a possible CSM, and all children reported as stillborn) (CDC VES, 

1989d, p. 46). Selected results from this sub-study are as follows: 

• Among reported stillbirths, 5 CSMs in the offspring of Vietnam veterans and 6 CSMs in 

the offspring of non-Vietnam veterans were found; 10 of which were not reported during 

the time of the interview. 

• Among reported live births, 21 CSMs in the offspring of Vietnam veterans and 6 CSMs 

in the offspring of non-Vietnam veterans were found. 

• The CSMs observed in Vietnam veterans were anencephaly (n = 10), spina bifida (n = 9), 

and hyrocephalus (n = 7). 

• The CSMs observed in non-Vietnam veterans were anencephaly (n = 7), spina bifida (n = 

2), and hyrocephalus (n = 3). (CDC VES, 1988c) 
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K-20 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

“Because record retrieval rates varied considerably by cohort status and because negative 

responses were not verified, we did not calculate or compare rates of CSM cases in the two 

cohorts; the results are expressed as numbers of verified cases” (CDC VES, 1988c). 

Strengths of the VES 

As listed in the VES documentation (CDC VES, 1989a, p. 32), the major strengths of the 

VES are as follows: 

• The random sampling method used to identify large representative samples of 

Vietnam and non-Vietnam veterans 

• The measures used to assure good comparability of the two cohorts 

• The rigorous vital status ascertainment and cause of death classification methods 

• The high participation rates in the interview component 

• The comparability of the examined cohorts (in the face of differential participation 

rates) 

• The attempt at independent validation of certain interview outcomes 

• The meticulous data control and bias-avoidance methods used in all components of 

the study 

Limitations of the VES 

As listed in the VES documentation (CDC VES, 1989a, p. 32), the major limitations of the 

VES are as follows: 

• The long time that has elapsed since the end of the Vietnam conflict 

• The differential participation rates in the examined cohorts 

• The lack of any reliable indirect estimate of the Agent Orange exposure (the study 

was not designed to focus on Agent Orange exposure) 

• The fact that the VES “exposure,” the Vietnam experience, represents a large variety 

of individual experiences (e.g., combat exposure) that are probably not homogeneous 

Selected Cancers Study 

Background 

Vietnam veterans are concerned that exposure to Agent Orange and especially its TCDD 

contaminant may negatively impact their health. in response to this concern and to the Veterans 

Health Programs Extension and Improvement Act of 1979 (Public Law 96-151. 96th Cong., 1st 

Sess.) and the Veterans’ Health Care, Training, and Small Business Loan Act of 1981 (Public 

Law 97-72. 97th Cong., 1st Sess.), the CDC conducted the Vietnam Experience Study (see 

above) and the Selected Cancers Study (CDC VES, 1989a, p. 3). 

The Selected Cancers Study is a case-control study of veterans’ risk to six rare cancers (nonHodgkin’s lymphoma, Hodgkin’s disease, soft-tissue and other sarcomas, nasal cancer, 

nasopharyngeal cancer, and primary liver cancer among Vietnam veterans) thought to be 

associated with TCDD exposure based on published literature (see 

http://www.cdc.gov/nceh/veterans/default1d.htm). This study “focuses on the risk of cancer after 

service in Vietnam in general. We only indirectly examine any possible association with 
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APPENDIX K K-21 

herbicide exposure through investigation of service characteristics such as military branch, 

region of service in Vietnam, calendar years of service, and specific duties that involved the 

handling of herbicides” (Selected Cancers Cooperative Study Group, 1990b, p. 2474). 

Methodology 

The three investigations within this study follow the same methodology and control series. 

The study includes a consensus diagnosis from three experts to confirm the cases (only these are 

included in the analysis), a standardized telephone interview, and microscopic slides or tissue 

blocks for 97 percent of lymphoma cases interviewed from pathology department where 

diagnosis was given (Selected Cancers Cooperative Study Group, 1990a, pp. 1, 12; Selected 

Cancers Cooperative Study Group, 1990b, p. 2474). The Environmental Support Group also 

reviewed the medical records of those stationed in Vietnam, when permission was granted 

(Selected Cancers Cooperative Study Group, 1990b). 

The cases and controls were randomly assigned to interviewers so each interviewer had a 

similar number of cases and control (see Table K-14). The telephone interviews took about 50 

minutes to complete, and were conducted in English, Spanish, and Cantonese by fluent speakers. 

Those who served in Vietnam were asked about dates of tour, branch of service, rank, unit, 

location in Vietnam, job duties, and self-perceived exposure to herbicides while in Vietnam. 

They were also asked to name the specific herbicides that they used on crops, in landscaping, in 

right-of-way maintenance along power lines, rail lines, and in forestry. in this study “stationed in 

Vietnam” includes those stationed off the coast. The U.S. Army and Joint Services 

Environmental Support Group then classified veterans’ units into those likely to be combat, 

combat support, or support based on information provided during the interview (they were not 

aware of the veterans’ control and case status) (Selected Cancers Cooperative Study Group, 

1990a, pp. 16, 18-19; Selected Cancers Cooperative Study Group, 1990b, p. 2475). 

TABLE K-14 Sample Size for the Cases and Controls in the Selected Cancers Study 

 Cases 

 

Controls 

NonHodgkin’s 

Disease 

Soft-Tissue 

and Other 

Sarcomas 

Hodgkin’s 

Disease 

Nasal 

Cancer 

Nasopharyngeal 

Cancer 

Liver 

Cancer

Controls Selected or 

Cases Identified 

2299 2354 612 2354 89 131 310 

Interviewed 1910 2073 521 2073 80 115 263 

Specimen Obtained N/Aa

 2004 511 2004 78 113 233 

Diagnosis Confirmed N/A 1511 386 343 70 113 168 

Excluded from 

Analysis 

Military/Vietnam 

service status 

unknown 

In/off coasts of 

Vietnam but not 

stationed there 

AIDS or related 

condition 

 7 

 27 

 1 

 5 

 13 

 290 

 4 

 8 

 3 

 0 

 1 

 17 

 0 

 1 

 3 

 1 

 1 

 1 

 2 

 2 

 0 
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K-22 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Not a U.S. resident 

before 1969 

History of von 

Recklinghausen’s 

neurobibromatosis or 

postirradiation 

osteosarcoma 

 99 

N/A 

 56 

N/A 

 23 

 6 

 15 

N/A 

 4 

N/A 

 21 

N/A 

 34 

N/A 

Total Available for 

Analysis 

1776 1157 342 310 62 89 130 

a

N/A = Not applicable. 

SOURCE: Selected Cancers Cooperative Study Group, 1990a, pp. 12-13, 1990b,c,d. 

Regression models Three models were used for the analysis (Selected Cancers Cooperative 

Study Group, 1990a,b,c,d) and they are as follows: 

• Model 1 = registry and age in 1968 

• Model 2 = registry, age in 1968, race/ethnicity, educational achievement 

• Model 3 = registry, age in 1968, race/ethnicity, educational achievement, spraying or 

mixing any herbicide other than in Vietnam, occupational contact with phenoxyherbicide 

other than in Vietnam, occupational contact with chlorophenols or dioxin other than in 

Vietnam, medical irradiation, having been raised in the Jewish religion, marital status, 

cigarette smoking, reported immunodeficiency disease other than AIDS, rheumatoid 

arthritis, systemic lupus erythematosus, use of immunosuppressive drugs, and use of 

phenytoin or related compounds, and other relevant potential confounders of Agent 

Orange exposure 

Study Strengths 

The strengths of this investigation are that the participation rates were high, only 7.5 percent 

of controls selected actually reported serving in Vietnam, and the fact that the same study design 

and control group was used for all six cancers proves against a general selection bias (Selected 

Cancers Cooperative Study Group, 1990b, p. 2481). 

Study Limitations 

The limitations of this investigation are that the researchers “could not measure serum TCDD 

levels in men recently diagnosed to have cancer because of the large quanitity of blood required” 

and like in any case-control study there is possible bias, residual confounding, and possible 

misclassification of the exposure or disease (Selected Cancers Cooperative Study Group, 1990b, 

pp. 2481-2482). 

Cases and Controls 

Part I: Non-Hodgkin’s lymphoma (NHL) This part of The Selected Cancers Study 

investigates the association between military service in Vietnam and exposure to phenoxyherbicides and NHL. 
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APPENDIX K K-23 

Cases and Controls The inclusion criterion for the cases includes 

• had an initial diagnosis of NHL, Hodgkin’s disease, or “lymphoma, not otherwise 

specified”; 

• men first diagnosed with NHL between December 1, 1984, and November 30, 1988; 

• lived in geographic location areas covered by the population-based cancer registries for 

five metropolitan areas (Atlanta, GA; Detroit, MI; San Francisco, CA; Seattle, WA; 

Miami, FL) and three states (Connecticut, Iowa, and Kansas); and 

• born between 1929 and 1953. (Selected Cancers Cooperative Study Group, 1990a, p. 28, 

1990b, pp. 2474-2475) 

The exclusion criterion includes 

• unknown military or Vietnam service status; 

• been in or off the coast of Vietnam but not stationed there; 

• have AIDS or AIDS-related illness; and 

• not residents of the United States before 1969 and were thus unlikely to have been 

eligible for U.S. military service in Vietnam. (Selected Cancers Cooperative Study 

Group, 1990a, p. 28, 1990b, pp. 2474-2475) 

The controls were selected based on random digit dialing and frequency-matched to lymphoma cases by geographic areas (registries) and age in 1968, and were the same controls for the 

other cancers investigated. 

 

Part II: Soft-tissue and other sarcomas This part of the Selected Cancers Study investigates 

the association between military service in Vietnam and exposure to phenoxyherbicides and softtissue and other sarcomas. 

Cases and controls The inclusion criterion for the cases includes 

• men first diagnosed with sarcoma between December 1, 1984, and November 30, 1988; 

• lived in geographic location areas covered by the population-based cancer registries for 5 

metropolitan areas (Atlanta, GA; Detroit, MI; San Francisco, CA; Seattle, WA; Miami, 

FL) and three states (Connecticut, Iowa, and Kansas); and 

• born between 1929 and 1953. (Selected Cancers Cooperative Study Group, 1990a, p. 42, 

1990c, p. 2486) 

 

The exclusion criterion includes 

• diagnosis of Kaposi’s sarcoma or mesothelioma; 

• unknown military or Vietnam service status; 

• been in or off the coast of Vietnam but not stationed there; 

• had AIDS or AIDS-related illness; 

• not residents of the United States before 1969 and were thus, unlikely to have been 

eligible for U.S. military service in Vietnam; and 
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K-24 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

• reported a history of von Recklinghausen’s neurofibromatosis or a possible 

postirradiation osteosarcoma. (Selected Cancers Cooperative Study Group, 1990a, p. 42, 

1990c, p. 2486) 

The controls were selected based on random digit dialing and frequency-matched to lymphoma cases by geographic areas (registries) and age in 1968, and were the same controls for the 

other cancers investigated. 

Part III: Hodgkin’s disease, nasal cancer, nasopharyngeal cancer, and primary liver cancer 

This part of the Selected Cancers Study investigates the association between military service in 

Vietnam and exposure to phenoxyherbicides and the following cancers: Hodgkin’s disease, nasal 

cancer, nasopharyngeal cancer, and primary liver cancer. 

Cases and controls The inclusion criterion for the cases includes 

• men first diagnosed with Hodgkin’s disease, nasal cancer, nasopharyngeal cancer, or liver 

cancer between December 1, 1984, and November 30, 1988; 

• lived in geographic location areas covered by the population-based cancer registries for 5 

metropolitan areas (Atlanta, GA; Detroit, MI; San Francisco, CA; Seattle, WA; Miami, 

FL) and three states (Connecticut, Iowa, and Kansas); and 

• born between 1929 and 1953. (Selected Cancers Cooperative Study Group, 1990a, pp. 

53, 63, 70, 76-77, 1990d, pp. 2496-2497) 

The exclusion criterion includes 

• unknown military or Vietnam service status; 

• been in or off the coast of Vietnam but not stationed there; 

• had AIDS or AIDS-related illness; 

• not residents of the United States before 1969 and were thus, unlikely to have been 

eligible for U.S. military service in Vietnam; and 

• reported a history of von Recklinghausen’s neurofibromatosis or a possible 

postirradiation osteosarcoma. (Selected Cancers Cooperative Study Group, 1990a, pp. 53, 

63, 70, 76-77, 1990d, pp. 2496-2497) 

The controls were selected based on random digit dialing and frequency-matched to 

lymphoma cases by geographic areas (registries) and age in 1968, and were the same controls for 

the other cancers investigated. 

Results 

Part I: Non-Hodgkin’s lymphoma (NHL) 

Demographics Compared to the controls, NHL cases were distributed differently among the 8 

registries, were significantly older, had significantly less formal education, smoked more 

cigarettes, were more likely to be never married, had systemic lupus erythematosus, took more 
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APPENDIX K K-25 

immunosuppressive drugs following an organ transplant and intravenous drugs not prescribed by 

a physician (p <0.05) (Selected Cancers Cooperative Study Group, 1990a, pp. 29-30, 1990b). 

There were no significant differences between the cases and controls with respect to being 

stationed in or off the coast of Vietnam, racial/ethnic group, sprayed or mixed any herbicide on a 

farm or ranch, sprayed or mixed any herbicide for right-of-way maintenance, lawn care, or 

forestry work, occupational exposure to phenoxyherbicides, occupational exposure to 

chlorophenols, raised in the Jewish religion, exposure to medical radiation ≥5 years before the 

date of diagnosis, diagnosed with rheumatoid arthritis, had an immune disease other than AIDS 

≥3 years before the data of diagnosis, had malaria, took medication to treat or prevention 

malaria, or took phenytoin or related compounds for epilepsy of seizures (Selected Cancers 

Cooperative Study Group, 1990b). 

Part II: Soft-tissue and other sarcomas 

Demographics Compared to controls, cases were distributed differently among the 8 registries 

and were significantly less likely to be white non-Hispanic, more likely to have occupational 

exposure to chlorophenols and more likely to work in a meat packing or processing plant 

(p <0.05) (Selected Cancers Cooperative Study Group, 1990a, p. 42, 1990c). 

There were no significant differences between the cases and controls with respect to age in 

1968, being stationed in or off the coast of Vietnam, highest level of education completed, 

regular smoking of cigarettes, sprayed or mixed any herbicide on a farm or ranch, sprayed or 

mixed any herbicide for right-of-way maintenance, lawn care, or forestry work, occupational 

exposure to phenoxyherbicides, had an immune disease other than AIDS ≥3 years before date of 

diagnosis, took drugs to suppress the immune system, had Gardner’s syndrome, or took 

clofibrate or a related compound (Selected Cancers Cooperative Study Group, 1990c). 

Part III: Hodgkin’s disease, nasal cancer, nasopharyngeal cancer, and primary liver cancer 

Demographics Compared to controls, cases of Hodgkin’s disease were significantly younger, 

had less formal education, and were more likely to have reported ever having smoked cigarettes 

regularly (p <0.05). However, there were no significant differences between the cases of 

Hodgkin’s disease and the controls with respect to the distribution within the 8 registries, being 

stationed in Vietnam or off the coast of Vietnam, race/ethnicity, reported having sprayed or 

mixed any herbicide on a farm or ranch, reported having sprayed or mixed any herbicide for 

right-of-way maintenance, lawn care, or forestry work, reported occupational exposure to 

phenoxyherbicides, reported occupational exposure to chlorophenols, raised in the Jewish 

religion, number of siblings lived with while growing up, raised in an urban setting, exposure to 

medical radiation ≥5 years before the date of diagnosis, had chemotherapy ≥5 years before the 

date of diagnosis, had mononucleosis, had a tonsillectomy, or had an appendectomy (Selected 

Cancers Cooperative Study Group, 1990a, p. 54, 1990d). 

Compared to controls, cases of nasal cancer were significantly older, had less formal 

education, and were more likely to have reported ever having smoked cigarettes regularly 

(p <0.05). However, there were no significant differences between the cases of nasal cancer with 

respect to the distribution within the 8 registries, being stationed in Vietnam or off the coast of 

Vietnam, race/ethnicity, reported having sprayed or mixed any herbicide on a farm or ranch, 

reported having sprayed or mixed any herbicide for right-of-way maintenance, lawn care, or 
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K-26 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

forestry work, reported occupational exposure to phenoxyherbicides, reported occupational 

exposure to chlorophenols, working in a pulp, saw or planning mill, worked around wood dust, 

worked with or around plywood, worked in metal planting, working with or around nickel, 

worked with or around chromium, or worked with wood as a hobby (Selected Cancers 

Cooperative Study Group, 1990a, p. 64, 1990d). 

Compared to controls, cases of nasopharyngeal cancer were significantly older, were less 

likely to be white non-Hispanic, had less formal education, were more likely to have reported 

ever having smoked cigarettes regularly, and more likely to have reported occupational exposure 

to chlorophenols (p <0.05). However, there were no significant differences between the cases of 

nasopharyngeal cancer with respect to the distribution within the 8 registries, being stationed in 

Vietnam or off the coast of Vietnam, reported having sprayed or mixed any herbicide on a farm 

or ranch, reported having sprayed or mixed any herbicide for right-of-way maintenance, lawn 

care, or forestry work, reported occupational exposure to phenoxyherbicides, nasopharyngeal 

cancer in blood relatives, or had an infectious mononucleosis ≥5 years before the date of 

diagnosis (Selected Cancers Cooperative Study Group, 1990a, p. 71, 1990d). 

Compared to controls, cases of liver cancer were distributed within the 8 registries differently 

and were significantly older, less likely to be white non-Hispanic, have less formal education, 

more likely to have reported ever having smoked cigarettes regularly, less likely to have reported 

having sprayed or mixed any herbicide on a farm or ranch, less likely to have occupational 

exposure to phenoxyherbicides, more likely to have had hepatitis ≥3 years before the date of 

diagnosis, more likely to had had cirrhosis ≥3 years before the date of diagnosis, and less likely 

to have worked with chemical solvents (p <0.05). However, there were no significant differences 

between the cases of liver cancer and the controls with respect to being stationed in Vietnam or 

off the coast of Vietnam, reported having sprayed or mixed any herbicide for right-of-way 

maintenance, lawn care, or forestry work, reported occupational exposure to chlorophenols, 

reported ever drinking alcohol regularly, taking androgenic steroids, or working in a dry-cleaning 

plant (Selected Cancers Cooperative Study Group, 1990a, p. 77, 1990d). 

All investigations (Part I, II, III) 

Association between military service in Vietnam and cancer There was a significant association 

between military service in Vietnam and NHL in the Selected Cancers Study based on Model 1, 

Model 2, and Model 3 (see above for covariate in each model) (Table K-15). However, there 

were no significant associations found between military service in Vietnam and soft-tissue and 

other sarcomas, Hodgkin’s disease, nasal cancer, nasopharyngeal cancer, or liver cancer (see 

Tables K-15, K-16, K-17, and K-18 for the results for various associations) (Selected Cancers 

Cooperative Study Group, 1990a,b,c,d). 

Histological Classification There was no significant differences between men with NHL 

stationed in or off the coast of Vietnam and those not stationed in or off the coast of Vietnam 

with regards to histological classification of the malignant neoplasms (i.e., low grade, 

intermediate grade, high grade [p = 0.73]) (Selected Cancers Cooperative Study Group, 1990b, p. 

2478). 

There were no significant differences between men with soft-tissue and other sarcomas 

stationed in or off the coast of Vietnam and those not stationed in or off the coast of Vietnam 

with regards to histological classification of the malignant neoplasms (i.e., fibromatous, 
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http://www.nap.edu/catalog/11908.html APPENDIX K K-27 TABLE K-15 Association Between Military Service in Vietnam and Cancer Model Non-Hodgkin’s Disease OR (95% CI) Soft-Tissue and Other Sarcomas OR (95% CI) Hodgkin’s Disease OR (95% CI) Nasal Cancer OR (95% CI) Nasopharnygeal Cancer OR (95% CI) Liver Cancer OR (95% CI) Model 1 1.45 (1.08-1.93) 1.02 (0.65-1.61) 1.20 (0.76-1.90) 0.70 (0.08-2.95) 0.60 (0.12-1.93) 1.22 (0.55-2.67) 

Model 2 1.46 (1.09-1.96) 1.01 (0.64-1.60) 1.17 (0.74-1.86) 0.67 (0.15-2.96) 0.57 (0.17-1.93) 1.27 (0.56-2.89) Model 3 1.47 (1.09-1.97) 1.00 (0.63-1.58) 1.14 (0.71-1.83) 0.66 (0.15-2.91) 0.52 (0.15-1.75) 1.16 (0.50-2.68) 

NOTE: See above for covariates for each of the three models. SOURCE: Selected Cancers Cooperative Study Group, 1990a, pp. 32, 45, 57, 66, 73, 79, 1990b,c,d. TABLE K-16 Risk of Cancer Among Vietnam Veterans Compared to the Risk Among Four Unexposed Referent Groups 

Unexposed Referent Groups 

Non-Hodgkin’s Disease OR (95% CI) 

Soft-Tissue and Other Sarcomas OR (95% CI) 

Hodgkin’s Disease OR (95% CI) 

Nasal Cancer OR (95% CI) 

Nasopharnygeal Cancer OR (95% CI) 

Liver Cancer OR (95% CI) 

Men who did not 

serve in Vietnam 

1.47 (1.09-1.97) 1.00 (0.62-1.59) 1.14 (0.71-1.83) 0.66 (0.15-2.91) 0.52 (0.15-1.75) 1.16 (0.50-2.68) 

Men who served in 

the military at any time but not in Vietnam 

1.63 (1.14-2.33) 0.88 (0.51-1.52) 1.09 (0.62-1.91) 0.37 (0.08-1.83) 0.68 (0.18-2.65) 0.87 (0.33-2.28) 

Men who served at 

any time from 1964-1972 in the military but not in Vietnam 

1.52 (1.00-2.32) 0.74 (0.39-1.41) 1.23 (0.65-2.36) 0.31 (0.04-2.20) Could not be 

calculated 

0.53 (0.14-1.94) 

Men who never 

served in the military 

1.41 (1.03-1.93) 1.05 (0.64-1.71) 1.17 (0.71-1.92) 1.38 (0.28-6.81) 0.48 (0.14-1.71) 1.34 (0.52-3.44) 

NOTE: Data from Model 3 (see above for covariates). SOURCE: Selected Cancers Cooperative Study Group, 1990a, pp. 33, 45, 57, 67, 74, 80; 1990b,c,d. 
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K-28 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

TABLE K-17 Association Between Branch of Military Service and Cancera for Non-Vietnam and 

Vietnam Veterans 

Branch of Military 

Service 

Non-Hodgkin’s Disease 

OR (95% CI) 

Soft-Tissue and 

Other Sarcomas 

OR (95% CI) 

Hodgkin’s Disease 

OR (95% CI) 

Non-Vietnam Veterans 

 Army 

 Air Force 

 Marines 

 Navy 

 Coast Guard 

0.82 (0.66-1.02) 

0.91 (0.67-1.25) 

0.77 (0.45-1.32) 

0.79 (0.57-1.11) 

1.45 (0.39-5.38) 

0.89 (0.64-1.25) 

0.58 (0.32-1.04) 

0.85 (0.36-1.99) 

1.25 (0.77-2.01) 

1.35 (0.15-12.2) 

0.78 (0.52-1.17) 

1.36 (0.81-2.29) 

1.77 (0.86-3.63) 

1.34 (0.81-2.24) 

N/A 

Vietnam Veterans 

 Army 

 Air Force 

 Marines 

 Navy 

 Coast Guard 

1.19 (0.79-1.80) 

1.02 (0.47-2.24) 

1.84 (0.78-4.34) 

1.89 (1.11-3.24) 

N/A 

0.70 (0.35-1.43) 

1.40 (0.49-3.99) 

1.71 (0.57-5.15) 

0.83 (0.30-2.24) 

N/A 

1.00 (0.51-1.97) 

1.69 (0.58-4.89) 

1.73 (0.51-5.88) 

1.06 (0.43-2.59) 

N/A 

NOTE: Data from Model 3 (see above for covariates). N/A = Odds ratio could not be calculated. a

Due to the small number of Vietnam veterans with nasal cancer, nasopharyngeal cancer, and liver cancer, 

the analysis in Part III was completed for Hodgkin’s disease only. 

SOURCE: Selected Cancers Cooperative Study Group, 1990a, pp. 34, 48, 58, Tables 3.6, 4.6, 5.6; 

1990b,c,d. 

TABLE K-18 Association Between Self-Reported Agent Orange Contact and Cancera

 Among Those 

Who Reported the Exposure and Served in Vietnam Compared to Those Who Did Not Report the 

Exposure but Who Served in Vietnam 

Type of Contact with Agent 

Orange 

Non-Hodgkin’s 

Disease 

OR (95% CI) 

Soft-Tissue and Other 

Sarcomas 

OR (95% CI) 

Hodgkin’s 

Disease 

OR (95% CI) 

Reported passing though a 

defoliated area 

0.82 (0.45-1.49) 1.60 (0.63-4.12) 0.65 (0.25-1.67) 

Reported any possible contact with 

Agent Orange 

1.08 (0.58-2.02) 0.68 (0.23-2.05) 0.76 (0.28-2.07) 

Reported being present when other 

were spraying Agent Orange 

0.98 (0.39-2.48) 0.38 (0.05-3.11) 0.74 (0.15-3.67) 

Reported getting Agent Orange in 

skin or clothes 

1.08 (0.40-2.96) 0.52 (0.06-4.39) 0.47 (0.06-3.99) 

Reported handling equipment or 

containers that had been used with 

Agent Orange 

0.41 (0.04-4.07) N/A N/A 

NOTE: Data from Model 3. N/A = Odds ratio could not be calculated. a

Due to the small number of Vietnam veterans with nasal cancer, nasopharyngeal cancer, and liver cancer, 

the analysis in Part III was completed for Hodgkin’s disease only. 

SOURCE: Selected Cancers Cooperative Study Group, 1990a, pp. 36, 48, 60, Tables 3.8, 4.8, 5.8; 

1990b,c,d. 
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APPENDIX K K-29 

TABLE K-19 Association Between Selected Characteristics of Military Service in Vietnam and Cancera

Characteristics 

Non-Hodgkin’s Disease 

OR (95% CI) 

Soft-Tissue and Other 

Sarcomas 

OR (95% CI) 

Hodgkin’s 

Disease 

OR (95% CI) 

Military service in 

Vietnam 

1.47 (1.09-1.97) 1.00 (0.63-1.58) 1.14 (0.71-1.83) 

Duration of service in 

Vietnam (years) 

<1 

1-1.4 

1.5-1.9 

≥2 

1.05 (0.70-1.57) 

1.98 (1.00-3.94) 

2.99 (1.41-6.31) 

1.54 (0.79-3.01) 

p for trend = 0.06 

0.77 (0.41-1.47) 

1.28 (0.45-3.66) 

0.92 (0.20-4.26) 

1.24 (0.44-3.45) 

p for trend = 0.80 

0.86 (0.45-1.65) 

2.43 (0.98-5.99) 

1.14 (0.30-4.37) 

1.11 (0.36-3.45) 

p for trend = 0.33 

Calendar years stationed in 

Vietnam 

Before 1966 

1966-1969 

After 1969 

1.38 (0.54-3.55) 

1.41 (1.01-1.98) 

1.64 (0.79-3.39) 

p for trend = 0.93 

0.46 (0.05-3.93) 

0.95 (0.56-1.62) 

1.30 (0.45-3.69) 

p for trend = 0.66 

0.41 (0.05-3.44) 

1.11 (0.64-1.93) 

1.63 (0.66-4.02) 

p for trend = 0.42 

Age at beginning of first 

tour in Vietnam (years) 

<21 

21-25 

≥26 

1.73 (1.11-2.70) 

1.20 (0.74-1.94) 

1.45 (0.81-2.60) 

p for trend = 0.52 

0.97 (0.47-2.01) 

1.34 (0.68-2.66) 

0.44 (0.13-1.52) 

p for trend = 0.26 

1.15 (0.61-2.18) 

1.06 (0.49-2.29) 

1.31 (0.42-4.10) 

p for trend = 0.95 

Rank at end of last tour in 

Vietnam 

E1-E3 

E4-E9 

Officer 

1.29 (0.61-2.72) 

1.44 (1.02-2.03) 

1.78 (0.80-3.96) 

p for trend = 0.84 

0.67 (0.19-2.35) 

1.11 (0.65-1.89) 

0.69 (0.15-3.22) 

p for trend = 0.66 

1.07 (0.37-3.04) 

1.19 (0.70-2.04) 

1.33 (0.28-6.26) 

p for trend = 0.97 

Type of unit in Vietnam 

Support 

Combat support 

Combat 

1.50 (1.02-2.21) 

1.18 (0.65-2.15) 

1.25 (0.63-2.45) 

p for trend = 0.76 

0.76 (0.37-1.53) 

1.03 (0.44-2.41) 

0.76 (0.25-2.28) 

p for trend = 0.85 

1.58 (0.90-2.77) 

0.50 (0.14-1.76) 

0.94 (0.34-2.59) 

p for trend = 0.17 

Corps in Vietnam 

I 

II 

III 

IV 

Blue-water Navy 

2.25 (1.21-4.18) 

1.22 (0.66-2.26) 

0.89 (0.50-1.58) 

0.90 (0.15-5.41) 

2.17 (1.22-3.86) 

p for trend = 0.11 

1.61 (0.69-3.76) 

0.74 (0.25-2.18) 

0.50 (0.17-1.44) 

N/A 

0.64 (0.18-2.21) 

p for trend = 0.33 

1.67 (0.67-4.18) 

0.52 (0.15-1.81) 

1.25 (0.57-2.75) 

0.93 (0.09-9.82) 

1.39 (0.56-3.46) 

p for trend = 0.59 

Ever in III Corps in 

Vietnam 

No 

Yes 

Blue-water Navy 

1.70 (1.07-2.71) 

0.96 (0.59-1.57) 

2.18 (1.23-3.88) 

p for trend = 0.06 

1.15 (0.57-2.32) 

0.67 (0.30-1.54) 

0.63 (0.18-2.20) 

p for trend = 0.73 

1.27 (0.60-2.67) 

1.12 (0.55-2.27) 

1.42 (0.57-3.52) 

p for trend = 0.92 
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K-30 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Land vs. sea duty in 

Vietnam 

All land-based men 

Sea-based blue-water 

Navy 

1.30 (0.93-1.83) 

2.18 (1.23-3.87) 

p for trend = 0.11 

1.07 (0.65-1.76) 

0.64 (0.18-2.21) 

p for trend = 0.41 

1.08 (0.64-1.82) 

1.41 (0.57-3.50) 

p for trend = 0.61 

NOTE: Data from Model 3. 

a

Due to the small number of Vietnam veterans with nasal cancer, nasopharyngeal cancer, and liver cancer, 

the analysis in Part III was completed for Hodgkin’s Disease only. 

SOURCE: Selected Cancers Cooperative Study Group, 1990a, pp. 37, 49, 59, Tables 3.7, 4.7, 5.7; 

1990b,c,d. 

lipomatous, myomatous, and other soft-tissue sarcomas [p = 0.82]) (Selected Cancers 

Cooperative Study Group, 1990c, p. 2488). 

Conclusions 

Part I: Non-Hodgkin’s lymphoma (NHL) “Compared with the other malignant neoplasms 

under investigation in the Selected Cancer Study, previous studies of Vietnam veterans more 

strongly support an association with NHL.” “Results of this study strongly suggest that Vietnam 

veterans have a roughly 50 percent increased risk of developing NHL approximately 15 to 25 

years after military service in Vietnam (OR = 1.47, 95% CI 1.09-1.97). The results do not show a 

similar increased risk among veterans who served in other locations during the Vietnam ear, 

suggestions that this association is specific to Vietnam service rather than military service in 

general.” “Although we could not test such hypotheses and we cannot completely rule out the 

role of chance or unrecognized bias, our results strongly suggest that Vietnam veterans are at 

increased risk of NHL and that this increased is not due to Agent Orange exposure” (Selected 

Cancers Cooperative Study Group, 1990b, pp. 2479-2480, 2482). 

Part II: Soft-tissue and other sarcomas “The results of this study do not indicate that the 

risk of sarcoma is increased among men who served in the U.S. military in Vietnam.” “The 

military service characteristics of men with sarcoma did not suggest that Vietnam veterans 

who might have been exposed to Agent Orange are at higher risk for the development of 

sarcoma.” “Our results are in agreement with those of most other studies and suggest that 

Vietnam veterans are not at increased risk for the development of sarcoma 15 to 25 years 

after service. We also failed to identify any subgroup of Vietnam veterans at higher risk or 

any subtype of soft-tissue sarcoma with greater risk for Vietnam veterans” (Selected Cancers 

Cooperative Study Group, 1990c, pp. 2489, 2491-2492). 

Part III: Hodgkin’s disease, nasal cancer, nasopharyngeal cancer, and primary liver cancer 

“Our results provide no evidence of higher risk of Hodgkin’s disease, nasal cancer, 

nasopharyngeal cancer, or primary liver cancer among Vietnam veterans.” “Except for 

Hodgkin’s disease, the malignant neoplasms described in this report have not received extensive 

attention in other studies of Vietnam veterans.” “Because most of the Vietnam veterans in this 

study were probably not (or were only minimally) exposed to Agent Orange, the results should 

not be considered an adequate test of the hypothesis that exposure to Agent Orange of TCDD is 
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APPENDIX K K-31 

associated with the development of these malignant neoplasms” (Selected Cancers Cooperative 

Study Group, 1990d, pp. 2503-2504). 

Agent Orange Validation Study 

Background 

The CDC conducted the two studies above (the VES and the Selected Cancer Study) in 

response to veterans’ concern that their service in Vietnam adversely affected their health. To 

study Agent Orange more directly, and to “determine if exposure scores based on military records 

of troop locations and spray locations can identify a large number of men exposed to Agent 

Orange, as would be needed for a large cohort study,” the CDC also conducted the Agent Orange 

Validation Study (CDC, 1988, p. 1253; see http://www.cdc.gov/nceh/veterans/default1b.htm). 

Agent Orange Validation Study Cohort 

The sample size of the study is given in Figure K-2. The Agent Orange Validation Study 

cohort included Vietnam veterans with the following inclusion criteria: 

• U.S. Army combat battalions 

• Single term of enlistment 

• Minimum or 16 week of active duty time 

• Served 18 months or more in the III Corps military region (includes Saigon) during 1967-

1968 (heavy spraying in this year during these years) 

• Military occupational specialty (MOS) other than “duty soldier” or “trainee” 

• Discharged at pay grade E-5 or lower 

• No deceased veterans (CDC, 1988, p. 1250) 

The Agent Orange Validation Study cohort included the following non-Vietnam veterans: 

• All who entered the U.S. Army between 1965 and 1971 

• Sample of men interviewed near the end of the Vietnam Experience Study, but were not 

invited for the medical examination (see description above) 

• Served in the continental United States or Germany 

Three hundred and sixty-seven non-Vietnam veterans met the criteria above and were 

frequency-matched by race and age to the Vietnam veterans originally selected. Two hundred 

non-Vietnam veterans were invited to participate in both the telephone interview and the medical 

examination (CDC, 1988, p. 1250). 

Demographics 

The demographics (mean age, race, region of residence, smoking, alcohol use, mean BMI, 

and mean total serum lipid level) of the Vietnam veterans were not significantly different than 

those of the non-Vietnam veterans. 

Many more Vietnam veterans self-reported direct herbicide exposure (25 percent) than nonVietnam veterans (6 percent) and indirect herbicide exposure (71 percent and 6 percent, 
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K-32 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

 

FIGURE K-2 Sample size of the Vietnam veterans in the Agent Orange Validation Study. 

SOURCE: CDC, 1988, pp. 1250-1251.

respectively). However, fewer Vietnam veterans self-reported any civilian occupation or home 

use exposure to herbicides compared to non-Vietnam veterans (20 vs. 33 percent and 33 vs. 44 

percent, respectively) (CDC, 1988). 
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APPENDIX K K-33 

Data from the Agent Orange Validation Study 

Potential confounders A priori potential confounders are age, race, body mass index, and selfreported civilian occupational and home exposures to herbicides. Preliminary data analysis 

showed that smoking history, alcohol consumption, and region of residence are also potential 

confounders (CDC, 1988, p. 1251). 

General methods The methods followed in this study are similar to those of the VES (see 

above). Briefly, RTI (and Equifax Inc, its subcontractor) located veterans and performed 

telephone interviews and the medical examinations were performed at the Lovelace Medical 

Foundation. The data were then abstracted by the U.S. Army and Joint Services Environmental 

Support Group (CDC, 1988, pp. 1249-1250). 

Exposure data Dates and locations of herbicide sprays in South Vietnam for Operation Ranch 

Hand missions and other sprays were abstracted from military records. Military unit locations 

were abstracted from military and personnel records. These data were then used to access the 

herbicide locations of the exposed compared to the unexposed (CDC, 1988, p. 1249). 

Exposure score The exposure score was calculated for each day of the study and for each 

company in 50 of the 65 battalions with abstractable data. The exposure score was calculated by 

5 methods (CDC, 1988, p. 1250) as follows: 

• Agent Orange intermediate score 

o “Weighted number of days on which at least one location for a company was within 2 

km of a recorded Agent Orange spray within 6 days after the spray” (where the 

weight is the number of different sprays within 2 km of a company location) 

o Unknown intermediate scores are also calculated since some unknown agents are 

actually Agent Orange 

• Agent Orange slow score 

o “Weighted number of days a company was within 2km of an Agent Orange spray 

after any earlier spray” (where the weight is the 5-year half life of Agent Orange) 

o Unknown slow scores are also calculated since some unknown agents are actually 

Agent Orange 

• Number of days a company was in one of the five large, heavily sprayed regions 

• Number of days of self-reported direct exposure during military service(spraying 

herbicide or being present during spraying, handling herbicide, getting herbicide on skin 

or clothing) 

• Number of days of indirect exposure to herbicides during military service (walking 

through or clearing vegetation in a previously sprayed area) (from interviews) 

Telephone interview Eight-hundred and seventy-one Vietnam veterans completed the 

interview. Men were asked about exposure to herbicides during military service, civilian work, 

and at home. Only 5 percent of Vietnam veterans reported spraying herbicides or handling spray 

equipment during military service (CDC, 1988, pp. 1251, 1254). 

There were no significant differences in median current serum TCDD levels in the Vietnam 

veterans among those with low, medium, and high exposure scores, based on self-reported 
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indirect exposure (p = 0.08). However, there was a borderline significant difference based on 

self-reported direct exposure (p = 0.05) (CDC, 1988). 

Medical examination The medical examination includes serum samples for TCDD 

measurements. Each participant fasted overnight; ate a low-fat, low-cholesterol breakfast; and 

the blood samples were collected 2 hours later. Current TCDD levels of Vietnam veterans are 

then compared to those of non-Vietnam veterans. 

Six-hundred and sixty-five Vietnam veterans and 103 non-Vietnam veterans gave blood 

samples, and 646 of the samples in Vietnam veterans and 97 samples in non-Vietnam veterans 

had TCDD results that met laboratory quality control criteria. 

Service in Vietnam was not associated with TCDD level after adjusting for age, race, region 

or residence, body mass index, smoking history, alcohol consumption, and reported civilian 

herbicide exposure (p = 0.23) (CDC, 1988, p. 1251). 

Conclusions 

“It seems . . . that most U.S. Army ground combat troops who did not handle or spray 

herbicides were not heavily exposed to TCDD in Vietnam” (CDC, 1988, p. 1254). “This 

study is consistent with other studies and suggests that most U.S. Army ground troops who 

served in Vietnam were not heavily exposed to TCDD, except perhaps men whose jobs 

involved handling herbicides” (CDC, 1988). 

Strengths of the Agent Orange Validation Study are that there are 

• no indications of selection bias or confounding; and 

• participation rates were modest at 66 percent for Vietnam veterans and 48 percent for 

non-Vietnam veterans, but they were “unlikely to cause bias.” 

Limitations of the Agent Orange Validation Study are that it 

• cannot be generalized to other Vietnam veterans since sample was not random; 

• did not include veterans from the chemical corps, a relatively small group with a high 

potential for exposure; and 

• military records could not only be used since “records may be unavailable for many of 

the herbicide applications most likely to have exposed troops” (CDC, 1988, pp. 1253, 

1249). 

Studies on Gulf War Veterans 

For the purposes of this report, short summaries of CDC studies on Gulf War veterans were 

taken directly from the CDC website (http://www.cdc.gov/nceh/veterans/default2.htm) and 

provided below. 

Health Effects of Exposure to Smoke from Oil Well Fires 

Researchers from the Centers for Disease Control and Prevention (CDC) and several 

other federal agencies conducted surveys of workers in Kuwait City in May 1991, and of 

firefighters in the oil fields in October 1991. Blood samples were tested for 31 volatile 

organic compounds (VOCs) and were compared with samples from a group of people 
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APPENDIX K K-35 

living in the United States. The samples from people living in the United States were 

collected as part of the Third National Health and Nutrition Examination Survey 

(NHANES III), a national survey of the health of Americans. The median concentration 

of VOCs among the firefighters was quite elevated. However, among the non-firefighting 

personnel, VOC con-centrations were equal to or lower than the levels found among the 

people living in the United States. 

 (http://www.cdc.gov/nceh/veterans/default2a.htm) 

NCEH also collaborated with the U.S. Department of Defense on a study of 30 members 

of an Army unit located in Germany. Blood from these military personnel was tested for 

VOCs at three points in time: before, during, and after their deployment to Kuwait. 

Tetrachloroethylene, a compound found in degreas-ing agents used to clean equipment, 

was the only VOC found to be elevated. 

 (http://www.cdc.gov/nceh/veterans/default2a.htm) 

Birth Defects 

In 1994, CDC collaborated with the Mississippi Department of Health and the U.S. 

Department of Veterans Affairs to investigate reports of adverse birth out-comes among 

members of two Mississippi National Guard Units that served in the Gulf War. This 

investigation found no increase above expected rates in the total number of birth defects 

or in the frequency of premature births and low birth-weight babies. The frequency of 

other health problems, such as respiratory infections, gastroenteritis, and skin diseases 

among children born to these veterans also did not appear to be elevated. 

(http://www.cdc.gov/nceh/veterans/default2b.htm) 

(See also Penman et al., 1996) 

In 1995, the Naval Health Research Center asked CDC to assist in a study of Goldenhar 

syndrome. Goldenhar syndrome is characterized by abnormal prenatal development of 

facial structures. Two clinicians from CDC reviewed birth records of 75,414 infants 

conceived after the Gulf War and born in military treatment facilities (34,069 infants born 

to Gulf War veterans and 41,345 born to nondeployed veterans). They identified five 

infants with Goldenhar syndrome who were born to Gulf War veterans and two infants 

born to nondeployed veterans. Because of the small number of cases found by the study, 

the statistical power of the study was low. It was not possible to conclude solely from this 

study whether there is a higher or lower risk for Goldenhar syndrome among infants born 

to Gulf War veterans. 

(http://www.cdc.gov/nceh/veterans/default2b.htm) 

(See also Araneta et al., 1997) 

Air Force Study 

Various members of a Pennsylvania Air National Guard unit reported illnesses 

potentially associated with their previous deployment to the Gulf War. in November 

1994, the Pennsylvania State Health Department, the U.S. Department of Veteran Affairs, 

and the U.S. Department of Defense requested that CDC conduct an independent 

investigation of those illnesses. The investigation, carried out by CDC’s National Center 

for Infectious Diseases, involved three phases: 

 
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K-36 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

1. Interviews with and examination of ill Gulf War veterans from the Air National 

Guard unit (the index unit) and review of medical records to verify and characterize 

illness 

2. A survey of 3,723 military personnel from four Air Force units, including veterans 

who were and were not deployed to the Gulf War, to determine the relative 

prevalence of symptoms and to develop a working case definition of illness 

3. A clinical evaluation of 158 Gulf War veterans from the index unit to further 

clinically characterize illness and to identify risk factors (by examination and 

laboratory tests) 

(http://www.cdc.gov/nceh/veterans/default2c.htm) 

A case was defined as a person having one or more chronic symptoms from at least two 

of three symptom categories (fatigue, mood-cognition, and musculoskeletal). A case was 

further classified as severe if each case-defining symptom was rated as severe; otherwise, 

the case was classified as mild-to-moderate. Cases were more likely to demonstrate 

poorer functioning, depression, and post-traumatic stress disorder. However, no 

consistent abnormalities were found by physical examination, routine laboratory tests, or 

tests for several infectious agents endemic to the Middle East. The prevalence of mild-tomoderate and severe cases was 39 percent and 6 percent, respectively, among Gulf War 

veterans versus 14 percent and 0.7 percent among nondeployed veterans. Fifty-nine (37 

percent) clinically evaluated Gulf War veterans did not qualify as cases, 86 (54 percent) 

were mild-to-moderate cases, and 13 (8 percent) were severe cases. The investigators 

identified a chronic multisystem condition that was significantly associated with 

deployment to the Gulf War, but was not associated with specific Gulf War exposures, 

and that also affected nondeployed personnel. 

(http://www.cdc.gov/nceh/veterans/default2c.htm) 

(See also CDC, 1995; Fukuda et al., 1998; Nisenbaum et al., 2000) 

Health Assessment of Gulf War Veterans from Iowa 

In April 1994, Senator Tom Harkin of Iowa requested that CDC conduct a health 

assessment of Gulf War veterans his state. The study was initiated in December 1994 and 

was conducted through a cooperative agreement between the Iowa Department of Public 

Health and CDC’s National Center for Environmental Health. The Iowa Department of 

Public Health contracted with investigators at the University of Iowa who took the lead in 

designing and conducting the study. From September 1995 through May 1996, a 

telephone survey was administered to 1,896 Gulf War veterans and to 1,799 military 

personnel who were not deployed to the Persian Gulf. 

(http://www.cdc.gov/nceh/veterans/default2d.htm) 

This was one of the first population-based epidemiologic studies to document that Gulf 

War veterans are reporting more medical and psychiatric conditions than their military 

peers. 

(http://www.cdc.gov/nceh/veterans/default2d.htm) 

The study identified several conditions that need to be studied in more detail, including 

cognitive dysfunction, depression, chronic fatigue, post-traumatic stress disorder, and 

respiratory illness (asthma and bronchitis). The conditions identified in this study appear 

to have measurably affected the functional activity and daily lives of these Gulf War 

veterans. However, these conditions may not be unique to Gulf War veterans and may be 

similar to the experience of veterans in other wars. Among Gulf War veterans, minimal 
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APPENDIX K K-37 

differences were observed between the National Guard or Reserve troops and the regular 

military personnel. 

(http://www.cdc.gov/nceh/veterans/default2d.htm) 

(See also Barrett et al., 2002; Black et al., 1999, 2000; Doebbeling et al., 2000, 2002; 

Iowa Persian Gulf Study Group, 1997; Zwerling et al., 2000) 

Iowa Asthma Follow-Up Study 

The original Iowa study was extended to collect physical examination data on a subset of 

the telephone survey participants to validate the self-report of asthma. Data were 

collected on 32 Gulf War veterans who reported asthma during the telephone survey, 42 

Gulf War veterans who reported no illnesses during the tele-phone survey, and 20 nonGulf War veterans who reported asthma during the telephone survey. The two groups of 

subjects with reported asthma were similar in symptoms, baseline pulmonary function 

tests, and bronchial hyperreactivity. The Gulf War veterans who reported asthma had 

significantly more current symptoms compared with the Gulf War veterans who reported 

no illness during the telephone survey. They also had comparatively lower baseline 

spirometry (a measure of how well the lungs exhale) and increased bronchial 

hyperreactivity. No differences in smoking history were found between the two groups 

with asthma. However, Gulf War veterans who reported asthma were more likely to be 

current and past smokers than the Gulf War veterans who did not report illness. 

(http://www.cdc.gov/nceh/veterans/default2e.htm) 

Cognitive Function and Symptom Patterns in Gulf War Veterans 

In November 1997, CDC funded a study by the Boston University School of Public 

Health to examine potential reasons for the memory and thinking problems reported by 

Gulf War veterans. in one component of this study, functional magnetic resonance 

imaging (fMRI) was used to examine possible differences in brain activation patterns 

within specific areas of the brain. Gulf War veterans and their nondeployed peers with 

differing levels of symptoms were compared. in another component of this study, Danish 

armed forces personnel were tested to determine whether they are experiencing the same 

types of memory and thinking problems reported by U.S. troops who participated in the 

Gulf War. The Danish troops were also asked about any symptoms that they may be 

experiencing. Both Danish troops who participated in the Gulf War and troops who were 

not deployed to the Gulf War were tested. The results will be compared with results from 

a group of U.S. Gulf War veterans that the Boston University School of Public Health 

and the Boston VA Medical Center have been following since they returned from the 

Gulf War. Findings have been published regarding the neuropsychological functioning of 

the Danish Gulf War troops. No significant differences in neuropsychological test 

performances were found between the Gulf War-deployed and non-Gulf War-deployed 

groups. Danish troops deployed to the Gulf War reported significantly more mood 

complaints (i.e., fatigue and confusion) than their nondeployed counterparts. Publications 

are still pending for the fMRI component of this study. 

(http://www.cdc.gov/nceh/veterans/default2f.htm) 

 (See also Proctor et al., 2003) 
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K-38 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Defining Gulf War Illness 

In November 1997, CDC funded a study to characterize and compare different 

approaches for defining the medically unexplained illnesses of Gulf War veterans. This 

study by the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson 

Medical School compared the symptoms of two groups of Gulf War veterans at two 

points in time. The study subjects included Gulf War veterans from the Department of 

Veterans Affairs’ Gulf War Registry who had participated in a previous study conducted 

by the New Jersey researchers, and veterans who had participated in the CDC Air Force 

study. Data-driven case definitions for illness previously derived from these two groups 

of Gulf War veterans were compared with standard or existing case definitions for 

unexplained multi-symptom illnesses (such as chronic fatigue syndrome, fibromyalgia, 

and multiple chemical sensitivity) to determine which definition best characterized Gulf 

War veterans’ unexplained illnesses. The study also tried to determine how well the 

derived and existing case definitions could be generalized in a new random sample of 

deployed and nondeployed Gulf War era veterans and active duty soldiers. The 

investigators are preparing manuscripts for publication which are expected by the end of 

2005. 

(http://www.cdc.gov/nceh/veterans/default2g.htm) 

Assessing the Potential Health Impact of the Gulf War on Saudi Arabia National Guard 

Members 

This study, initiated in 1999, involved a collaborative effort of health researchers from 

the United States (U.S. Department of Defense and CDC) and Saudi Arabia. The team 

examined hospitalization data for 15,612 Saudi Arabia National Guard (SANG) troops. 

The goal of this study was to compare hospitalization rates and health outcomes among a 

group of SANG soldiers who were stationed in a combat area in January 1991 (Al Khafji) 

with soldiers who were stationed in a non-combat area (Riyadh). The investigators 

identified 148 SANG soldiers who had at least one hospitalization between 1991 and 

1999. The adjusted rate of hospitalization was higher in the combat-exposed group (risk 

ratio = 1.80, 95% confidence interval = 1.25-2.59). No unusual patterns of diagnoses 

were found. Because the overall number of hospitalizations was low, the absolute 

difference in risk was found to be very small. 

(http://www.cdc.gov/nceh/veterans/default2h.htm) 

(See also Gackstetter et al., 2005; Hooper et al., 2005) 

Epidemiologic Study of the Occurrence of Amyotrophic Lateral Sclerosis (ALS) Among 

Gulf War Veterans 

In June 1999, the Department of Veterans Affairs and U.S. Department of Defense 

requested that CDC assist in a study of amyotrophic lateral sclerosis (ALS) among Gulf 

War veterans. ALS is a fatal neurodegenerative disease that destroys the brain and spinal 

cord nerve cells that control muscle movement. As the brain and spinal cord nerve cells 

die, muscles weaken and shrink, and rapid severe paralysis occurs. Neither a cause nor a 

cure for ALS is known at this time. This investigation of ALS was initiated to determine 

if there is a higher than expected incidence of ALS among veterans of the 1991 Gulf War 

and to examine possible risk factors for the disease. CDC’s Environmental Health 

Laboratory conducted laboratory analyses of blood and urine specimens to look for signs 

of exposure to heavy metals. Initial results found military personnel who were deployed 

to the Gulf region during the 1991 Gulf War experienced a greater post-war risk of ALS 
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APPENDIX K K-39 

than those who were not deployed to the Gulf. Among approximately 2.5 million eligible 

military personnel, 107 confirmed cases of ALS were identified (an overall occurrence of 

0.43 per 100,000 persons per year). Overall, the attributable risk associated with 

deployment was 18 percent (95% CI = 4.9 to 29.4%). Findings regarding exposure to 

heavy metals are pending. 

 (http://www.cdc.gov/nceh/veterans/default2i.htm) 

(See also Horner et al., 2003) 

Deployment to the Gulf War and Subsequent Development of Cancer

In 2002, George Washington University School of Public Health and Health Services 

began a study to determine if cancer patterns among veterans of the 1991 Gulf War 

veterans differ from the patterns found among Gulf War era veterans not deployed to the 

Persian Gulf. CDC and the Association of Schools of Public Health funded the study. 

Initial work by the study investigators using data from the District of Columbia and the 

New Jersey Cancer Registries found a statistically significant excess of testicular cancer 

in Gulf War deployed veterans compared to non-Gulf War veterans. The current study is 

focusing on extending the analysis to include cancer data from additional states. These 

states include Texas, California, Florida, New York, Maryland, and Illinois. This study is 

expected to continue through July 2005. 

(http://www.cdc.gov/nceh/veterans/default2j.htm) 

(See also Levine et al., 2005)

Gulf War Research Planning Conference 

In early 1999, CDC helped sponsor The Health Impact of Chemical Exposures During 

the Gulf War: A Research Planning Conference. The U.S. Department of Health and 

Human Services’ Office of Public Health and Science, the National Institutes of Health, 

and the Agency for Toxic Substances and Disease Registry cosponsored the conference 

with CDC. The intent was to obtain broad public input into the development of a multiyear research plan for investigating the relationship between chemical exposures during 

the Gulf War and illnesses affecting Gulf War veterans. Concurrent workgroups 

developed research recommendations in the following areas: 

• Pathophysiology/etiology of illnesses among Gulf War veterans 

• The most appropriate methods for assessing and diagnosing the health effects of 

chemical exposures 

• The most appropriate treatment approaches 

• Ways to prevent similar illnesses in future military deployments 

(http://www.cdc.gov/nceh/veterans/default2k.htm) 

A final report summarizing conference recommendations was released in March 2000 and is 

accessible at http://www.cdc.gov/nceh/publications/gulfwar/report.pdf. The background 

document prepared for the conference that reviews Gulf War-related research conducted before 

1999 is accessible at http://www.cdc.gov/nceh/publications/gulfwar/bdgw65.pdf. 

Web Based Central Library (Medsearch) 

CDC, the U.S. Department of Defense’s Deployment Health Support Directorate, and the 

Department of Veterans Affairs collaborated to create a centralized Internet site, known 
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K-40 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

as Medsearch. Veterans and members of the armed forces can visit the site to find 

information on Gulf War-related medical research developed by or for government 

agencies. The idea for the online medical library came from a recommendation at a CDC 

conference in 1999. The conference participants called for a central location where both 

veterans and researchers could access the latest research on illnesses among Gulf War 

veterans. The Internet site developers worked with veterans and researchers to ensure that 

Medsearch is easy to use. Many of the documents available on Medsearch are written in 

nontechnical language. Medsearch can be accessed at http://www.gulflink.osd.mil/ 

medsearch. 

 (http://www.cdc.gov/nceh/veterans/default2l.htm) 

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Journal of Clinical Epidemiology 55(5):477-487. 

Fukuda, K., R. Nisenbaum, G. Stewart, W. W. Thompson, L. Robin, R. M. Washko, D. L. Noah, D. H. 

Barrett, B. Randall, B. L. Herwaldt, A. C. Mawle, and W. C. Reeves. 1998. Chronic multisymptom 

illness affecting Air Force veterans of the Gulf War. Journal of the American Medical Association

280(11):981-988. 

Gackstetter, D. G., T. I. Hooper, M. S. Al Qahtani, T. C. Smith, Z. A. Memish, K. M. Schlangen, D. F. 

Cruess, D. H. Barrett, M. A. K. Ryan, and G. C. Gray. 2005. Assessing the potential health impact of 

the 1991 Gulf War on Saudi Arabian National Guard soldiers. International Journal of Epidemiology

34(4):801-808. 

Hooper, T. I., T. C. Smith, G. C. Gray, M. S. Al Qahtani, Z. A. Memish, D. H. Barrett, K. M. Schlangen, 

D. F. Cruess, M. A. K. Ryan, and G. D. Gackstetter. 2005. Saudi-United States collaboration in health 

research: An approach for success. American Journal of Infection Control 33(3):192-196. 

Horner, R. D., K. G. Kamins, J. R. Feussner, S. C. Grambow, J. Hoff-Lindquist, Y. Harati, H. Mitsumoto, 

R. Pascuzzi, P. S. Spencer, R. Tim, D. Howard, T. C. Smith, M. A. K. Ryan, C. J. Coffman, and E. J. 

Kasarskis. 2003. Occurrence of amyotrophic lateral sclerosis among Gulf War veterans. Neurology

61(6):742-749. 

Iowa Persian Gulf Study Group. 1997. Self-reported illness and health status among Gulf War veterans: A 

population-based study. Journal of the American Medical Association 277(3):238-245. 
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K-42 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Levine, P. H., H. A. Young, S. J. Simmens, D. Rentz, V. E. Kofie, C. M. Mahan, and H. K. Kang. 2005. 

Is testicular cancer related to Gulf War deployment? Evidence from a population-based study of Gulf 

War era veterans and cancer registries. Military Medicine 170(2):149-153. 

Nisenbaum, R., D. H. Barrett, M. Reyes, and W. C. Reeves. 2000. Deployment stressors and a chronic 

multisymptom illness among Gulf War veterans. Journal of Nervous and Mental Disorders

188(5):259-266. 

Penman, A., R. S. Tarver, and M. M. Currier. 1996. No evidence of increase in birth defects and health 

problems among children born to Persian Gulf War Veterans in Mississippi. Military Medicine

161(1):1-6. 

Proctor, S. P., R. F. White, T. Heeren, F. Debes, B. Gloerfelt-Tarp, M. Appleyard, T. Ishoy, B. Guldager, 

P. Suadicani, F. Gyntelberg, and D. Ozonoff. 2003. Neuropsychological functioning in Danish Gulf 

War veterans. Journal of Psychopathology and Behavioral Assessment 25(2):85-94. 

Selected Cancers Cooperative Study Group. 1990a. The association of selected cancers with service in the 

U.S. military in Vietnam. Final Report. Altanta, GA: CDC. 

http://www.cdc.gov/nceh/veterans/default1d.htm (accessed April 19, 2007). 

Selected Cancers Cooperative Study Group. 1990b. The association of selected cancers with service in the 

U.S. military in Vietnam: I. Non-Hodgkin’s lymphoma. Archives of Internal Medicine 150(12):2473-

2483. 

Selected Cancers Cooperative Study Group. 1990c. The association of selected cancers with service in the 

U.S. military in Vietnam: II. Soft-tissue and other sarcomas. Archives of Internal Medicine 150(12): 

2485-2492. 

Selected Cancers Cooperative Study Group. 1990d. The association of selected cancers with service in the 

U.S. military in Vietnam: III. Hodgkin’s disease, nasal cancer, nasopharyngeal cancer, and primary 

liver cancer. Archives of Internal Medicine 150(12):2495-2505. 

Zwerling, C., J. C. Torner, W. R. Clarke, M. D. Voelker, B. N. Doebbeling, D. H. Barrett, J. A. Merchant, 

R. F. Woolson, and D. A. Schwartz. 2000. Self-reported postwar injuries among Gulf War veterans. 

Public Health Reports 115(4):346-349. 

APPENDIX K-4 

SELECTED STUDIES ON VETERANS FROM THE CRISP DATABASE4

(Table follows.) 

 4 Not intended to be a comprehensive list. See http://crisp.cit.nih.gov for additional projects.
Copyright © National Academy of Sciences. All rights reserved.

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http://www.nap.edu/catalog/11908.html APPENDIX K K-43 Primary Investigator Project Name Grant Number Start Date End Date Beebe, G Hepatitis B Virus and Liver Cancer in Army Veterans of WW II 1Z01CP005329-11 Doebbeling, Bradley Illness Among Persian Gulf War Veterans: Case Validation 5M01RR000059-411069 

Dohrenwend, Bruce Social Status and PTSD in U.S. Vietnam Veterans 5R01MH059309-03 9/28/1999 12/1/2003 Giardina, Charles Mustard Gas Exposure and Carcinogenesis of the Lung 1R21ES013775-01 Golier, Julia Psychobiologic Alterations in Persian Gulf War Veterans 

With/Without PTSD 

5M01RR000071-400470 6/22/1905 

Haley, Robert Pathophysiologic Studies of Ill Gulf War Veterans and 

Controls 

5M01RR000633-310606 6/21/1905 

Hrubec, Zdenek Resource Support of Medical Studies on Veteran Twins 5R01MH018820-04 4/1/1970 3/31/1974 Jablon, Seymour Epidemiologic Studies in Etiology of Cancer in Veterans 3N01CP04333600174 6/28/1974 Jerskey, Beth Combat Trauma and Mid-Life Marital Outcomes: A Twin 

Study 

5F31MH071017-02 3/1/2004 6/30/2005 

King, Daniel PTSD and Its Etiology: A Quintet of Inquiries 1R01MH049168-01 6/1/1992 5/31/1995 

Laufer, Robert A Study of Veterans: Impact of The Vietnam War 3R01MH026832-06S1 9/1/1980 12/31/1984 Lee, Chulhee Exposure to Disease During Growing Ages and War 

Service 

5P01AG010120-100001 

Linet, M Studies of Radiation Related Cancer 1Z01CP010102-01 

McCaffery, Jeanne SES, Health Behaviors and CVD Among Vietnam-EraTwins 5R01HL072819-02 6/1/2004 5/31/2007 

Murphy, Ronald Combat Exposure, Early Trauma, and Alcohol Problems 1R03AA010027-01 5/1/1994 4/30/1996 
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http://www.nap.edu/catalog/11908.html K-44 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS Primary Investigator Project Name Grant Number Start Date End Date Norman, James Hepatitis “B” Virus and Liver Cancer in Veterans 5N01CP031021-00783 6/30/1983 Page, William Cancer in Navy Korean War Microwave (Radar) Workers 3N01CP040536-00694 9/15/1994 10/31/1997 Page, William Studies of Cancer in Veteran Twin Registry 5N01CP015690-00591 3/15/1991 3/14/1994 

Pitman, Roger Twin Study of Biologic Markers for PTSD 5R01MH054636-09 9/30/1995 5/31/2007 

Robinette, C Studies of Cancer in Veteran Twin Registry 3N01CP015690-00191 3/15/1991 

Rose, Kathryn Combat Stress and Cardiovascular Risk Among Aging 

Men 

1R21HL080422-01A1 9/31/2006 11/30/2007 

Schmidt, Silke Genetic Epidemiology of ALS in Veterans 5R01ES013244-03 8/19/2004 6/30/2009 

Schwartz, David Iowa Persian Gulf Research Project: Follow-Up Study on 

Asthma 

5M01RR000059-411045 12/1/2001 11/30/2002 

Scrimshaw, Nevin Exposure to Disease During Growing Ages and War 

Service 

3P01AG010120-08S20001 

Tanner, Caroline Genes, Environment and Parkinson’s Disease: Studies in 

Four Unique Cohorts 

1U54ES012077-010001 8/26/2002 7/31/2007 

Vaccarino, L Posttraumatic Stress Disorder and Cardiovascular 5R01AG026255-03 Vandenborne, Krista Evaluation of Muscle Function in Persian Gulf Veterans 5M01RR000040-420711 12/1/2001 11/30/2002 Vernon, Sally A Cancer Study Among Female Veterans in Texas, 1979-

2001 

5R03CA103512-02 9/30/2004 8/31/2006 

Yehuda, Rachel Psychobiological Alterations in Aging Combat Veterans 

w/PTSD 

5M01RR000071-400427 

SOURCE: Crisp Database, http://crisp.cit.nih.gov/.
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L-1 

Appendix L 

Additional Classification and Secrecy 

Information 

APPENDIX L-1 

HISTORY OF RADIATION STUDIES CLASSIFICATION 

The following paragraphs are excerpted from the ACHRE Report, Chapter 13 (1995): 

The Manhattan Project’s “Security Manual” followed the Army rules, requiring classification of information as Confidential, and even at the higher level of Secret, in the absence of likely harm to national security (Manhattan Engineer District, 1945). Before the 

end of World War II, therefore, there was precedent for using the classification system to 

do more than protect national security. 

 (p. 2) 

The era of atomic energy presented the government with unique questions of secrecy. 

The government built the atomic bomb behind an extraordinary shield of wartime secrecy. The very existence of the newly created communities surrounding AEC laboratories in Los Alamos, New Mexico; Hanford, Washington; and Oak Ridge, Tennessee; was 

a secret. Children at Oak Ridge schools did not use their full names, and houseguests 

were introduced as “Mr. Smith” (Warren, 1966). Following the Hiroshima bombing, the 

government faced the somewhat paradoxical task of protecting its single most important 

military secret while having to inform the public, if not the world, about both the hazards 

and peacetime spin-offs that the creation of the bomb had engendered—from radiation 

fallout and waste to nuclear power and radioisotopes for medical research and treatment. 

 (p. 2) 

At the war’s end, a committee (known after its chair as the Tolman Committee) convened 

to determine what information from the Manhattan Project should be declassified. In its 

report, the Tolman Committee concluded that “in the interest of national welfare it might 

seem that nearly all information should be released at once” (Committee on Declassification to Major General L. R. Groves, 1945). But national welfare had to be considered in 

light of national security. Still, “it is not the conviction of the [Tolman] Committee that 

the concealment of scientific information can in any long term contribute to the national 

security of the United States” (Committee on Declassification to Major General L. R. 

Groves, 1945). The progress of science, the committee reasoned, depends on the free 

flow of information, and long-term national security depends on the progress of science. 
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In the short term, however, the security of the nation required some secrecy. Thus, the 

Tolman Committee concluded that secrecy could be justified for reasons of national security and then only if “there is a likelihood of war within the next five or ten years” 

(Committee on Declassification to Major General L. R. Groves, 1945). Applying this 

general philosophy to the question of secrecy in medical research, it recommended that 

“all reports on medical research and all health studies” be immediately declassified except for those reports that contained information independently classified in the interest 

of short-term national security (Committee on Declassification to Major General L. R. 

Groves, 1945). 

(p. 2) 

While the Tolman Committee report generally advocated openness, it also set the precedent for keeping declassification guides secret. The report recommended that “the whole 

of the Declassification Guide should not, however, be generally distributed since it gives 

an overall picture of the whole project and makes mention in certain instances of extremely secret matters. The portions of the Declassification Guide needed for the work of 

anyone concerned with declassification should be made available” (Committee on Declassification to Major General L. R. Groves, 1945). By following this recommendation, 

the AEC, and later the Department of Energy, would keep from the public the everaccumulating rules governing weapons-related information. Indeed, the first three declassification guides covering information on nuclear weapons, published in 1946, 1948, and 

1950, were declassified only in 1995 (Manhattan Engineer District, 1946; Atomic Energy 

Commission, 1948, 1950). 

 (p. 2) 

In 1946 Congress enacted the Atomic Energy Act, which, in creating the AEC, expressly 

addressed the protection of atomic energy information. The act provided that all information related to atomic energy was to be considered as Restricted Data (RD) until the AEC 

reviewed it and decided that it should be unprotected (RD was, therefore, said to be “born 

secret”). The act prohibited the unauthorized disclosure of RD (making it a capital crime 

to do so in the course of espionage) and prohibited anyone from receiving access to it 

without first receiving a security clearance. At the same time, however, the act instructed 

the AEC not to protect information if the AEC did not consider its disclosure harmful to 

the national security. Thus, the statute defined RD to mean “all data concerning the 

manufacture or utilization of atomic weapons, the production of fissionable material, or 

the use of fissionable material in the production of power, but shall not include any data 

which the Commission from time to time determines may be published without adversely 

affecting the common defense and security” (Atomic Energy Act, 1954). 

 (p. 2), [emphasis added] 

When it began operation in 1947, the AEC was heir to two traditions: one in which official secrets could extend beyond national security to matters of prestige and another in 

which the interest in promoting openness and limiting secrecy to matters of national security was recognized. In public, AEC biomedical officials and advisers advocated the latter 

policy. In secret they embraced the former and even expanded it to encompass “embarrassment.” Through as late as 1949, the declassification of reports on human experiments 

involved their review for public relations and legal liability implications. Documents revealing the dual tracks of public policy making and the secret review process did not become public until 1994. Important pieces of the story remain unclear, including the way 

in which AEC officials and advisers reconciled seemingly contrary principles. 

 (p. 3) 
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APPENDIX L L-3

. . . [W]hen Manhattan Project medical official Hymer Friedell recommended in late 1946 

that one of the reports on the plutonium injection experiments be declassified, officials 

inside the new AEC reacted strongly. On March 19, 1947, AEC Medical Division chief 

Major B. M. Brundage countermanded the declassification decision, on grounds of “public relations.” The plutonium report produced the strongest reaction, but it was not the 

only report on human data at issue. Brundage’s March 19 memo also stated that further 

reports (“Studies of Human Exposure to Uranium Compounds” and “Uranium Excretion 

Studies”) should remain classified. On March 21, an AEC declassification officer confirmed the reclassification on the ground that “these documents may involve matters 

prejudicial to the best interests of the Atomic Energy Commission in that experiments 

with humans are involved.” The memo expressed hope that “a definite policy in this matter will be announced or explained in the near future” (Batson, 1947). 

 (p. 3) 

In April 1947 that hope was partly fulfilled when Colonel O. G. Haywood of the Corps of 

Engineers wrote to H. A. Fidler, an AEC information officer, that “it is desired that no 

document be released which refers to experiments with humans and might have adverse 

effects on public opinion or result in legal suits. Documents covering such work should 

be classified as secret” (Haywood, 1947). 

 (p. 3) 

References 

ACHRE (Advisory Committee on Human Radiation Experiments). 1995. Final report. Washington, DC: 

Government Printing Office. http://hss.energy.gov/healthsafety/ohre/roadmap/achre/report.html (accessed March 7, 2007). 

Atomic Energy Commission. 1948. Declassification guide. ACHRE No. DOE-050495-B. 

Atomic Energy Commission. 1950. Declassification guide for responsible reviewers. ACHRE No. DOE052595-B. 

Batson, R. T. 1947. Reclassification of documents. ACHRE No. DOE-101394-A. Letter to Dr. A. H. 

Dowdy. 

Committee on Declassification to Major General L. R. Groves. 1945. Report of Committee on Declassification (Tolman Committee report). ACHRE No. DOE-120594-D. 

Haywood, O. G. 1947. Medical experiments on humans. ACHRE No. DOE-051094-A-62. Memo to H. A. 

Fidler. 

Manhattan Engineer District. 1945. Security manual. ACHRE No. DOE-050595-B. 

Manhattan Engineer District. 1946. Declassification guide for responsible reviewers. ACHRE No. DOE050495-B. 

Warren, S. L. 1966. Transcript of audio recording. ACHRE No. UCLA-101794-A. Interviewed by A. 

Tusler. 

APPENDIX L-2 

LEVELS OF CLASSIFICATION, FROM PIKE, 2002 

Unclassified—Limited: “the distribution category applied to the a wide range of unclassified 

types of official information, which although not requiring protection as National Security Information, is limited to official use and not publicly releasable. Other similar markings, such as 

For Official Use Only (FOUO) and Limited Official Use are not used to identify classified in-
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L-4 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

formation . . . six Distribution Statements designated A through F, were approved establishing 

categories of Unclassified/Limited Data” (Pike, 2002): 

A. Approved for Public Release: “available to the public, foreign nationals, companies, 

foreign governments, and may be exported without a license” 

B. Limited to Government Agencies: “covers weapons test and evaluation data, contractor performance evaluation records, foreign government data and proprietary information” 

C. Limited to Government Agencies and Their Contractors: involves “critical technologies which advance the state of the art in an area of significant or potentially significant military application” 

D. Limited to DoD and DoD Contractors Only: “designed to protect information on system or hardware in the development of concept stage, which must be protected to 

prevent premature dissemination” 

E. Distribution to DoD Components Only 

F. Further Dissemination Only as Directed: “normally imposed only on classified 

documents, but may be used on unclassified documents where specific authority 

exists” 

 

Information or material that requires additional protection against unauthorized disclosure in the interest of national security is classified in one of three designations namely: 

Top Secret, Secret or Confidential. 

Confidential (C) is applied to information or material the unauthorized disclosure of 

which reasonably could be expected to cause damage to the national security. Examples 

of damage include the compromise of information that indicates strength of ground, air, 

and naval forces in the United States and overseas areas; disclosure of technical information used for training, maintenance, and inspection of classified munitions of war; revelation of performance characteristics, test data, design and production data on munitions of 

war. 

Secret (S) is applied to information or material the unauthorized disclosure of which reasonably could be expected to cause serious damage to the national security. Examples of 

serious damage include disruption of foreign relations significantly affecting the national 

security; significant impairment of a program or policy directly related to the national security; revelation of significant military plans or intelligence operations; compromise of 

significant military plans or intelligence operations; and compromise of significant scientific or technological developments relating to national security. 

Top Secret (TS) is applied to information or material the unauthorized disclosure of 

which reasonably could be expected to cause exceptionally grave damage to the national 

security. Examples of exceptionally grave damage include armed hostilities against the 

United States or its allies; disruption of foreign relations vitally affecting the national securely; the compromise of vital national defense plans or complex cryptology and communications intelligence systems; the revelation of sensitive intelligence operations, and 

the disclosure of scientific or technological developments vital to national security. 

Special Access Program (SAP) is any program which imposes need-to-know or access 

controls beyond those normally required for access to Confidential, Secret, or Top Secret 

information. It is the policy of the Department of Defense to use security classification 
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APPENDIX L L-5

categories to limit access to classified information on a need-to-know basis to personnel 

who have been determined to be trustworthy, and to apply the need-to-know principle in 

the regular system so that there will be no need to resort to formal Special Access Programs. Also, need-to-know control principles shall be applied within Special Access Programs. In this context Special Access Programs may be created or continued only on specific showing that normal management and safeguarding procedures are not sufficient to 

limit need-to-know or access, and the number of persons who need access will be reasonably small and commensurate with the objective of providing extra protection for the 

information involved. Each Special Access Program is assigned a classified code word, 

or an unclassified nickname, or both. 

Sensitive Compartmented Information (SCI) is information and material that requires 

special controls for restricted handling within compartmented intelligence systems and 

for which Code Word compartmentation is established. Special Activity is an activity, or 

functions in support of such activity, conducted in support of national foreign policy objectives abroad that is planned and executed so that the role of the U.S. Government is 

neither apparent nor acknowledged publicly; but that is not intended to influence U.S. political processes, public opinion, polices, or media and does not include diplomatic activities or the collection and production of intelligence or related support functions. 

References 

Pike, J. 2002. Security and classification. Gloucester, MA: Granite Island Group, Technical Surveillance 

Counter Measures. http://www.tscm.com/classification.html (accessed April 10, 2007). 

APPENDIX L-3 

NUREMBERG CODE OF 1947 

Trials of War Criminals before the Nuremberg Military Tribunals, 1949; Nuremberg Code, 

1947; Office on NIH History, Office of Intramural Research: 

1. The voluntary consent of the human subject is absolutely essential. This means that 

the person involved should have legal capacity to give consent; should be so situated 

as to be able to exercise free power of choice, without the intervention of any element 

of force, fraud, deceit, duress, over-reaching or other ulterior form of constraint or 

coercion; and should have sufficient knowledge and comprehension of the elements 

of the subject matter involved as to enable him to make an understanding and 

enlightened decision. This latter element requires that before the acceptance of an affirmative decision by the experimental subject there should be made known to him 

the natures, duration, and purpose of the experiment; the method and means by which 

it is to be conducted; all inconveniences and hazards reasonably to be expected; and 

the effects upon his health or person which may possibly come from his participation 

in the experiment. The duty and responsibility for ascertaining the quality of the consent rests with each individual who initiates, directs or engages in the experiment. It 

is a personal duty and responsibility which may not be delegated to another with 

impunity. 

2. The experiment should be such as to yield fruitful results for the good of society, unprocurable by other methods or means of study, and not random and unnecessary in 

nature. 
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3. The experiment should be so designed and based on the results of animal experimentation and knowledge of the natural history of the disease or other problems under 

study that the anticipated results [will] justify the performance of the experiment. 

4. The experiment should be so conducted as to avoid all unnecessary physical and 

mental suffering and injury. 

5. No experiment should be conducted, where there is an a priori reason to believe that 

death or disabling injury will occur; except, perhaps, in those experiments where the 

experimental physicians will also serve as subjects. 

6. The degree of risk to be taken should never exceed that determined by the humanitarian importance of the problem to be solved by the experiment. 

7. Proper preparations should be made and adequate facilities provided to protect the 

experimental subject against even the remote possibilities of injury, disability or 

death. 

8. The experiment should be conducted only by scientifically qualified persons. The 

highest degree of skill and care should be required through all stages of the experiment of those who conduct or engage in the experiment. 

9. During the course of the experiment, the human subject should be at liberty to bring 

the experiment to an end, if he has reached the physical or mental state, where continuation of the experiment seems to him to be impossible. 

10. During the course of the experiment, the scientist in charge must be prepared to terminate the experiment at any stage, if he has probable cause to believe, in the exercise of the good faith, superior skill and careful judgment required of him, that a continuation of the experiment is likely to result in injury, disability, or death to the 

experimental subject. 

References 

Nuremberg Code. 1947. In Doctors of infamy: The story of the Nazi medical crimes, A. Mitscherlich and 

F. Mielke. New York: Schuman. http://www.cirp.org/library/ethics/nuremberg/ (accessed April 25, 

2007). 

Office on NIH History, Office of Intramural Research. Laws related to the protection of human subjects. 

http://www.history.nih.gov/laws%5Chtml%5Cnuremberg.htm (accessed April 25, 2007). 

Trials of war criminals before the Nuremberg military tribunals. 1949. Control Council Law 10(2):181-

182. http://www.copernicusgroup.com/irbForms/NurembergCode.pdf (accessed March 7, 2007). 

APPENDIX L-4 

EXCERPTS FROM TAYLOR AND JOHNSON, 1975 

This report was the result of a request to the Inspector General and Auditor General of the 

Department of the Army (DoA) by the Secretary of the Army to research the use and 

treatment of human volunteers in chemical agent research. The request was prompted by 

congressional inquiries, during 1975 and 1976, by the Senate Select Committee on Intel-
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APPENDIX L L-7

ligence Activities and joint hearings by the Senate’s Labor and Public Welfare Committee and the Judiciary Committee, individual Members of Congress, private citizens, and 

the press regarding the use of human volunteers in testing of hallucinogenic substances in 

DoA chemical warfare research. Although the report focused largely on psychochemical 

testing programs and on testing programs from approximately 1950 to 1975, it also related certain specific aspects of the history of chemical warfare research in regards to 

treatment of human volunteers and general attitudes toward and compliance with the Nuremberg Codes of 1947. The major conclusion of these authors was that the secrecy, applied to the projects, to the overall research program, and even to the official guidelines 

governing use of human volunteers, left ample room for misinterpretation, lack of knowledge about, and outright disregard for established policies and guidelines. 

The June 1942 request for human volunteers to the Secretary of War, and its subsequent 

approval, gave authority to the War Department to use human volunteers in the World 

War II sulfur mustard and Lewisite testing programs. The approval of this request became the basis on which such authority was retained by the Army and the Chemical Warfare Service to use human volunteers in all other World War II and later testing programs 

up to the mid 1950s. In July 1950, research was placed under the control of the Army by 

the Organization of the Army Act. Despite the establishment in 1947 of the Nuremberg 

Codes regarding the appropriate use and treatment of human subjects in research, Taylor 

and Johnson reported that no documentation could be found about whether the Army was 

explicitly bound by the Codes. By 1952, the Armed Forces Medical Policy Council filed 

a request to use human subjects and suggested that the Nuremberg Codes be used as 

guidelines. 

The possible guidelines were discussed at a meeting at Edgewood Arsenal in March 

1953. Recommendations were made at the conference that distinctions be made between 

hazardous and non-hazardous test situations so that non-hazardous procedures/tests 

would not require approval of the human-use research protocols. The examples given for 

non-hazardous situations were training exercises in which men, equipped with gas masks, 

went through gas chambers filled with high concentrations of sulfur mustard. A further 

proposal was that any human-use codes based on the Nuremberg Codes should only apply to biological warfare testing, not to chemical or radiological testing. This proposal 

was rejected. 

Formalized guidelines were finally issued in June 1953 in a Chief of Staff Memo 

(MM385). These guidelines represented an official adoption of the Nuremberg Codes (although somewhat modified) and were meant to apply to all types of chemical, radiological, and biological warfare testing. Further, they required all projects to be approved by 

the Secretary of the Army. However, no detailed descriptions of what types of experiments required this approval were included, and the report authors argue later that this 

was a “loophole” that permitted “selective compliance” with the guidelines. For example, 

in August 1953 seven research projects were sent for approval, one on vesicants and 

other agents, one on phosgene, and five on nerve agents. Not sent for approval was a research project labeled a “local field exercise” at Fort McClellan, Alabama (Operation 

TOP HAT). This operation involved use of Chemical Corps personnel in tests of decontamination methods for biological warfare agents, sulfur mustard, and nerve gases. These 

personnel were not informed and were not volunteers. The justification for the lack of a 

request for approval was that the project fell under the “line of duty” definition and was 

not subject to protocol approval. 
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Another example given by Taylor and Johnson pointed out that protocols were often 

submitted to test a class of drugs, rather than a specific drug at defined dosage levels. One 

project entitled, “Retention of Nerve Gas in the Human Respiratory Tract” was given 

only a cursory examination prior to approval, despite the fact that the specific nerve 

agents to be used were not listed in the proposal. By 1955, when research into psychochemicals began, approvals were still being given for general research types and not for 

specific protocols. In 1957, more potent nerve agents were being tested, but the protocols 

for this research were not sent for examination and approval on the justification that they 

were simply extensions of projects already approved years earlier. By 1959, Secretary of 

the Army Brucker gave blanket approval for all projects utilizing “non-lethal incapacitating agents,” and the period between 1959 and 1975 was typified by great inconsistency in 

policy and practices relating to research with human volunteers. The situation became so 

bad, and the outcry from Congress, the press, and the citizenry so intense, that all research with human volunteers was suspended in 1975 by Acting Secretary of the Army 

Norman Augustine. 

References 

Taylor, J. R., and W. N. Johnson. 1975. Research report concerning the use of volunteers in chemical 

agent research. DAIG-IN 21-75. Washington, DC: Department of the Army, Office of the Inspector 

General and Auditor General. 

APPENDIX L-5 

EXCERPTS FROM IOM, 1993 

The lack of exposure data for the WWII human subjects caused the committee to attempt 

to gather as much information as possible about the experimental protocols, the equipment used, and any injuries from official reports of the testing programs. The committee 

found that an atmosphere of lingering secrecy still existed in the Department of Defense 

regarding some of the testing programs. Reports of the specific experimental protocols 

were not always easy to obtain; in some cases, reports were not available or were obtained as the study was almost complete. Fortunately, enough information was gathered 

to allow reasonable estimates of the exposures to human subjects, who were repeatedly 

exposed to mustard agents and Lewisite in gas chamber tests or under so-called field 

conditions. 

 (pp. vi-vii) 

As the full scope of the WWII testing protocols was revealed, compelling ethical questions emerged. At times, it seemed as if every new discovery only posed more questions. 

As the study progressed, the bits and pieces of information finally coalesced into a picture of abuse and neglect that was impossible for the committee to ignore. One of the first 

discoveries was that the end point of all the WWII mustard agent and Lewisite experiments was tissue injury—from mild skin burns to severe, and widespread, skin burns that 

took more than a month to heal. The chamber and field tests were actually called “manbreak” tests. 

(p. vii) 

Both veteran self-reports and official documents revealed that some subjects suffered 

damaging injuries to the lungs and upper respiratory system from inhalation of the agents. 

Committee analysis of expected gas mask efficiencies further showed that projected nor-
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APPENDIX L L-9

mal mask leakage under the hot, humid conditions of the gas chambers would have, in 

some cases, resulted in exposure levels as high as those reported on World War I 

battlefields. 

 (p. vii) 

The first response of many of the committee members to these discoveries was to try to 

understand the actions of the investigators in historical context—it was a war and the experiments were conducted before the Nuremberg Code of 1947 established formal principles to govern the proper treatment of human subjects. However, examination of the 

treatment and care of WWII chemical warfare production workers, and the conduct of 

later military experiments with human subjects from 1950 to 1975, demonstrated a wellingrained pattern of abuse and neglect. Although the human subjects were called “volunteers,” it was clear from the official reports that recruitment of the WWII human subjects, as well as many of those in later experiments, was accomplished through lies and 

half-truths. 

 (p. vii) 

Most appalling was the fact that no formal long-term follow-up medical care or monitoring was provided for any of the WWII human subjects, other exposed military personnel, 

or chemical warfare production workers, despite knowledge available by 1933 that mustard agents and Lewisite could produce long-term debilitating health problems, particularly in those people suffering severe burns and inhalation injuries. There was not even 

adequate short-term follow-up of the human subjects by the Department of Defense. Subjects in the chamber tests were sworn to secrecy and simply released on leave at the conclusion of the experiments. Some of these men still had blisters or evidence of skin burns 

upon release, but were not given any instructions about how to obtain knowledgeable 

medical care if they had needed it. 

(p. vii) 

Although the experiments began in a wartime climate of urgency and secrecy, it was 

clearly a mistake in this case to continue the secrecy after the conclusion of the war. Follow-up of the exposed human subjects could have provided a wealth of information on 

the effects of these war gases and could have served as a basis for legitimate disability 

claims by injured subjects. By the end of the war, the use of nitrogen mustard as a chemotherapeutic agent (developed as part of the WWII testing program) clearly showed the 

serious health effects that the previous “volunteers” might be expected to experience. 

(p. viii) 

In the face of the abuses uncovered, the committee members nevertheless sought to maintain an appropriate balance of their scientific responsibilities in assessing the available 

literature and their ethical responsibilities as physicians and scientists. In this effort, the 

committee members were guided by their stated task and their own individual judgments 

of the scientific and historical information examined. Thus, the committee believes that 

the findings and recommendations contained in this report are entirely justified by the 

scientific, medical, and historical evidence examined. There are, however, specific statements the committee wishes to offer as commentary on its findings. 

 (p. viii) 

First, the committee believes that each veteran who served as a human subject in the 

WWII experiments deserves honor for his sacrifice. These men risked their health and 

safety to help develop better means of protection against chemical warfare. Yet, in most 
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L-10 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

cases, their participation in these experiments was not even acknowledged in their service 

records and was, in fact, officially denied for decades. Further, these men were ordered to 

keep their participation secret. They did so for nearly 50 years, in some cases despite serious, disabling diseases that they believed were caused by their exposures. There can be 

no question that some veterans, who served our country with honor and at great personal 

cost were mistreated twice—first, in the secret testing and second, by the official denials 

that lasted for decades. They deserve recognition. 

(p. viii) 

Second, the committee believes that any future military research with human subjects 

should be conducted according to publicly established ethical principles similar to those 

that apply to civilian research. The Department of Defense should consider including civilian medical experts in reviews of all proposed military research protocols involving 

human subjects. As was shown in the examination and evaluation by the Department of 

the Army Inspector General’s report of the military drug and chemical testing programs 

from 1950 to 1975 . . . a climate of secrecy provides a permissive environment for the 

neglect of established rules of conduct. Such neglect should never be allowed to occur 

when human experimentation is involved. 

 (pp. viii-ix) 

References 

IOM (Institution of Medicine). 1993. Veterans at risk: The health effects of mustard gas and lewisite. 

Washington, DC: National Academy Press. 

 
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Appendix M 

Biographical Sketches of Committee Members, 

Consultants, and Staff 

Jonathan M. Samet, M.D., M.S. (Chair), is a professor and the Chair of the Department of 

Epidemiology of the Johns Hopkins University’s Bloomberg School of Public Health. Dr. Samet 

also has joint Johns Hopkins’ appointments in the Department of Medicine and the Oncology 

Center, and serves as the Director of the Institute for Global Tobacco Control and as the CoDirector for the Risk Sciences and Public Policy Institute. Before coming to Johns Hopkins, he 

was Professor and Chief of the Pulmonary and Critical Care Division in the Department of 

Medicine of the University of New Mexico School of Medicine. His research has emphasized the 

assessment of health effects of environmental pollutants using epidemiological approaches. His 

work addressing indoor and outdoor air pollution and occupational exposures, including asbestos 

and radon, has made use of risk assessment methods as a tool for translation of scientific findings 

into policy. Dr. Samet received his M.D. from the University of Rochester’s School of Medicine 

and Dentistry and his M.S. from the Harvard School of Public Health. He interned at the 

University of Kentucky Medical Center and then served in the U.S. Army as an anesthesiologist 

at Gorgas Hospital (Balboa Heights, Canal Zone) from 1971 to 1973. Following his military 

service, Dr. Samet completed his internal medicine residency in Medicine at the University of 

New Mexico and then a research and clinical fellowship at Harvard Medical School’s Channing 

Laboratory. He is board certified in internal medicine and the subspecialty of pulmonary 

medicine. Dr. Samet was elected to the Institute of Medicine in 1997 (Section 9) and has served 

as a member and chair of numerous committees for the National Academies. He currently chairs 

the Board on Environmental Studies and Toxicology. In addition, he is a member of the 

Committee on Science, Technology, and Law. 

Margaret A. Berger, J.D., is the Suzanne J. and Norman Miles Professor of Law at Brooklyn 

Law School. Professor Berger’s research interests focus on scientific evidentiary issues, and she 

has contributed to the field of postadmission legal education by developing new approaches to 

the judicial treatment of scientific evidence. She has authored numerous briefs, articles, chapters 

in books, and books which address the topic of the admissibility and interpretation of scientific 

evidence. Professor Berger holds a J.D. from Columbia University School of Law. She has held 

membership positions on the National Academies’ Committees on Tagging Smokeless and Black 

Powder and the Committee on DNA Technology in Forensic Science: An Update. Professor 

Berger is currently a member of the National Academies’ Committee on Science, Technology, 
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M-2 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

and Law and co-chairs a subcommittee on the Reference Manual on Scientific Evidence. She 

also serves on a National Academy Committee on Identifying the Needs of the Forensic Science 

Community, and on a Committee on Assuring the Integrity of Research Data. 

Kirsten Bibbins-Domingo, Ph.D., M.D., MAS-CR, is an Assistant Professor of Medicine and 

of Epidemiology and Biostatistics at the University of California, San Francisco (UCSF). She is 

the co-director of the UCSF Center for Vulnerable Populations and an attending physician at San 

Francisco General Hospital. Dr. Bibbins-Domingo received her A.B. from Princeton University 

and her Ph.D. in biochemistry, her M.D. and her Masters of Clinical Research from UCSF. She 

completed her residency in internal medicine at UCSF that included training at the San Francisco 

Veterans Administration Medical Center (SFVAMC) and continues to have several active 

collaborations with researchers in epidemiology and health services at the SFVAMC. Dr. 

Bibbins-Domingo’s research interests include the epidemiology of cardiovascular disease, race 

and gender health and health-care disparities, and the quality of cardiovascular care, particularly 

heart failure disease management. She has published original research on the development of risk 

factors for cardiovascular disease, including diabetes, impaired kidney function, and high blood 

pressure, as well as the use of novel biomarkers as diagnostic and screening tests for 

cardiovascular disease. 

Eric G. Bing, M.D., Ph.D., M.P.H., is the Endowed Professor of Global Health and HIV 

Research at the Charles Drew University of Medicine and Science in Los Angeles. He is the 

Director of the Drew Center for AIDS Research, Education and Services (Drew CARES), the 

Institute for Community Health Research and co-director of the Center for HIV Identification, 

Prevention and Treatment Services (CHIPTS). Dr. Bing’s research interests include mental 

health care, substance abuse treatment, community mobilization, service systems, and HIV 

prevention research in civilian and military settings in the United States and abroad. He works 

with militaries in multiple countries in developing disease prevention programs for soldiers. Dr. 

Bing received his M.D. from Harvard Medical School and his M.P.H. and Ph.D. in epidemiology 

from the University of California, Los Angeles’s (UCLA’s) School of Public Health. He 

completed his psychiatric training at the UCLA Neuropsychiatric Institute/West Los Angeles VA 

Medical Center. Dr. Bing served as a member of the National Academies’ Ryan White CARE 

Act committee. 

Bernard D. Goldstein, M.D., is the former Dean of the University of Pittsburgh’s Graduate 

School of Public Health and remains active as a professor in the Department of Environmental 

and Occupational Health. Dr. Goldstein’s research interests include risk assessment, toxicology, 

workplace hazards, internal medicine, preventive medicine, occupational and environmental 

medicine, and environmental health policy. He has conducted research on air quality and 

leukemia and various aspects of public health decision making. Dr. Goldstein was the founder 

and former Director of the Environmental and Occupational Sciences Institute at the University 

of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School. Dr. Goldstein 

also served as Assistant Administrator for Research and Development at the U.S. Environmental 

Protection Agency. He received his M.D. from the New York University School of Medicine. 

Dr. Goldstein was elected to the Institute of Medicine in 1991 (Section 9) and has served as a 

member and chair of numerous committees for the National Academies which address subjects 

including risk assessment methodology, exposure to radioactive materials, and biological 
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APPENDIX M M-3

markers. He currently serves as chair of the NRC Standing Committee on Risk Analysis Issues 

and Reviews, chair of the IOM Environmental and Occupational Health Interest Group, and as a 

member of the Roundtable on Environmental Health Sciences, Research, and Medicine. Dr 

Goldstein’s residency training included a rotation through the Manhattan VA Hospital. 

Guy H. McMichael III, J.D., is president of GHM Consulting which offers federal relations and 

management consulting advice. Mr. McMichael served as a senior official in the Department of 

Veterans Affairs (VA) for 30 years and provided advice and direction at the highest levels of VA 

in the development and execution of a complex array of programs administered by the agency. 

During his tenure with VA, he served as Acting Under Secretary for Benefits, Acting Chief 

Information Officer, Acting Chief of Staff, Chief Judge of VA’s Board of Contract Appeals, VA 

General Counsel and head of Congressional Relations. He also served as the agency’s designated 

Dispute Resolution Specialist. Prior to joining VA, Mr. McMichael served as General Counsel 

for the United States Senate Committee on Veterans Affairs for 6 years. Following his military 

service in the U.S. Army, he began his public service as a Deputy Prosecuting Attorney for the 

State of Indiana. Mr. McMichael holds a J.D. from University of Michigan Law School. He 

received the VA’s Exceptional Service Award on three separate occasions and was also a 

recipient of the VA’s Distinguished Career Award. Mr. McMichael also serves as a Director of 

the Wounded Warrior Project, a nonprofit organization. 

John R. Mulhausen, Ph.D., M.S., C.I.H., is the Manager of Corporate Industrial Hygiene for 

the 3M Company. Dr. Mulhausen is responsible for the leadership of the Corporate Industrial 

Hygiene organization and oversight of its programs worldwide in a $21 billion per year global 

manufacturing company. Prior to joining 3M, Dr. Mulhausen worked for the U.S. Army 

Environmental Hygiene Agency. Dr. Mulhausen also holds an Adjunct Assistant Professor 

position in the Division of Environmental and Occupational Health, School of Public Health at 

the University of Minnesota. He has presented and published in the fields of exposure 

assessment, industrial hygiene and industrial hygiene statistics. He was one of the editors for the 

American Industrial Hygiene Association’s “A Strategy for Assessing and Managing 

Occupational Exposures.” Dr. Mulhausen is certified in the comprehensive practice of industrial 

hygiene and is a Fellow of the American Industrial Hygiene Association. 

Richard Scheines, Ph.D., is professor and Head of the Department of Philosophy at Carnegie 

Mellon University. In addition, Dr. Scheines is a professor of the Human-Computer Interaction 

Institute as well as the Department of Machine Learning. Dr. Scheines’ research focuses on the 

relationship between causal hypotheses and statistical evidence. Dr. Scheines has collaborated 

for more than two decades with statisticians and computer scientists on characterizing what can 

and cannot be learned about causal claims from statistical data in a variety of empirical settings, 

and to develop and implement algorithms for causal discovery that are practical and relevant. He 

has applied these techniques to the question of whether lead affects IQ, the efficacy of online 

courses, the effect of welfare reform on single mothers, and many other policy domains. Dr. 

Scheines received his Ph.D. in history and philosophy of science from the University of 

Pittsburgh in 1987, and has published 5 books and over 80 articles since joining Carnegie Mellon 

in 1988. Dr. Scheines was recently on the Institute of Medicine Committee on Food Marketing 

and the Diets of Children and Youth, where cause and effect relationships were examined 

involving marketing and its effects on children’s preferences, purchase requests, and diets. 
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Kenneth R. Still, Ph.D., M.S., M.B.A., F.A.T.S., C.I.H., C.S.P., C.H.M.M., is a retired U.S. 

Navy Captain in the Medical Service Corps. Dr. Still served as the Senior Director of Safety and 

Occupational Health for the Commander of the U.S. Pacific Fleet, Pearl Harbor, Hawaii, as well 

as the Officer-In-Charge of the Navy’s only Toxicology Research laboratory Program in Dayton, 

Ohio. Dr. Still retired from the U.S. Navy in November 2005 and is currently the Scientific 

Director and toxicology consultant for Occupational Toxicology Associates, Inc., chairs an 

Independent Toxicology Panel for an International corporation, and provides consulting services 

for several DoD programs, including the Breast Cancer Research Program under the aegis of the 

Congressionally Directed Medical Research Program. Dr. Still has held numerous adjunct 

faculty/associate professorships including the John Burns School of Medicine at the University 

of Hawaii, and the Uniform Services University of Health Sciences, Bethesda, Maryland. He 

held a visiting research scientist appointment at the Naval Health Research Center 

Environmental Health Effects Laboratory in Dayton, Ohio, for several years. Dr. Still’s main 

research interests include human health risk assessment, exposure assessment, and regulatory 

and mechanistic toxicology. His research addresses the areas of neurobehavioral, reproductive, 

inhalation/respiratory, biochemical, and occupational toxicology. He has more than 250 

publications in the areas of his research. Dr. Still received his Ph.D. in chemical/physiological 

ecology from Oklahoma State University, his M.S. from Portland State University in the same 

field, and his M.B.A. from Chaminade University of Honolulu in financial management. Dr. Still 

holds certifications in the comprehensive practice of industrial hygiene, safety, hazardous 

materials management, and several environmental arenas. Dr. Still is a Fellow of the Academy of 

Toxicological Sciences and the American Industrial Hygiene Association. He has served as a 

liaison on numerous committees for the National Academies which have addressed the topics of 

toxicology hazard evaluation, reproductive and developmental toxicants, and acute exposure 

guidelines. Dr. Still has also served on many working groups for governmental agencies. He 

received the Vice President Al Gore Hammer Award for Reinventing Government for work on 

the Environmental Protection Agency Acute Exposure Guidelines. 

Duncan C. Thomas, Ph.D., M.S., is the Director of the Biostatistics Division within the 

Department of Preventive Medicine at the University of Southern California and holds the Verna 

Richter Chair in Cancer Research. Dr. Thomas was Co-Director of the Southern California 

Environmental Health Sciences Center (funded by the National Institute of Environmental 

Health Sciences) and is Director of its Study Design and Statistical Methods of Research Core. 

His research interests include the development of statistical methods in epidemiology, with 

special emphasis on cancer epidemiology, occupational and environmental health, and genetic 

epidemiology. He is also one of the senior investigators in the California Childrens Health Study, 

the only long-term cohort study of the chronic effects of air pollution in children. He has 

published more than 200 peer-reviewed journal articles in these areas of research and is the 

author of Statistical Methods in Genetic Epidemiology (Oxford University Press, 2004). Dr. 

Thomas is a Fellow of the American College of Epidemiology and a past President of the 

International Genetic Epidemiology Society. Dr. Thomas received his Ph.D. in epidemiology and 

health from McGill University and his M.S. in mathematics from Stanford University. He has 

served as a member of the National Academies’ committees to review radioepidemiology tables 

and the biological effects of populations of exposures to low levels of ionizing radiation (BEIR 

V) and was a member of President Clinton’s Advisory Committee on Human Radiation 

Experiments. 
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APPENDIX M M-5

Sverre Vedal, M.D., M.Sc., is a professor in the Department of Environmental and 

Occupational Health Sciences, Occupational and Environmental Medicine Program, at the 

University of Washington School of Public Health and Community Medicine. Prior to joining 

the faculty of the University of Washington, Dr. Vedal worked as an academic pulmonologist at 

the University of British Columbia in Vancouver and then at the National Jewish Medical and 

Research Center in Denver, Colorado. Dr. Vedal is well published in the application of 

epidemiological methods to evaluating the health effects of air pollution and occupational lung 

disease, and is funded by National Institutes of Health in researching health effects of air 

pollution sources. Dr. Vedal received his M.D. from the University of Colorado’s School of 

Medicine and his M.Sc. in epidemiology from Harvard University. He is board certified in 

internal medicine and pulmonary medicine. Dr. Vedal is a member of the Review Committee of 

the Health Effects Institute in Boston, Massachusetts, and a member of air pollution panels of the 

Clean Air Scientific Advisory Committee of the Environmental Protection Agency’s Science 

Advisory Board. Dr. Vedal served as a member of the National Academies’ committee 

addressing air quality management. 

Allen J. Wilcox, M.D., M.P.H., Ph.D., is a Senior Investigator in the Epidemiology Branch of 

the National Institute of Environmental Health Sciences, where he served for 10 years as the 

Chief of the Epidemiology Branch. He also holds a professorship in epidemiology at the 

University of Bergen (Norway) and an adjunct appointment as Professor of Epidemiology at the 

University of North Carolina, Chapel Hill. Dr. Wilcox’s research focuses on reproductive and 

perinatal epidemiology, a field to which he has made methodologic as well as etiologic 

contributions. Dr. Wilcox received an M.D. from the University of Michigan, and an M.P.H. in 

Maternal and Child Health and a Ph.D. in Epidemiology from the University of North Carolina. 

He is certified by the American Board of Preventive Medicine as a specialist in Public Health 

and General Preventive Medicine. He retired in 2001 as a Captain from the U.S. Public Health 

Service, Commissioned Corps, where he was awarded the Meritorious Service Medal, the 

highest honor granted by the Public Health Service. He has twice received the National Institutes 

of Health Director’s Award. Dr. Wilcox has served as the President of the Society for 

Epidemiologic Research, the Society for Pediatric Epidemiologic Research, and the American 

Epidemiological Society. Dr. Wilcox has held numerous editorships, and since 2001 has served 

as the Editor-in-Chief of Epidemiology. 

Scott L. Zeger, Ph.D., is the Hurley-Dorrier Professor of Biostatistics and Chair of the 

Department of Biostatistics of the Johns Hopkins Bloomberg School of Public Health. Dr. Zeger 

is jointly appointed to the Department of Epidemiology and served as the Senior Associate Dean 

for Academic Affairs. His research is on regression analysis for correlated responses. Dr. Zeger 

has focused in two areas: (1) when observations come in clusters, for example in longitudinal 

research, family studies in genetics or in sample surveys and (2) when a single time series is 

observed. His research has extended generalized linear models (logistic, linear, log-linear, and 

survival models) to be applicable in these cases. Dr. Zeger has published extensively in peerreviewed journals and is co-author of two books. Dr. Zeger received his Ph.D. in statistics from 

Princeton University. He is a Fellow of the American Statistical Association and of the American 

Association for the Advancement of Science. He was a member of several committees for the 

National Academies, including the Committee on Applied and Theoretical Statistics, the 

Committee on Estimating the Health-Risk-Reduction Benefits of Proposed Air Pollution 
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M-6 IMPROVING THE PRESUMPTIVE DISABILITY DECISION-MAKING PROCESS FOR VETERANS 

Regulations, and the Committee on Gulf War and Health: Health Effects Associated with 

Exposure During the Persian Gulf War. 

Lauren Zeise, Ph.D., is the Chief of the Reproductive and Cancer Hazard Assessment Branch in 

the Office of Environmental Health Hazard Assessment at the California Environmental 

Protection Agency. Dr. Zeise’s main research areas of interest include cancer and reproductive 

risk assessment. Her current work addresses cancer and reproductive risk methodologies and 

characterizations, establishment of baseline risks, and guidance for evaluating risks to the fetus, 

children, and adolescents from environmental exposures. She is widely published. Dr. Zeise 

received her Ph.D. from Harvard University. She is currently serving on the U.S. Environmental 

Protection Agency’s Science Advisory Board. Dr. Zeise has served as a member of numerous 

committees for the National Academies which have addressed topics such as air quality, 

assessing exposure of herbicides in Vietnam, copper in drinking water, and risk characterization. 

She currently serves on the Board on Environmental Studies and Toxicology and is also a 

member on the Committee on Toxicity Testing and Assessment of Environmental Agents. 

Volunteer Scientific Consultant 

Melissa A. McDiarmid, M.D., M.P.H., D.A.B.T., is a professor of Medicine and Director of the 

University of Maryland School of Medicine’s Occupational Health Program. Dr. McDiarmid 

also directs the Department of Veterans Affairs surveillance program for veterans exposed to 

depleted uranium. Previously, Dr. McDiarmid was Director of the Office of Occupational 

Medicine for the U.S. Occupational Safety and Health Administration (OSHA) in Washington, 

D.C. Prior to OSHA, she was an Assistant Professor of Environmental Health Sciences at the 

Johns Hopkins School of Hygiene and Public Health. Principal career interests for Dr. 

McDiarmid have been the study of health effects and toxicology of metals and environmental 

reproductive and developmental hazards. She has authored numerous journal articles and book 

chapters on various occupational and environmental medicine topics related to health-care 

workers, medical surveillance and management, reproductive health, and occupational cancers. 

Dr. McDiarmid received her M.D. from the University of Maryland, her M.P.H. from the Johns 

Hopkins University School of Public Health where she also completed her fellowship training in 

Occupational Medicine. She is board certified in Internal Medicine, Occupational Medicine, and 

Toxicology. Dr. McDiarmid is serving as a Volunteer Scientific Consultant to IOM’s Committee 

on Evaluation of the Presumptive Disability Decision-Making Process for Veterans. 

Consultant 

Robert J. Epley is an independent consultant working in the areas of strategic planning, 

training, performance management, and the operations of federal entitlement programs. Mr. 

Epley served with the Department of Veterans Affairs for 31 years, dividing his tenure between 

positions in headquarters and in the field. In VA field offices, he progressed through positions as 

benefits counselor and claims examiner to director of two regional offices in Detroit and St. 

Louis. At VA headquarters, Mr. Epley was chief of field operations for the education program, 

and later he served as deputy director and director of the Compensation & Pension Service. His 

final position with VA was associate deputy under secretary for policy and program 

management, where he was responsible for administration and oversight of the Veterans Benefits 

Administration’s business lines: compensation, pension, housing, insurance, vocational 
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APPENDIX M M-7

rehabilitation, and education. During his tenure with VA, Mr. Epley received two Vice President 

Al Gore Hammer Awards for reinventing government and two Presidential Rank Awards. 

Staff 

Catherine C. Bodurow, M.S.P.H., holds a research faculty position at the Georgia Institute of 

Technology and serves as a Senior Research Scientist in the Deputy Director’s Office of Georgia 

Tech Research Institute. She was on loan to the Institute of Medicine (IOM) of the National 

Academies as a Senior Program Officer and Study Director. Ms. Bodurow also served as a 

Senior Scientist in the Office of Science Coordination and Policy of the Office of Prevention, 

Pesticides and Toxic Substances at the U.S. Environmental Protection Agency. Her research 

interests include exposure and risk assessment, epidemiology, and the application of real-time 

sensor technology in occupational and environmental exposure assessment. She has presented 

and published in these fields. Ms. Bodurow received her B.A. in chemistry from Kalamazoo 

College and her M.S.P.H. from the University of North Carolina at Chapel Hill. She has served 

on numerous national and international committees and chaired several national technical 

committees. 

Frederick (Rick) Erdtmann, M.D., M.P.H., is the Director of the Board on Military and 

Veterans Health and the Medical Follow-Up Agency at the Institute of Medicine (IOM) of the 

National Academies. Prior to joining the IOM he was a career military physician in the U.S. 

Army. While in the military he served as chief of several large departments of Preventive 

Medicine at U.S. installations at home and overseas. He also was commander of the military 

community hospital at Ft Carson, Colorado, and later served as Hospital Commander for the 

Walter Reed Army Medical Center. He had several assignments at the Army Surgeon General’s 

Office working on military health care policies. He received his undergraduate degree from 

Bucknell University and his M.P.H. from the University of California, Berkeley. He is a graduate 

of Temple University Medical School and is board certified in the specialty of Preventive 

Medicine. 
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