Evidence-based Synthesis Program Department of Veterans Affairs

Health Services Research & Development Service Evidence-based Synthesis Program 

A Critical Review

of the Literature Regarding

Homelessness among Veterans

Department of Veterans Affairs

Health Services Research & Development Service

April 2011

Prepared for:

Department of Veterans Affairs

Veterans Health Administration

Health Services Research & Development Service

Washington, DC 20420

Prepared by:

Evidence-based Synthesis Program (ESP) Center

Portland VA Medical Center

Portland, OR

Devan Kansagara, MD, MCR, Director

Investigators:

(all authors contributed equally to this report): 

Howard Balshem, MS

Vivian Christensen, PhD

Anais Tuepker, PhD
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PREFACE

Health Services Research & Development Service’s (HSR&D’s) Evidence-based Synthesis 

Program (ESP) was established to provide timely and accurate syntheses of targeted healthcare 

topics of particular importance to Veterans Affairs (VA) managers and policymakers, as they 

work to improve the health and healthcare of Veterans. The ESP disseminates these reports 

throughout VA.

HSR&D provides funding for four ESP Centers and each Center has an active VA affiliation. The 

ESP Centers generate evidence syntheses on important clinical practice topics, and these reports 

help:

• develop clinical policies informed by evidence,

• guide the implementation of effective services to improve patient outcomes and to 

support VA clinical practice guidelines and performance measures, and 

• set the direction for future research to address gaps in clinical knowledge.

In 2009, the ESP Coordinating Center was created to expand the capacity of HSR&D Central 

Office and the four ESP sites by developing and maintaining program processes. In addition, 

the Center established a Steering Committee comprised of HSR&D field-based investigators, 

VA Patient Care Services, Office of Quality and Performance, and Veterans Integrated Service 

Networks (VISN) Clinical Management Officers. The Steering Committee provides program 

oversight, guides strategic planning, coordinates dissemination activities, and develops 

collaborations with VA leadership to identify new ESP topics of importance to Veterans and the 

VA healthcare system.

Comments on this evidence report are welcome and can be sent to Nicole Floyd, ESP 

Coordinating Center Program Manager, at nicole.floyd@va.gov.

Recommend citation: Balshem H, Christensen V, Tuepker A, Kansagara D. A Critical 

Review of the Literature Regarding Homelessness among Veterans. VA-ESP Project 

#05-225: 2011

This report is based on research conducted by the Evidence-based Synthesis 

Program (ESP) Center located at the Portland VA Medical Center, Portland, OR 

funded by the Department of Veterans Affairs, Veterans Health Administration, 

Office of Research and Development, Health Services Research and 

Development. The findings and conclusions in this document are those of the 

author(s) who are responsible for its contents; the findings and conclusions do 

not necessarily represent the views of the Department of Veterans Affairs or 

the United States government. Therefore, no statement in this article should 

be construed as an official position of the Department of Veterans Affairs. No 

investigators have any affiliations or financial involvement (e.g., employment, 

consultancies, honoraria, stock ownership or options, expert testimony, grants or 

patents received or pending, or royalties) that conflict with material presented in 

the report.
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TABLE OF CONTENTS

EXECUTIVE SUMMARY

Background.................................................................................................................................................... 1

Methods......................................................................................................................................................... 1

Data Synthesis............................................................................................................................................... 2

Peer Review................................................................................................................................................... 2

Results ........................................................................................................................................................... 2

Limitations of the Evidence........................................................................................................................... 5

Future Research............................................................................................................................................. 5

Abbreviations Table....................................................................................................................................... 7

INTRODUCTION

Background.................................................................................................................................................... 9

METHODS

Topic Development...................................................................................................................................... 11

Search Strategy............................................................................................................................................ 11

Study Selection............................................................................................................................................ 12

Data Synthesis............................................................................................................................................. 12

Conceptual Model ....................................................................................................................................... 12

Peer Review................................................................................................................................................. 13

RESULTS

Definitions of Homelessness ....................................................................................................................... 15

Assessing the Limitations of the Current Research..................................................................................... 15

Data Sources................................................................................................................................................ 18

Methodological Considerations................................................................................................................... 21

Key Question #1a. What is the prevalence and incidence of homelessness among Veterans? ................... 22

Key Question #1b. How has the prevalence and incidence of homelessness among Veterans 

changed over time? ..................................................................................................................... 23

Key Question #1c. How prevalent are psychiatric illness, substance abuse, and chronic medical 

illness among homeless Veterans?.............................................................................................. 23

Key Question #2a. Which risk factors are associated with new homelessness or a return to 

homelessness among Veterans? How do these risk factors differ from 

non-Veteran populations? ........................................................................................................... 25

Key Question #2b. Have risk factors for homelessness among Veterans changed over time? ................... 26

Key Question #3. Are there factors specific to military service that increase the risk of 

homelessness, or is the increased risk a marker for pre-military comorbidities 

and social support deficiencies?.................................................................................................. 26

Key Question #4. What is the relationship between incarceration and homelessness among Veterans?.... 34
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SUMMARY AND DISCUSSION ................................................................................................................ 41

Recommendations for Future Research....................................................................................................... 42

REFERENCES ................................................................................................................................................... 44

FIGURES

Figure 1. Risk Factors for Veteran Homelessness: Conceptual Model ...................................................... 14

APPENDIX A. Peer Review Comments/Author Responses............................ 53

APPENDIX B. Technical Experts Consulted and Reviewers................... 59
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EXECUTIVE SUMMARY

BACKGROUND

In 2009, President Obama and Secretary Shinseki committed to ending homelessness among 

Veterans. In support of that effort, the Federal Strategic Plan to Prevent and End Homelessness 

2010 developed by the United States Interagency Council on Homelessness (USICH) 

established as one of its goals to prevent and end homelessness among Veterans in five years. 

An understanding of the epidemiology of homelessness among Veterans and the methodological 

strengths and weaknesses of this evidence base may inform program-planning efforts and future 

research needs. Understanding the risk factors for homelessness among Veterans and how these 

risk factors compare to the general population is important in developing identification and 

prevention programs for Veterans at risk for homelessness. This report was requested by VA 

Central Office and The National Center for Homelessness Among Veterans as part of that effort 

to identify what is known and what is not known about the prevalence of homelessness among 

Veterans, and about the risk factors for homelessness among Veterans, including risk factors 

related to military service and incarceration.

The key questions were:

Key Questions #1a. What is the prevalence and incidence of homelessness among Veterans?

#1b. How has the prevalence and incidence of homelessness among Veterans 

changed over time?

#1c. How prevalent are psychiatric illness, substance abuse, and chronic 

medical illness among homeless Veterans?

Key Questions #2a. Which risk factors are associated with new homelessness or a return to 

homelessness among Veterans? How do these risk factors differ from nonVeteran populations?

#2b. Have risk factors for homelessness among Veterans changed over time?

Key Question #3. Are there factors specific to military service that increase the risk 

of homelessness, or is the increased risk a marker for pre-military 

comorbidities and social support deficiencies?

Key Question #4. What is the relationship between incarceration and homelessness among 

Veterans?

METHODS

Key questions were developed with the input of experts from the National Center for 

Homelessness Among Veterans and the VA New England Healthcare System, and with 

feedback from national experts on homelessness and homelessness among Veterans. A search 

for relevant literature was conducted in MEDLINE, the Cochrane Database of Systematic 

Reviews, Sociological Abstracts, and Criminal Justice Abstracts from database inception through 
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July 2010. We also monitored Table of Contents alerts for several publications to identify 

new research published in 2010; searched several non-medical qualitative journals including 

Qualitative Research and Qualitative Health Research; and sought guidance on other sources 

from a survey of technical experts. For all Key Questions, the reference lists of articles returned 

were reviewed for any additional relevant studies. Because of the exploratory nature of this 

review, few restrictions were placed on articles to be considered for inclusion.

DATA SYNTHESIS

The existing evidence base relevant to this topic does not lend itself to a quantitative synthesis, 

since sample populations and variables investigated were rarely consistent across studies. In 

this report, we did not conduct a quantitative data synthesis or meta-analysis, but rather focused 

on presenting the strength of each existing study’s findings and developing a conceptual model 

for understanding what these findings mean collectively, as well as indicating where there are 

significant gaps in our knowledge on this topic.

PEER REVIEW

A draft version of this report was reviewed by six technical experts. Reviewer comments were 

addressed and our responses were incorporated in the final report (Appendix A).

RESULTS

KEY QUESTION #1A. What is the prevalence and incidence of homelessness among 

Veterans?

The recently released report Veteran Homelessness: A Supplemental Report to the 2009 Annual 

Homeless Assessment Report to Congress (2009 Veteran AHAR) estimates that on a single night 

in January 2009 there were 75,609 homeless Veterans and that an estimated 136,334 Veterans 

spent at least one night in an emergency shelter or transitional housing program between October 

1, 2008 and September 30, 2009. With nearly 23 million Veterans in the U.S. population in 2009, 

the prevalence of Veterans experiencing homelessness on a single night in January 2009 was 

approximately 33 for every 10,000 Veterans. Approximately 60 out of every 10,000 Veterans 

spent at least one night in an emergency shelter or transitional housing between October 1, 2008 

and September 30, 2009.

KEY QUESTION #1B. How has the prevalence and incidence of homelessness among 

Veterans changed over time?

Because of changes in reporting and in the methods for counting the number of homeless, 

estimates of the prevalence of homelessness among Veterans over time are not comparable. 

With regard to the percentage of Veterans among the homeless, in 1996, the National Survey of 

Homeless Assistance Providers and Clients estimated that 23 percent of the homeless population 

were Veterans. More recently, the first four Annual Homeless Assessment Reports (AHARs) 

estimated that the percentage of Veterans among the homeless stayed relatively steady at about 

15 percent. The most recent AHAR reported a decrease to 16 percent of adults and 12 percent of 
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all homeless individuals. The demographic composition of the Veteran homeless population is 

changing. According to the CHALENG report, VA facilities have recently reported an increase of 

24 percent in homeless Veteran families seeking services. In addition, the percentage of homeless 

women Veterans is expected to increase as the percentage of female Veterans has increased 

dramatically in recent years.

KEY QUESTION #1C. How prevalent are psychiatric illness, substance abuse, and chronic 

medical illness among homeless Veterans?

There are few studies directly assessing the prevalence of psychiatric illness, substance abuse, 

or chronic illness in the general population of homeless Veterans. The 2009 Veteran AHAR 

estimates that approximately 53 percent of homeless Veterans have some kind of disability. This 

estimate is based on a definition of disability that includes substance abuse, mental illness, and 

physical disabilities. Estimates for specific disabilities are not provided. However, most other 

studies rely on already morbid populations seeking treatment for services and so cannot provide 

estimates of prevalence in the homeless population as a whole. Prevalence estimates from a 

limited evidence base vary. A study based on a convenience sample of homeless adults admitted 

to homeless shelters in Santa Clara County, California between November 1989 and March 

1990 found that 17 percent of Veterans had been admitted for overnight treatment of psychiatric 

problems; that 29 percent reported actual and 39 percent perceived alcohol abuse; and 22 percent 

reported illegal drug use. More recently, a survey of randomly selected homeless adults in 

Pittsburgh and Philadelphia found that 61.4 percent reported psychiatric problems, 79.5 percent 

reported alcohol or drug abuse or dependence, and 66.1 percent reported having at least one 

chronic medical condition.

KEY QUESTION #2A. Which risk factors are associated with new homelessness or a 

return to homelessness among Veterans? How do these risk factors differ from non-Veteran 

populations?

Risk factors most strongly and consistently associated with homelessness in both Veteran and 

non-Veteran populations include childhood risk factors such as inadequate care by the parents, 

experiencing foster care or group placement, and prolonged periods of running away from home. 

Low or unstable income, low social support and a history of incarceration appear to place both 

Veterans and non-Veterans at increased risk for homelessness.

The most important risk factors for homelessness do not differ substantially between Veteran and 

non-Veteran populations. There are notable differences in the prevalence of some characteristics 

often found to be protective: Veteran homeless tend to be older and better educated; to have had 

better, early family cohesion; and are more likely to be or have been married than non-Veteran 

homeless. The reasons for this lack of expected protection are not well understood. It may be 

that the differences between these populations are too small to influence outcomes significantly. 

Alternatively, there may be unique Veteran experiences associated with either service or postdeployment readjustment that actively undermine the protective mechanism associated with 

these factors in other populations.
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KEY QUESTION #2B. Have risk factors for homelessness among Veterans changed over time?

Evidence shows that over time, certain risk factors become more salient than others and affect 

different sub-populations. With the increasing number of women in the military, military 

sexual trauma (MST) has become an important and prevalent additional trauma-associated 

risk factor. The wars in Iraq and Afghanistan have led to an increase in the number of National 

Guard Veterans serving often repeated tours of duty in these conflicts. Since these Veterans 

are more likely to have families during and immediately after deployment, the importance of 

factors related to homelessness among families may increase. Economic and structural factors 

also strongly influence who is at risk. In good economic times, those most vulnerable because 

of personal risk factors will become homeless; as economic conditions worsen, an increasing 

number of those less vulnerable will also become homeless.

KEY QUESTION #3. Are there factors specific to military service that increase the risk of 

homelessness, or is the increased risk a marker for pre-military comorbidities and social 

support deficiencies?

Some studies have found that homeless Veterans have lower prevalence of some general population 

risk factors (such as family dysfunction) and higher prevalence of protective factors (such as higher 

educational levels). These findings suggest that pre-military risk factors or comorbidities do not 

account for the over-representation of Veterans among the nation’s homeless. Veterans appear to 

be at risk for homelessness for much the same reasons as other Americans. However, their unique 

experiences as Veterans may mean that the pathways through which they come to be exposed to or 

develop these risks may be qualitatively different. This is an area which warrants further research.

An example of the influence of unique Veteran experiences may be found in considering the 

existing evidence on the impact of combat exposure. Although associated with only a subset 

of Veterans and homeless Veterans, prolonged or intense combat exposure has been found to 

negatively impact mental health, employment, income and social support, thus indirectly but 

substantially increasing the risk of homelessness among those Veterans who have had intense 

combat exposure compared to those who have not. Given that non-Veterans in the United States 

are unlikely to experience intense combat exposure, their pathways to low social support or poor 

mental health can only partially inform our understanding of homelessness among Veterans.

Some behaviors which may place Veterans at increased risk of homelessness seem likely to 

emerge during military service or during the readjustment/post-deployment period. These include 

problem alcohol use, problem substance use and/or low social support. While exposure to these 

risk factors is not intrinsic to military service, evidence suggests that military culture and/or the 

inherently disruptive nature of military service tours increase the likelihood of negative outcomes 

for both substance use and social support. 

Though only examined to date by one small study, MST has been associated with increased risk 

of homelessness among female Veterans. Further research is needed.

KEY QUESTION #4. What is the relationship between incarceration and homelessness 

among Veterans?

After a steady rise in the number of Veterans in prison since 1985, the number, which peaked 

at about 153,100 in 2000, had declined by about 9 percent to 140,000 by 2004. Literature on 
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incarceration and homelessness makes apparent the demographic similarities between homeless 

and incarcerated populations – both are typically poor, uneducated, and minority populations 

with few job skills – and suggests a bi-directional association between homelessness and 

incarceration. Factors found to be associated with homelessness among the incarcerated include 

ineffective discharge planning, legal and regulatory restrictions, full sentencing laws, and 

financial instability.

LIMITATIONS OF THE EVIDENCE

Although there is consistent evidence associating specific risk factors such as substance abuse 

and mental illness with homelessness, there are significant limitations with the data in terms of 

how well risk factors were defined and prevalence measured. Association does not, on its own, 

indicate causality, and very few studies reviewed were designed to measure the direction of 

associations. Studies are limited by several factors, including: inclusion of morbid populations 

seen in clinical settings that may not be generalizable to the broader population of Veterans; 

use of varying and often inconsistent definitions of homelessness; use of measures of unproven 

validity; and limitations in study design.

FUTURE RESEARCH

This report identifies a number of gaps in the literature and makes key suggestions to define an 

agenda for future research on Veteran homelessness:

• Longitudinal studies with Operation Enduring Freedom (OEF)/Operation Iraqi Freedom 

(OIF) Veterans are needed to capture data on exposures occurring before homelessness 

occurs. Given the VA’s current policy of pro-active enrollment and engagement of this 

cohort, opportunities exist to conduct longitudinal studies that collect information on all of 

the risk factors identified in this report. This research should control for structural risk factors 

such as housing market costs and available assistance programs.

• Longitudinal studies with all new cohorts of enlisting military service members could better 

determine the pre-existing presence of risk factors such as low social support, alcohol or 

substance abuse problems before military service. Policies should be developed to facilitate 

the use of data from enlistment screenings in research.

• Qualitative studies employing longitudinal, ethnographic methods to investigate the distinct 

experiences of homeless Veterans will help researchers to understand what is unique 

about Veteran exposure to risk factors common to the general homeless population. This 

remains poorly understood at present but may have important implications for designing 

homelessness prevention programs that will be effective for Veterans.

• Current research suggests that risk for violent criminal behavior varies by service branch. 

Research to confirm these differences and how to identify individuals at risk for continued 

post-military violent criminal behavior may help target interventions to those most at risk for 

post-military incarceration.
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• Research on the post-deployment period is needed, with a particular focus on risk factors 

for loss of income and social support during this transition period, as well as rates of shortterm homelessness experienced during this period. These data could be collected as part 

of longitudinal studies looking for relationships between short-term and more chronic 

homelessness, a topic that has been the focus of past research.

• Further research on MST, its relationship to homelessness, and appropriate MST prevention 

and treatment programs is recommended.

• Research on Veterans Courts and other types of specialty courts should be conducted in order 

to determine how they can most effectively provide alternatives to incarceration for Veterans.

• Systems-perspective research on collaborations among Departments of Corrections, the VA, 

the Department of Housing and Urban Development (HUD), and local community health 

agencies could inform efforts to reduce the likelihood of homelessness upon re-entry from 

incarceration, including developing a better understanding of how to identify those most at 

risk for homelessness post-release.

• Most of the measures used to assess risk factors and personal characteristics of the homeless, 

including measures of substance abuse, mental health, and measures of social support, have 

been developed and normed on populations living in conditions very different from the 

homeless. The applicability of these measures to homeless populations is unknown. Research 

should be undertaken to assess the applicability of these measures, and to modify or develop 

new measures where warranted. Similarly, better defined research on the aspects of social 

support most relevant to improving Veterans’ post-deployment adjustment would contribute 

both to addressing Veteran homelessness and the literature’s broader understanding of the 

function of social support.

• Long-term studies repeatedly collecting both quantitative and qualitative data, though 

always relatively difficult and costly to conduct, would greatly improve our understanding 

of Veterans’ difficulties in re-engagement and re-integration over long periods of time after 

deployment, not just in the initial post-deployment year, which is more frequently studied.

• Studies that include both individual and structural risk factors should be conducted to assess 

both their independent and contingent effects.

• Research is needed to investigate the relationship between the unique Veteran experience of 

“family readjustment difficulties” in the post-deployment period and other, more generalized 

concepts such as social support, as well as the relationship between family readjustment 

difficulties and clinical diagnoses of mental illness.

• To our knowledge, the direct relationship between injury/disability and increased risk 

of homelessness has not been well studied in the Veteran population. There is a need for 

research designed to examine injury as a risk factor for homelessness, both directly and 

indirectly, and taking into account the complex effects of serious injury on both income and 

quality of life/well-being.
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ABBREVIATIONS TABLE

ACCESS Access to Community Care and Effective Service Supports

AFDC Aid to Families with Dependent Children

AHAR Annual Homeless Assessment Report

ASI Addiction Severity Index

CHALENG Community Homelessness Assessment, Local Education and Networking Group

CI Confidence interval

CMHS Center for Mental Health Services

CoC Continuum of Care

DCHV Domiciliary Care for Homeless Veterans

DRRI Deployment Risk and Resilience Inventory

DSM-IV Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition

ELI Extremely Low Income

ESP Evidence-based Synthesis Program

FMR Fair market rent

GAINS National GAINS Center: Gathering information; Assessing what works;

Interpreting/integrating the facts; Networking; Stimulating change

GAO Government Accounting Office

HCHV Health Care for Homeless Veterans

HCMI Homeless Chronically Mentally Ill Veterans Program

Health VIEWS Health of Vietnam Era Veteran Women’s Study

HEARTH Homeless Emergency and Rapid Transition to Housing

HMIS Homeless Management Information System

HR Hazard ratio

HSR&D Health Services Research and Development Service

HUD Department of Housing and Urban Development

MCS Millennium Cohort Study

MOS Medical Outcomes Study

MPSI Multi-Problem Screening Inventory

MST Military sexual trauma

N or n Number

NSHAPC National Survey of Homeless Assistance Providers and Clients

NVVRS National Vietnam Veterans Readjustment Survey

OEF Operation Enduring Freedom

OIF Operation Iraqi Freedom
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OR Odds ratio

p Probability

PIT Point-in-time

PTSD Post-traumatic stress disorder

SAMHSA Substance Abuse and Mental Health Services Administration

SSDI Social Security Disability Insurance

SSI Social Security Supplementary Income

TANF Temporary Assistance for Needy Families

TCE Targeted Capacity Expansion

USICH United States Interagency Council on Homelessness

VA Veterans Affairs

VAMC VA Medical Center

VHA Veterans Health Administration

VISN Veterans Integrated Service Networks
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EVIDENCE REPORT

INTRODUCTION

BACKGROUND 

In 2009, President Obama and Secretary Shinseki committed to ending homelessness among 

Veterans.1 In support of that effort, the Federal Strategic Plan to Prevent and End Homelessness 

2010 developed by the United States Interagency Council on Homelessness (USICH) has 

established as one of its goals to prevent and end homelessness among Veterans in five years.2

An understanding of the epidemiology of homelessness among Veterans and the methodological 

strengths and weaknesses of this evidence base may inform program-planning efforts and future 

research needs. Understanding the risk factors for homelessness among Veterans and how 

these risk factors compare to the general population is important in developing identification 

and prevention programs for Veterans at risk for homelessness. This report was requested by 

VA Central Office and The National Center for Homelessness Among Veterans as part of that 

effort to identify what’s known and what’s not known about the prevalence of homelessness 

among Veterans, and about the risk factors for homelessness among Veterans, including risk 

factors related to military service and incarceration. Given the scope of this assignment and our 

awareness of other comprehensive review efforts examining the literature on the effectiveness 

of interventions designed to reduce homelessness, this report focuses on the characteristics, both 

individual and social, associated with homelessness among Veterans.

Contextual Information: Structural Risk Factors for Homelessness

Any discussion of risk factors for homelessness would be incomplete without acknowledging 

the complex and multi-dimensional interaction of individual and structural risk factors. Research 

has consistently demonstrated that structural factors such as lack of affordable housing, cuts in 

income assistance programs, and labor market changes have created social conditions that have 

fostered an increase in the homeless population in contemporary U.S. society. For contextual 

purposes, we include here a brief discussion of this evidence. Much of the literature on structural 

risk factors focuses on the general homeless population, and is therefore not Veteran specific. 

However, these structural risk factors for homelessness create a societal context that likely 

affects Veterans in much the same way as it does the homeless population in general, so a brief 

background discussion of these issues is relevant.

Lack of Affordable Housing

Lack of affordable housing has been recognized as one of the main structural causes of 

homelessness in the general population.3-7 Over the past three decades there has been a dramatic 

decrease in the availability of affordable housing units for low income renters. In 1970 there was 

a surplus of 500,000 affordable housing units.8 By 2008, Extremely Low Income (ELI) renter 

households, defined as earning less than 30 percent of the median income for the metropolitan 

area or rural county where they live, experienced a deficit of 3.1 million units.9 In addition, rental 

assistance programs such as the Section 8 program, which enables low income households to 
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afford rents in privately owned units, have not been able to assist more than a small number of 

those who qualify. Only about one-third of those who qualify for housing assistance occupied 

subsidized housing.10 It is estimated that the current gap between the number of affordable 

housing units and the number of people needing them is the largest on record, at 4.4 million 

units.9

Diminishing Employment Prospects 

A labor market shift from well paying jobs to minimum wage jobs with fewer benefits has had 

a direct affect on homelessness. A 2007 survey by the U.S. Conference of Mayors found that 

17.4 percent of homeless adults in families were employed, while 13 percent of homeless single 

adults or unaccompanied youth were employed.11 For workers earning minimum wage, the real 

value of their pay has fallen considerably during the past several decades. For instance, the real 

value of minimum wage fell 26 percent from 1979 to 2004, the last year for which we were able 

to find such data.11 The decrease in the real value of income for minimum wage earners has had 

a significant impact on their ability to pay for housing.9 Between 1997 and 2005, the number of 

working families paying more than 50 percent of their income for housing increased 87 percent 

from 2.4 million to 4.5 million. Among renters alone, the increase in the number of working 

families who spend more than 50 percent on housing increased 103 percent, from 1 million 

to 2.1 million.12 Currently, 71 percent of extremely low income renters spend more than half 

of their income on rent.9 Furthermore, unemployment has risen sharply in recent years. At the 

beginning of the current recession (December 2007), the Bureau of Labor Statistics reported that 

the number of unemployed persons was 7.7 million, with an unemployment rate of five percent. 

In July 2010, the number of unemployed persons was 14.7 million with an unemployment rate of 

9.5 percent. The number of people experiencing long-term unemployment (27 weeks or longer) 

grew from 22 percent to 45 percent of the unemployed (from 2.6 million to 6.6 million) between 

December 2008 and July 2010.9

Decrease in Entitlement Payments

A series of policy changes with regard to federal entitlements has steadily eroded the real dollar 

value of both Supplemental Security Income (SSI) and Aid to Families with Dependent Children 

(AFCD) payments, now called Temporary Assistance for Needy Families (TANF). The monthly 

purchasing power of a family receiving AFDC fell by almost one-third, from $568 in 1970 to 

$385 in 1984. Because of tightened eligibility criteria the number of people who have been able 

to rely on the government for support has been reduced.8 The purchasing power of entitlement 

payments plays a significant role in the ability to secure housing. The fair market rent (FMR) 

for a two-bedroom unit ($959) exceeds the entire maximum AFDC grant for a mother with two 

children in every state except Alaska,13 and is greater than the 2010 maximum federal monthly 

Social Security Disability Insurance (SSDI) payment of $674.9 Furthermore, only 10 to 15 

percent of homeless individuals received SSI or SSDI assistance, most often because they do not 

know they qualify or they fail to complete the application process.14
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METHODS

TOPIC DEVELOPMENT

Key questions for this review were developed with the input of experts from the National 

Center for Homelessness Among Veterans and the VA New England Healthcare System, and 

with feedback from national experts on homelessness and homelessness among Veterans (see 

Appendix B).

The final key questions are:

Key Questions #1a. What is the prevalence and incidence of homelessness among Veterans?

#1b. How has the prevalence and incidence of homelessness among Veterans 

changed over time?

#1c. How prevalent are psychiatric illness, substance abuse, and chronic medical 

illness among homeless Veterans?

Key Questions #2a. Which risk factors are associated with new homelessness or a return to 

homelessness among Veterans? How do these risk factors differ from nonVeteran populations?

#2b. Have risk factors for homelessness among Veterans changed over time?

Key Question #3. Are there factors specific to military service that increase the risk 

of homelessness, or is the increased risk a marker for pre-military 

comorbidities and social support deficiencies?

Key Question #4. What is the relationship between incarceration and homelessness among 

Veterans?

SEARCH STRATEGY

To answer these questions, we began with a horizon scan for any studies or reviews of studies 

about homelessness and Veterans. The search was performed in December 2009 in MEDLINE 

(coverage: 1947-present) and the Cochrane Database of Systematic Reviews (coverage: 

1993-present), with no limitations on publication year. A supplementary search was conducted 

in Sociological Abstracts (coverage: 1952-present). Searches in those databases covered the 

literature available from the beginning of their coverage year through December 2009, and 

were updated to include coverage through July 2010. We also monitored Table of Contents 

alerts for several publications to indentify new research published in 2010. To answer Key 

Question #3, we conducted an additional search of several non-medical qualitative journals, 

including Qualitative Research and Qualitative Health Research, with keyword searches on 

(homeless) AND (military OR combat OR veteran). To answer Key Question #4, we conducted 

a broad search of MEDLINE, Sociological Abstracts, and Criminal Justice Abstracts (coverage: 

1968-present) to identify any studies or reviews of studies of Veterans and incarceration. 

Keyword searches were conducted in each database for any articles including ((veteran*) AND 
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(jail OR incarcerat* OR prison*)). In addition, a supplementary search of Google Scholar 

was conducted, looking for any articles meeting the criteria (allintitle: veteran incarcerate OR 

incarcerated OR incarceration OR prison OR prisoner OR jail). Google Scholar searches were 

limited to title words because of the large number of articles returned by a more general keyword 

search.

We sought additional key sources outside indexed journals from homeless researchers and 

policy-makers identified through snowball sampling (Appendix B). For all key questions, the 

reference lists of articles returned were reviewed for any additional relevant studies.

STUDY SELECTION

Because of the exploratory nature of this review, few restrictions were placed on articles to be 

considered for inclusion. Abstracts and full-text articles were not dual reviewed for inclusion. 

The authors each had responsibility for specific key questions, and reviewed abstracts and fulltext articles for those key questions to identify any that might have relevance to the topic of 

prevalence, risk factors, psychiatric disorders, substance abuse, or chronic medical conditions 

(VC), military and combat related issues (AT), and incarceration and diversion (HB).

DATA SYNTHESIS

The existing evidence base relevant to this topic does not lend itself to a quantitative synthesis, 

since sample populations and variables investigated were rarely consistent across studies. In 

this report, we did not conduct a quantitative data synthesis or meta-analysis, but rather focused 

on presenting the strength of each existing study’s findings and developing a conceptual model 

for understanding what these findings mean collectively, as well as indicating where there are 

significant gaps in our knowledge on this topic.

CONCEPTUAL MODEL

Based on a preliminary review of the evidence, the authors developed a conceptual model 

that provided an analytic framework for understanding the connections between risk factors 

investigated in different studies. Initially focused on the specific risk factors associated with 

military service, our conceptual model grew to include pre-military risk factors, as well as 

factors that, in their general definition, are not unique to Veterans (low or unstable income, for 

example). We constructed a visual model (Figure 1) to help qualitatively identify the experiences 

and intermediate outcomes that may be relevant in understanding Veteran homelessness. The 

conceptual model evolved out of our review and is grounded in the available evidence, with 

those associations supported by more than one study marked by solid lines, while associations 

shown by only one study, or where existing evidence is inconsistent, indicated by dashed lines.

A few comments on the assumptions and rationale behind the model are in order. First, several 

exposures with the same strength of associational evidence are grouped together in one box. This 

is the case with “low income/low social support/arrests and convictions” and again with all the 

pre-military service exposures examined. This was done for two reasons: to simplify the model 

and to graphically suggest that it is likely these exposures interact with one another in ways 
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which are not well isolated or identified in existing research. As is frequently acknowledged in 

the literature, risk factors for homelessness rarely occur in isolation. Second, the model includes 

two “black boxes” representing the presence of unmeasured variables. While the primary 

purpose of the model is to represent what is currently known based on evidence, a secondary 

purpose of the model is to conceptually make sense of the evidence. Where the mechanism 

or mediating factors linking two statistically associated variables has not been adequately 

explored – as, for example, in one study associating Military Sexual Trauma (MST) directly with 

homelessness – the evidence passes through the black box. In contrast, research investigating low 

social support, low or unstable income, and arrests/convictions generally makes a clear case for 

the ways in which these exposures place one at risk for homelessness, and thus no mediating box 

is included. Third, time is included in the model, which allows the direction of the association to 

be assumed in some cases (as with early life exposures).

The strength of the associations as indicated in the model is based upon the strength of existing 

evidence for the Veteran population, but it attempts to indicate how Veteran-specific exposures 

impact what we have called the “shared exposures,” i.e., those common to the general homeless 

population in the United States. One strength of this model is that it allows the reader to 

conceptualize the relationships among risk factors unique to the experience of Veterans together 

with risk factors common to broader populations of homeless individuals. For example, the 

association between low social support and homelessness is a general one that has been observed 

in other homeless populations, as has the association between low social support and mental 

illness. However, the association between mental illness and combat exposure is unique to 

Veterans. We feel it may be important for future intervention efforts to understand these Veteranunique exposures and their impact on shared exposures, and have thus highlighted them in this 

report, even as we conclude that homeless Veterans have much in common with the non-Veteran 

homeless.

This conceptual model, though derived independently by the review team and more inclusive 

of structural risk factors, bears similarities to the model put forward by Rosenheck and Fontana 

(1994), who looked at data from the National Vietnam Veterans Readjustment Survey (NVVRS) 

to investigate risk factors for Veteran homelessness.15 The NVVRS was a landmark attempt to 

understand the impact of the Vietnam War on both the physical and social health of Veterans, 

and no study to date has replicated its nationally representative, mixed-methods data collection 

design for investigating multiple risk factors. The current generation of Veterans who have 

experienced the conflicts in Iraq and Afghanistan may exhibit different characteristics and is 

deserving of research of similar scope.

PEER REVIEW

A draft version of this report was reviewed by six experts in the field of homelessness. Their 

comments and our responses are presented in Appendix A.
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n Homelessness: Conceptual Model
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RESULTS

DEFINITIONS OF HOMELESSNESS

The current definition of a “homeless Veteran” combines both Veteran status and homeless status. 

The VA considers a Veteran as a person who “served in the active military, naval, or air service” 

and was not dishonorably discharged. However, many studies of homeless Veterans include as a 

Veteran anyone who reports having served in the military, regardless of active duty or discharge 

status. Reported Veteran status is rarely confirmed through a review of VA administrative 

data. Veterans are considered homeless if they meet the definition of “homeless individual” 

established by the McKinney-Vento Homeless Act (P.L. 100-77). The McKinney-Vento Act 

defines a homeless individual as an individual who lacks a fixed, regular, and adequate nighttime 

residence, and a person who had a nighttime residence that is: a supervised publically or 

privately operated shelter designed to provide temporary living accommodations; an institution 

that provides a temporary residence for individuals intended to be institutionalized; or a public or 

private place not designed for or ordinarily used as a regular sleeping accommodation for human 

beings.16

The current definition of homelessness under the McKinney-Vento Act does not include those 

living in transitional housing not exclusively for the mentally ill, those who are in imminent 

threat of losing their housing, those fleeing a situation of domestic violence or other lifethreatening condition, as well as unaccompanied youth and certain types of homeless families 

with children. Recent amendments to McKinney-Vento through the Homeless Emergency and 

Rapid Transition to Housing (HEARTH) Act will expand the definition of homelessness to 

include these families and individuals.16 Changes in the definition of who is counted as homeless 

were scheduled to go into effect in November, 2010. These changes, along with demographic 

changes in the nature of the military, particularly among those serving in the Operation Iraqi 

Freedom (OIF) and Operation Enduring Freedom (OEF) era, and as a result of the increase in 

women serving in the military, are likely to have an impact both on the numbers and needs of 

homeless Veterans and their families.16

ASSESSING THE LIMITATIONS OF THE CURRENT RESEARCH

There are several limitations of the studies that have examined the individual level risk factors 

for homelessness.

Problems in Sampling and Populations

Sampling limitations are common. Most studies include samples that disproportionately 

comprise the chronically homeless rather than the newly homeless. Studies often rely on small, 

geographically isolated samples, which make it difficult to make generalizations about the larger 

homeless population.17-19 In addition, several studies examine former homeless individuals, often 

termed “ever homeless,” in order to draw more generalizable conclusions about the homeless 

experience. Although such studies are useful, their sample selection includes only those, who for 

whatever reason, have made it out of homelessness, thus undersampling those who may have 
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higher rates of symptom severity for risk factors such as substance abuse and mental illness.

Few studies directly assess the prevalence of psychiatric, substance abuse, or chronic illness in 

the general population of homeless Veterans. Most studies rely on already morbid populations 

seeking treatment for services and so cannot provide estimates of prevalence in the population 

as a whole. Fischer and Breakey20 further point out that much research has relied on nonrandom 

sampling frames, which may introduce bias, thus influencing prevalence rates of certain 

attributes. Rates of alcohol, drug, and mental health problems, for instance, tend to appear 

larger among homeless individuals sampled in shelters, clinics and on the streets; and lower in 

sampling sites such as food or service providers.20

Comparators

Few studies include appropriate housed control groups to determine the difference in prevalence 

for certain risk factors. Matched for race, gender, and age, census data or large household surveys 

give a sense of the differences in the homeless population as compared to the general housed 

population, but a more narrowly focused control group of marginally housed individuals living 

in poverty would present a more accurate picture of the predictive factors that are related to 

homelessness. Studies that include univariate comparisons often do so without calculating risk 

ratios.19-22

Settings

Research on homelessness is often conducted in service settings, including shelters and 

rehabilitation centers, which increases the chance of over-representing the chronically homeless 

and under-representing those who are homeless for short periods of time. Because the chronic 

homeless tend to have higher rates of substance abuse and mental illness, an over-representation 

of the chronically homeless will result in an overestimation of such characteristics.23 Thus, choice 

of sampling site affects prevalence rates.21

Definitions

Existing studies also frequently differ in the definitions of key dependent variables, including 

homelessness itself. Some studies interpret homelessness as literal homelessness (sleeping in 

a shelter or on the street), while other studies include more liberal definitions. Some studies 

examine the dichotomy of ever/never being homeless, while others employ a strict point-in-time 

or cross-sectional definition and do not collect data on sample participants’ lifetime experience of 

homelessness.

Measures and Measurement Issues

Measurements used to operationalize the included risk factors have not been consistent. For 

example, social support in some cases is measured as “having someone close to you that can 

provide support,” while other studies use marital status as a surrogate to determine the level 

of one’s social support status. Even questions regarding Veteran status can lead to different 

estimates. Asking, “Are you a Veteran?” for example, can generate a different response than 

asking, “Did you serve in the armed forces?” In addition, studies do not always include the 
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same variables in their models. Several studies failed to include variables that have been found 

significant in other research, such as childhood adversity, employment history and former 

incarceration, and so may not adequately control for possible confounders. In addition, structural 

factors such as housing affordability or job market conditions have largely been left out of the 

research design in many of the studies examining risk factors for homelessness, although they 

have largely been significant in the models that have included them.22 Thus, it is impossible to 

determine if controlling for structural risk factors would have altered the results of such research.

In addition to the methodological inconsistencies described above, we found great variability in 

the methods and instruments used to determine the prevalence of alcohol abuse, substance abuse, 

and mental illness among homeless Veterans. The type of measurement used (current use, past 

use, or lifetime use) is also largely inconsistent. We found that a large percentage of studies have 

based their findings on self-report (which depends greatly on the willingness of self-disclosure 

of study participants) or on instruments in which there is no clear evidence of validation for the 

homeless population. Differences in prevalence between studies using self-report vs. standard 

instruments can be stark. Fischer and Breakey point out, moreover, that estimates based on prior 

treatment history may not be accurate because of the various ways in which individuals seek help 

from service providers. Some patients, for example, seek help through outpatient services and, 

so, would not be included in counts of hospitalized patients – a common measurement threshold 

for prevalence estimates of mental illness and substance abuse.20

Much of the research that examines the associations between substance abuse/mental illness and 

homelessness does so from a pathology perspective rather than from an adaptation perspective.24

By using instruments that are designed primarily for use on clinical populations, such research 

may misinterpret adaptive behaviors as pathology. We suggest that researchers should provide 

evidence of validation for the instruments used when reporting the associations between 

substance abuse and/or mental illness among homeless Veterans. By addressing the validation of 

instruments used on the homeless population, researchers will be able to draw a more accurate 

picture of the risk factors associated with homelessness among Veterans.

Study Design

Many of the studies examining Veteran homelessness employ a cross-sectional research design, 

which limits the interpretation of cause and effect regarding substance abuse/mental illness and 

homelessness. Thus, in many cases, it is unclear as to whether substance abuse and/or mental 

illness preceded homelessness, or if substance abuse and/or mental illness are the result of 

adaptations to the stresses and dangers associated with the homeless experience.

Summary of Limitations

Because of the inconsistencies in the instruments used and the inherent differences found in 

study design, comparisons across studies are problematic. We agree with Fischer and Breakey 

that comparisons of studies should take into account differences in problem definition, method of 

assessment, sampling techniques, and demographic characteristics of the sample.20
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DATA SOURCES

A recent Government Accounting Office (GAO) review of Federal data and other studies on 

homelessness concluded that “these data have a number of shortcomings and consequently do 

not capture the true extent and nature of homelessness.”25 While that review was broadly focused 

on data on homeless populations in general, it did include a review of data available on homeless 

Veterans, and many of its findings are equally applicable to data on the Veteran sub-population.

Annual Homeless Assessment Report (AHAR) and Community Homelessness 

Assessment, Local Education, and Networking Group (CHALENG) Report Data

There are three current data sources widely relied on for estimating the number of homeless 

Veterans:

• The AHAR provides estimates of Veteran homelessness from two data sources:

◦ the Department of Housing and Urban Development’s (HUD’s) Point-in-Time (PIT) 

estimate, that gives an approximation of the number of homeless individuals and families 

during a single night in January;

◦ the Homeless Management Information System (HMIS) estimates, which produce counts 

of the sheltered homeless population during a calendar year; and

• The annual CHALENG for Veterans report uses a combination of data sources to determine a 

count of Veteran homelessness.

PIT estimates are gathered on a single night during the last week in January. Continuum of Care 

(CoC) applications are submitted to HUD annually as part of the competitive funding process 

and provide one-night, PIT estimates of both sheltered and unsheltered homeless populations.14

Information about homeless subgroups are also collected.

HMIS are electronic administrative databases that are designed to record and store client-level 

information on the characteristics and service needs of homeless persons. HMIS data are used to 

produce counts of the sheltered homeless population over a full year. It includes people who used 

emergency shelter or transitional housing programs at some time during the course of a year.14

Since 1994, the VA has estimated the number of Veterans receiving services in its CHALENG 

program. Estimates are derived through partnerships with representatives from each local VA 

medical center (VAMC) and service providers from state and local governments and nonprofit 

organizations. Using a point-in-time estimate, each VAMC estimates the greatest number of 

Veterans who are homeless on any given day in the previous fiscal year. Various sources are used 

to arrive at the estimates and include HUD PIT counts, previous Census estimates, VA client 

data, VA staff impressions, or combinations of sources.26

Estimates from the most recent CHALENG report are based on PIT estimates of the number 

of Veterans homeless on any day during the last week of January 2008. While these estimates 

include both sheltered and unsheltered Veterans, like all PIT estimates, the CHALENG count 

is likely to undercount those who are not chronically homeless. In addition, these estimates 
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are often adjusted to better align with estimates based on the HUD PIT count, noting that 

“CHALENG has increasingly relied upon HUD PIT counts as the basis of its own estimate.”26

The reasons for this are unclear. This approach establishes the HUD count as a gold standard 

despite the CHALENG authors’ own acknowledgment that the HUD PIT counts may not have 

included areas with concentrations of homeless Veterans known by those responsible for the 

CHALENG estimate.26

HUD and the VA have recently collaborated in producing and releasing a Veteran-specific 

supplement to the annual AHAR. This report Veteran Homelessness: A Supplemental Report to 

the 2009 Annual Homeless Assessment Report to Congress27 (2009 Veteran AHAR) is a major 

contribution to our understanding of the extent and nature of homelessness among Veterans. The 

report is based on PIT and HMIS data collected as described above using a standard, validated 

method to minimize potential duplication in the count, and with statistical adjustments made to 

account for undercounting. The 2009 Veteran AHAR provides national one-day and one-year 

estimates of homeless Veterans and describes their demographic characteristics and patterns of 

shelter use. We recommend that the Veteran AHAR be used as the most comprehensive and reliable 

source of information on the prevalence of homelessness among Veterans currently available. The 

report is available at: http://www.hudhre.info/documents/2009AHARVeteransReport.pdf.

Our report should be seen as a complementary report that provides a critical review of the 

research and literature on homelessness among Veterans.

In addition to the AHAR and CHALENG counts, which attempt to provide national estimates 

of the number of homeless Veterans, other data sources are used to provide estimates of 

subpopulations of homeless Veterans and their individual characteristics, and to identify risk 

factors for homelessness among Veterans. What follows is an overview of some of the more 

central of those data sources. This is not intended to be a comprehensive review of all data 

sources on homeless Veterans; rather, it is a review of what we consider to have been a core set 

of those data sources – those that have been consistently used in a number of studies, and those 

which we consider exemplars of the strengths and weaknesses of data on homeless Veterans.

National Vietnam Veterans Readjustment Study (NVVRS)

One of the earliest sources of data on Veteran homelessness and on related factors such as drug 

and alcohol use and post-traumatic stress disorder (PTSD) was the NVVRS. Conducted between 

September 1984 and November 1988, this study of 1,200 Veterans provided a representative 

sample of all persons on active duty in the U.S. military during the Vietnam War era (August 5, 

1964 through May 7, 1975).

Although it was a well-conducted study, the population may not be representative of postVietnam era Veterans. Theater Veterans of the Vietnam War era were younger and less likely 

to be female or minorities than subsequent Veteran cohorts. They also served during a period 

of a military draft – while Veterans of the post-Vietnam era served in an all volunteer military, 

over 40 percent of the respondents to the NVVRS had been drafted or enlisted to avoid the 

draft. While in 1974, 60 percent of the active duty force were age 25 or younger, by 2000, that 

percentage had declined to 46 percent; and while in 1974, only 3 percent of the active duty force 
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were women and 20 percent were minorities, by 2000, women accounted for 15 percent and 

minorities 35 percent of those on active duty.28 Since the Vietnam era, the military has also seen 

an increase in service members with family obligations.29

Two current studies, the Health of Vietnam Era Veteran Women’s Study (Health VIEWS)30 and 

the Millennium Cohort Study (MCS),31 may provide additional information on the prevalence 

of risk factors for homelessness among women Veterans (Health VIEWS) and among OEF-OIF 

Veterans (MCS).

National Survey of Homeless Assistance Providers and Clients (NSHAPC)

One of the most widely used sources of information on homelessness in general, as well as on 

homelessness among Veterans, is the NSHAPC. This survey was conducted between October 

18, 1996 and November 14, 1996 and included a nationally representative sample of over 4,000 

homeless clients of nearly 12,000 homeless assistance providers. The survey collected data on, 

among other things, Veteran status, mental health, drug and alcohol use, and homelessness status 

(currently or formerly). While in 1996, 13 percent of adult U.S. population were Veterans, 23 

percent of the then currently homeless clients were Veterans. Considering males only, 33 percent 

of the male homeless clients were Veterans compared with 31 percent of the adult male U.S. 

population.

While a number of later studies of homelessness among Veterans made use of the NSHAPC 

data, several limitations to the data should be noted. First, the study includes information only 

on clients of services for the homeless and does not include information on the homeless who 

did not access services. It also entirely excludes the homeless in communities that had few or no 

homeless assistance programs. In addition, all client data, including data on physical and mental 

health problems, use of alcohol and drugs, and incarceration were based on self-report. Finally, 

because the survey collected data on homelessness was only for the period of one month, as 

with all point-in-time surveys, it will likely reflect a bias towards those who are chronically as 

opposed to episodically or temporarily homeless.

Health Care for Homeless Veterans (HCHV)

Many of the studies of homelessness among Veterans are based on data from clinical populations 

receiving services in VA programs, and so may have limited applicability to an understanding of 

homelessness among Veterans more generally. While these are often large national data sets, they 

nevertheless capture data only on those Veterans participating in those programs. In addition, 

these programs are often focused on Veterans with particularly acute service needs. A description 

of some of the programs most frequently used as sources of data follows.

Homeless Chronically Mentally Ill Veterans Program (HCMI)

The HCMI program was established in 1987 at 43 Veteran Administration Medical Centers in 

26 states and the District of Columbia as a program for Veterans with psychiatric problems. 

An initial assessment of the program conducted between May 1987 and March 1988 found 

that the median age of participants was 40 (younger than Veterans in the general population); 

that 67 percent needed specialized psychiatric, and 72 percent needed medical evaluation or 
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treatment: that 46 percent reported significant substance abuse and 65 percent reported a previous 

hospitalization for either a psychiatric or substance abuse problem; that 47 percent were living in 

shelters, 9 percent were doubling up, 8 percent had a room or apartment, and 35 percent had no 

residence; and that over half were Vietnam era Veterans.

Domiciliary Care for Homeless Veterans (DCHV)

The DCHV program was also established in 1987 as a 20-site expansion of the VA’s 

existing domiciliary care program. It was targeted at Veterans who were either medically or 

psychiatrically disabled, and who were either homeless or at imminent risk for homelessness. In 

an initial assessment of the program conducted between November 1987 and November 1988, 

nearly 90 percent of admitted Veterans received major psychiatric or substance abuse diagnoses; 

69 percent had been hospitalized at a VAMC for a substance abuse, psychiatric, or medical 

problem in the previous year; 47 percent had a current substance abuse problem, 36 percent a 

current psychiatric problem, and 16 percent were dual diagnosed; and 54 percent had a serious 

chronic, medical illness.

Access to Community Care and Effective Service Supports (ACCESS)

The ACCESS program was established by Substance Abuse and Mental Health Services 

Administration (SAMHSA) in 1993 as a five-year demonstration project to identify effective 

approaches to providing services to homeless persons with serious mental illnesses. Clients were 

eligible for case management services if they were homeless, suffered from severe mental illness, 

and were not involved in ongoing treatment in the community. Of those who eventually enrolled 

in the case management phase of the program, 67 percent were diagnosed with a psychotic 

disorder (37 percent with schizophrenia, 32 percent with other psychoses, 20 percent with 

bipolar disorder), 49 percent were diagnosed with major depression, 22 percent with personality 

disorder, and/or 19 percent with anxiety disorder (diagnoses are not mutually exclusive); 43 

percent were diagnosed with alcohol abuse; and 38 percent were diagnosed with drug abuse.

METHODOLOGICAL CONSIDERATIONS

Estimates of the number of homeless are sensitive both to the definitions of homelessness (who 

is deemed homeless) and the methods for counting the homeless population.21, 23 Point-in-time 

estimates are more likely to capture the chronically homeless population than HMIS counts, 

and may undercount those who are transitionally or episodically homeless. The HMIS counts, 

however, are sensitive to under-reporting, since CoCs are not required to submit HMIS data. 

The Veteran AHAR statistically adjusts the raw count to account for undercounting in the PIT 

estimate of one-day sheltered and unsheltered homelessness, and uses statistical adjustments and 

weighting of the HMIS to produce national one-year estimates of the sheltered homeless.27 The 

accuracy of those estimates will be sensitive to the validity of the assumptions underlying the 

adjustments. Appendix A of the Veteran AHAR provides a description of the methodology used 

to adjust the PIT counts,27 and Appendix B.5 of the 2009 AHAR provides a description of the 

methods used to adjust and weight the HMIS estimate.14

There are several data collection issues that make estimating the number of homeless Veterans 

difficult. Those who are doubled up with family or friends but who would otherwise be without 
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shelter are generally not included in homeless samples.32 Estimates of Veteran homelessness 

often will miss the hidden homeless who sleep in automobiles, in campgrounds or in other 

areas not easily identified by researchers, as well as those who may intentionally hide from 

researchers.32

KEY QUESTION #1A. What is the prevalence and incidence of 

homelessness among Veterans?

For reasons discussed earlier in the Limitations section, the exact number of homeless Veterans is 

unknown. The most recent CHALENG for Veterans report estimates that on on a single night in 

January 2008 there were 107,000 homeless Veterans.26 This represents a decrease of 18 percent 

from the estimate of 131,000 homeless Veterans reported in the 2008 CHALENG report.26 It 

is argued that this is primarily the result of changes in counting methods rather than an actual 

decline in the number of homeless Veterans.33 The CHALENG report further speculates that 

improved methods (such as adjusting estimates to better coincide with local HUD PIT counts), 

VA program interventions, changing demographics, and recent events (i.e., reduction in estimates 

due to ongoing recovery from the effects of Hurricane Katrina) may have had an impact on the 

reported prevalence of homelessness among Veterans.26 With nearly 23 million Veterans in the 

U.S. population in 2008, and an estimated 107,000 homeless, the rate of homelessness among 

Veterans was approximately 47 for every 10,000 Veterans. This rate is more than double the rate 

of homelessness in the general adult population.14

The recently released 2009 Veteran AHAR estimates that on a single night in January 2009 there 

were 75,609 homeless Veterans and that an estimated 136,334 Veterans spent at least one night 

in an emergency shelter or transitional housing program between October 1, 2008 and September 

30, 2009.27 Based on the Veteran AHAR estimate of 75,609 homeless Veterans on a single night 

in January 2009, approximately 33 of every 10,000 Veterans were homeless.

In 2009, Veterans made up just under 10 percent of the U.S. adult population, and over 11 

percent of the adults in emergency shelters or transitional housing between October 1, 2008 

and September 30, 2009. This accounts for 1 of every 168 Veterans in the U.S. or 1 in every 10 

Veterans living in poverty.27 In addition, it has been argued that from 89,553 to 467,877 Veterans 

are at risk for homelessness.33 In the United States, men in general are more likely to be homeless 

than women, and the Veteran population continues to be disproportionately male, so some of this 

increased risk can be ascribed to this. However, while females comprise only 6.8 percent of the 

total Veteran population, they made up 7.5 percent of homeless Veterans.27

While Blacks make up only 11 percent of the overall Veteran population, they were 34 percent 

of the homeless Veterans. Similarly, Hispanics comprise only 5 percent of all Veterans, but 11 

percent of homeless Veterans; and American Indian and Alaska Natives, while comprising less 1 

percent of all Veterans, were over 3 percent of the homeless Veterans.27

In 2009, nearly half of all Veterans were between the ages of 31 and 50, and over a third were 

between 51 and 61. Over 11,000 Veterans between the ages of 18 and 30 used an emergency shelter 

or transitional housing in 2009, suggesting a potential growing need to address the problem of 

homelessness among Veterans of Operation Iraqi Freedom and Operation Enduring Freedom.27
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KEY QUESTION #1B. How has the prevalence and incidence of 

homelessness among Veterans changed over time?

Because of changes in reporting and in the methods for counting the number of homeless, 

estimates of the prevalence of homelessness among Veterans over time are not comparable. The 

16th CHALENG report estimated that there were 107,000 Veterans homeless on a single day in 

January 2008.26 In contrast, the 2009 Veteran AHAR estimates that there were 75,609 homeless 

Veterans on a single night in January 2009.27 While this 30 percent decrease in the number of 

homeless could be real, it is more likely an artifact of changes in the methods for counting and 

adjusting estimates; therefore, we suggest caution when using previous estimates to examine 

changes in prevalence over time. HUD and the VA intend to continue to collaborate on future 

annual Veteran supplements to the AHAR which should result in more consistent estimates for 

tracking trends in homelessness among Veterans.

However, even these new estimates should be interpreted with caution for several reasons. First, 

as HUD points out, the HMIS data on Veteran status are for sheltered homeless only. Some 

researchers have speculated that Veterans, are more likely than other homeless groups to remain 

unsheltered.14 Second, some of the residential programs for the homeless that are funded through 

the U.S. Department of Veterans Affairs do not report data to the CoC. Moreover, there is anecdotal 

evidence that homeless Veterans do not always reveal their Veteran status to program staff.14

It has been speculated that the number of homeless Veterans will increase, as Veterans return from 

OEF and OIF suffer from high rates of mental illness and traumatic brain injury; these and other 

returning Veterans may experience problems in obtaining employment within the civil sector.34

The accuracy of these speculations may not be known for many years, as historically Veteran 

homelessness usually occurs long after return to civilian life. In a study of over 1,400 homeless 

males, 76 percent of combat Veterans and half of all noncombat Veterans first became homeless 

more than a decade after leaving military service.35 In addition, the demographic composition of 

the Veteran homeless population is changing. As documented by Kuhn et al. (2010), VA facilities 

recently reported an increase of 24 percent in homeless Veteran families seeking services from 

those facilities. Indeed, family issues such as child care were among the top 10 needs reported 

by homeless individuals in the most recent CHALENG survey.26 A recent study assessing risk 

factors for homelessness among female Veterans found that 16 percent of homeless Veterans 

had children under the age of 18 living with them during the prior 12 months.36 The percentage 

of homeless women Veterans is expected to increase as the percentage of female Veterans has 

increased dramatically in recent years. Over 165,000 female troops have been deployed to Iraq 

and Afghanistan, a much higher number than deployed during the Vietnam and Gulf Wars.16

Researchers should remain alert to the possibility that changing demographics within the military 

may, in the future, be associated with different, potentially more rapid paths to homelessness.

KEY QUESTION #1C. How prevalent are psychiatric illness, substance 

abuse, and chronic medical illness among homeless Veterans?

There are few studies directly assessing the prevalence of psychiatric, substance abuse, or 

chronic illness in the general population of homeless Veterans. Most studies rely on already 

morbid populations seeking treatment for services and so cannot provide estimates of prevalence 
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in the population as a whole. Of the studies we located which focus on substance abuse and 

mental illness among homeless Veterans, we found very little consistency in the methods and 

instruments used to determine the prevalence of substance abuse and mental illness. The type of 

measurement (current use, past use, and lifetime use) was also inconsistent, which can greatly 

affect reported prevalence rates, as those reporting lifetime drug abuse or mental illness will 

have higher rates compared with those reporting current abuse or illness. It is also difficult to 

determine from the included studies if distinctions were made between hazardous use, abuse, and 

dependence. The severity of abuse has implications for functioning, risk, and capacity to engage 

in services.

Several studies have based their findings on self-report, a method which depends greatly on the 

willingness and accuracy of self-disclosure of study participants, or on instruments for which 

it is unclear if they have been validated with homeless populations. Differences in prevalence 

between studies using self-report vs. those using standard instruments can be substantial. Fischer 

and Breakey20 point out, moreover, that estimates based on prior treatment history may not be 

accurate because of the various ways in which individuals seek help from service providers. 

Some patients, for example, seek help through outpatient services and thus would not be 

included in counts of hospitalized patients – a common measurement threshold for prevalence 

estimates of mental illness and substance abuse. Because of these inconsistencies, comparisons 

across studies are problematic.

Furthermore, many of the studies examining Veteran homelessness employed a cross-sectional 

research design, which limits the interpretation of cause and effect regarding substance abuse/

mental illness and homelessness. Nevertheless, we feel that the evidence is adequate and 

consistent enough with evidence regarding the prevalence of these conditions in homeless 

populations in general,21, 22, 37 to state that the prevalence of mental health, substance abuse, 

and medical problems among Veteran homeless is high, despite access to Veteran Health 

Administration (VHA) services.

Existing evidence suggests that homeless Veterans have higher rates of substance abuse (drug 

and alcohol abuse), mental illness, and chronic illness when compared to housed Veterans. 

However, here, too, estimates vary. A study based on a convenience sample of homeless adults 

admitted to homeless shelters in Santa Clara County, California between November 1989 and 

March 1990 found that 17 percent of Veterans had been admitted for overnight treatment of 

psychiatric problems, 29 percent reported actual and 39 percent perceived alcohol abuse, and 22 

percent reported illegal drug use.35 More recently, in a cross-sectional, community-based survey 

of homeless male Veterans (N=127) and non-Veterans (N=298) in Pittsburgh and Philadelphia 

during a five-month period in 1997, O’Toole et al.37 sampled from emergency shelters, 

transitional and supportive housing units, and soup kitchens or drop-in sites to ensure adequate 

representation of all homeless persons. That study found that 61.4 percent of homeless Veterans 

reported psychiatric problems, 79.5 percent reported alcohol or drug abuse or dependence, and 

66.1 percent reported having at least one chronic medical condition.37 In addition, Veterans were 

more likely to report a chronic medical condition than non-Veterans (66% vs. 55%, p = 0.04). 

Of the 127 male Veterans included in the study, 24 percent reported hypertension, 19 percent 

hepatitis/cirrhosis, and 7 percent each diabetes and heart disease, while 36 percent reported two 

or more chronic conditions. Of note, the usual sources of care for the Veteran population were 
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shelter-based clinics (48 percent) as opposed to community clinics (35 percent). As a whole, 

homeless Veterans have higher rates of chronic illness compared to homeless non-Veterans, but 

tend to have similar rates of substance abuse (alcohol or drug abuse) and mental illness when 

compared to their non-Veteran counterparts, although Veterans tend to have better access to 

care.37

A study of homeless Veterans with physical, mental, and substance abuse disorders seeking 

treatment from the DCHV Program examined indicators for chronic homelessness. The study 

consisted of two samples, with both samples including short-term (<12 months since age 18) and 

chronic (>12 months since age 18) homeless Veterans. The study found chronic homelessness to 

be associated with substance abuse disorders for both samples, but only one sample showed an 

association between mental illness (depression and anxiety) and chronic homelessness.38

In a secondary analysis of national VAMCs’ administrative data on over 40,000 housed and 

homeless patients receiving inpatient care between 1996 and 1998, Adams et al.39 found that 

a significantly greater proportion of homeless patients than housed had a psychiatric disorder 

(42.1% vs. 22.1%, p <= 0.001) or substance abuse (37.7% vs. 6.9%, p <= 0.001) as a discharge 

diagnosis. Homeless persons in this study included both the literal homeless and those doubled 

up, i.e. staying temporarily with family or friends. No major differences were found between 

housed and homeless Veterans regarding surgical or medical conditions.

KEY QUESTION #2A. Which risk factors are associated with new 

homelessness or a return to homelessness among Veterans? How do 

these risk factors differ from non-Veteran populations?

Risk factors most strongly and consistently associated with homelessness include childhood risk 

factors such as inadequate care by the parents, experiencing foster care or group placement, and 

prolonged periods of running away from home. These risk factors have also been consistently 

found to be associated with homelessness in the general population.21, 40, 41 Overall, homeless 

Veterans and non-Veterans tend to have similar rates of alcohol and substance abuse.35, 37

Comparisons of rates of mental illness and overall health status between Veterans and nonVeterans have not found a consistent association across studies.35, 42

There do not appear to be differences between Veterans and non-Veterans with regard to some 

of the factors most immediately associated with homelessness. However, there do appear to be 

unique, military-related pathways by which Veterans are exposed to these factors, since Veteranspecific exposures such as combat injury, intense or prolonged combat, and Military Sexual 

Trauma all have an impact on shared exposures such as mental illness and low or unstable 

income.

There are notable differences in the prevalence of some characteristics often found to be 

protective. Veteran homeless tend to be older and better educated, have had better early 

family cohesion, and are more likely to be or have been married than non-Veteran homeless. 

The reasons for the absence of expected protections are not well understood. It may be that 

the differences between these populations are too small to influence outcomes significantly. 

Alternatively, there may be unique Veteran experiences associated with either service or post-
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deployment readjustment that actively undermine the protective mechanism associated with 

these factors in other populations. For example, it may be that individuals with strong positive 

family experiences or high social support in the form of marriage may actually be more 

negatively affected by the physical and emotional dislocation of combat service than those who 

have weaker social support networks. Similar arguments have been offered to explain why 

National Guard Veterans, who are often older, more established in their civilian lives, and less 

connected to the social supports and services offered to active military post-deployment, are 

often considered, at least anecdotally, to have particularly severe post-deployment readjustment 

difficulties.43 Research is needed to move these explanations beyond mere conjecture, however.

KEY QUESTION #2B. Have risk factors for homelessness among 

Veterans changed over time?

We found no evidence to suggest that risk factors themselves change over time. What the 

evidence does show is that over time, certain risk factors become more salient than others and 

that they affect different sub-populations. Military-related trauma, for instance, has always been a 

risk factor for the subsequent development of mental illness putting one at risk for homelessness. 

Historically, the trauma most closely associated with military service has been PTSD, but with 

the increasing number of women in the military, military sexual trauma (MST) has become an 

important and prevalent additional trauma-associated risk factor. Similar comments can be made 

regarding the increasing number of family-involved Veterans. The wars in Iraq and Afghanistan 

have led to an increase in the number of National Guard Veterans serving often repeated tours 

of duty in these conflicts. Since these Veterans are more likely to have families during and 

immediately after deployment, the importance of factors related to homelessness among families 

has increased. Similarly, if certain aspects of combat experience put Veterans at increased 

for homelessness – something which the evidence suggests – these will only be relevant risk 

factors during periods when U.S. forces are engaged in combat missions. Finally, economic 

and structural factors will strongly influence who is at risk. In good economic times, those most 

vulnerable because of personal risk factors will become homeless; as economic conditions 

worsen, an increasing number of those less vulnerable will also become homeless.

KEY QUESTION #3. Are there factors specific to military service that 

increase the risk of homelessness, or is the increased risk a marker 

for pre-military comorbidities and social support deficiencies?

Very little research designed to investigate military specific risk factors for homelessness 

has been conducted. Pre-military risk factors or comorbidities do not account for the overrepresentation of Veterans among the nation’s homeless. Prolonged or intense combat 

exposure appears to indirectly increase the risk of homelessness through its impact on mental 

health, employment, and social support.15, 44-51 Some exposures that may increase the risk of 

homelessness, like alcohol/drug abuse and low social support, frequently emerge during service 

or the post-deployment period.52, 53 Though only examined to date by one small study, MST has 

been associated with increased risk of homelessness among female Veterans.36

No study has comprehensively looked at risk factors for emerging OEF/OIF cohorts of Veterans. 
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Future research should employ longitudinal study designs and more detailed data concerning 

combat exposures to track the general population of Veterans’ exposures to clearly-defined 

potential risk factors during active duty and the readjustment/post-deployment period.

Pre-military Risk Factors or Comorbidities Do Not Account for the Overrepresentation of Veterans among the Nation’s Homeless

Some studies have found that homeless Veterans have lower prevalence of some general 

population risk factors (such as family dysfunction) and higher prevalence of protective factors 

(such as higher educational levels) when compared with other homeless individuals.36, 54, 55

These findings suggest that pre-military risk factors or comorbidities do not account for the 

over-representation of Veterans among the nation’s homeless. As has been found for the general 

population, some childhood risk factors are strongly associated with Veteran homelessness,15

but the limited evidence available suggests that these risk factors are no more prevalent among 

Veterans than among the general population. Veterans as a group appear to actually be at 

decreased risk for some exposures associated with homelessness in the general population.

In bivariate analysis, Rosenheck and Fontana (1994)15 found an increased risk ratio for 

homelessness for those who had been in foster care, but only 0.7 percent of their sample 

had experienced such care. Their structural equation model also found that childhood abuse, 

childhood trauma and psychiatric treatment before age 18 were all significantly associated with 

homelessness, but they did not report how the prevalence of these exposures compared with 

prevalence in the general homeless population.15 Tessler, Rosenheck and Gamache55 found that 

while pre-military misconduct and childhood family instability were both significantly more 

prevalent among younger cohorts of homeless Veterans compared to older cohorts, overall, 

Veterans were significantly less likely than the general homeless sample to have experienced 

either exposure.

In terms of protective factors, Tessler, Rosenheck and Gamache found that homeless Veterans 

were likely to be slightly (on average < 1 year) more educated than homeless non-Veterans,55

a finding similar to that of Rosenheck and Koegel’s earlier study.42 This is consistent with the 

finding that education may be protective against homelessness within Veteran populations, as 

was found by Washington, Yano and McGuire’s36 small single-site study comparing currently 

housed and non-housed female Veterans.

Studies examining whether Veterans as a group possess better social support than the general 

population have produced mixed results, which is likely due, in part, to poor consensus on how 

to define and measure social support. Marital status is the most common measure of social 

support, and findings with regard to marriage suggest that homeless Veterans are more likely than 

homeless non-Veterans to have ever been married.42, 55 More centrally, the validity of marriage 

as a useful measure of social support has been questioned; more nuanced and better validated 

measures such as the Medical Outcomes Study (MOS) Social Support Survey 56 or Lin’s Strong 

Ties Measure57 would strengthen any findings regarding this risk factor. The NVVRS employed a 

richer definition of social support, but its findings did not report differences in pre-military social 

support between overall Veteran and comparison general population.

Rosenheck and Koegel42 used data from three surveys of homeless service users in 1986-1987 to 
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investigate differences between Veteran and non-Veteran homeless men, and found no significant 

differences in risk factors associated with physical or psychiatric illness; homeless Veterans were 

more likely to have been treated in the past for alcohol problems, but the authors suggest that this 

is likely an artifact of greater access to care through VA services. Though these findings are now 

dated and ideally should be tested against findings from a more current sample, there is to date 

no study to contradict Rosenheck and Koegel’s conclusion that “veterans appear to be at risk for 

homelessness for much the same reasons as other American men.”42

While Veterans thus appear to be at risk for homelessness for much the same structural reasons 

as other Americans, there are qualitative differences in their pathways of exposure which warrant 

further research. The influence of unique exposures (such as combat exposure or MST) on more 

proximate, shared exposures (such as poor mental health) requires research designed specifically 

to investigate this topic further.

Prolonged or Intense Combat Exposure Indirectly but Substantially Increases the 

Risk of Homelessness 

Two studies that investigated homelessness outcomes in relation to exposures to hypothesized 

military service risk factors were identified: Rosenheck and Fontana15 and Washington, Yano 

and Macguire.36 Rosenheck and Fontana looked at pre-service, military service (combat 

exposure and participation in atrocities), and post-service experiences as risk factors for Veterans 

serving during the Vietnam War era; Washington and colleagues examined military and other 

sexual trauma among female Veterans of several eras. Rosenheck and Fontana’s data allowed 

for a division of the sample into ever-homeless and never-homeless, while Washington and 

colleagues did not collect data on past housing status and, in fact, noted in their results that much 

of their housed population might be at risk for homelessness due to common characteristics. 

This difference in how “homelessness” was defined may account for some of the differences 

in their findings, as may the fact that Rosenheck and Fontana’s study included only men and 

was conducted nearly two decades before Washington and colleagues’ study, which included 

only women. Both studies were observational, cross-sectional studies which could not examine 

causality, although Rosenheck and Fontana’s structural equation model allowed for modeling 

of temporal relationships among some variables. A longitudinal study collecting baseline data 

prior to military service and tracking individuals through time to determine ever/never homeless 

outcomes would contribute greatly to the evidence base in this area.

No study identified in our review found a direct significant association between prolonged/

intense combat exposure and homelessness.The definition of prolonged or intense combat 

exposure has varied, which increases the difficulty in evaluating existing evidence. The NVVRS 

examined both intensity and duration of combat.44 It also found an association between PTSD 

and lower military pay-grade, which Seal49 used as part of a proxy definition for combat exposure 

(along with branch of service and single vs. repeat deployment). Rosenheck and Fontana15 found 

no direct association between homelessness and intense combat exposure, but they found direct 

effects of combat exposure on non-PTSD psychiatric illness (schizophrenia was not assessed), 

substance abuse, not being married, and low social support after discharge, all of which were 

associated with homelessness. They did find a weak association between homelessness and 

“participation in wartime atrocities,”15 a uniquely regrettable military exposure; this measure 
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has not been replicated by other studies. Research primarily comparing Vietnam-era and postVietnam era Veterans has found that Veterans most at risk for homelessness are in the age cohorts 

least likely to have served in combat.58 Long-term, longitudinal research involving Veterans 

from OIF and OEF should be undertaken to reassess the role of combat and its associated risk 

for homelessness.The recent development of the Deployment Risk and Resilience Inventory 

(DRRI)59 provides a multi-scale inventory capable of capturing data on more nuanced aspects 

of combat experience and associated stress, and which has been validated for use with OIF 

Veterans. Future research should consider the use of this inventory.

As previously mentioned, however, risk factors for homelessness rarely occur in isolation. 

For this reason, the conceptual attempt to understand Veteran homelessness requires 

acknowledgement of synergistic effects that may occur after exposure to multiple direct or 

indirect risk factors.

Combat’s Impact on Mental Health

Clearly, not all mental health problems experienced by Veterans are related to their military 

service. Despite pre-service screening, some military service members will enter the military 

with mental health problems that may or may not be known at the time. As already discussed, 

childhood trauma, which frequently leads to mental health problems, has been shown to increase 

the risk of homelessness in both Veteran and general populations. Similarly, Rosenheck and 

Fontana’s15 finding that psychiatric treatment of any kind before the age of 18 increased the risk 

of homelessness among the 0.7 percent of Veterans in their sample receiving such treatment 

suggests that, for the small population affected, pre-existing mental health problems are likely 

to exert a significant and diverse influence on their well-being. Our focus here, however, is on 

mental illness that is more directly linked to military service, the best-studied example of which 

is combat-related PTSD. Estimates of lifetime PTSD expression within Veteran populations vary, 

but one recent national study of OEF/OIF Veterans entering VA care found a prevalence of 21.8 

percent for PTSD, a notable portion of the 42.7 percent with any mental health diagnosis.49

PTSD, it should be noted, is more prevalent in the general population than is often assumed, 

and as one study60 of incarcerated Veterans found, combat exposure may not be the type of 

trauma most strongly associated with developing PTSD, even among Veterans. As the literature 

on PTSD expands, there is an increasing acceptance that, at least in some cases, psychosocial 

context – the daily stresses individuals encounter – may be as important to the expression of 

PTSD symptoms as the severity of the original trauma.61 Keeping these caveats in mind, several 

studies have consistently found an association between prolonged or intense combat exposure 

and an increased risk of a PTSD diagnosis, PTSD symptoms, and/or anxiety or depression, 

even when controlling for predisposing factors. The NVVRS report44 as well as Rosenheck and 

Fontana’s study based on the same data set15 both found PTSD more prevalent among those 

who had served longer tours of duty and who reported higher “war zone stress” as measured by 

a variety of traumatic exposures. An association between combat exposure and PTSD has also 

been found by a longitudinal study that looked at twin pairs with discordant Vietnam theater/

era service,45, 46 as well as cross-sectional studies of mixed Veteran cohorts receiving VA primary 

care47, active duty and reserve Iraq Veterans48, 49 and combined Iraq/Afghanistan National Guard 

Veterans returning for a repeat deployment.50
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However, the evidence linking PTSD to homelessness remains limited by the small number, 

small size and/or non-generalizable sampling methods of existing studies. Positive PTSD 

screening was found to be associated with homelessness by Washington, Yano and McGuire36

but not by Rosenheck and Fontana,15 where the authors concluded that PTSD’s effect was likely 

to be accounted for by other psychiatric disorders with which it shared variance.15 In general, 

analysis of the association between mental illness and Veteran homelessness is limited by the 

inconsistency of mental health conditions assessed across and within studies. For example, 

Washington, Yano and McGuire36 found an association between positive PTSD/anxiety disorder 

screening and homelessness, but not positive depression screening or problem alcohol use, and 

schizophrenia was not assessed. The NVVRS did not assess participants for schizophrenia, a 

condition associated with homelessness in the general population.15 Perhaps not surprisingly, 

given that the study’s sample was of men seeking care for mental health issues, Tessler, 

Rosenhack and Gamache55 did not find any significant difference between the Addiction Severity 

Index (ASI)-Psychiatric scores of Veteran and non-Veteran homeless men.

As several authors of the studies reviewed noted, the existential challenges of life as a homeless 

person are likely to negatively impact an individual’s mental health, so cross-sectional studies 

of the prevalence of mental illnesses among the homeless are unlikely to provide definitive 

evidence on the extent to which mental illness affects one’s risk for homelessness. There is 

consistent evidence from research on the general homeless population that indicates mental 

illness (schizophrenia, bipolar disorder, and depression) is associated with homelessness, 

including the duration of homelessness.19, 62-64 There is some disagreement, however, as to 

whether mental illness itself increases the risk of homelessness.65

Combat’s Impact on Income and Employment

While an association between unstable employment and/or low income and homelessness seems 

intuitive, few studies have examined the strength of these associations within Veteran homeless 

populations. Washington, Yano and McGuire36 found that among female Veterans, homelessness 

was associated with being unemployed and being disabled. Rosenheck and Fontana15 did not 

include NVVRS data on post-deployment employment, disability, or income in their analysis and 

so could draw no conclusions.

In a study analyzing data from multiple waves of the Panel Study of Income Dynamics between 

1968 and 2003, MacLean51 found that combat exposure (not further defined by intensity or 

duration) increased the rates of disability and unemployment among Veterans compared to noncombat Veterans, both in their early working years and throughout life. MacLean’s analysis 

suggested a direct cumulative disadvantage effect that negatively affected combat Veterans 

regardless of pre-military service characteristics such as education. In contrast, Resnick and 

Rosenheck’s66 study of 5,862 male Veterans participating in a vocational rehabilitation program, 

the majority of whom reported being homeless, found that service in a theater of operations was 

associated with better chances of employment at program discharge. However, Veterans with 

PTSD or other severe mental illness were found to have less successful employment outcomes 

(fewer days worked), a finding consistent with other studies which have found negative 

correlations between severity of PTSD symptoms and wage levels/full-time employment44, 47, 67, 68

and between PTSD diagnosis and stability of employment.44
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Combat’s Impact on Social Support

As among the general homeless population, low social support, though inconsistently defined, 

has been associated with Veteran homelessness. Rosenheck and Fontana15 found that low 

social support in the year after discharge from the military had the strongest direct effect 

on homelessness risk. In bivariate analysis, the separate measure of not being married was 

also associated with an increased risk of homelessness, although the study design could 

not investigate whether homelessness preceded or followed not being (currently) married. 

Washington, Yano and McGuire36 found that among female Veterans, marriage (a narrow but 

common measure of social support) was protective against homelessness.

Social support is a complex construct, and there is considerable academic discussion about 

the mechanisms through which social support actually makes a difference in people’s lives, 

and what kinds of support matter most. Social support is by its nature located both within the 

individual’s personal relationships (who may be married, have strong family ties, etc.) and the 

society around him or her (which may provide more institutional avenues for social support);

when it is extended to consider one’s relational position within society, and the opportunities for 

more institutional support, this is often conceptualized as social capital.69, 70 All of the Veteran 

specific research studies identified defined social support predominantly in terms of individual 

relationships, with less attention paid to social capital/social support at the level of social 

institutions. None of the studies reviewed specifically investigated what type of social capital is 

most likely to provide support for homeless Veterans to move out of homelessness.

The only study identified which directly assessed associations between combat exposure and 

social support was the NVVRS,44 which found an association between high war-zone stress 

(intense combat exposure) and poor family functioning, as well as more frequent divorce or 

marital problems. Several Department of Defense and other government agency reports have 

expressed concern at the impact that repeat or lengthy deployments may be having on the mental 

health of OEF/OIF troops,71, 72 but this concern has been poorly translated into research on the 

psychosocial difficulties of post-deployment life. Some of the findings from the studies reviewed 

suggest that poor social support may also be associated with worse employment outcomes,66

though the direction of the relationship is not clear. PTSD remains better researched than (re)

adjustment disorders or employment difficulties, so the literature on PTSD provides the best 

source of data on combat’s influence on social support.

Prolonged combat exposure increases the risk of developing PTSD, which the NVVRS found to be 

associated with extreme isolation and extreme unhappiness.44 More recent studies have found an 

association between PTSD and poorer emotional well-being and poorer social functioning among 

Veterans.73 A 2008 literature review74 cited numerous studies finding PTSD negatively impacted 

family functioning, but its references to Veteran-specific literature were limited in both number 

and strength of findings. In contrast, Magruder and colleagues47 did not find any association, in 

their random sample of male primary care patients at two VAMCs, between PTSD and social 

support (as measured by living alone or with someone). Rosenheck, Leda and Gallup,75 in 

their analysis of 1988-1989 data from homeless male Veterans seeking residential treatment or 

intensive case management for mental illness, did not find any significant association between 

Veterans with “combat stress” (a measure defined using PTSD diagnostic criteria) and social 
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adjustment as measured by marriage, employment or justice system history. However, the 

authors pointed out that this was likely to be a result of their sampling limitations, and that 

compared to the general population of Veterans at the time, the entire sample exhibited “severe 

social and vocational problems,” suggesting the underlying impact of mental illness on multiple 

intermediate outcomes that might increase the risk of homelessness.

Some Exposures, Like Alcohol/Drug Abuse and Low Social Support, That 

May Increase Risk of Homelessness Frequently Emerge During Service or the 

Readjustment Period

Drug and/or alcohol abuse, though widely studied and popularly accepted as risk factors for 

homelessness, have not been consistently shown to increase the risk of homelessness among 

Veterans. There is limited evidence suggesting that alcohol and drug use increase the risk of 

homelessness, but there are many potential confounding factors. While exposure to these risk 

factors is not intrinsic to military service, evidence suggests that military culture and/or the 

inherently disruptive nature of military service tours increase the likelihood of negative outcomes 

for both alcohol/drug abuse and social support. These weak associations with the onset of 

alcohol/drug abuse and low social support post-service explain why “military service” in general 

is included in the conceptual model, even though in other ways (through employment and 

educational training, for example) military service may provide protection against homelessness.

A higher prevalence of problem alcohol use has been shown among Veterans compared to the 

general populations. Kulka et al. found that 40 percent of male Veterans had abused alcohol for 

some period in their lives, compared to 25 percent among male civilians.44 While results varied 

by race and sex, the general finding of the NVVRS was that problem alcohol and substance use, 

though higher among both male and female Veterans than among the general population, was not 

higher among male Vietnam theater Veterans compared to male Vietnam era Veterans.44 More 

recently, Erbes and colleagues, examining a small, self-selecting sample of OEF/OIF Veterans 

enrolling at a VAMC, found 27 percent reported current (as opposed to lifetime) hazardous 

drinking practices.73

Bray and Hourani52 analyzed data from cross-sectional Department of Defense surveys of active 

duty service members conducted regularly between 1980 and 2005. Their analysis found that, 

despite earlier declines in heavy drinking in 2005, more than one in six active duty personnel were 

likely to be heavy drinkers.52 These findings lend support to concerns cited by the authors that 

military culture, in contrast to its attitudes towards smoking and illicit drug use, remains permissive 

of problem alcohol use; the influence of this experience while in the military may shape postservice behavior. Arguably, rates of alcohol and drug use among active duty service members might 

reflect usage in the general population in their age cohort, especially for younger cohorts among 

whom substance use is generally believed to be highest. However, Bray and Hourani’s analysis 

did control for socio-demographic trends on substance use and still found no decline.52 More 

significantly, Jacobson and colleagues conducted a longitudinal study that collected baseline and 

post-deployment data on alcohol use, and found that the Reserve and National Guard personnel 

and younger service members who deployed with combat exposures were more likely to develop 

new problem alcohol use during the post-deployment period, and that this risk was greatest among 

those also diagnosed with PTSD or PTSD and depression.53 This finding suggests an alternate 
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concern: that problem alcohol use may be related not just to the immediate stresses or “culture” 

of military service but also to its after-effects. Rosenheck, Leda and Gallup75 using data from 

homeless male Veterans seeking residential treatment in the late 1980s, had previously found an 

association (p<.02) between “combat stress” – defined by Diagnostic and Statistical Manual of 

Mental Disorders, Fourth Edition (DSM-IV) PTSD symptoms – and alcohol problems, along with 

a marginally significant association between combat stress and substance use. Similarly, Benda’s 

(2006) study of Veterans seeking domiciliary care for substance abuse found a negative association 

between PTSD severity and the length of time before readmission. All of these findings highlight, 

again, the inter-connection of potential risk factors.

However, the evidence on the association between alcohol and/or drug use problems and 

homelessness is limited. Rosenheck and Fontana’s analysis of NVVRS data15 found that 

substance abuse, particularly alcohol abuse, had a direct effect on risk of homelessness. Tessler, 

Rosenheck and Gamache55 found that homeless Veterans scored significantly higher on the 

ASI-Alcohol score than homeless non-Veterans, suggesting that alcohol problems may be more 

common to the experiences of homeless Veterans. The study found no significant difference in 

mean ASI-Drugs scores in the two populations, but did find younger Veteran cohorts (those born 

after 1953) scored significantly higher on the ASI-Drugs score than did older cohorts. Age is only 

one factor that may be of relevance in understanding differences in risk related to substance use 

within the homeless Veteran population. The NVVRS, for example, found that drug and alcohol 

abuse problems were most pronounced among Hispanic combat Veterans,44 and another study 

that focused on homeless Native American Veterans76 found they were more likely than other 

homeless Veterans to have an alcohol use problem, but less likely to have drug use problems (or 

a psychiatric diagnosis). Leda, Rosenheck and Gallup77 found, among their sample of homeless 

mentally ill Veterans seeking treatment, that substance abuse diagnoses were less common 

among women than among men. Benda78 found that, among a random sample of homeless male 

Veterans seeking domiciliary care, combat exposure was on a par with alcohol and drug abuse as 

a predictor for readmission for substance abuse treatment (HR 1.56-1.97 CI, p<.01); the female 

sample did not have sufficient combat exposure to test this association, but as Benda suggests, 

this is likely to have changed as more women are exposed to combat-like conditions.78

Military Sexual Trauma (MST) May Place Veterans at Increased Risk of 

Homelessness

Awareness of the problem of MST has increased dramatically in the past decade,79 although 

evidence indicates that sexual harassment and assault, especially, but not only, directed against 

female service members occurred in earlier eras of service as well. A 1999 study of female VA 

outpatients found military sexual assault was reported by 23 percent of respondents;80 another 

study from the 1990s of inpatient and randomly selected outpatient female Veterans at one 

VAMC similarly found that 14 percent of female Veterans under age 50 reported attempted rape 

during military service.81 Kimerling’s analysis of data from over 125,000 OEF/OIF Veterans, 

who are now routinely screened for MST, found a prevalence of 15.1 percent positive MST 

screening among women and 0.7 percent positive screening among men.82

The only study to date which has examined the association between MST and homelessness 

is Washington, Yano and McGuire’s study of housed and non-housed female Veterans in the 
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Los Angeles area.36 That study found that sexual assault during military service was associated 

with Veteran homelessness. Kimerling did not look at housing outcomes, but found significant 

associations between positive MST screening and PTSD diagnosis, other anxiety disorders, 

depression, adjustment disorder, substance disorder or alcohol disorder.82 Benda’s study 

constructed hazard models which indicated that sexual and physical abuse, regardless of when 

they occurred (in childhood or adulthood, during or after military service), were stronger 

predictors of readmission to substance abuse treatment for homeless female Veterans than for 

homeless male Veterans, who rarely reported military sexual or physical abuse.78 Hankin and 

colleagues found that female Veterans who reported having ever experienced sexual assault were 

twice as likely to report current alcohol abuse and three times as likely to report symptoms of 

depression.80 A 2003 literature review83 studied mental service utilization among female Veterans 

and concluded that sexual trauma, whether service-related or not, was associated with PTSD. 

Murdoch and Nichol found that sexual harassment while in the military – which was experienced 

by 90 percent of female Veterans under age 50 in the sample – was significantly associated with 

an increased risk of anxiety, depression, and poorer general health on three different measures, 

all of which could contribute cumulatively to increased risk for homelessness.81

Sexual and physical abuse are probably under-reported both inside and outside of military settings, 

and given the fact that non-military related sexual abuse cannot be service-connected, there is 

an especial risk that it remains under-reported among Veterans.83 It has been argued that female 

Veterans suffer from higher rates of PTSD than male soldiers and have experienced higher rates 

of sexual assault than the general population.16 Experience with sexual assault has been linked to 

PTSD, depression, alcohol and drug abuse, disrupted social networks, and employment difficulties, 

all factors known to increase one’s risk for homelessness.16 The possibility that there is a cumulative 

effect of abuse on an individual’s resiliency or well-being, coupled with poor confidence in rates of 

reporting, make it difficult to determine to what extent MST acts as an independent risk factor for 

homelessness. Given the range of associated outcomes, it may be that MST, like combat exposure, 

exerts greater influence on intermediate outcomes than on homelessness itself. Further research into 

the extent of MST’s association with these outcomes is recommended.

KEY QUESTION #4. What is the relationship between incarceration 

and homelessness among Veterans?

After a steady rise in the number of Veterans in prison since 1985, the number, which peaked 

at about 153,100 in 2000, had declined by about nine percent to 140,000 by 2004.84 The age 

adjusted incarceration rate for Veterans, which accounts for the older distribution of the Veteran 

population when compared to the general population, is about 1,253 per 100,000 or about 10 

percent lower than the rate for non-Veterans. An older study of mentally ill Veterans found 

15.7 percent had an incarceration history.85 A more recent national study found three percent of 

Veterans were incarcerated.86

Incarcerated Veterans were more likely to have committed violent offenses than the incarcerated 

non-Veteran population.84 Over half of Veterans serving in state prisons (57 percent), but fewer 

than half of non-Veterans (47 percent) were in prison for violent offenses. While about 20 

percent of non-Veterans were incarcerated for homicide (12 percent) or rape/sexual assault (9 
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percent), over a third of Veterans were serving sentences for homicide (15 percent) and rape/

sexual assault (23 percent). A similar pattern is found for active-duty personnel held in military 

prison. In 2004, 46 percent of all inmates in military custody were incarcerated for violent 

offenses, with rape or sexual assault being the most common reason for incarceration, accounting 

for 29 percent of inmates in military prisons.84

Incarcerated Veterans have also been found to have higher rates of drug abuse,85, 87-89 treatment 

for mental health disorders,85-87 and PTSD87 than unincarcerated Veterans. On the other hand, 

incarcerated Veterans have comparable rates of alcohol abuse and mental health disorders, and 

lower rates of drug use than incarcerated non-Veterans.84

Finally, while Veterans in federal prison were twice as likely to be White, non-Hispanic (49 

percent) as non-Veterans (24 percent), incarceration patterns for Veterans showed the same 

types of racial and ethnic disparities in imprisonment as in the general population. While the 

2005-2007 American Community Survey estimated that 82 percent of Veterans were White, nonHispanic, 10 percent Black, and 5 percent Hispanic in 2004; 49 percent of Veterans in federal 

prisons were White, non-Hispanic, 38 percent were Black, and 5 percent were Hispanic. In state 

prisons 54 percent of Veterans were White, 32 percent Black, and 6 percent Hispanic.84

Incarceration and Homelessness

In a review of the literature on incarceration and homelessness, Metraux and colleagues note the 

demographic similarities between homeless and incarcerated populations – both are typically 

poor, uneducated, and minority populations with few job skills – and suggest a bi-directional 

association between homelessness and incarceration.90 They found that about 10 percent of 

those entering prison have a recent history of homelessness, and that at least 10 percent of those 

leaving prison experience some period of subsequent homelessness. In reviewing studies of the 

homeless, they found that as many as 20 percent of the adult homeless population is likely to 

have some lifetime experience of incarceration.

Metraux et al. found in their review of the literature that inmates of local jails, as opposed to 

state or federal prison inmates, had a cyclic pattern of homelessness and incarceration leading 

to prolonged residential instability. In contrast, because prisons are often located remotely from 

inmates’ local communities, social ties that may be necessary to support successful integration 

upon release are often disrupted. Inmates of prison, therefore, are more likely to become 

homeless within 30 days of release.90

In exploring the factors associated with homelessness among the incarcerated, their review found 

shelter use prior to incarceration to be the strongest predictor of shelter use upon re-entry from 

prison. Other factors found to be associated with homelessness among the incarcerated include:

• Ineffective discharge planning: Prisons are generally remote from the communities to 

which prisoners will be returning, making access with local service agencies difficult;

• Legal and regulatory restrictions: Many laws limit access to public housing, drivers’ 

licenses, and eligibility for government financial support programs;

• Full sentencing laws: Laws requiring sentence completion mean fewer prisoners are 
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released on parole and probation, eliminating a source of support and supervision during 

the period of re-integration into the community; and

• Financial instability: Loss of job skills and reluctance of employers to hire former 

convicts can make it difficult to earn enough to make rent payments.90

In addition to factors that put prisoners at risk for subsequent homelessness, the review points to 

the “criminalization” of many of the activities of the homeless as factors increasing their risk for 

incarceration. This leads to what the review describes as an “‘institutional circuit,’ where a series 

of institutions provide sequential stints of housing in place of a stable, community-based living 

situation.”90

Legal and Regulatory Barriers

A recently updated report by the Legal Action Center, After Prison: Roadblocks to Reentry,

91

describes the barriers faced by people with criminal records. Particularly for those with drugrelated offenses, these barriers include restrictions on driving, limits on access to public 

assistance programs, and limits on access to public housing. Several studies have pointed to the 

impact of child support requirements on incarcerated parents, noting that incarcerated parents 

with child support obligations on average owe $10,000 upon entering prison, and owe on average 

$20,000 when released.92, 93 Minimum wage workers have little hope of making the typical 

monthly payment obligations of from $225 to $300 per month, often leading to further financial 

and legal difficulties. This problem is of particular relevance noting that in the most recent 

CHALENG report, legal assistance for child support was ranked as the second highest unmet 

need of responding homeless Veterans.26

Studies of Homelessness and Incarceration among Veterans

Very few studies have specifically investigated homelessness and incarceration in the Veteran 

population. The most salient feature of the literature is its sparseness. However, those few 

studies support the broader evidence that suggests that homelessness and incarceration have a 

bi-directional relationship.90 Homelessness, through the criminalization of the activities of daily 

living while homeless, such as panhandling, vagrancy, trespassing, and public urination; and 

through criminal activities taken on either to cope with homelessness, such as alcohol and drug 

use, or to survive, such as stealing and prostitution, often leads to incarceration. Conversely, 

incarceration, by its separation from home communities and through legal restrictions on reintegration with those communities, often puts individuals at risk for homelessness upon release.

A 2003 study assessed whether substance abuse and psychiatric illness are related to offenses, 

and attempted to identify the strongest predictors of and protective factors against criminal 

offenses among homeless Veterans with substance abuse problems (n = 188).94 Measures 

included the Addiction Severity Index (ASI); the Multi-Problem Screening Inventory (MPSI); 

the Multidimensional Scale of Perceived Social Support; the Self-Efficacy Scale; and the Ego 

Identity Scale. Respondents were found to be representative of the population from which 

they were drawn. Half were White, about 40 percent were Black, and most had lived in a rural 

area during adolescence; and there were high levels of depression and suicidality. One-third 

(33 percent) reported no offenses in the past year and 41 percent reported committing multiple 
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offenses. Alcohol abuse (OR = 2.04, 95% CI = 1.80, 2.30), drug abuse (OR = 3.57, 95% CI = 

3.01, 4.05), and number of prior psychiatric hospitalizations (OR = 1.27, 95% CI = 1.15, 1.39) 

were significantly associated with committing a crime in the past year, while depression and 

suicidal thoughts were not. In a separate analysis, those sexually abused before age 18 were 

two and a half times more likely to have committed a crime in the past year (OR = 2.50, 95% 

CI = 2.33, 2.70). On the other hand, those with a strong sense of self-efficacy, resilience, or 

ego-integrity were significantly less likely to have committed a crime in the past year (OR = 

0.28, 95% CI = 0.17, 0.41; OR = 0.32, 95% CI = 0.20, 0.47; OR = 0.48, 95% CI = 0.40, 0.58, 

respectively). Those who reported usual, full-time employment in the previous three years were 

about half as likely to have committed a crime in the previous year (OR = 0.46, 95% CI = 0.30, 

0.61) and higher levels of education were associated with lower likelihood of committing a crime 

(OR = 0.57, 95% CI = 0.43, 0.71). The authors suggest that in homeless Veterans who abuse 

substances, co-morbid mental health problems may increase the likelihood of incarceration; but 

that even among this population, a strong sense of self-efficacy, resilience, and ego-integrity can 

reduce the likelihood of incarceration.94

A study of patients with serious mental health disorders recruited from a VA mental institution 

found that lifetime homelessness was most strongly associated with lifetime history of 

incarceration (OR = 4.36, 95% CI = 2.73, 6.94) but was also associated with lower levels 

of treatment adherence (OR = 0.80, 95% CI = 0.66, 0.96 ); that recent homelessness (in the 

previous four weeks) was strongly associated with recent incarceration (OR = 26.41, 95% CI = 

5.23, 133.4); and those who had any lifetime experience of homelessness were four times more 

likely to have a lifetime history of incarceration (OR = 4.24, 95% CI = 2.67, 6.71). While the 

authors note that these findings suggest a strong bi-directional association of homelessness and 

incarceration, the findings may not be generalizable beyond VA patients with bipolar disorders.95

A small study (n= 62) evaluated self-selected, mentally ill Veteran inmates who were either 

homeless at the time of arrest or anticipated being homeless after release.96 Most were Black 

(74 percent) and unmarried (89 percent). Over a quarter (26 percent) were homeless at the 

time of arrest, and three-quarters (75 percent) had had a prior episode of homelessness. Nearly 

all subjects (94 percent) reported a prior arrest and 73 percent were being detained on felony 

charges. The primary psychiatric diagnoses were schizophrenia (37 percent), mood disorders (35 

percent), PTSD (5 percent), adjustment disorders (5 percent), and pedophilia (3 percent). Eightythree percent reported either a diagnosis of substance abuse disorder or significant problems with 

alcohol and drugs, and 76 percent reported a history of prior psychiatric hospitalization. The 

authors suggest the study shows that large urban jails may be useful locations for outreach to 

mentally ill, homeless Veterans.96

Jail Diversion Programs for Veterans

Because of the strong association between homelessness and incarceration, interventions that 

divert offenders from prison have been seen by some as promising approaches both to limit 

the direct negative effects of incarceration and to mitigate the association of incarceration with 

subsequent homelessness. The literature on diversion programs specifically targeting Veterans 

is very sparse, as such programs are relatively new. However, more general diversion programs 

have a long history dating back to the 1970s, and there is a large body of literature both 
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describing and evaluating the effectiveness of these programs. A comprehensive and systematic 

review of that literature is beyond the scope of this review. However, because of the potential 

importance of these programs in addressing issues of homelessness, we provide a brief overview 

of the various types of diversion programs that have been developed.

Broadly, diversion programs fall into two categories, pre-booking vs. post-booking diversion. 

In pre-booking programs, individuals are diverted prior to arrest, often through the discretion 

and decision of specially trained police. In post-booking programs, individuals are diverted after 

arrest but before prosecution and incarceration, and the program is generally overseen by the 

court. This review will focus on post-booking programs, as they are generally the more formal 

programs and the better-studied.

Post-booking programs operate either out of standard criminal courts or out of specialty courts that 

target specific types of offenders such as the mentally ill, drug users and, more recently, Veterans. 

Early diversion programs focused on diverting mentally ill offenders from jail and towards 

treatment options with a goal to reducing jail time and recidivism, and providing effective mental 

health treatment. In an early survey of jail diversion programs for the mentally ill, Steadman 

and colleagues provided a definition of jail diversion programs as “specific (formal or informal) 

programs that screen defined groups of detainees for the presence of mental disorder; use mental 

health professionals to evaluate all those detainees identified in the screening; and negotiate

with prosecutors, defense attorneys, community-based mental health providers, and the courts to 

produce a mental health disposition outside the jail in lieu of prosecution or as a condition of a 

reduction in charges (whether or not a formal conviction occurs)” (italics in the original).97

In 1995, the SAMHSA established the National GAINS Center as a locus for the collection 

and dissemination of information on effective mental health and substance abuse programs for 

individuals with co-occurring disorders who come into contact with the justice system (web site 

at: http://gainscenter.samhsa.gov/html). Between 2002 and 2007, through its Center for Mental 

Health Services (CMHS), SAMHSA provided Targeted Capacity Expansion (TCE) grants to 

support the development of evidence-based jail diversion programs. This funding only supported 

programs that operated out of traditional court programs; funding could not support programs 

operating out of specialty courts. With recognition of the increasing number of combat Veterans 

returning from overseas with PTSD and of the associated risk for involvement with the criminal 

justice system, in 2008, CMHS began funding a Jail Diversion and Trauma Recovery Program 

to support implementation and expansion of jail diversion programs specifically for individuals 

with PTSD and other trauma-related disorders, providing prioritized eligibility for Veterans. 

Since 2008, CMHS has awarded 13 grants through this program. All programs have specific and 

similar requirements for program evaluation and standard data elements for collection.

A national multi-site evaluation of the programs funded through the TCE grants found mixed 

results among the programs and overall. The most consistent effect was an increase in service 

utilization, with diversion being associated with increases in counseling, mental health 

hospitalizations, emergency room use, and use of mental health medications. However, this effect 

was found, in general, to decrease in time with service utilization, being lower at the 12-month 

follow-up period than at three months. In addition, while differences in access to and quantity 

of treatment were significant, treatment intensity in both groups, diverted and non-diverted, 
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were low.98 Findings were mixed for changes in drug and alcohol use, with some sites showing 

decreased use while others showed increased use for both drug and alcohol use, and there was 

little evidence of effectiveness on mental health outcomes or quality of life. Across all sites, 

diversion programs resulted in significant increases in days at risk (not institutionalized) and days 

in the community, and fewer days in jail. However, there was no change in recidivism.

The findings from this study are consistent with the findings of other studies and reviews.99-103

Some care should be taken in interpreting these findings as studies varied in quality and there 

was substantial variation in the characteristics of the programs evaluated. Nevertheless, the 

lack of significant findings on a number of outcomes and the consistency of findings related to 

criminal justice outcomes suggests that what biases there were likely did not act to overestimate 

the effectiveness of these programs. If true, these findings suggest that while diversion programs 

may not be effective in treating the mental health needs of the participants, that from a public 

policy and safety perspective, diversion programs can lead to reduced days in jail and increased 

days in the community without increasing risks for public safety.

Finally, with regard to issues related to homelessness, one evaluation of these same programs 

found that consistent housing throughout the 12-month study period was the factor most strongly 

associated with post-enrollment arrests. The only other factors significantly associated with no 

vs. any post-enrollment arrest was prior arrests and number of prior jail days.99 These findings 

underscore the importance of stable housing for successful diversion programs.

Mental Health and Drug Courts

While many of the earlier programs and their evaluations were limited to diversion programs 

overseen by the traditional court system, later programs, in an attempt to enhance program 

effectiveness, developed a model of specialty mental health and drug courts which sought to bring 

together the experts and resources needed for effective oversight and treatment of these detainees. 

In his review of studies of diversion programs for persons with mental illness, Sirotich101 looked 

at six studies in which diversion programs were overseen by mental health courts. Similar to 

the findings for non-specialty courts, Sirotich found inconsistent results among the programs 

supervised by mental health courts, with the most consistent finding being that divertees showed no 

increase in the number of jail days relative to those not diverted; two studies reported a decrease in 

jail time for mental health court participants but not for those receiving treatment as usual; and two 

studies reported no change in jail time for either group.101 Finally, in a review of drug court effects 

on recidivism, Wilson and colleagues found offenders participating in drug courts less likely to reoffend than those treated with traditional justice programs.104 That review found weak evidence that 

effectiveness varied by the specific drug court model employed. Programs that dismissed charges or 

expunged records appeared to be more successful than those in which the incentives for successful 

completion were more ambiguous. Programs that used a single treatment provider appeared slightly 

more successful than those providing treatment by multiple providers. Regardless of model, studies 

were inconclusive as to whether effectiveness would persist after the individual left the program.

Veterans Courts

Noting an increase in the number of Veterans appearing in court for criminal offenses often related 

to substance abuse and mental health disorders, and building on the models of mental health and 
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drug courts, a number of jurisdictions have begun to develop Veterans Courts. The first such court 

was established in Anchorage, Alaska in 2004105 to provide an alternative to jail time for Veterans 

charged with misdemeanors. In 2009, Judge Robert T. Russell described the 10 Key Components 

of the Veterans Treatment Court of Buffalo, New York, which was established in January 2008. 

These components were modeled on the key components of drug courts as described by the U.S. 

Department of Justice.106 As noted above, it was about that time that SAMHSA began funding 

to support Jail Diversion and Trauma Recovery Programs with priority for program eligibility 

given to Veterans. That program now provides support and technical assistance to programs in 13 

states, including Colorado, Connecticut, Georgia, Illinois, Massachusetts, and Vermont (funded in 

2008); Florida, North Carolina, New Mexico, Ohio, Rhode Island and Texas (funded in 2009); and 

Pennsylvania (funded in 2010). Veterans Courts have also been established in Tulsa, Oklahoma 

and Nevada; and California law allows the court to grant special consideration to anyone who 

alleges that he or she has committed an offense as a result of sexual trauma, traumatic brain injury, 

PTSD, substance abuse, or a mental health problem as a result of military service.107 In addition, 

a Department of Veterans Affairs Information Letter reported that as of April 2009 more than one 

third of VAMCs indicated that they currently engaged or intended to engage with local justice 

system partners to coordinate services for justice-involved Veterans.108 Likely because these 

programs are new, we have found no studies evaluating their effectiveness.

Veterans leaving prison are at high risk for homelessness because of the many social and legal 

barriers to re-integration. That makes prisons a good place to do outreach to Veterans at risk 

for homelessness. However, to address the problem will require a multi-modal approach that 

brings together the corrections agencies responsible for releasing the Veteran, the justice system 

responsible for parole or probationary oversight, the mental health system in the community 

where the Veteran will be released to help address any psychiatric and substance use problems, 

the local VA and Veterans Health Administration (VHA) agencies, and the local housing agencies 

to help link the Veteran to housing or supportive housing as needed. This will require not only 

developing new collaborative approaches, but also sponsoring research on ways in which these 

collaborations (and which types of collaborations) can most effectively reduce the likelihood of 

homelessness upon re-entry, including developing a better understanding of how to identify those 

most at risk for homelessness post-release.

Conversely, homeless Veterans are at risk for imprisonment because of the criminalization of the 

activities of daily living while homeless, and as a result of activities to help cope and survive while 

homeless. To break the cycle of homelessness⇒incarceration⇒homelessness, the VA should 

encourage research on Veterans Courts to determine how to implement them so as to effectively 

divert already homeless Veterans (or Veterans at risk for homelessness because of criminal activities) 

from increasing their risk for continued (or new) homelessness by creating opportunities to avoid 

prison and the negative consequences deriving from both a criminal record and incarceration.
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SUMMARY AND DISCUSSION

Our review of the evidence suggests that there is no easily generalizable path into homelessness. 

Both Veteran and non-Veteran homeless individuals are more likely than those in the general 

population to have been exposed to one or more risk factors such as childhood instability 

or trauma, mental illness, alcohol or substance abuse, chronic illness, low social support in 

adulthood, and low or unstable income. However, the precise strength of the association of each 

of these factors with the outcome of homelessness remains poorly measured, both for the Veteran 

homeless population as a whole and for sub-populations of interest such as women Veterans. 

This is due in part to the lack of studies designed to examine the directionality of relationships 

of these variables to the outcome of homelessness, but also in part to the inherently complex 

process of becoming homeless, which occurs as the result of multiple influences (both structural 

and individual), each with various potential moments of intervention.

While homeless Veterans are exposed to much the same broadly defined risk factors as other 

homeless individuals, the qualitative nature of those exposures will in some cases be different 

because of Veterans’ experiences during military service or during the post-deployment period. 

The conceptual model developed for this report is a first step in identifying areas where we need 

to gather stronger evidence in order to understand how the unique experiences of Veterans, such 

as combat exposure or readjustment difficulty, might be contributing to their risk of experiencing 

other more generally shared risk factors for homelessness such as low or unstable income.

Veteran homelessness is unique in that some factors generally believed to be protective, such 

as being better educated or having better social support, do not appear to have quite the same 

protective efficacy in the Veteran population. While we have speculated in this report that their 

experiences as Veterans might somehow actively work against the protective value associated 

with these factors in other populations, this is an area which has not been adequately researched 

and where longitudinal research employing mixed methods would be of great value in 

substantiating or refuting such a hypothesis.

Veterans become separated from their normative communities in different ways: physically, 

through enlistment in the military or incarceration in jail or prison, and socially and culturally 

through mental illness, substance abuse, and disability. Each presents its own challenges for 

re-entry into and re-integration with support networks in former communities. The Veteran 

“advantage” in better social support is hypothesized on the basis of repeated measures of 

higher rates of ever-marriage, but as other authors have pointed out, this may not be the most 

meaningful measure of social support in this context. It is possible that the additional financial 

and emotional responsibilities of supporting a spouse and dependents may, under certain 

circumstances, actually enhance the risk of homelessness. As with education, however, higher 

levels of social support among homeless Veterans as compared to homeless non-Veterans does 

not appear to offer protection against homelessness.

While recent trends in the number of Veteran homeless are encouraging, studies suggesting that 

lowered recruitment standards may be related to the increase in homelessness among Veterans of 

the early all volunteer force should, if true, make us alert to a potential increase in homelessness 

among Operation Iraqi Freedom (OIF)/Operation Enduring Freedom (OEF) Veterans who were 

similarly recruited with lowered standards.109, 110
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As mentioned in the introduction, ending homelessness entails the two distinct tasks of relieving 

homelessness among those who currently lack housing, and preventing the occurrence of homelessness among those at risk. The existing evidence illustrates in many ways the methodological 

difficulties inherent in identifying risk factors, such as mental illness, in a population where the 

condition of interest (homelessness) is likely to produce the risk factor. Causal links between 

many individual level factors and homelessness have not been well-established in the literature, 

and there may be a bi-directional relationship between homelessness and risk factors such as 

mental illness, substance abuse and incarceration. Moreover, given that homelessness may not 

occur for many years after deployment, targeting military level risk factors may be difficult, especially during the post-deployment period. It may be important to repeatedly engage and evaluate Veterans both qualitatively and quantitatively for years after service. Large-scale, long-term 

longitudinal studies, such as the Department of Defense Millenium Cohort Study, provide important opportunities for this type of research.31 Furthermore, an assessment of a given Veteran’s 

risk for homelessness will be incomplete if only individual level risk factors are evaluated. The 

structural level risk factors of the environment (affordable housing, employment opportunities) 

into which a Veteran has re-integrated need to be assessed as these are likely to contribute to the 

homelessness risk milieu.

RECOMMENDATIONS FOR FUTURE RESEARCH

This report identifies a number of gaps in the literature and makes key suggestions to define the 

agenda for future research on Veteran homelessness:

• Longitudinal studies with Operation Enduring Freedom (OEF)/Operation Iraqi Freedom 

(OIF) Veterans are needed to capture data on exposures occurring before homelessness 

occurs. Given the VA’s current policy of pro-active enrollment and engagement of this 

cohort, opportunities exist to conduct longitudinal studies that collect information on all 

of the risk factors identified in this report. This research should control for structural risk 

factors such as housing market costs and available assistance programs.

• Longitudinal studies with all new cohorts of enlisting military service members could 

better determine the pre-existing presence of risk factors, such as low social support, 

alcohol or substance abuse problems, before military service. Policies should be 

developed to facilitate the use of data from enlistment screenings in research.

• Qualitative studies employing longitudinal, ethnographic methods to investigate the 

distinct experiences of homeless Veterans will help researchers to understand what 

is unique about Veteran exposure to risk factors common to the general homeless 

population. This remains poorly understood at present but may have important 

implications for designing homelessness prevention programs that will be effective for 

Veterans.

• Current research suggests that risk for violent criminal behavior varies by service 

branch. Research to confirm these differences and how to identify individuals at risk for 

continued post-military violent criminal behavior may help target interventions to those 

most at risk for post-military incarceration.
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• Research on the post-deployment period is needed, with a particular focus on risk factors 

for loss of income and social support during this transition period, as well as rates of 

short-term homelessness experienced during this period. These data could be collected 

as part of longitudinal studies looking for relationships between short-term and more 

chronic homelessness in the longer term, which has been the focus of past research.

• Further research on military sexual trauma (MST), its relationship to homelessness, and 

appropriate MST prevention and treatment programs, is recommended.

• Research on Veterans Courts and other specialty courts should be continued in order to 

improve their performance and find effective alternatives to incarceration for Veterans.

• Systems perspective research on collaborations among Departments of Corrections, the 

VA, the Department of Housing and Urban Development (HUD), and local community 

health agencies could inform efforts to reduce the likelihood of homelessness upon reentry from incarceration, including developing a better understanding of how to identify 

those most at risk for homelessness post-release.

• Most of the measures used to assess risk factors and personal characteristics of the 

homeless, including measures of substance abuse, mental health, and measures of 

social support, have been developed and normed on populations very different from 

the homeless. The applicability of these measures to homeless populations is unknown. 

Research should be undertaken to assess the applicability of these measures and to 

modify or develop new measures where warranted. Similarly, better defined research 

on the aspects of social support most relevant to improving Veterans’ post-deployment 

adjustment would contribute both to addressing Veteran homelessness and the literature’s 

broader understanding of the function of social support.

• Long-term studies repeatedly collecting both quantitative and qualitative data, though 

always relatively difficult and costly to conduct, would greatly improve our understanding of Veterans’ difficulties in re-engagement and re-integration over long periods of time 

after deployment, not just in the initial post-deployment year which is more frequently 

studied.

• Studies that include both individual and structural risk factors should be conducted to assess both their independent and contingent effects.

• Research is needed to investigate the relationship between the unique Veteran experience 

of “family readjustment difficulties” in the post-deployment period and other, more generalized concepts such as social support, as well as the relationship between family readjustment difficulties and clinical diagnoses of mental illness.

• To our knowledge, the direct relationship between injury/disability and increased risk 

of homelessness has not been well studied in the Veteran population. There is a need for 

research designed to examine injury as a risk factor for homelessness, both directly and 

indirectly, and taking into account the complex effects of serious injury on both income 

and quality of life/well-being.
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REFERENCES

1. Homeless on Veterans Day. The New York Times. November 11, 2009.

2. US Interagency Council on Homelessness. Opening Doors, Federal Strategic Plan to Prevent and End Homelessness 2010.

3. Elliott M, Krivo LJ. Structural Determinants of Homelessness in the United States. Social 

Problems. 1991;38(1):113-31.

4. Ji E-G. A study of the structural risk factors of homelessness in 52 metropolitan areas in 

the United States. Int Socl Work. 2006;49(1):107-17.

5. Lee BA, PriceSpratlen T, Kanan JW. Determinants of Homelessness in Metropolitan Areas. Journal of Urban Affairs. [10.1111/1467-9906.00168]. 2003;25(3):335-56.

6. O’Connell MJ, Kasprow W, Rosenheck RA. Rates and risk factors for homelessness 

after successful housing in a sample of formerly homeless veterans. Psychiatr Serv. 2008 

Mar;59(3):268-75.

7. Shinn M, Weitzman BC, Stojanovic D, Knickman JR, Jimenez L, Duchon L, et al. Predictors of homelessness among families in New York City: from shelter request to housing stability. American Journal of Public Health. [Research Support, Non-U.S. Gov’t 

Research Support, U.S. Gov’t, P.H.S.]. 1998 Nov;88(11):1651-7.

8. Koegel P, Burnam MA, Baumohl J. The causes of homelessness. In: Baumohl J, editor. 

Homelessness in America. Phoenix: The Oryx Press; 1996. p. 24-33.

9. DeCrappeo M, Pelletiere D, Crowley S, Teater E. Renters in the great recession, the crisis 

continues: National Low Income Housing Coalition. 2010 June.

10. Daskal J. In search of shelter: The growing shortage of affordable rental housing. Washington, DC: Center on Budget and Policy Priorities. 1998.

11. National Coalition for the Homeless. Why Are People Homeless? July 2009.

12. Pelletierre D. The rental housing affordability gap: Comparison of 2001 and 2003 American Housing Surveys: National Low Income Housing Coalition. 2006 March.

13. Dolbeare C. Housing policy: A general consideration. In: Baumohl J, editor. Homelessnes 

in America. Phoenix: The Oryx Press; 1996. p. 34-45.

14. The 2009 Annual Homeless Assessment Report to Congress: Office of Community Planning and Development, U.S. Department of Housing and Urban Development. June 2010.

15. Rosenheck R, Fontana A. A model of homelessness among male veterans of the Vietnam 

War generation. Am J Psychiatry. 1994 Mar;151(3):421-7.

16. Perl L. Veterans and Homelessness: Congressional Research Service. 2009 June 26, 2009.
45

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17. Dietz TL. Predictors of reported current and lifetime substance abuse problems among a 

national sample of U.S. homeless. Subst Use Misuse. 2007;42(11):1745-66.

18. Johnson TP, Fendrich M, Johnson TP, Fendrich M. Homelessness and drug use: evidence 

from a community sample. Am J Prev Med. [Research Support, N.I.H., Extramural]. 

2007 Jun;32(6 Suppl):S211-8.

19. Susser E, Moore R, Link B. Risk factors for homelessness. Epidemiol Rev. [Review]. 

1993;15(2):546-56.

20. Fischer P, Breakey W. The epidemiology of alcohol, drug, and mental disorders among 

homeless persons. Am Psychol. 1991;46(11):1115-28.

21. Shelton KH, Taylor PJ, Bonner A, van den Bree M, Shelton KH, Taylor PJ, et al. Risk 

factors for homelessness: evidence from a population-based study. Psychiatric Services. 

[Research Support, N.I.H., Extramural]. 2009 Apr;60(4):465-72.

22. Johnson TP, Freels SA, Parsons JA, Vangeest JB. Substance abuse and homelessness: social selection or social adaptation? Addiction. [Research Support, Non-U.S. Gov’t]. 1997 

Apr;92(4):437-45.

23. Phelan JC, Link BG. Who are “the homeless”? Reconsidering the stability and composition of the homeless population. American Journal of Public Health. [Research Support, 

U.S. Gov’t, P.H.S. Review]. 1999 Sep;89(9):1334-8.

24. Snow DA, Anderson L, Koegel P. Distorting Tendencies in Research on the Homeless. 

American Behavioral Scientist. 1994;37(4):15-.

25. Cackley AP, Schmidt P, Barry NS, Boggs K, Burnett R, Chatlos W, et al. Homelessness: 

A common vocabulary could help agencies collaborate and collect more consistent data: 

United States Government Accountability Office. 2010.

26. Kuhn JH, Nakashima J. The Sixteenth Annual Progress Report: Community Homelessness Assessment, Local Education and Networking Group for Veterans - Services for 

homeless veterans assessment and coordination: Community Homelessness Assessment, 

Local Education and Networking Group for Veterans. 2010 March 17.

27. Veteran Homelessness: A Supplemental Report to the 2009 Annual Homeless Assessment 

Report to Congress: Office of Community Planning and Development, U.S. Department 

of Housing and Urban Development and the U.S. Department of Veteran Affairs. January 

2011.

28. Farrell BS, Gosling TW, Keisling SE, Nalwalk KM, Petrucci S, Shoemaker LL. Military 

personnel: Active duty benefits reflect changing demographics, but opportunities exist to 

improve United States Government Accountability Office. 2002.

29. Stewart DB. Military personnel: Active duty benefits reflect changing demographics, but 

continued focus is needed United States Government Accountability Office. 2002.
46

A Critical Review of the Literature

Regarding Homelessness among Veterans Evidence-based Synthesis Program

30. Health ViEWS: Health of Vietnam Era Women’s Study. 2011 [cited 2011 March 9, 2011]; 

Available from: http://www.research.va.gov/programs/csp/csp579.cfm.

31. The Millenium Cohort Study. 2011 [cited 2011 March 9, 2011]; Available from: http://

www.millenniumcohort.org/index.php.

32. Link B, Phelan J, Bresnahan M, Stueve A, Moore R, Susser E. Lifetime and fiveyear prevalence of homelessness in the United States: new evidence on an old debate. 

American Journal of Orthopsychiatry. [Research Support, U.S. Gov’t, P.H.S.]. 1995 

Jul;65(3):347-54.

33. Cunningham M, Henry M, Lyons W. Vital mission - Ending homelessness among veterans: National Alliance to End Homelessness. 2007 November.

34. Institute of Medicine Committee on the Initial Assessment of Readjustment Needs of 

Military Personnel V, Their F. Returning home from Iraq and Afghanistan: Preliminary 

assessment of readjustment needs of veterans, service members and their families. 2010.

35. Winkleby MA, Fleshin D. Physical, addictive, and psychiatric disorders among homeless 

veterans and nonveterans. Public Health Rep. 1993 Jan-Feb;108(1):30-6.

36. Washington D, Yano EM, McGuire J. Risk factors for homelessness among women veterans. Journal of Health Care for the Poor and Underserved. 2010 February 2010;21:82-91.

37. O’Toole TP, Conde-Martel A, Gibbon JL, Hanusa BH, Fine MJ. Health care of homeless 

veterans. J Gen Intern Med. 2003 Nov;18(11):929-33.

38. Wenzel SL, Gelberg L, Bakhtiar L, Caskey N, Hardie E, Redford C, et al. Indicators of chronic homelessness among veterans. Hosp Community Psychiatry. 1993 

Dec;44(12):1172-6.

39. Adams J, Rosenheck R, Gee L, Seibyl CL, Kushel M. Hospitalized younger: a comparison of a national sample of homeless and housed inpatient veterans. J Health Care Poor 

Underserved. 2007 Feb;18(1):173-84.

40. Koegel P, Melamid E, Burnam MA. Childhood risk factors for homelessness among 

homeless adults. Am J Public Health. [Research Support, U.S. Gov’t, P.H.S.]. 1995 

Dec;85(12):1642-9.

41. Susser ES, Lin SP, Conover SA, Struening EL. Childhood antecedents of homelessness 

in psychiatric patients. American Journal of Psychiatry. [Research Support, Non-U.S. 

Gov’t]. 1991 Aug;148(8):1026-30.

42. Rosenheck R, Koegel P. Characteristics of veterans and nonveterans in three samples of 

homeless men. Hosp Community Psychiatry. 1993 Sep;44(9):858-63.

43. Department of Defense Task Force on Mental Health. An achievable vision: Report of the 

Department of Defense Task Force on Mental Health. Falls Church, VA: Defense Health 

Board. 2007.
47

A Critical Review of the Literature

Regarding Homelessness among Veterans Evidence-based Synthesis Program

44. Kulka R, Schlenger W, Fairbank J, Hough R, Jordan B. Trauma and the Vietnam War 

generation: report of the findings from the National Vietnam Veterans Readjustment 

Study. New York: Brunner/Mazel; 1990.

45. Goldberg J, True W, Eisen S, Henderson W. A twin study of the effects of the Vietnam 

War on Posttraumatic Stress Disorder. Journal of the American Medical Association. 

1990;263(9):1227-32.

46. Roy-Byrne P, Arguelles L, Vitek ME, Goldberg J, Keane TM, True WR, et al. Persistence 

and change of PTSD symptomatology--a longitudinal co-twin control analysis of the 

Vietnam Era Twin Registry. Social Psychiatry & Psychiatric Epidemiology. [Research 

Support, U.S. Gov’t, Non-P.H.S. Research Support, U.S. Gov’t, P.H.S. Twin Study]. 2004 

Sep;39(9):681-5.

47. Magruder KM, Frueh BC, Knapp RG, Johnson MR, Vaughan JA, 3rd, Carson TC, et 

al. PTSD symptoms, demographic characteristics, and functional status among veterans 

treated in VA primary care clinics. Journal of Traumatic Stress. [Research Support, U.S. 

Gov’t, Non-P.H.S.]. 2004 Aug;17(4):293-301.

48. Hoge CW, Auchterlonie JL, Milliken CS, Hoge CW, Auchterlonie JL, Milliken CS. Mental health problems, use of mental health services, and attrition from military service after 

returning from deployment to Iraq or Afghanistan. Jama. [Research Support, U.S. Gov’t, 

Non-P.H.S.]. 2006 Mar 1;295(9):1023-32.

49. Seal KH, Metzler TJ, Gima KS, Bertenthal D, Maguen S, Marmar CR, et al. Trends and 

risk factors for mental health diagnoses among Iraq and Afghanistan veterans using Department of Veterans Affairs health care, 2002-2008. American Journal of Public Health. 

[Research Support, Non-U.S. Gov’t Research Support, U.S. Gov’t, Non-P.H.S.]. 2009 

Sep;99(9):1651-8.

50. Polusny MA, Erbes CR, Arbisi PA, Thuras P, Kehle SM, Rath M, et al. Impact of prior 

Operation Enduring Freedom/Operation Iraqi Freedom combat duty on mental health in a 

predeployment cohort of National Guard soldiers. Military Medicine. [Research Support, 

Non-U.S. Gov’t Research Support, U.S. Gov’t, Non-P.H.S.]. 2009 Apr;174(4):353-7.

51. Maclean A. The things they carry: combat, disability and employment among U.S. men. 

Am Sociol Rev. 2010;75(4):563-85.

52. Bray R, Hourani L. Substance use trends among active duty military personnel: findings 

from the United States Department of Defense Health Related Behavior Surveys, 1980-

2005: US Department of Defense. 2007. Report No.: Addiction 102.

53. Jacobson IG, Ryan MA, Hooper TI, Smith TC, Amoroso PJ, Boyko EJ, et al. Alcohol use 

and alcohol-related problems before and after military combat deployment. Jama. [Research Support, N.I.H., Extramural Research Support, U.S. Gov’t, Non-P.H.S.]. 2008 Aug 

13;300(6):663-75.
48

A Critical Review of the Literature

Regarding Homelessness among Veterans Evidence-based Synthesis Program

54. Rosenheck R, Kasprow W, Frisman L, Liu-Mares W. Cost-effectiveness of supported housing for homeless persons with mental illness. Arch Gen Psychiatry. 2003 

Sep;60(9):940-51.

55. Tessler R, Rosenheck R, Gamache G. Comparison of homeless veterans with other homeless men in a large clinical outreach program. Psychiatr Q. 2002 Summer;73(2):109-19.

56. Sherbourne CD, Stewart AL. The MOS social support survey. Soc Sci Med. 

1991;32(6):705-14.

57. Lin N, Dean A, Ensel WM. Social support, life events, and depression: Academic Pr; 

1986.

58. Rosenheck R, Frisman L, Chung AM. The proportion of veterans among homeless men. 

Am J Public Health. 1994 Mar;84(3):466-9.

59. Vogt DS, Proctor SP, King DW, King LA, Vasterling JJ. Validation of scales from the Deployment Risk and Resilience Inventory in a sample of Operation Iraqi Freedom veterans. 

Assessment. 2008 Dec;15(4):391-403.

60. Saxon AJ, Davis TM, Sloan KL, McKnight KM, McFall ME, Kivlahan DR. Trauma, 

Symptoms of Posttraumatic Stress Disorder, and Associated Problems Among Incarcerated Veterans. Psychiatr Serv. [10.1176/appi.ps.52.7.959]. 2001;52(7):959-64.

61. Miller KE, Rasmussen A. War exposure, daily stressors, and mental health in conflict 

and post-conflict settings: Bridging the divide between trauma-focused and psychosocial frameworks. Social Science & Medicine. [10.1016/j.socscimed.2009.09.029]. 

2010;70(1):7-16.

62. Koegel P, Burnam MA. Alcoholism among homeless adults in the inner city of Los Angeles. Archives of General Psychiatry. [Comparative Study Research Support, Non-U.S. 

Gov’t Research Support, U.S. Gov’t, P.H.S.]. 1988 Nov;45(11):1011-8.

63. Folsom D, Jeste DV. Schizophrenia in homeless persons: a systematic review of the literature. Acta Psychiatr Scand. 2002 Jun;105(6):404-13.

64. Reardon ML, Burns AB, Preist R, Sachs-Ericsson N, Lang AR. Alcohol use and other 

psychiatric disorders in the formerly homeless and never homeless: Prevalence, age of 

onset, comorbidity, temporal sequencing, and service utilization. Substance Use & Misuse. 2003;38(3-6):601-44.

65. Sullivan G, burnam A, Koegel P. Pathways to homelessness among the mentally ill. Soc 

Psychiatry Psychiatr Epidemiol. 2000;35:444-50.

66. Resnick SG, Rosenheck RA. Posttraumatic stress disorder and employment in veterans 

participating in Veterans Health Administration Compensated Work Therapy. J Rehabil 

Res Dev. 2008;45(3):427-35.
49

A Critical Review of the Literature

Regarding Homelessness among Veterans Evidence-based Synthesis Program

67. Smith MW, Schnurr PP, Rosenheck RA, Smith MW, Schnurr PP, Rosenheck RA. Employment outcomes and PTSD symptom severity. Mental Health Services Research. 

[Comparative Study Research Support, U.S. Gov’t, Non-P.H.S.]. 2005 Jun;7(2):89-101.

68. Savoca E, Rosenheck R. The civilian labor market experiences of Vietnam-era veterans: 

The influence of psychiatric disorders. J Men Health Policy Econ. 2000;3(4):199-207.

69. Harpham T, Grant E, Thomas E. Measuring social capital within health surveys: key issues. Health Policy Plan. 2002 Mar;17(1):106-11.

70. Irwin J, LaGory M, Ritchey F, Fitzpatrick K. Social assets and mental distress among 

the homeless: Exploring the roles of social support and other forms of social capital on depression. Social Science & Medicine. [10.1016/j.socscimed.2008.09.008]. 

2008;67(12):1935-43.

71. An Achievable Vision: Report of the Department of Defense Task Force on Mental 

Health: U.S. Department of Defense. 2007.

72. Committee on the Initial Assessment of Readjustment Needs of Military Personnel V, 

Their F, Board on the Health of Selected P, Institute of M. Returning Home from Iraq and 

Afghanistan: Preliminary Assessment of Readjustment Needs of Veterans, Service Members, and Their Families. Washington, D.C.: The National Academies Press; 2010.

73. Erbes C, Westermeyer J, Engdahl B, Johnsen E, Erbes C, Westermeyer J, et al. Post-traumatic stress disorder and service utilization in a sample of service members from Iraq and 

Afghanistan. Military Medicine. 2007 Apr;172(4):359-63.

74. Karney B, Ramchand R, Osilla K, Caldarone L, Burns R. Predicting the immediate and 

long-term consequences of Post-Traumatic Stress Disorder, depression and traumatic 

brain injury in veterans of Operation Enduring Freedom and Operation Iraqi Freedom. In: 

Tanielian T, Jaycox L, editors. Invisible wounds of war: psychological and cognitive injuries, their cosequences, and services to assist recovery. Santa Monica, CA: Rand Corporation; 2008. p. 119-66.

75. Rosenheck R, Leda C, Gallup P. Combat stress, psychosocial adjustment, and service use 

among homeless Vietnam veterans. Hosp Community Psychiatry. 1992 Feb;43(2):145-9.

76. Kasprow WJ, Rosenheck R. Substance use and psychiatric problems of homeless Native 

American veterans. Psychiatr Serv. 1998 Mar;49(3):345-50.

77. Leda C, Rosenheck R, Gallup P. Mental illness among homeless female veterans. Hosp 

Community Psychiatry. 1992 Oct;43(10):1026-8.

78. Benda BB. Survival analyses of social support and trauma among homeless male and 

female veterans who abuse substances. Am J Orthopsychiatry. 2006 Jan;76(1):70-9.

79. Report of the Defense Task Force of Sexual Assault in the Military Services | National 

Sexual Violence Resource Center (NSVRC): U.S. Department of Defense. 2009.
50

A Critical Review of the Literature

Regarding Homelessness among Veterans Evidence-based Synthesis Program

80. Hankin CS, Skinner KM, Sullivan LM, Miller DR, Frayne S, Tripp TJ. Prevalence of 

depressive and alcohol abuse symptoms among women VA outpatients who report experiencing sexual assault while in the military. Journal of Traumatic Stress. [Research Support, U.S. Gov’t, Non-P.H.S.]. 1999 Oct;12(4):601-12.

81. Murdoch M, Nichol KL. Women veterans’ experiences with domestic violence and with 

sexual harassment while in the military. Arch Fam Med. 1995 May;4(5):411-8.

82. Kimerling R, Street AE, Pavao J, Smith MW, Cronkite RC, Holmes TH, et al. Militaryrelated sexual trauma among Veterans Health Administration patients returning from 

Afghanistan and Iraq. American Journal of Public Health. [Research Support, U.S. Gov’t, 

Non-P.H.S.]. 2010 Aug;100(8):1409-12.

83. Suffoletta-Maierle S, Grubaugh A, Magrude K, Monnier J, Frueh B. Trauma-related 

mental health needs and service utilization among female veterans. J Psychiatr Pract. 

2003;9(5):367-75.

84. Noonan ME, Mumola CJ. Veterans in State and Federal Prison, 2004. Washington, DC: 

US Department of Justice, Office of Justice Programs, Bureau of Justice Statistics. 2007.

85. Rosenheck RA, Banks S, Pandiani J, Hoff R. Bed closures and incarceration rates among 

users of Veterans Affairs mental health services. Psychiatric Services (Washington, DC). 

2000;51(10):1282-7.

86. Greenberg G, Rosenheck R. Mental Health and Other Risk Factors for Jail Incarceration Among Male Veterans. Psychiatric Quarterly. [10.1007/s11126-009-9092-8]. 

2009;80(1):41-53.

87. Black DW, Carney CP, Peloso PM, Woolson RF, Letuchy E, Doebbeling BN. Incarceration and veterans of the first Gulf War. Military Medicine. 2005;170(7):612-8.

88. Erickson SK, Rosenheck RA, Trestman RL, Ford JD, Desai RA. Risk of incarceration between cohorts of veterans with and without mental illness discharged from inpatient units. 

Psychiatric Services (Washington, DC). [10.1176/appi.ps.59.2.178]. 2008;59(2):178-83.

89. McGuire J, Rosenheck RA, Kasprow WJ. Health status, service use, and costs among 

veterans receiving outreach services in jail or community settings. Psychiatr Serv. 2003 

Feb;54(2):201-7.

90. Metraux S, Caterina R, Cho R. Incarceration and homelessness. Stephen Metraux. 

2008:1-.

91. Samuels P, Mukamal D. After Prison: Roadblocks to Reentry: Legal Action Center2004.

92. Pearson J, Davis L. Serving parents who leave prison: final report on the work and family 

center. Denver, Colorado: Center for Policy Research. 2001.

93. Thoennes N. Child support profile: Massachusetts incarcerated and paroled parents. Denver, Colorado: Center for Policy Research. 2002.
51

A Critical Review of the Literature

Regarding Homelessness among Veterans Evidence-based Synthesis Program

94. Benda BB, Rodell DE, Rodell L. Crime among homeless military veterans who abuse 

substances. Psychiatr Rehabil J. 2003 Spring;26(4):332-45.

95. Copeland LA, Miller AL, Welsh DE, McCarthy JF, Zeber JE, Kilbourne AM. Clinical and 

demographic factors associated with homelessness and incarceration among VA patients 

with bipolar disorder. Am J Public Health. 2009 May;99(5):871-7.

96. Stovall JG, Cloninger L, Appleby L. Identifying homeless mentally ill veterans in jail: a 

preliminary report. J Am Acad Psychiatry Law. 1997;25(3):311-5.

97. Steadman HJ, Barbera SS, Dennis DL. A National Survey of Jail Diversion Programs for 

Mentally Ill Detainees. Hosp Community Psychiatry. 1994;45(11):1109-13.

98. Broner N, Lattimore PK, Cowell AJ, Schlenger WE. Effects of diversion on adults with 

co-occurring mental illness and substance use: outcomes from a national multi-site study. 

Behavioral Sciences & the Law. [Article]. 2004;22(4):519-41.

99. Case B, Steadman HJ, Dupuis SA, Morris LS. Who succeeds in jail diversion programs 

for persons with mental illness? A multi-site study. Behavioral Sciences & the Law. 

[10.1002/bsl.883]. 2009;27(5):661-74.

100. Shafer MS, Arthur B, Franczak MJ. An analysis of post-booking jail diversion programming for persons with co-occurring disorders. Behavioral Sciences & the Law. [10.1002/

bsl.603]. 2004;22(6):771-85.

101. Sirotich F. The Criminal Justice Outcomes of Jail Diversion Programs for Persons With 

Mental Illness: A Review of the Evidence. J Am Acad Psychiatry Law. 2009;37(4):461-

72.

102. Steadman HJ, Cocozza JJ, Veysey BM. Comparing outcomes for diverted and nondiverted jail detainees with mental illnesses. Law and Human Behavior. 1999;23(6):615-27.

103. Steadman HJ, Naples M. Assessing the effectiveness of jail diversion programs for 

persons with serious mental illness and co-occurring substance use disorders. Behavioral 

Sciences & the Law. 2005;23(2):163-70.

104. Wilson DB, Mitchell O, MacKenzie DL. A systematic review of drug court effects on 

recidivism. Journal of Experimental Criminology. 2006;2(4):459-87.

105. 105. Toomey S. Diversion program for vets is offered. Anchorage Daily News. July 14, 

2004.

106. Russell RT. Veterans Treatment Court: A Proactive Approach. New England Journal on 

Criminal and Civil Confinement. 2009;35:357-.
52

A Critical Review of the Literature

Regarding Homelessness among Veterans Evidence-based Synthesis Program

107. Hawkins JMD. Coming Home: Accommodating the Special Needs of Military Veterans 

to the Criminal Justice System. Ohio St J Crim L. 2010;7:563-849.

108. Under Secretary for H. Information and recommendations for services provided by VHA 

facilities to Veterans in the criminal justice system. 2009.

109. Moral Waivers and the Military. The New York Times. 2007.

110. Schmitt E. Its Recruitment Goals Pressing, the Army Will Ease Some Standards. New 

York Times. 2004.
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e Regarding Homelessness among Veterans Evidence-based Synthesis Program

eer Review Comments/Author Responses

NTS - Epidemiological evidence regarding homelessness among Veterans

Comment Response

s, scope, and methods for this review clearly described?

ers and letters used in the research objectives are distracting. I would 

ullets for the sub questions.

We have revised the format of the document to comply with the standard VA Evidence-based Synthesis Program (ESP) style template. We think this should address the concerns of the reviewer.

ds section should precede the discussion on the structural causes of 

This has been corrected in a way that follows the template of the ESP program.

a sources could benefit from elaboration on limitations and that the 

ent research are a laundry list – are there key issues that you could 

We have added a more detailed section describing the limitations of the datasets and hope that this addresses the concerns of the reviewer.

arch questions.

ned are very cogent and relevant to the current policy issues and 

he evidence synthesis reflects a tremendous amount of work and the 

mmended.

 developed as part of this paper is nicely conceived and constructed 

more prominently represented in the paper as (1) a means of 

) a contextualizing in greater detail of the intermediate and mediating 

 paper. Toward both of these objectives, the schematic could be 

 to more clearly define these relational dynamics.

We thank the reviewer for their comments on the Conceptual Model. We have modified the model and hope that the relationships are easier to follow. We’ve also relocated the Figure and discussion of the model and hope that it acts, as the reviewer suggests, as a frame for organizing the subsequent discussion of the topic.

nsive.

cation of bias in our synthesis of the evidence?

and fair.

see comment 4.4 below.
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e Regarding Homelessness among Veterans Evidence-based Synthesis Program

Comment Response

nd challenge with this synthesis is that for much of the research on 

homeless Veterans, there are inconsistent definitions, metrics for 

dologic rigor assigned to sampling, unmeasured population dynamics, 

 You do a very nice job of describing this at the beginning of the paper 

 prominently factored into some of the conclusions presented in the 

example of this is in the discussion about social support and its role 

at exposure, etc. There are objective measures of social and social 

used the Rand Social Support Network Survey in our studies) that 

lated with several features of homelessness. The surrogate measure 

weaker, nontemporal, and without any validation that I am aware 

out any conclusions being drawn off that metric. Similarly, as you 

esearch on substance use and abuse has historically been challenged 

ow use is measured, whether it reflects current use while homeless or 

re likely contributant use). There are also definite distinctions between 

and dependence and its impact on functioning, risk, and capacity to 

owing which studies employed any of the Addiction Severity index 

ir determinations would be helpful in considering the rigor of the data 

er attention to this level of detail is needed in the synthesis. This is an 

nd expanding the search beyond homeless veterans to homelessness in 

will be of help. The only other concern that needs to be addressed is 

data – inferences drawn from data that are now 20-25 years old may 

ynamics of homelessness today.

Corrected. We have included a more direct discussion describing the inconsistencies that we found among the various studies that examine the prevalence of substance abuse or mental illness among homeless Veterans. We have also identified additional measures that might provide better insights into issues of social support and social capital.

dies on the epidemiology of homelessness among Veterans that we have overlooked?

he most comprehensive that I’ve read.

ment of the literature and innovative use of emerging search programs

eam to consider is whether it is better to take well-constructed and 

ous studies about homelessness in the general population and apply 

rans over what are sometimes less well constructed or significantly 

f selection bias, validity/reliability of findings, etc.) that is specific to 

any of papers specific to homeless veterans are drawn from samples 

VA programs or services for homeless persons and reflect a level 

t and capacity that may not be reflective of the overall population 

 most of whom do not get there care in the VA. This is particularly 

y or dimensional relationships are being inferred or considered.

Because of the exploratory nature of this review, and because the purpose of the report was to provide background on what’s known about homelessness among Veterans, we felt it better addressed the goals of the report to identify and report on studies specifically about Veterans and to discuss the limitations of those studies. We supplemented this with a brief background discussion of the literature on homelessness more broadly and hope that this report will prove useful in identifying the need for more methodologically rigorous and broadly applicable studies about homelessness among Veterans.
55

e Regarding Homelessness among Veterans Evidence-based Synthesis Program

Comment Response

at the substance abuse prevalence section is a little light, I believe 

Also, the reference was from an older study. For example O’Connell, 

2010 report on HUD VASH client demographics and include data on 

 Rosenheck fairly frequently reports this data as well in his studies.

We have revised our discussion of the substance abuse issues and hope that it addresses the concerns of the reviewer.

tional suggestions or comments below. If applicable, please indicate the page and line numbers from the draft report.

Report states Veterans are 2x the risk of homelessness compared 

on. Need to clarify comparison as children should not be included 

since men are more likely to be homeless (not just Veterans), 

o-thirds of all homeless adults, it is important to factor this into 

these adjustments it appears veteran status alone places individuals 

We have added language to address the reviewers comment.

Homeless Veterans are more likely to be African-American. This is 

We have included additional language addressing the over-representation of Blacks among the homeless and of the over-representation of Veterans, both Black and White among the homeless.

ng the minimum wage the paper uses 2004 as a reference point to 

 its declining value; however, the minimum wage was increased after 

he selection of 2004 appear to be used to bias the conclusion. Also, 

m wages higher than the federal minimum wage. It may be more 

he declining value of the minimum wage in relation to the increasing 

We have edited the text to provide a more general description of the declining value of the minimum wage in relation to the cost of housing. 

stion 1b: Paper states Veterans are more likely to be unsheltered than 

oes not state this as factual, only speculates that this is a possibility.

We have revised the language to indicate the speculative nature of this perspective.

 “Kuhn reports 24% increase in homeless families”. Need to clarify 

he reader to incorrectly conclude that this is the increase in overall 

This increase only reflects what VA staff report they have seen at 

We have revised the language here to be clearer that we are reporting on an increase in staff reports of increases in people seeking services.

: No mention is made on the impact of child support. Legal 

pport is ranked as the second highest unmet need in the CHALENG 

affordable child support obligations often act as a significant barrier 

o resume independent community living. This burden is particularly 

ders. The typical incarcerated parent owes $20,000 in child support 

ison, with payment schedules averaging $225 to $300 per month 

ocial Policy, 2008). Minimum wage workers have little hope of 

s while supporting themselves. Unresolved child support debts can 

bank accounts, denial of credit, inability to secure a lease, failure in 

mmonly a part of job applications, forfeiture of driver’s licenses, and 

We have expanded this section to address the issue of child support and thank the reviewer for their very helpful comment.
56

e Regarding Homelessness among Veterans Evidence-based Synthesis Program

Comment Response

ments are deducted automatically from paychecks, workers often quit 

shed, returning to the underground economy to avoid child support. 

cipation in the underground economy often means a return to illegal 

w and Social Policy, 2007). Hence, legal assistance around the issue 

 key to helping Veterans meet their obligations to society, while still 

void relapsing to homelessness.

a thorough copy edit. We agree and have done so.

and on the limitations of each data source. We have added a more detailed section describing the limitations of the 

datasets and hope that this addresses the concerns of the reviewer.

dry list and the narrative doesn’t flow. Is there a better structure? 

We agree that this section needed better organization. We have reorganized so that similar topics are addressed together, and, as suggested by the reviewer have added subheads to make clear how the topics are grouped together.

graph: double check the definition. I think the first line is inaccurate. 

 include those living in transitional housing as homeless.

We checked Perl (2009) and the McKinney-Vento Act. No change to our statement is needed. Currently, only those living in transitional housing for the mentally ill are included. The Hearth Act will add others living in transitional housing to the definition of homelessness.
57

e Regarding Homelessness among Veterans Evidence-based Synthesis Program

Comment Response

blems with your conceptual model:

D and Mental Illness together, in the center of the model, and directly 

omelessness (giving the association a strong arrow and two asterisks, 

t form of association you have in the model). This contradicts what 

aces in your report, where you say there is a lack of evidence directly 

melessness (e.g., pps 29 and 33). The problem here, obviously, is 

uld not be coupled like this. MI is of course a catchall term and 

gnosis. Associations with MI in general should best be broken down 

mponents. Even severe mental illness (which typically includes only 

or affective disorders) is a better designation than just MI. And 

own box, which, according to the evidence you review, should 

ociation with homelessness. Including the model as it is would be 

 as it would in effect create a PTSD-Homelessness link that future 

e from this review.

ubstance abuse have only weak, indirect associations with 

odel. This would contradict your text, where on p 28 you cite, 

el study and a Winkleby et al. study as finding such associations. 

a broad range of research among non-Veterans who make this 

ciation. If you mean to disassociate homelessness and SA, as you 

odel (and invite others to cite you), then you need to insert specific 

explicitly explains your decision to do this.

1) We thank the reviewer for sharing these concerns. Further discussion led to a substantial revision of the model for overall clarity. We dropped the use of the more general term “mental illness.” “Underlying psychiatric illness” was added to a box labeled “shared early life exposures,” since the strongest evidence on this issue for a homeless veteran population comes from Rosenheck and Fontana 1994, which used psychiatric treatment before age 18 as a variable. As our reports notes, it is unfortunate that few studies involving homeless veterans actually assess for schizophrenia, unless they are among individuals seeking treatment for mental illness, in which case the sampling frame raises serious issues for the generalizability of any associations found.There is now a box labeled “PTSD/Depression/Anxiety.” While frequent comorbidity might provide justification for this cluster, our model groups these conditions together because a) the veteran-specific evidence cited (Washington and Yano 2010) also groups PTSD and anxiety disorders together, and b) because the general homelessness literature cited finds associations between depression and homelessness (as well as psychiatric disorders). Our report states that “the evidence linking PTSD to homelessness remains limited by the small number, small size and/or nongeneralizable sampling methods of existing studies.” This is not the same thing as stating that there is no evidence, and we stand by the model’s representation of an association between PTSD/Depression/Anxiety and homelessness. Here as elsewhere in the revised model, we have added a black box along the association pathway to indicate that the mechanism for the association is poorly understood. We hope this will encourage users of our model to direct future efforts towards understanding mediating factors.2) We thank the reviewer for pointing out the discrepancy between the research that we site describing the association between substance abuse and homelessness and the weak link presented in the conceptual model. We have revised the model to indicate that substance abuse has a strong association with homelessness, but that the path through which substance abuse effects the risk of homelessness remains unknown. We also note in the text that evidence for substance abuse as a causal factor for homelessness has been inconsistent. Much of the research on substance abuse and homelessness employs a cross-sectional sampling frame, and thus, cannot demonstrate cause and effect. We discuss the limitations of studies examining substance abuse and homelessness in detail in our “Assessing the Limitations of the Current Research” section.
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e Regarding Homelessness among Veterans Evidence-based Synthesis Program

Comment Response

ALENGE and AHAR counts should do more to look at the 

ms involved in the estimates. CHALENGE, as you say, has traditionally 

expert assessments, which (as you never point out) is a notoriously 

ess homeless population size (plenty of cites available on this) and 

nt. This is not a slam on CHALENGE but a recognition that they were 

e limited data that was available and that the report primarily seeks 

eeds fulfillment among the homeless Vet population. AHAR on the 

 reliance on mainstream homeless services data, is biased towards 

, as you point out on 22, a substantial gap (52,000 to 107,000) in the 

stead of examining further, you sidestep by only saying both numbers 

s of the problem.” As I said earlier, the Vet-AHAR bridges these two 

its estimate and in its methodology, and needs to be included here.

your stating the overrepresentation of risk for homelessness among 

istinguish between studies such as were done by Rosenheck and his 

age adjust the populations to get a more accurate representation of risk, 

on’t.

We have expanded on the discussion in this section and have included a discussion of the recently released Veteran AHAR along with data from that report. However, we feel that we adequately discussed the methodological problems of the CHALENG and AHAR counts along with the strengths and weaknesses of the epidemiology of the homeless more generally.We understand the reviewer to be referring to the study by Rosenheck and Frishman (1994) of Vietnam-era Veterans that suggested that overrepresentation was attributable to disproportionate numbers of Veterans in the youngest cohorts (age 20-34) of homeless White males, and the follow-up study by Gamache and colleagues (2001). We do not disagree with the reviewer about this. However, we are suggesting that, for the reasons discussed in the section on Assessing the Limitations of the Current Research, more work needs to be done to understand why Veterans are over-represented.

estion #2a but don’t put any text to answer it. This is confusing, and the 

ut cannot be sure, that this question is answered in the text to 2b. Why 

tions, then, or at least signal somewhere that 2a is answered in 2b

We agree, this was confusing and have combined the questions as suggested by the reviewer.

ion that there appear to be “unique, military related pathways by 

e these risks [for homelessness]” yet there are NO specifics, and NO 

athways either in the response to Question #2b or in the response 

ction in which the author states these pathways will be taken up in 

weak finding by Rosenheck and colleagues between heavy combat 

e omission in offering up specific evidence to back up this assertion, 

Best Evidence Synthesis” is very surprising.

The concept of a pathway, as used in our report, is crucially different from a direct association. Given that the existing evidence does not find that Veterans differ substantially from non-Veterans in terms of the risk factors most strongly associated with homelessness in general, it is important to try to understand what, if anything, is qualitatively different about Veterans’ experiences that might increase their risk of these shared or common exposures. The conceptual model was revised to clarify how military specific exposures are associated with a number of other exposures that are in turn shared with the general population; these shared exposures are more often directly associated with homelessness, but the influence of military-specific exposures on the prevalence or severity of shared exposures may be significant. These chains of exposures are the pathways referenced. The discussion of these issues has been expanded under the section describing the evolution of the conceptual model on pages 13-14. More generally the section devoted to answering Key Question 3 is structured to explore the evidence for these pathways, which, as the report suggests, might include the specific salience, in a Veteran population, for examining military sexual trauma and/or combat exposure as precursors to PTSD/Anxiety/Depression, or post-deployment readjustment difficulties leading to low income.
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A Critical Review of the Literature

Regarding Homelessness among Veterans Evidence-based Synthesis Program

APPENDIX B. Technical Experts Consulted and

Reviewers

Technical Experts Consulted

Ted Amann

Director of Homeless Programs

Central City Concern

Portland, Oregon

Monica Beemer

Executive Director

Sisters of the Road

Portland, Oregon

Lillian Gelberg, M.D., MSPH

Professor of Family Medicine

UCLA Geffen School of Medicine

Los Angeles, California

Don Miller

Chief Counsel

Housing and Urban Development

Portland, Oregon

Fran Randolph

Director of the Division of Services and Systems Improvement

SAMHSA, Center for Mental Health Services

Jim Reuler, M.D. 

Professor, Department of Medicine

Oregon Health and Science University

Portland, Oregon

Robert Rosenheck, M.D.

Director, Northeast Program Evaluation Center and

Professor of Psychiatry and Public Health

Yale University School of Medicine

New Haven, Connecticut

Annetta C. Smith

Population Division

U.S. Census Bureau
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A Critical Review of the Literature

Regarding Homelessness among Veterans Evidence-based Synthesis Program

Reviewers

Mary K. Cunningham

Senior Research Associate

Urban Institute

Amy Kilbourne, Ph.D., MPH

VA Serious Mental Illness Treatment Resource and Evaluation Center

John Kuhn

National CHALENG Coordinator

Stephen Metraux, Ph.D.

National Center for Homelessness Among Veterans

Thomas O’Toole, M.D.

Providence VA Medical Center

David Smelson, Psy.D.

Bedford VA Medical Center