NATIONAL CENTER Series 4

For HEALTH STATISTICS Number 7

VITAL and HEALTH STATISTICS

DOCUMENTS AND COMMITTEE REPORTS

use of Vital and Health Records

in EpidemiologicResearch

A Report of the

United States National Committee

on Vital and Health Statistics

An analysis of the changing needs for data in epidemiologic

research in relation to the present vital and health statistics

system with recommendations for use of existing vital and

health records and for developing new data for epidemiologic

studies.

DHEW Publication No. (HSM) 73-1265

Washington, D. C. March 1968

U.S. DEPARTMENT OF

HEALTH, EDUCATION, AND WELFARE Public Health Service

John W. Gardner William H. Stewart

Secretary Surgeon General
Public Health Service Publication No. 1000-Series 4-No. 7
NATIONAL CENTER FOR HEALTH STATISTICS

THEODORE D. WOOLSEY, Director

PHILIP S.LAWRENCE, SC.D., Associate Director

OSWALD K. SAGEN, PH.D.,, Assistant Director for Health Statistics

WALT R. SIMMONS, M.A., Assistant Director for Research and Scientific

ALICE M. WATERHOUSE, M. D., Medical Consultant

JAMES E. ‘KELLY, D. D. S., Dental Advisor

LOUIS R. STOLCIS, M.A.,Executive O//icer

DONALD GREEN, lf@~afio~of/icey

Development

Development

OFFICE OF HEALTH STATISTICS ANALYSIS

IWAOM.MORIYAMA,Ph.D.,Director

DEAN E.KRUEGER, Deputy Director

Public Health Service Publication No. 1000-Series 4-No. 7

Library of Congress Catalog Card Iiurnber 67-62375
FOREWORD

This report, prepared under the auspices of the U.S. National Committee on Vital and Health Statistics considers ways in which vital and

health statistics systems can better serve the changing need for data

in epidemiologic research. These needs arise from the increasing concern with chronic noninfectious diseases and the measurement problems

related to the nature of these diseases,

Recommendations are made for modifying the content of basic vital

and health records, and for developing new ways of making data from

these records available for epidemiologic research and other uses.

Robert L. Berg, M.D.

Chairman

U.S. National Committee on

Vital and Health Statistics

...

Ill
U.S. NATIONAL COMMITTEE ON VITAL AND HEALTH STATISTICS

Robert L, Berg, M.D., Chairman Herbert E. Klarman, Ph.D.

Professor and Chairman, Department of Department of Public Health Administration

Preventive Medicine and Community Health School of Hygiene and Public Health

The University of Rochester The Johns Hopkins University

Medical Center Baltimore, Maryland

Rochester, New York

Iwao M. Moriyama, Ph. D., Executive Secretary Everett S. Lee, Ph.D.

Director, Office of Health Statistics Analysis

National Center for Health Statistics

Public Health Service*

Washington, D.C.

Donald J. Davids

Chief, Records and Statistics Section

Colorado State Department of Public Health

Denver, Colorado

William Haenszel

Chief, Biometry Branch

National Cancer Institute

National Institutes of Health

Public Health Service*

Bethesdaj Maryland

Clyde V. Kiser, Ph.D.

Senior Memker, Technical Staff

Milbank Memorial Fund

40 Wall Street

New York, New York

Department of Sociology and Anthropology

University of Massachusetts

Amherst, Massachusetts

John R. Philp, M.D.

Health Officer

County of Orange Health Department

P. O. Box 355

Santa Ana, California

Donovan J. Thompson, Ph.D.

Department of Preventive Medicine

Schgol of Medicine

University of Washington

Seattle, Washington

Theodore D. Wmlsey, Ex officio

Director, National Center for Health Statistics

Public Health Service*

Washington, D.C.

SUBCOMMITTEE ON

USE OF VITAL AND HEALTH STATISTICS

Brian MacMahon, M.D., Chairman

Professor of Epidemiology

Harvard School of Public Health

Boston, Massachusetts

Lillian Guralnick, Secretaryl

Social Science Research Analyst

Health Insurance Research Branch

Divison of Health Insurance Studies

Social Security Administration*

Washington, D.C.

1. M. Moriyama, Ph. D., Ex officio

Executive Secretary

U.S. National Committee on Vital and Health

Statistics

Washington, D.C.

John Cassel, M.D., M.P.jf.

Professor of Epidemiology

Schcol of Public Health

University of North Carolina

Chapel Hill, North Carolina

Carl L. Erhardt, SC.D., Director2

Health Intelligence Statistics

The City of New York Health Services Administration

New York, New York

*

Department of Health, Education, and Welfare

IN EPIDEMIOLOGIC RESEARCH

Elmer A. Gardner, M.D., Director3

Community Mental Health Center

Health Sciences Center

Temple University

Philadelphia, Pennsylvania

Robert W, Miller, M.D.

Chief, Epidemiology Branch

National Cancer Institute

National Institutes of Health

Public Health Service*

Bethesda, Maryland

Donald L. Rucknagel, M.D.

Department of Human Genetics

University of Michigan Medical Schcd

Am Arbor, Michigan

Colitt White, M.D.

Professor of Biometry

Department of Epidemiology and Public Health

School of Medicine

Yale University

New Haven, Connecticut

lWhen appmn“ ted to the Suhcommittse, Miss Guralnick was a Statistician, Office of Health Statistics Analysis, National Center for Health Statistics, Public Health Service, Department of Health, Education, and Welfare, Wasbingtcm, D.C.

%fntil July 1, 1966, Dr. Erhardt was Associate Director, Office of Research, City of New York Deportment of Health.

3When appointsd to the Subcommittee, Dr. Gardner was Assistant Professor and Director, Division of Preventive Psyohia@, University of

Rochester School of Medicine and Dentistty, Rochester, New York.

iv
CONTENTS

Page

Foreword ------------------------------------------------------------

U.S. National Committee on Vital and Health Statistics --------------------

Subcommittee on Use of Vital and Health Statistics in Epidemiologic

Research -----------------------------------------------------------

Introduction ----------------------------------------------------------

Need for Review ------------------------------------------------------

Procedure ------------------------------------------------------------

Findings and Recommendations -----------------------------------------

Access to Vital and Health Records ----------------------------------

Record Linkage --------------------------------------------------

The Unique Number ----------------------------------------------

Ascertainment of Death -------------------------------------------

Followup --------------------------------------------------------

Information on Vital and Health Records ------------------------------

Cause of Death --------------------------------------------------

Congenital Malformations -----------------------------------------

Other Items -----------------------------------------------------

Development of Other Resources -------------------------------------

Summary of Recommendations ------------------------------------------

Appendix I. Selected Bibliography on Record Linkage -------------------

Appendix II. The Underlying Cause Concept ----------------------------

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IN THIS REPORT the changing needs for data in epidemiolo~”c research are examined in relation to the pvesent vital and health statistics systems.

The ascendancy of chronic noninfectious diseases as major causes of

movbidity and mortality requires new types ofdu$a and changes of emphasis in existing types of data. New measurement problems are often

encountered in these diseases, in which onset may be insidious, pro.

gression slow, and the interval between causes and effects long.

Each source of vital and health statistics is examined in terms of the

information requested on the basic record, the present means of access

to the data on the vecord, and the tabulations now being prepared by the

National Centev for Health Statistics.

Linkage of vcwious vital and health records is seen as a means of increasing their sepavate valwe, and fuvther exploitation of this device is

recommended. Use of some ynivenal identity numbev fov this purpose

should be explored along with the possibility of assigning such numbers

at bivth,

A National Death Index would be a great- asset in epidemiologic research. The National Center for Health Statistics is urged to explore

the technical pvoblems in establishing this vesouvce. Extension of the

scope of patholo~”cal conditions vecorded on death certificates beyond

those contributing to death should be considered.

Other recommendations are made for development of vital records information on congenital ma~ormations and for inclusion of a sample of

newbovn infants in the Health Examination Survey.

vi
USE OF VITAL AND HEALTH RECORDS IN

EPIDEMIOLOGIC RESEARCH

t!~~~i% some t~ths, ad not commonly-believed opinions, to

arise ~?om my meditations upon these neglected papevs (the Bills of

Mortality), I proceeded j%rther, to consider what benefit the knowledge

of the same would hying to the world; that I might not engage myself in

idle, and useless speculations, but . . . present the world with some real

fYuit Jrom those ayyie blossoms.”

John G~aunt, 1662

INTRODUCTION

The practice of epidemiology, or indeed of

public health, would today be inconceivable without access to vital and health records and the tabulations routinely assembled from them. The data

obtained by Graunt’s “antient matron” searchers

have been replaced by legally required certificates

of birth and death. These documents, and the

breadth of their application, have changed remarkably in the last 50 years, and today they

probably constitute the single most important resource of epidemiologic investigation. In addition,

entirely new sources of health statistics have been

developed, notable among these, in the United

States, being the several programs of the National

Health Survey.

With respect to epidemiologic purposes, vital

and health records serve the following functions:

1. As source data for the measurement of the

incidence and prevalence of disease.

These measurements serve administrative as well as epidemiologic purposes,

Because of the limitations of diagnostic

information derived from certificates of

birth and death, it is to this general purpose of providing source data that most

of the newly introduced types of health

statistics have been addressed.

2.

3.

4.

5.,

For comparison of disease rates in different populations, indifferent parts of the

same population, and in similar groups

over a period of time, in order to develop

hypotheses regarding the etiology of disease. Studies over time may also serve

to evaluate the effectiveness of preventive or therapeutic measures.

For identification of groups of people at

high risk of particular diseases. Such

groups may be of significance in disease

control or they may be particularly suitable for studies of etiology and therapy.

As the starting point for “follow-back”

studies in which a series of cases with

particular characteristics (e.g., dying

from a particular disease) is identified

from the primary source (in this instance,

the death certificate) and supplementary

information is sought from other sources

(e.g., the certifying physician) relevant to

etiology or other subjects of interest.

As the end point for studies in which subsets of the population are selected because

of their unusual characteristics or environmental exposures and followed to

identify diseases or other outcomes suspected of being related to the selected

factors.

1
Erhardt 1 and Moriyama~ have recently compiled some examples of the ways in which vital

records are being utilized for epidemiologic

research. Major projects in this country that are

dependent on vital records include the extensive

series of studies of veterans carried on by the

Follow-Up Agency of the National Academy of

Sciences, National Research Council, the largescale studies of the effects of smoking on health

by the National Heart Institute and the American

Cancer Society, the followup programs of registries of cancer and other specific diseases,, and

a great many smaller scale studies aimed at

specific problems.

It is difficult to assess the extent of epidemiologic use of the statistics published in

Vital Statistics of the United States or in the

reports from the National Health Survey. Reference to any journal of epidemiology or public

health will yield examples of such uses, but extensive use is also made of them by individual

investigators in searching for ideas and in preliminary testing of hypotheses-activities that

largely pass unrecorded.

NEED FOR REVIEW

The emphasis of epidemiologic investigation

has shifted markedly in the last two decades. A

decline in interest in the infectious diseases and

increase in concern with the noninfectious diseases have resulted from the change in relative

importance of these categories of disease in

many parts of the world, including the United

States. It is also recognized that, although major

tasks still remain in the improvement of control

over the infectious diseases, the contribution of

epidemiology to the development of control

methods is largely past —new advances are being”

made predominantly as the result of work in the

experimental laboratory and. through the better

application of existing knowledge. On the other

hand, the identification of cigarette smoking as

the major cause of this centuryis epidemic of

lung cancer has clearly demonstrated the polErhardt, C. L. Vital records are useful. Harvard, Pub.

Health Alumni Bull. 227-11, 1965.

2Moriyama, I. M.: Use of vital records for epidemiological

research. J. Chronic W?. 17: 889-897, 1964.

tential contribution of epidemiologic research. at

the present stage of knowledge of those chronic

diseases that now constitute the predominant

health problems in this country.

This shift in emphasis of epidemiologic investigation has required great changes in methodology, if not in philosophy. New or newly emphasized methods are required to deal with

problems such as:

1.

2.

3.

4.

5.

Detection of causal associations in which

decades or generations may lapse between

cause and effect.

Measurement of existence and stage of

diseases whose onset and progression are

insidious and often unknown to the patient

for many years.

Description of demographic distribution of

conditions of low mortality for which the

quality of medical diagnosis may vary

markedly between populations and population subgroups.

Scientific and administrative problems of

cohort studies that require large numbers

and long-term followup.

Detection of clustering of disease in time

or place at a much lower level of intensity

than that observed in frank infections.

With these types of problems in minfi, “it has

seemed useful to review existing health statistics and their sources to determine whether they

should and could be modified to better serve

epidemiologic needs.

The review has been further stimulated by

recognition of the enormous increase that has

occurred and will continue in the technical feasibility of data reduction, retrieval, and analysis

on a large scale. The potential of this improved

technology may be unrealized if the basic records

are not appropriately modified.

In the past, the nature of health statistics

and the usefulness of vital records have &en

limited by the fact that the records were established and continued for legal rather than

health purposes. In the last 50 years, however,

there has been increasing acceptance of the use

of vital records for public health and scientific

purposes. There is, rherefore, a good prospect
that the demonstration of significant epidemiologic needs will be influential in producing

changes or applications in vital records and

statistics. While most of the information that

has been added to vital records and the new

sources that have developed have been based on

a request for voluntary response, rather than as

a legal requirement, there is no evidence that

quality or completeness of information has been

compromised on this account.

PROCEDURE

The subcommittee has limited its consideration to the uses of health records and statistics in

investigating the etiology of disease. Although

this may imply a rather narrow definition of

“epidemiologic uses, “ it embraces the most important use of epidemiologic data. Other subcommittees of the National Committee have, of

course, keen concerned with medical care, demography, and other areas in which “epidemiologic” data have application.

The committee has reviewed the standard

certificates of birth, death, fetal death, marriage

and divorce, now in the final stages of a decennial revision, as well as the tabulations regularly developed from these sources and published

in Vital Statistics of the United States. Programs,

data forms, and reports of the three main components of the National Health SurveJ –The Health

Interview Survey, the Health Examination Survey,

and the Health Records Survey— were considered.

The purposes of and current activities in special

disease registries, record linkage, and genetic

uses of linked vital records were reviewed.

The subcommittee did not deal with important issues of confidentiality of vital and

health records and protection of the privacy of

individuals. While these issues underlie any use

of vital records for epidemiologic purposes and

might be important in the implementation of

several of its recommendations, the subcommittee did not consider itself constituted with

the legal and other representation that would be

required for a meaningful discussion of the issues.

It should ke pointed out, however, that legal and

procedural safeguards against the misuse of vital

record information have been part of the operation

of Federal and State statistical systems for many

years, and that these safeguards have been phenomenally successful. The distinction between

the use and dissemination of data on individuals

as individuals and their use for describing the

characteristics of groups without the identification of individuals has become widely recognized and accepted as a basis for statistical and

epidemiological use of c,mfidential records.

Computers now provide new and even more effective techniques for protection against the tpisuse of confidential information.

The subcommittee did not take up the question of infectious disease reporting, the national

component of which is now the responsibility of

the National Communicable Disease Center

(NCDC), Atlanta, Ga. However, it is believed that

a review of this area would be useful, and the

National Committee might consider the establishment of a subcommittee with special competence

in infectious disease and with representation from

NCDC and State Health Departments to review

this field.

With respect to each of the types of records

reviewed, the subcommittee considered (a) the information existent, or requested, on the basic record, (b) the tabulation now prepared from this

information by the National Center for Health Statistics (NCHS), and (c) the existing means of access to the information contained on the records.

By far the most important gap between

existing and potential usefulness seemed to lie

in connection with item c, access to records.

Since the major recommendations of the subcommittee are in this area, it will be considered

first.

FINDINGS AND RECOMMENDATIONS

Access to Vital and Health

Records

The problem of access to vital records has

become acute with the revolutionary changes in

data processing techniques already referred to.

The potential for record utilization has been expanded almost beyond limit, provided the records

and their storage are in such forms as permit

machine access. Aggravating the problem is the

fragmentation of the U.S. vital record system

into more than 50 politically, geographically, and

administratively independent systems. The effects

of this fragmentation are especially evident in

studies th~ require that people be followed over

3
long periods of time, as is usually the case in

investigations of the etiology of chronic diseases.

Two particularly urgent needs are apparent:

(a) methods that will improve our ability to “link”

records pertaining to the same person or family,

and (b) facilities to improve our ability to trace

death records of persons enrolled in investigations.

Record Linkage

The potential of the information to be obtained by linkage of records is obvious. The

linkage of records pertaining to an individual

allows the correlation of events and circumstances

of his life extending over the long periods associated with the incubation and development of

chronic disease. The linkage of records pertaining to members of the same family allows

studies of the genetic determinants of disease as

well as the familial environment. No one seriously

questions the premise that the linkage of health

records of as many varieties as possible would

be of great value for patient care and administrative purposes as well as for the purposes of

etiologic investigations.

The practical aspects of the record linkage

problem are less clear. A number of experimental record linkage systems have been set up

in recent years, and a bibliography of relevant

publications is given in Appendix I. Basic questions still at issue are (a) what identifying information most accurately allows linkage of

records of the same individual or family, (b) what

records can be linked with the greatest profit in

terms of derived information, and (c) ‘what is the

most appropriate population size to ke covered.

Unfortunately, the answers to these questions are

not generalizable to all times or all places, and

although some of them have keen answered for

investigations of particular problems in particular

places, it appears that available information is

insufficient to recommend inauguration of any

particular record linkage system in the United

States as part of routine record procedures.

Two general recommendations do seem appropriate however. First, exploration of individual and family record linkage should continue to

be pressed as a high priority research area to

identify which linkages are likely to be most profitable and which methods most efficient. Second,

the basic records themselves should already be

in process of modification so that (a) record

linkage for the purpose of specific short-term

studies, whether performed clerically or electronically, is facilitated and improved in accuracy, and (b) record systems are prepared for

the incorporation of routine machine linkage

when the time comes. Perhaps the most important single component of this modification

would be the acceptance and wider use of the

concept of a unique number to identify each individual in a population.

“The Unique Number

The idea that each individual would have a

unique number and that this number would identify

all his health (and other) records is an old one,

The advantages of such a procedure for record

linkage are obvious. The widening use of the

Social Security number in the United States puts

the concept within the realm of feasibility for

a large proportion of the population, perhaps for

the first time. Several other numbering systems

have been proposed, and even tried. A unique

birth certificate numbering system, begun in

1947, has subsequently been dropped in many

areas, presumably because of lack of use.

The wider the use of a particular number,

the greater is the amount of information that can

be linked. At the same time, the more frequently

an individual is asked for that number the more

likely he is to remember it correctly or have it

available, which again encourages its use for

other purposes. Thus, there is a circular effect

operating-in favor of the more widespread numbering system. This consideration argues overwhelmingly for the adoption of the Social Security

number as the unique identifying number for

health record purposes. If there was doubt about

this previously, it was dispelled by the implementation of the Medicare program, in which the

Social Security number is the basic identifying

device.

The Social Security number is not ideal, A

proportion of the population still has no number;

a person may, by request, have more than one

number; numbers are not usually assigned until

wage earning begins; the lack of any apparent

pattern to the assigned number (i.e., a person

4
cannot directly relate his number to his birth

date or any other readily remembered set of

figures) makes for frequent errors in recording

and transcribing. Some of these problems will

decrease as time passes and use of the numbers

spreads. Others may be mitigated by deliberate

efforts.

In the latter context, for example, it is noted

that NCHS and representatives of State Health

Departments are planning to confer with the

Social Security Administration (SSA) to explore

the possibility that a number assigned to an individual at birth by the State Health Department

(from a list previously supplied by SSA) could

later become the Social Security number when

the individual makes application for assignment

of a number.

Hospitals should be asked to incorporate

Social Security numbers as part of their basic

identifying information. (Presumably, this will

in any event be necessary for Medicare patient s.)

They should be asked to explore the feasibility

of the use of the Social Security number in place

of their own record numbering system. This

would greatly improve access to records of a

particular patient identified by means of his

Social Security number in some other context.

The U.S. Standard Certificate of Death now

contains a place for the Social Security number.

The States are urged to retain this item in their

own certificates and to press for its completion

in all possible instances. Whether or not it subsequently becomes possible to assign a “Social

Security number !! at birth, it would be of great

value to incorporate Social Security numbers of

both parents on the Certificate of Live Birth.

Family record linkages would be enormously

facilitated by this procedure.

Ascertainment of Death

U.S. death certificates contain a considerable

amount of information regarding the decedent, and

the presumed cause of his death. The quality of

the information is high and the completeness of

registration is excellent. These certificates constitute a most valuable source of information for

epidemiologic studies,

The major problem arises in locating the

death certificate of a specific individual unless

the date and place of his death are known with

accuracy. The registration system is centralized

only with respect to certain advisory functions

and the preparation of national statistical tabulations. After the national statistical tabulations

have been prepared, the centralized copies of the

basic records are discarded. To locate the death

certificate of a person whose place of death is not

known might involve separate searches in more

than 50 different States and cities. There is considerable variation across the country in the

ease with which searches of these archives can

be conducted. In addition, there is an understandable reluctance on the part of some Registrars to undertake searches for certificates

which may not exist in their archives. It should

be noted that, in some jurisdictions, while the

cost of the search is borne by the Registrar’s

office, the reimbursement goes directly into the

State treasury and does not compensate the Registrar’s office for the additional labor involved.

As only one example of the type of problem

that this fragmentation can provoke, it may be

pointed out that in a current study of the mortality

among steelworkers undertaken by the National

Cancer Institute, more than 30 clerical steps are

involved in tracing the subjects from employment

to death. In addition to the size of the task involved in tracing deaths, there is also a problem

with completeness, since it is, in practice, never

practical to search for untraced cases in all 50

jurisdictions. Searches are usually restricted to

two or three States with the highest rates of immigration from the area of the study.

The idea of a National Death Index located

in the National Center for Health Statistics has

been discussed, more or less casually, from

time to time in the past. The index would permit

identification of the fact, place and date of death,

and, probably, State death certificate number.

Access to information on the death certificates

themselves would, as now, be through individual

State registries.

It is believed that the mounting volume of

studies of the chronic diseases alone makes the

establishment of such as index an urgent necessity. There are, in addition, needs for such

an index in connection with Medicare, and other

medical care and commercial purposes. The cost

of the index could be justified entirely by its

5
epidemiologic uses, but the additional medical

care and commercial uses ‘appear to eliminate

cost as a serious deterrent.

In epidemiology, the index would be used

primarily for studies of prognosis or cause of

death among persons having particular diseases

or undergoing particular exposure, for example:

1.

2.

3.

4.

5.

Selected occupations, e.g., steelworkers,

the rubber industry, hard-rock and uranium miners, smelters, etc.

Professional societies whose members

have unusual laboratory exposure, e.g.,

American Chemical Society, American

Society of Immunologists.

Groups undergoing health status evaluations (as predictors of longevity or causes

of death) e.g., participants in the National

Health Survey, Kaiser-Permanente multiphasic examinations, studies of infant

development and health status, executive

health (preventive maintenance) programs, and the American Cancer Society’s

study of more than 1 million persons.

Other suspected special risk groups, e.g.,

children who received SV 40 or other

contaminated vaccines or drugs, persons

exposed to ionizing radiation, blood

donors, cases of accidental poisoning,

etc.

Members of special disease registries—

cancer, mental illness, congenital malformation,

It is therefore recommended, that a Nationul

Death Index be established. Problems that require detailed technical study include the amount

and nature of information that will be required for

accurate identification, cost of the index, and the

extent to which this cost can be met by commercial uses.

Followup

in some studies it is sufficient to identify

the dead members of the study group--members

not so identified being assumed to be alive. However, when death ascertainment is known to be

incomplete, or when pathologic end points short

of death are being studied, it is usually necessary

to trace individuals over periods of years or

decades.

In this country, in the presence of considerable migration and the absence of cent inuous

population registration, a national health service

or other national identification system, such a

followup can be extremely difficult. Nevertheless,

there are numerous resources and methods that

can be utilized. Many workers appear to be unaware of the range and potential of these resources. In connection with its own research

program the Division of Radiological Health

(DRH), USPHS, prepared in 1962 a roster of

followup facilities.q More than 30 sources are

described, together with the legal basis on which

they may be utilized and the usual procedures

involved. It is believed that it would be most

useful to make such a document readily available

through publication, and it is recommended that

NCHS arrange for the preparation and publication

of a revised version of the DRH manuscript or a

newly prepared document with similar intent.

Costs of various procedures should be included.

Information on Vital and Health

Records

Having in mind the undesirability of burdening routinely prepared documents with information

required only for ad hac and limited purposes,

there are few recommendations to be made regarding the content of existing vital and health

records. However, some areas of concern were

identified,

Cause of Death

The present standard certificate of death

restricts information on pathologic conditions

existing in the decedent to those which the certifying physician considered as contributing to the

death. In fact, however, with many chronic condi -

3Staff of the Cooperative Thyrotoxicosis Therapy Follow.

Up Study: Resources for Locating Patients. Division of Radio.

logical Health, U.S. Public Health Service, 1962. (mimeo.

graphed)
tions it may be impossible to determine in individual cases whether or not an existent condition

contributed to the death; such a determination

may be possible only in terms of statistical

probability based on comparison of mortality

rates in groups of persons with and without the

condition, In many instances, therefore, selection

of pathologic conditions to appear on the certificate is arbitrary and inconsistent. A memorandum on this matter is reproduced in Appendix II

as a basis for discussion.

The matter, while clearly a theoretical

problem, did not appear of great practical moment so long as statistical tabulations, and,

generally speaking, access to certificates,

were on the basis of a single pathologic condition

selected as the “underlying” cause. This single

selection made quite obvious the arbitrary nature

of the information presented and the necessity

to restrict the use of diagnostic information to

pathologic conditions likely to be selected as the

underlying cause if they were present.

However, NCHS is now committed to early

initiation of a program of coding and tabulating

multiple causes of death listed on individual

certificates. It then becomes much more crucial

which conditions are included on and which omitted

from the certificate, From two points of view--

(a) for investigating in statistical terms which

conditions do in fact contribute to death and in

what degree, and (b) improving the death certificate as a general research tool— it seems important to shift the emphasis in certification from

conditions supposedly contributing to death to

conditions present at the time of death, or of

which residua are present at the time of death.

How such additional information might best

be collected has not been evaluated. Thus, in

designing a possible Part III of the cause of

death question on the death certificate, seeking

information on other significant conditions present, .it is not clear whether more complete

certification would be obtained by means of an

open- ended question or by a checklist of conditions such as diabetes, hypertension, congenital

malformation, and so on. Such questions may be

approachable through follow- back studies start -

ing from current certificates, and it is suggested

that such studies be undertaken as a basis for

specific proposals for the next revision of the

standard certificate.

Congenital Malformations

As other causes decline, the congenital malformations become responsible for an increasing

proportion of mortality and morbidity in infancy

and childhood. Because certain forms of malformation have been clearly shown to be preventable, and because of the relatively short

interval between cause and effect, this category

of diseases is a prime target for investigative

effort. Birth certificates can provide a major

resource for this effort by providing access to

(1) very large numbers of cases of common malformations, (2) large numbers of cases of common malformations with characteristics of particular value, e.g., being a twin. (3) series of

cases of malformations of such rarity that series

cannot be assembled from clinical sources, and

(4) population-based series that can be used to

investigate geographic and temporal clustering.

Birth certificates can never be expected to

provide a complete ascertainment of malformations—partly because of the impossibility of

defining a malformation. However, descriptive

features make it quite evident that different

etiologic factors are operative in different categories of malformation, and, in some instances,

within a single diagnostic category of malformation. Birth certificates will be a useful resource even if their information is limited to

‘those major, externally evident, anomalies which

could be expected to be fully reported in a

reasonably competent system.

It is to be hoped, therefore, that all States

will retain the malformation item proposed on

the standard live birth certificate, and make

efforts to improve reporting of this item. With

respect to the maintenance of surveillance of

malformation reporting, in order to detect geographic or temporal clustering at an early stage,

it is recommended that a comparison k made between reporting on birth certificates and systems,

such as have been set up in New Jersey and

British Columbia, that are based on reporting

independent of the birth certificate.

It is further recommended that consideration

be given to the possibility of examination of a

7
nationally selected sample of newborn infants

(including late fetal deaths) as one of the cycles

of the Health Examination Survey. With respect

to congenital malformation specifically, such a

survey would provide estimates of the prevalence

of congenital malformations detectable at birth—

heretofore unavailable except with respect to

the patients of a few highly specialized hospitals—

and a standard against which to evaluate other

means of estimating malformation rates, Because

of the special problems of conducting examinations immediately after birth, such a survey

would require different sampling procedures

from those that have been used so far in the

Health Examination Survey. However, sampling

of maternity facilities and of blocks of time

within such facilities (rather than direct sampling

of individuals born) would seem to provide a

relatively simple method for assembling a representative national sample of births.

Other Items

Level of education of parents has replaced

occupation on the standard certificates of live

birth and fetal death. The replacement results

from the difficulty of interpreting and coding

the occupation item, and belief that, as an index

of social class (which is the main purpose of the

occupation item), education is equally valid, In

view of the very limited use of occupation as

recorded on death certificates, an attempt might

also be made to collect education data on death

certificates in selected areas. The greater dif -

ficulty of obtaining education data on decedents,

as contrasted with parents, is recognized, and in

the evaluation phase the item should probably be

sought as a supplement to, rather than replacement for, information on occupation.

In many studies of the effects of social and

psychologic stress it would be advantageous to

have the names (rather than simply the number)

of the children as an item on the certificate of

divorce. It is understood, however, that there is

a reluctance on the part of Registrars to press

for this item.

Development

of Other Resources

It seems worthwhile to identify two resources

that do not appear to have been utilized to their

fullest potential for epidemiologic investigation,

although there are no specific recommendations

as to how their utilization might be increased,

The first consists of the records of deaths

coming under the purview of the medical examiner. The medical examiners’ investigations

of such deaths are detailed and the records are

public. Medical examiners in general appear to

be favorably disposed to the utilization of the

records for scientific investigation, and, in some

instances, have initiated epidemiologic investigations based on their material. The records

offer extensive possibilities for analysis alone,

or as the starting point for investigations in which

additional information is sought.

The second resource consists of the records

of health insurance schemes. The value of such

records is demonstrated by the series of reports

based on the experience of the Health Insurance

Plan (HIP) of Greater New York. While it is true

that HIP incorporates medical care as well as

an insurance program, essentially similar records are usually required as the basis for payment even when the medical service is not performed by the insuring company. Remarkably

little use has been made, for example, of the

voluminous material that must exist in Blue

Cross- Blue Shield plans relevant to studies of

the familial clustering of disease, the association

of diseases in individuals, and ‘the natural history

of chronic diseases.

Lastly, in connection with the major programs of medical care now being initiated—

notably Medicare, the Title 19 provisions of

Medicare as they relate to children, and the

heart-cancer-stroke and community mental health

centers—it is hoped that adequate statistical and

epidemiologic consultation will be obtained at

this early stage to ensure the ultimate usefulness

of the medical records.
SUMMARY OF RECOMMENDATIONS

1,

2.

3.

4.

5.

Linkage of various vital and health records should continue to be explored as a

high priority research area, to identify

which linkages are likely to be most

profitable and which methods most efficient.

The Social Security number should be

accepted as the most practical numerical identification of individuals, and incorporated into all vital and health records, Where possible, the Social Security

number should become the actual identification number for the specific record of

the individual. Hospitals should be asked

to consider this last possibility.

NCHS, representatives of State Health

Departments, and the Social Security

Administration should explore the possibility of assigning a Social Security number to dn individual at birth. This recommendation supposes that the Social Securit y Administration is itself not already

considering the use of a birth numbering

system for its own purposes.

Social Security numbers of parents should

be added to the certificates of live birth

and fetal death.

Because of the great epidemiologic usefulness of a National Death Index, NCHS

should explore with some urgency the

technical problems involved in the establishment of such a resource. Apart

from estimates of cost and the extent to

which this would be mitigated by commercial use, there is need for information

6.

7.

8.

9.

on the amount and nature of the information required to identify decedents,

and the computer technology most appropriate to such an extensive operation.

It should be stressed that an index is

meant, not a repository for the death certificates themselves.

A document should be prepared and published for the assistance of investigators

in followup studies, along the lines of that

prepared for their own staff by the Division of Radiological Health. Sources of

followup, legal bases, usual procedures,

and costs should be included.

The basis for inclusion of pathologic conditions on the death certificate may need

to be extended beyond the present restriction to conditions presumed to have

contributed to the death. Information might

be sought on all significant conditions

present at the time of death, or of which

significant residua are present at the

time of death. The best way of obtaining

this information should be sought in

follow- back studies based on current

certificates in preparation for the next

revision of the standard certificate.

Efforts should be made to extend, improve, and utilize information on congenital malformations reported on vital

records, particularly the birth certificate.

Consideration should be given to the

possibility of examination of a national

sample of newborn infants (including fetal

deaths) as one of the cycles of the Health

Examination Survey.

00

9
APPENDIX I

SELECTED BIBLIOGRAPHY ON RECORD LINKAGE

Acheson, E. D.: The oxford Record Linkage Study, Report

on the Second Year’s Operations. Oxford Regional Hospital

Board. Oxford, England 1963.

Acheson, E. D.: The Oxford Record Linkage Study, a review of the method with some preliminary results. F’rvc.Roy.

Soc.Med. 57:11, 1964.

Acheson, E. D.: The Oxford Record Linkage Study, a central file of morbidity. &it. J, Preo. &SocW Med. 18:8, Jan. 1964.

Acheson, E. D., and Evans, J. G.: The Oxford Record Linkage Study. Biometrics 2:367, 1963.

Acheson, E. D., Truelove, S. C., and Witts, L. J.: National

epidemiology. Brit.M.J. 1:668, 1961.

Bahn, A. K.: Methodological study of population of oub

patient psychiatric clinics, Maryland 1958-59. Public Health

Monograph No. 65. PHS Pub. No. 821. Washington, D.C., 1961.

Bahn, A. K.: The development of an effective statistical

system in mental illness. Arn.J.Psychiat. 116:798, 1960.

Bahn, A. K.: Person matching by electronic methods.

Communications of the Association for Computing Machinery

5:404, 1962.

Babn, .4. K., and Bahn, R.: Considerationsin using social

security numbers on birth certificates for research purpoees.

Pub. HeaZth Rep. 79:937, 1964.

National Office of Vital Statistics: Some aspects of vital

statistics registration in Canada, by A. E. .Bailey. Vital

Statiez!ice-SpeciaZ Rep&k Vol. 23, No. 22. Public Health

Service. Washington, D.C., 1947. pp. 252-61.

National Center for Health Statistics: Summary report on

Tennessee’s “Record of Events,” by M, R, Baird, and E. H.

Halpin. The Public Health Conference on Records and StGtie tics, PHS Dec. No. 473. Public Health Service. Washington, D.C., Dec. 1959

Central Bureau of Statistics: Population changes 1961.

Official Statistics of Sweden (Population and Vital Statistics) Stockholm, 1963.

Davidson, L.: Retrieval of mispelled names in an airline

passenger records system. Communications of the i4ssoc&

ation for Compu$ing Machiney. 5:169, 1962.

Dunn, H. L.: Record linkage. Am. J. Pwb.Heatth. 36:1412,

1946.

Dunn, H. L.: A national identity registration system to

synthesize social statistics. Estadiatica, Journal of the Inter

American Statistical htstitute 11:605, Sept. 1953.

Harris, R.: Letter to Dr. Councell dated Mar. 8, 1965.

Kennedy, J. M.: Linkage of birth and marriage records

using a digital computer. Atomic Energy of Canada Ltd.,

Report No. 1258, Chalk River, Ontario, 1961. p. 18.

Kennedy, J. M.: The use of a digital computer for record

linkage. Proceeding of the Seminar on the Uee of Vital and

Health Statistics for Genetic and Radiation Studies, 1962,

pp. 155-159.

Kennedy, J. M., Newcombe, H. B., Okazaki, E. A., and

Smith, M. E.: List processing methode for organizing filee of

linked records. Atomic Energy of Canada Ltd., Report No. 2078,

1964.

Kjelsberg, M., and Metzner, H.: Record system used in the

Tecumseh Community Health Study. Personal communication.

Marshall, J. T.: Canada’s national vital statistics index.

Population Strtdies 1(2):204, Sept. 1947. (Printed in Great

Britain.)

Masi, A. T., Sartwell, P. E., and Shulman, L. E.: The use

of record linkage to determine familial occurrence of diseaee

fromhospital records (Haehimoto’s disease). Am.J.Pub.Health

54(11): 1887-1894, NOV. 1964.

McKeown, T. and others:. Session VII, panel discussion,

session on epidemiological studiee. Second international Conference on Congenital Malformations. The International Medical

Congress, Ltd., New York, 1964. pp. 341-351.

Minet, P. L.: Fertilitd pr~coce d’une cohorte de mariages

clans une province canadienne. Biology Branch. Atomio Energy

of Canada Ltd. Basel 14:186-196. Chalk River, Ontario, 1964.

National Center for Health Statistics: “Studygroup on record

linkage. The Public Health Conference on Records and Statistics, PHS Dec. No. 603. Public Health Service. Washington,

U.S. Government Printing Office, Nov. 1964.

National Centsr for Health ”Statistics: Planning session for

study group on record linkage. The PUWC Health Conference

on Records and Statistics, PHS Dec. No. 603.1. Public Health

Service. Washington. U.S. Government Printing Office, Jan.

1965.
Newcombe, H. B.: Detection of genetic trends in public

health. E/feet of Radiation on Human He?edity. World Health

Organization, Geneva, 1957. pp. 157-168.

Newcombe, H. B.: Record linkage as a means of studying

the somatic effects of low doses of radiation. Science 130:

994.959, 1959.

Newcombe, H. B.: Population genetics, population records.

hlethodology in Human Genetics. Holden-Day, Inc., 1962. pp.

92.113.

Newcombe H. B.: Untapped knowledge of human populations.

Transactions of the Royal Society of Canada. Vol. LVI, Series

III, Section 111, June 1962. pp. 173-180.

Newcombe, H. B.: Risk of fetal death to mothers of differwrt ABO and RH blood types. Am. J. Human Genet. 15(4):

449-464, Dec. 1963.

Newcornbe, H. B.: Pedigrees for population studies, a progress report. Cold Spring Harbor Symposia on Quantitative

Biology, 29:21, 1964. ‘

Newcombe, H. B.: Panel discussion, session on epidemiological studies. Second International Conference on Congenital

Malformations. The International Medical Congress, Ltd., New

York, 1964. pp. 345-349.

Newcombe, H. B.: Environmental versus genetic interpretations of birth.order effects. Eugenios Quarterly, Nov. 1964.

p. 36.

Nmvcombe, H. B.: Screening for effects of maternal age

and birth order, in a register of handicapped children. Ann.

Human Genet. 27:367-382. London, 1964.

Newcombe, H. B.: Use of vital statistic. United Nations

World Population Conference, Belgrade, Yugoslavia, Aug. 30

to Sept. 10, 1965.

Newcombe, H. B., Axford, S. J., and James, A. P.: A plan

for the study of fertility of relatives of children euffering from

hereditary rind other defects. Atomic Energy of Canada Ltd.,

Report No. 511, Nov. 1957. p. 50.

Newcombe, H. B., James, A. P., and Axford, S. J.: Family

linkage of vi tef and health recorde. Atomic Energy of Canada

Ltd., Report No, 470. Chalk River, Ontario, July 1957. (Reprinted Aug. 1961 and May 1964.)

Newcombe, H. B., and Kennedy, J. M.: Record linkage,

reeking maximum use of tbe discriminating power of identifying i~formation. Communications of the Association for Computing Machinery 5(11):563-566,1962.

Newcombe, H. B., and Kennedy, J. h!.: Demographic analysis and computer programs. United Nations World Population

Conference, Belgrade, Yugoslavia, Aug. 30 to Sept. 10, 1965.

Newcombe, H. B., Kennedy, J. M., Axford, S. J., and James

A. P.: Automatic linkage of vital records. Science 130(3381):

954-959, Oct. 1959.

Newcombe, H. B., and Rbynas, P. O. W.: The cost of individual follow-up studies of large populations. Proceedings

of the International Population Conference- Paper No. 16. (Reprinted as Atomic Ener~ of Canada Ltd., Report No. 1255,

Sept. 1961. p. 8.)

Newcombe, H. B., and Rhynas, P.O. W,: Family linkage

ofpopulation records. On the Use of VitaJrznd Health Statistics fo? Genetic and Radiation St&ies. United Nations Pub.,

Sales No. 61. XVII(8) :135-154, 1962.

Newcombe, H. B., and Rhynas, P.O. W.: Child spacing

following stillbirth and infant death. Eugenics QuarteT?y 9(l):

25-35, Mar. 1962.

Newcombe, H. B., and Tavendale, O. G.: Effectsof father’s

ageontherisk ofchildhandicap or death. -4m.J.Human@~e~.

17(2):163-178, 1965.

National Office of Vital Statistics: A coordinated system

of vital records and statistics, the need for coordination, by

H. L. Dunn. Public Health Service. Washington, D. C., JUly

1953.

Phillips, W., Jr., and Bahn, A. K.: Experience with cornputer matcbingby names. Proceedings of the Som.al Statistics Sections, American Statistical Asso&ation, 1963.

Phillips, W., Jr., Bahn, A. K., and Miyasaki, M.: Personmatching hyelectronic metbods. Communications of the Association foT Computing Machiney 5:404, 1962.

Phillips, W., Jr., and Gorwitz, K., and Bahn, A. K.: Electronic maintenance of case registers. Pub. Health Rep. 77:

503, 1962.

Schwartz, E. E.: Some observations on tbe Canadian family allowances program. The Social Serv4ce Review Vol. XX,

No. 4. Dec. 1946.

Statistical Commission: Twelfth session, Item 9 of the

provisional agenda E/CN/3/293. United Nations Economic

and SociaJ Council. Feb. 7, 1962. p. 38.

Vinge, Margit, Head, Documentation Unit, Central Bureau

of Statistics, Stockholm. Letter dated Mar. 9, 1965, tn Louis

R. Stolcis with attachments.

000

11
APPENDIX II

THE UNDERLYING CAUSE CONCEPT

At the November 1961 Geneva meeting of the

Subcommittee on Classification of Diseases of

the Expert Committee on Health Statistics, it was

suggested that the “concept of underlying cause

might be reexamined to see if a more satisfactory

conceptual basis for classifying causes of death

could not be developed.” The concept can be reviewed in the light of uses made of information

obtained on death certificates, and from the

viewpoint of the data available for decedents.

No matter how the medical certification is designed, its source is the existing observations

on the decedent, and its statistical function is to

serve public health and medical needs.

Cause of death information is now used: (1)

to describe the most important current health

problems; (2) to record frequency of certain

rare, fatal diseases; (3) to serve as a starting

point of epidemiologic studies of specific populations characterized by the disease to which the

death was assigned; and (4) to assess the frequency of conditions associated with death, but

which are not the direct cause. of death.

Does the underlying cause of death supply

data that are appropriate to these uses? If not,

what questions on the medical certification would

elicit a more valid response for these applications? Are there other uses not nov served

that could be met with a change in the kind of

information requested?

The first use, to describe the most important

current health problems, has changed, at least in

the United States, in the last decade. The National

Health Survey can now provide data on the major

illnesses found among the living population.

While it was never sound to use mortality data

as an estimate of morbidity, this was commonly

done in the past. Such a use is no longer defensible. The function of the death certificate is still

that of providing information on those diseases

that cause death. These data augment those obtained on morbidity by supplying data for diseases that cause death without previous signs or

symptoms; by evaluating the severity of disease

through the fact that it has caused “premature”

death; by supplying counts for diseases, that,

owing to their rare occurrence, or occurrence

in a limited population (say, under 1 month of

age) are not easily reached through survey

methods. In all of these cases, the concept of an

underlying cause of death can provide valid

information, But if disease incidence were viewed

as a continuum of information beginning with the

~ccurrence of signs and symptoms in the living

population, followed by disabling illness and

finally, death, then the information collected on

the death certificate should be restructured 10

parallel the “prevalence” concept used in the

collection of morbidity data. The underlying cause

concept cannot provide prevalence data, or the

counts needed for case fatality data.

The second use, to record the frequency of

rare disepses with high fatality rates is clearly

met by the underlying cause concept. There should

not be any difficulty in collecting such information

under other definitions of the cause of death,

The third use, as a starting point of epidemiologic studies, is now practically limited to

studies of diseases selected as the underlying

cause of death. Many investigators would pre12
fer to follow every occurrence of a disease in

the population of decedents rather than thepopulation of persons whose deaths were assigned to

this disease. The larger population can be approached by coding all the diseases reported on

the death certificate. The mention of these diseases will still be limited to the physician’s interpretation of the response required by the

present certificate. A thoughtful certifier may

select only those diseases related to the death,

while another physician may list all serious

diseases present at death. If the epidemiologist

wishes to know for how many persons a particular disease contributed to death, it may be

possible to obtain the information from the current certificate when all conditions reported on

the record are coded. If the epidemiologist needs

information on how many persons died with a disease, this count cannot be obtained with the present form of the medical certification.

The fourth use, to assess frequency of conditions associated with death but not the direct

cause of death, has been cited as the chief reason for coding all the conditions reported on the

death certificate, rather than the underlying

cause alone. As pointed out in the previous paragraph, the wording on the present form does not

elicit a report of all conditions present at death,

not even all serious conditions. Response to

specific queries concerning diseases present at

death has demonstrated that the entries on the

certificate represent the physician’s judgment or

understanding of the nature of the report expected from him. The form must be redesigned

if conditions present at death are needed.

In summary, the underlying cause concept

cannot generally provide prevalence or incidence

data. It can provide counts for diseases causing

death, or contributing to the event of death. Where

there is more than one disease contributing to

the death, the present wording of the certificate

does not encourage a complete response. Where

there is a serious disease present that is unrelated to the sequence of events resulting in

death, the certificate specifically discourages

such an entry.

Once a decision is reached on what data are

needed about death for medical and public health

purposes, the requirements must be phrased to

fit into the way death certificates are completed,

and what is known about decedents. The medical

and social information at hand for a decedent

may vary from that assembled for the person under

systematic lifelong medical care to the one-time

posthumous observation made by the medical examiner of an unidentified person. For the former

individual there may be a record of his physical

condition at regular intervals, each illness episode, his last illness, and perhaps an autopsy

protocol. On the basis of this information, what

should be recorded on the death certificate?

How can the questions os instructions in the medical certification be phrased to elicit the data

needed? Can these questions be so phrased to

serve also for the death in w!lich little information

is known?

What approach should be taken to psrmit

separation of data by qualit y—that based on complete histories; on attending physician records

for a terminal illness only, on autopsy only, etc?

Some exploration of quality of diagnostic information and its effect on medical certification has

been reported in special studies, such as one by

L M. Moriyama and others. 4 Thus far, there has

not been any consideration of establishing a routine collection of information on the quality of

medical certification. Is it possible or desirable

to make such measures part of the collection

system for m.,rtality statistics?

If it can be decided what data should be collected through the medical certifications on death

records, it m~.y become easily evident as to

whether these data can be obtained through the

underlying cause approach, or through a new

concept. A new concept, and the questions or

instructions needed to produce the desired answers would then need to be tested. An experiment would need to be devised to learn

whether or not the new form is producing the

expected data.

4Moriyama,L M., Dawber, T. R., and Kannel, W. B.: Evaluation of Diagnostic Information Supporting Medical Certification of Deaths from Cardiovascular Diseases. National Cancer fnstitute Monograph No. 19, Jan. 1966. pp. 405-419.

* U. S. GOVERNMENT PRINTUJG OFFICE : 1973 515-214/70

13
OUTLINE OF REPORT SERIES FOR VITAL AND HEALTH Statistics

Public Health Service Publication No. 1000

Sei’ies 1.

SeVies 2.

Series 3.

Series 4.

Series 10.

SeYies 11.

Series 12.

SeVies 13.

Series 20.

Sevies 21.

SeTies 22.

l+og~ams and collection procedu~es.— Reports which describe the general programs of the National

Center for Health Statistics and its offices and divisions, data collection methods used, definitions,

and other material necessary for understanding the data.

Data evaluation and methods reseavch. —Studies of new statistical methodology including: experimental tests of new survey methods, studies of vital statistics collection methods, new analytical

techniques, objective evaluations of reliability of collected data, contributions to ,statistical theory.

Analytical studies. — Reports presenting analytical or interpretive studies based on vital and health

statistics, carrying the analysis further than the expository types of reports in the other series.

Documents and committee ~epovts. —Final reports of major committees concerned with vital and

health statistics, and documents such as recommended model vital registration laws and revised b~h

and death certificates.

Data fvom the Health Intemiew Survey. —Statistics on illness, accidental injuries, disability, use of

hospital, medical, dental, and other services, and other health-related topics, based on data collected

in a continuing national household interview survey.

Data fyom the Health Examination Suvvey. —Data from direct examination, testing, and measurement of national samples of the population provide the basis for two types of reports: (1) estimates

of the medically defined prevalence of specific diseases in the United States and the distributions of

the population with respect to physical, physiological, and psychological characteristics; and (2)

analysis of relationships among the various measurements without reference to an explicit finite

universe of persons.

Data fvom the Institutional Population Surveys. —Statistics relating to the health characteristics of

persons in institutions, and on medical, nursing, and personal care received, based on national

samples of establishments providing these services and samples of the residents or patients.

Data from the Hospital DischaYge .Swvey. —Statistics relating to discharged patients in short-stay

hospitals, based on a sample of patient records in a national sample of hospitals.

Data on mortality. —Various statistics on mortality other than as included in annual or monthly

reports— special analyses by cause of death, age, and other demographic variables, also geographic

and time series analyses.

Data on natality, marriage, anddivoYce. -Various statistics on natality, marriage, and divorce other

than as included in annual or monthly reports—special analyses by demographic variables, also

geographic and time series analyses, studies of fertility.

Data fyom the National Natality and Mortality surveys. —Statistics on characteristics of births and

deaths not available from the vital records, based on sample surveys stemming from these records,

including such topics as mortality by socioeconomic class, medical experience in the last year of

life, characteristics of pregnancy, etc.

For a list of titles of reports published in these series, write to: office of Information

National Center for Health Statistics

U.S. Public Health Service

Washington, D.C. 20201
$I