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Vietnam-Era Twin Registry - Survey Instruments

These research initiatives attempted to collect information from all twins in the VET Registry. A PDF version of the survey instrument used in each initiative is provided. Contact VET Registry staff for more information regarding these data collection projects.

In 1988, the Registry became available for use by both VA and non-VA investigators. The twin identification process from military records took approximately 3 years from 1983-1986. Several waves of mail and telephone surveys involving Registry members have collected a wealth of health-related information on Registry twins, their adult offspring, and mothers’ of the offspring. Visit the history and formation page to learn more about the Registry.

Survey of Health

The Survey of Health was the initial questionnaire mailed by the VET Registry to 7,369 twin pairs identified from military records. It contained self-report questions about zygosity, respondent’s likeness to their brother during childhood, general health, specific diagnoses, hospitalization for specific medical conditions, comparison of health to brother’s health, combat exposure, symptoms of post traumatic stress disorder (PTSD), cigarette and alcohol consumption, military experiences, marital status, fertility, offspring, education, employment, and income. The questionnaire didn't include a measure of self-reported race/ethnicity or any measures of depression. Review the Survey of Health questions.

National Heart, Lung, and Blood Institute study

The National Heart, Lung, and Blood Institute (NHLBI) study was the second survey of VET Registry members. An effort was made to obtain responses from both members of any twin pair in the VET Registry where at least one brother had participated in the Survey of Health (1987). The survey included questions on a variety of disorders of interest to the NHLBI such as: cardiovascular and pulmonary risk factors, self-reported heart, pulmonary, and blood disorders, sleep problems, diet and exercise.  This study was intended to serve as a prelude to a clinical examination protocol studying cardiovascular disease on a selected subset of twins contained in the VET Registry, however the clinical exam didn't take place. Review the NHLBI study survey questions.

Harvard Drug Study

The Harvard Drug Study was the third major survey of the VET Registry members. Trained interviewers administered the Diagnostic Interview Schedule Version 3 Revised (DIS-III-R) to 8,169 twins via telephone in order to assess a variety of psychiatric disorders.  The aim of this study was to gauge the relative contribution of familial environment, non-familial environment and genetics on the development and course of drug and alcohol abuse and dependence. The survey has been broken into several files, each quite large (10 MB):

Male Health Survey

The Male Health Survey asked VET Registry members 95 general questions relating to male health and the effects of aging. Responses were received from 5361 individuals (1621 complete pairs). Survey questions fell into several categories: General Health (questions about general body systems), Male Health (urinary and prostate symptoms), Sleep and Work patterns (hours slept, snoring), Smoking and Alcohol use, and Hair Pattern (location and degree of baldness).

One study determined the extent of genetic influence on erectile dysfunction (ED) in a sample of middle-aged men. Two ED related questions were asked about difficulty in achieving and in maintaining an erection in the past month. Data were also collected regarding known risk factors for development of ED. This study did demonstrate an ED-specific genetic component, even when adjusted for risk factors such as diabetes, hypertension, body shape (obesity), age, smoking, alcohol intake and coronary heart disease. Review the Male Health Survey questions.

CSP #569: Veteran Health Study (or A Twin Study of the Course and Consequence of Post-Traumatic Stress Disorder in Vietnam Era Veterans)

This study used the Vietnam-Era Twin (VET) Registry to estimate current prevalence of mental and physical health conditions and to answer questions about how PTSD might influence the lives of Veterans decades after the end of the war. Review the CSP #569 survey questions.