Health effects of military service. Lessons learned from the Vietnam experience

This article examines the methodologic difficulties encountered in studies of the long-term effects of the Vietnam War on the psychological and physical health of veterans. Alternate study designs and exposure and outcome measurements are examined in relation to psychological (post-traumatic stress disorder and alcohol use or abuse) and physical (mortality and birth defects in children) health outcomes. All major epidemiologic studies of post-traumatic stress disorder and alcohol use or abuse utilize cross-sectional research designs. Mortality and birth defect studies use cohort, case-control, or proportionate mortality strategies. Exposure is measured using either definitive dichotomous indicators of service in Southeast Asia or more complex indicators of the Vietnam experience (i.e., combat, herbicide exposure, atrocities, abusive violence) that are of suspect validity. In studies of psychological health, outcomes are based exclusively on self-reported symptoms, while investigations of mortality and birth defects use death certificates and hospital records. Epidemiologic research on the effects of the Vietnam conflict has been hampered by problems in research design and the inherent difficulties of measuring wartime exposures and long-term health outcomes.