Postservice mortality in Vietnam veterans - 30-year follow-up

Background: During the 1980s, the postservice mortality component of the Vietnam Experience Study was conducted to examine the health effects of the Vietnam experience. This study was limited by the relatively short follow-up and the young age of the veterans. Thus,a follow-up mortality investigation on this cohort was undertaken to further assess the impact of the Vietnam experience on chronic conditions. Methods: Vital status and underlying cause-of-death data on the Vietnam Experience Study cohort (18313 male US Army veterans) were retrospectively ascertained from the end of the original study through 2000. Cox proportional hazards regression was used to calculate crude and adjusted rate ratios (RRs) for all-cause and cause-specific mortality, comparing Vietnam and non-Vietnam veterans. Results: All-cause mortality was 7% higher in Vietnam vs non-Vietnam veterans during 30-year follow-up (95% confidence interval [CI], 0.97-1.18), The excess mortality among Vietnam veterans was isolated to the first 5 years after discharge from active duty and resulted from an increase in external causes of death (RR, 1.62; 95% CI, 1.16-2.26). Cause-specific analyses revealed no difference in disease-related mortality. Vietnam veterans, however, experienced excess unintentional poisoning (RR, 2.26; 95% CI, 1.12-4.57) and drug-related (RR, 1.70; 95% CI, 1.01-2.86) deaths throughout follow-up. Conclusions: Vietnam veterans continued to experience higher mortality than non-Vietnam veterans from unintentional poisonings and drug-related causes. Death rates from disease-related chronic conditions, including cancers and circulatory system diseases, did not differ between Vietnam veterans and their peers, despite the increasing age of the cohort (mean age, 53 years) and the longer follow-up (average, 30 years).