Military service and mortality risk in older adults: A nationwide retrospective cohort analysis of NHANES data

Military service presents a paradoxical health impact, simultaneously enhancing physical fitness while increasing risks of injuries, mental health disorders, and war-related illnesses. The long-term mortality consequences for aging veterans remain insufficiently characterized. This study examines the association between military service and mortality outcomes among US adults aged 50 years and older, including all-cause mortality, premature death, and cause-specific mortality. We analyzed 17,984 participants from the National Health and Nutrition Examination Survey (1999-2018) with complete data on military service status and mortality outcomes. Using weighted multivariate modeling, Kaplan-Meier survival analyses, and subgroup analyses, we evaluated mortality risks while adjusting for demographic, socioeconomic, and health covariates (gender, age, ethnicity, education, marital status, income, diabetes, and hypertension). During 250 months of follow-up (3985 deaths), veterans showed longer mean survival time (139.36 ± 1.38 months) than nonveterans (129.66 ± 1.43 months). In fully adjusted models, military service was positively associated with survival time (β = 21.87, 95% confidence interval [CI] = 17.03-26.70, P < .001). However, non-veterans demonstrated reduced risks for premature mortality (odds ratio = 0.69, 95% CI = 0.58-0.82, P < .001), malignancy-related deaths (odds ratio = 0.73, 95% CI = 0.55-0.96, P = .025), and other cause-specific mortality compared to veterans. While military service is associated with longer overall survival in older adults, it confers increased risks of premature death and cancer mortality. These findings highlight the need for targeted health interventions for aging veterans, particularly for cancer prevention and early detection.