Military Service, Childhood Socio-Economic Status, and Late-Life Lung Function: Korean War Era Military Service Associated with Smaller Disparities

BACKGROUND: Military service is associated with smoking initiation, but U.S. veterans are also eligible for special social, financial, and healthcare benefits, which are associated with smoking cessation. A key public health question is how these offsetting pathways affect health disparities; we assessed the net effects of military service on later life pulmonary function among Korean War era veterans by childhood socio-economic status (cSES). METHODS: Data came from U.S.-born male Korean War era veteran (service: 1950-1954) and non-veteran participants in the observational U.S. Health and Retirement Study who were alive in 2010 (average age = 78). Veterans (N = 203) and non-veterans (N = 195) were exactly matched using coarsened exact matching on birth year, race, coarsened height, birthplace, childhood health, and parental and childhood smoking. Results were evaluated by cSES (defined as maternal education <8 yr/unknown or ≥8 yr), in predicting lung function, as assessed by peak expiratory flow (PEF), measured in 2008 or 2010. FINDINGS: While there was little overall association between veterans and PEF [β = 12.8 L/min; 95% confidence interval (CI): (-12.1, 37.7); p = 0.314; average non-veteran PEF = 379 L/min], low-cSES veterans had higher PEF than similar non-veterans [β = 81.9 L/min; 95% CI: (25.2, 138.5); p = 0.005], resulting in smaller socio-economic disparities among veterans compared to non-veterans [difference in disparities: β = -85.0 L/min; 95% CI: (-147.9, -22.2); p = 0.008]. DISCUSSION: Korean War era military service appears to disproportionately benefit low-cSES veteran lung functioning, resulting in smaller socio-economic disparities among veterans compared with non-veterans.