" What Did You Do in the War, Daddy ?": Paternal Military Conscription During WWII, Economic Hardship and Family Violence in Childhood, and Health in Late Life in Japan.

Childhood adversity is a risk factor for poor health in late life and includes economic hardship and family violence, whose prevalence is high among offspring of military conscripted father. We assessed the association between paternal military conscription (PMC) and paternal war death (PWD) during Second World War and self-rated health (SRH) among older adults in Japan. Data were obtained from a population-based cohort of functionally independent people aged 65 years or older from 39 municipalities across Japan in 2016. Information on PMC and SRH was obtained through a self-report questionnaire. A total of 20,286 participants were analyzed with multivariate logistic regression to investigate the association between PMC, PWD, and poor health. Causal mediation analysis was performed to see whether childhood economic hardship and family violence mediated the association. Among participants, 19.7% reported PMC (including 3.3% PWD). In the age- and sex-adjusted model, older people with PMC showed higher risk of poor health (odds ratio [OR]: 1.16, 95% confidence interval [CI] [1.06, 1.28]), while those with PWD were not associated (OR: 0.96, 95% CI [0.77, 1.20]). Causal mediation showed a mediation effect of childhood family violence exposure on the association between PMC and poor health (proportion mediated: 6.9%). Economic hardship did not mediate the association. PMC, but not PWD, increased the risk of poor health in older age, which was partially explained by the exposure to family violence in childhood. There appears to be a transgenerational health impact of war which continues to affect the health of offspring as they age.