Abstract
BACKGROUND: Optimism has been linked to better physical health across various outcomes, including greater longevity. However, most evidence is from Western populations, leaving it unclear whether these relationships may generalize to other cultural backgrounds. Using secondary data analysis, we evaluated the associations of optimism among older Japanese adults. METHODS: Data were from a nationwide cohort study of Japanese older adults aged ≥65 years (Japan Gerontological Evaluation Study; n = 10,472). In 2010, optimism and relevant covariates (i.e., sociodemographic factors, physical health conditions, depressive symptoms, and health behaviors) were self-reported. Optimism was measured using the Japanese version of the Life Orientation Test-Revised (LOT-R). Lifespan was determined using mortality information from the public long-term care insurance database through 2017 (7-year follow-up). Accelerated failure time models examined optimism (quintiles or standardized continuous scores) in relation to percent differences in lifespan. Potential effect modification by gender, income, and education was also investigated. RESULTS: Overall, 733 individuals (7%) died during the follow-up period. Neither continuous nor categorical levels of optimism were associated with lifespan after progressive adjustment for covariates (e.g., in fully-adjusted models: percent differences in lifespan per 1-SD increase in continuous optimism scores= -1.2%, 95%CI: -3.4, 1.1 higher versus lower optimism quintiles= -4.1%, 95%CI: -11.2, 3.6). The association between optimism and lifespan was null across all sociodemographic strata as well. CONCLUSION: Contrary to the existing evidence from Western populations, optimism was unrelated to longevity among Japanese older adults. The association between optimism, as evaluated by the LOT-R, and longevity may differ across cultural contexts.