Work frequency and subsequent health and well-being among older adults in Japan: An outcome-wide study.

BACKGROUND: Working in later life has been linked to health and well-being, yet how work frequency relates to these outcomes remains uncertain. We examined associations between work frequency and subsequent multiple domains of health and well-being among older adults. METHODS: We used two datasets from the Japan Gerontological Evaluation Study (JAGES). Dataset 1 used three-wave panel data (2016, 2019, 2022; n = 41,758) for 42 self-reported outcomes. Dataset 2 linked 2016-2019 panel data to municipal long-term care insurance records through 2022 (n = 56,153), capturing mortality, dementia, and functional disability; together, analyses covered 46 indicators. Work frequency was categorized as not working, lower-frequency (1-3 times/month or several times/year), moderate-frequency (1-3 days/week), and higher-frequency (≥4 days/week) working. Models adjusted for 2016 covariates and prior outcome values. RESULTS: Moderate-frequency working showed favorable associations in 24 of 46 (52.2%) indicators. Higher-frequency working showed favorable associations in 25 of 46 (54.3%) indicators but was also associated with lower sports and hobby group participation and higher smoking and drinking prevalence (4 of 46, 8.7%). Both moderate- and higher-frequency working were associated with lower mortality (OR = 0.71 and 0.60; P for trend < 0.001). Analyses stratified by gender, age, education, and household income showed similar patterns, with limited effect modification. CONCLUSIONS: Older adults who worked showed lower mortality and more favorable values on many indicators than those who did not, and differences varied by frequency. Interpretation requires caution: health shapes who keeps working, and work quality was unmeasured; both warrant further study.