AIM: Early retirement is prevalent and can alter daily habits, potentially impacting health. This study aims to explore the association between early retirement and frailty and to examine the modifying effect of sociodemographic characteristics. METHODS: We conducted a population-based matched cohort study that included 1 779 628 early retirees aged 45-64 years and an equal number of employed individuals from Taiwan's National Health Insurance (2010-2021). Early retirement was defined as unemployment before age 65 years without reemployment. Frailty was assessed using the multimorbidity Frailty Index (mFI) based on the International Classification of Diseases, 10th Revision, Clinical Modification codes. Covariates such as demographics, socioeconomic status, and medical conditions were adjusted using propensity score weighting. Generalized estimating equations determined the association between early retirement and frailty. Subgroup analyses were conducted by age, sex, income and occupation. RESULTS: The results showed that early retirees exhibited a significant increase in mFI score changes compared to their employed counterparts, with a coefficient rise of 0.372 (95% CI, 0.303-0.441). Early retirement was associated with higher mFI scores among younger individuals (aged 45-54 years)
men
those with lower incomes
and individuals working as employers, private-sector employees, freelancers, farmers and fishers. Conversely, early retirement was linked to lower mFI scores among civil servants. CONCLUSION: These findings support the development of targeted retirement policies and occupational health programs. Further research on frailty mediators, such as physical activity, diet and social participation is crucial for improving clinical care and informing health policies to mitigate the negative impacts of early retirement on high-risk populations. Geriatr Gerontol Int 2025
25: 425-433.