Socioeconomic Status, Frailty, and All-Cause Mortality in Korean Older Adults: A 3-Year Population-Based Prospective Study

BACKGROUND: Little is known regarding the effects of socioeconomic status (SES) and frailty on mortality in Korea. OBJECTIVE: This study investigated the combined impact of low SES and frailty on all-cause mortality in Korean older adults. METHODS: Study sample at baseline comprised 7,960 community-dwelling adults (56.8% women) aged 65 years and older. The Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of low SES and frailty for all-cause mortality. RESULTS: Overall, low SES plus frailty resulted in an increased risk of all-cause mortality (HR = 1.56, 95% CI = 1.09–2.23, P = 0.015) even after adjustments for all the measured covariates, as compared with high SES plus nonfrailty (HR = 1). Among older adults aged 65–75 years, the increased mortality risk of either low SES plus nonfrailty (HR = 1.37, 95% CI = 1.02–1.84, P = 0.038) or high SES plus frailty (HR = 2.09, 95% CI = 1.12–3.91, P = 0.021) remained significant even after adjustments for all the covariates, as compared with high SES plus nonfrailty (HR = 1). CONCLUSION: The current findings suggest that either low SES or frailty is significantly associated with increased all-cause mortality in Korean older adults.