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.