Frailty Index Predicts Future All-cause Mortality and Quality of Life: A 2-Year Follow-up Study Among Korean Older Adults From a Population-based Cohort Study

Abstract

Objectives: The frailty index (FI), a proxy measure of accelerated biological aging, predicts adverse outcomes in older adults. We investigated whether the FI predicts mortality in a community-based Korean older adult population and its association with subjective health status over 2 years. Methods: This prospective cohort study included 936 community-dwelling individuals aged ≥60 years. The FI, calculated from 28 self-reported baseline variables, was scored on a scale from 0 to 1 (<0.25: non-frail; 0.25-0.34: mildly frail; ≥0.35: moderately to severely frail). The primary outcome was 2-year all-cause mortality. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated. Quality of life was assessed using the European Quality of Life Five-Dimension Three-Level (EQ-5D-3L), with the proportions reporting extreme problems and prevalence ratios of problems across frailty groups. Analyses were conducted using the GENMOD procedure in SAS version 9.4. Results: Of the 936 participants, 111 (11.9%) were non-frail, 230 (24.6%) were mildly frail, and 595 (63.6%) were moderately to severely frail. The prevalence of moderate to severe frailty increased with age. The moderate-severe frailty group had a ≥5-fold increased risk of mortality compared to the non-frail group (adjusted RR, 5.79; 95% CI, 1.39 to 24.07). Among those completing follow-up, the moderate-severe frailty group reported more problems across all EQ-5D-3L domains at 2 years. Conclusions: Frail older adults are at increased risk of mortality, but this risk was significant only for those in the moderate-to-severe frailty category at 2-year follow-up. The FI is a valuable predictor of premature death and health challenges in older adults.