Association of the Healthy Aging Index with all-cause mortality: Results from the Korean frailty and aging cohort study.

Abstract

Objective: This study investigated the association between the Healthy Aging Index (HAI) and all-cause mortality and its potential modification by sociodemographic or lifestyle factors.

Methods: We analyzed data from 2303 community-dwelling adults aged 70-84 years who participated in the Korean Frailty and Aging Cohort Study (2016-2023). The HAI was constructed using five domains-physical function, cognitive function, social well-being, psychological health, and physiological health-each scored from 0 to 3. The total HAI score (range: 0-15) was evaluated as a continuous variable and by tertiles (poor, 0-9; moderate, 10-11; high, 12-15 points). All-cause mortality was assessed biennially from 2018 to 2023 from family or neighbor interviews or electronic medical records. Cox proportional hazards regression models were used for statistical analyses.

Results: During the 6-year follow-up, 152 (6.6 %) participants died. After adjusting for covariates, each 1-point increase in HAI was associated with an 18 % lower risk of all-cause mortality (hazard ratio [HR], 0.82; 95 % confidence interval [CI]: 0.76-0.88). Compared with the high HAI group, the HRs for the moderate and poor HAI groups were 1.27 (95 % CI: 0.70-2.28) and 2.77 (95 % CI: 1.58-4.88), respectively (P for trend <0.001). HAI and educational level showed a significant interaction.

Conclusions: Lower levels of healthy aging were associated with higher mortality, particularly among older adults with lower educational attainment. These findings highlight the need for targeted strategies to promote healthy aging, especially among those with lower levels of education.