Multi-group frailty trajectories among older Koreans: Results from the Korean Longitudinal Study of Aging

Background: Studies that examined changes in frailty in older populations have been increasing. However, frailty patterns are often portrayed as having single trajectories corresponding to age, and different courses of change in frailty and related factors remain unexplored. Objectives: We aimed to identify distinct frailty trajectories over time and examine the relationship of frailty trajectories with the sociodemographic and lifestyle-related factors among older Koreans. Methods: We used data of 3160 community-dwelling Korean adults aged >65 years from the Korean Longitudinal Study of Aging (2006-2016). We conducted the analyses using group-based trajectory modeling, analysis of variance or chi-square tests, and multinomial logistic regression. Results: We identified three frailty trajectory groups among older Koreans: no frailty, increasing frailty, and high frailty based on a deficit-related frailty measure. Each frailty trajectory group showed unique sociodemographic and lifestyle characteristics. Compared to individuals in the no frailty group, those in the increasing frailty group were more likely to be older, less educated, unemployed, current smokers, and current drinkers. Compared to those in the no frailty group, individuals in the high frailty group were more likely to be older, unemployed, current drinkers, and without regular exercise. Conclusions: Using longitudinal data over a 10-year period, we identified multiple frailty trajectories in a cohort of older Koreans, which highlights a significant heterogeneity in frailty development. Our findings suggest the importance of socioeconomic status in determining different patterns of frailty change and the role of lifestyle factors in delaying frailty.