Group Characteristics by Self-Rated Health Trajectories Among Frail Older Adults: A Group-Based Trajectory Modeling Approach

Purpose: This study aimed to identify distinct trajectories of self-rated health (SRH) among frail older adults and examine sociodemographic and health-related factors associated with each trajectory group. Methods: A secondary analysis was conducted using data from Waves 5–9 of the Korean Longitudinal Study of Aging (KLoSA). Of 10,436 participants, 552 community-dwelling adults aged 65 years or older who met the frailty criteria were included. Group-based trajectory modeling was applied to identify SRH trajectories, and multinomial logistic regression was performed to examine predictors of trajectory group membership, with the high-health declining group serving as the reference. Results: Five SRH trajectories were identified: Low-Declining SRH (Group 1), Increasing SRH (Group 2), Decline-Then-Increasing SRH (Group 3), Moderate-Declining SRH (Group 4), and High-Declining SRH (Group 5; reference). Compared with the reference group, Group 1 exhibited lower levels of weekly physical activity (OR = 0.47), social participation (OR = 0.46), and income (OR = 0.59), as well as a higher prevalence of hypertension, diabetes, and denture use. Group 2, which showed linear improvement, included more women (OR = 0.35) and individuals with lower income (OR = 0.52). Group 3 was less likely to receive the Basic Old-Age Pension (OR = 0.31), suggesting relatively higher socioeconomic status. Group 4 demonstrated lower social participation (OR = 0.54) and higher prevalence of hypertension (OR = 1.69). Conclusion: Frail older adults demonstrate heterogeneous SRH trajectories. Social participation, health behaviors, and economic resources are key determinants of SRH patterns. SRH may serve as a practical screening indicator for identifying high-risk groups and informing tailored community-based care strategies.