Healthy aging trajectories and their predictors among Chinese older adults: Evidence from a 7-year nationwide prospective cohort study

This study aimed to identify healthy aging trajectories of Chinese older adults, and explore the factors contributing to these trajectories. We used data from four waves (2011-2018) of China Health and Retirement Longitudinal Study. We developed a healthy aging metric based on the healthy aging framework of World Health Organization (WHO) and Bayesian multilevel item response theory (IRT) method. The healthy aging trajectories were identified using the latent class growth analysis. The predictors of trajectories were explored using multinomial logistic regression analysis. Additionally, we developed two alternative metrics for healthy aging based on the Chinese Healthy Ageing Index (CHAI) and Rowe and Kahn's model of successful aging, respectively. We compared these metrics to the one developed based on the WHO's healthy aging framework. We identified three distinct healthy aging trajectories with varying scores and decline rates. Individuals who were female, had lower educational levels, resided in rural areas, experienced depression, had more chronic diseases, participated in fewer social activities, had fewer childhood friends, experienced more adverse childhood events, and had worse family financial status in childhood were more likely to experience a worse healthy aging trajectory compared to their counterparts. Supplementary analysis showed that healthy aging metric based on WHO definition and IRT method had the strongest association with health outcomes compared to the metrics based on CHAI, as well as Rowe and Kahn model. Our findings provide a foundation for the development of tailored interventions to enhance and sustain healthy aging among Chinese older adults.