Association between social determinants of health and intrinsic capacity trajectories: A population-based longitudinal study

BACKGROUND: Global aging is a significant public health challenge. Social determinants of health are crucial in shaping healthy aging trajectories by influencing intrinsic capacity, a key indicator of functional ability and well-being in older adults. However, the association between social determinants of health and intrinsic capacity trajectories remains underexplored. This study examines the associations between social determinants of health and intrinsic capacity trajectories among Chinese community-dwelling older adults. PARTICIPANTS AND SETTING: Community-dwelling adults aged ≥60 years from the China Health and Retirement Longitudinal Study (2011-2015). METHODS: Bifactor models of intrinsic capacity were constructed. Multigroup confirmatory factor analysis was used to test the longitudinal measurement invariance of intrinsic capacity. Growth mixture modeling was performed to identify distinct intrinsic capacity trajectory classes, and multivariate logistic regression was employed to determine the social determinants of health associated with these classes. RESULTS: A total of 5798 community-dwelling older adults were included. Four distinct intrinsic capacity trajectory classes were identified: high-increasing (20.6 %), medium-maintaining (37.1 %), medium-decreasing (29.0 %), and low-decreasing (13.3 %). Compared with the high-increasing trajectory, illiteracy, low-middle income, no social activities, being separated/divorced/widowed/never married, smoking, non-drinking, low physical activity, rural residence, non-age-friendly home environment, and no health insurance were associated with a higher likelihood of belonging to the low-decreasing trajectory. CONCLUSIONS: These findings provide evidence for the early identification of heterogeneous intrinsic capacity trajectories and support the implementation of stratified intervention strategies.