Social Determinants of Intrinsic Capacity: A National Cohort Study

Abstract

INTRODUCTION: Intrinsic capacity (IC), a composite of physical and mental capacities, is a marker of healthy aging. Social determinants of health (SDOH), namely the economic and social environments across a lifespan, are the most fundamental factors influencing health outcomes and health disparities. However, there is limited evidence on the influence of the individual and combined burden of the SDOH on IC. METHODS: Data were obtained from the China Health and Retirement Longitudinal Study (2011-2015), and data analysis was conducted in 2023. Linear mixed-effect regression was employed to investigate the association between SDOH and IC in a longitudinal analysis. RESULTS: This study comprised 7,669 participants (mean [SD] age, 68.5 [7.1] years; 49.8% female; mean [SD] IC, 7.2 [1.6]). In the longitudinal analysis, all five SDOH domains were independently and significantly associated with IC. The absence of social association within the social and community context domain exhibited the weakest association with IC (β: -0.11 [95% CI -0.20, -0.02]), while illiteracy within the education access and quality domain demonstrated the strongest association with IC (β: -0.51 [95% CI -0.60, -0.42]). Furthermore, the adverse effects of SDOH on IC became more distinguishable with the cumulative number of SDOH variables (coefficient for 2 SDOH, -0.41 [-0.64, -0.19]; 3 SDOH, -0.70 [-0.93, -0.48]; ≥4 SDOH, -1.10 [-1.33, -0.88]) compared with those without any SDOH. CONCLUSIONS: Certain SDOH levels were significantly and negatively associated with IC. Targeted interventions may be needed to improve SDOH in individuals at high risk of poor IC.