Age-friendly community environments and longitudinal changes in intrinsic capacity among older adults: Evidence from CHARLS 2011-2015

BACKGROUND: Age-friendly communities (AFCs) may support healthy aging by providing physical, social, and service environments that help older adults maintain intrinsic capacity (IC). However, longitudinal evidence linking AFCs with IC trajectories remains limited. METHODS: We used data from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study. A total of 1604 adults aged 60 years or older were classified into IC decline, stable, and improvement groups according to four-year changes in a five-domain IC score. AFC was assessed using a composite index aligned with the World Health Organization age-friendly framework. Multinomial logistic regression was used to examine the association between AFC and IC trajectories. Subgroup and revised sensitivity analyses were conducted. RESULTS: During follow-up, 420 participants (26.2%) experienced IC decline, 715 (44.6%) remained stable, and 469 (29.2%) showed improvement. In the fully adjusted model, each one-point increase in AFC score was associated with a lower risk of IC decline relative to stable IC (RRR = 0.938, 95% CI: 0.904-0.973). Compared with the lowest AFC quartile, the highest quartile was associated with a 43.0% lower risk of IC decline (RRR = 0.570, 95% CI: 0.380-0.855; P for trend = 0.002). Associations were stronger among younger-old adults, women, and rural residents. CONCLUSION: Higher AFC levels were associated with reduced risk of IC decline among Chinese older adults. Community environmental interventions may help preserve IC, particularly in vulnerable subgroups.