Effects of China's Clean Air Act on Frailty Levels Among Middle-Aged and Older Adults: A Population-Based Quasi-Experimental Study.

This article examines the impact of China’s Clean Air Action (CCAA), a national air pollution control policy implemented from 2013 to 2017, on frailty levels among Chinese adults aged 45 and older. Using data from the China Health and Retirement Longitudinal Study (CHARLS) and employing propensity score matching with difference-in-differences analysis, the study found that the CCAA significantly reduced frailty progression—measured by the Frailty Index (FI)—among individuals who were robust or prefrail before the policy, but showed no significant effect on those already classified as frail. Specifically, the CCAA lowered the risk of worsening from robust to prefrail or frail by 7.0% and from prefrail to frail by 3.9%, without facilitating recovery from frail or prefrail states. The policy’s benefits were consistent across subgroups defined by age, gender, Hukou status, education, and social participation, highlighting the value of proactive air quality improvements in mitigating frailty deterioration in midlife and older populations.