Mediation analysis of leisure activities on the association between cognitive function and mortality: longitudinal study of 42,942 Chinese adults 65 years and older.

Abstract

Previous studies have associated cognitive function and leisure activities with mortality. This study aimed to evaluate whether leisure activities causally mediate this association. This longitudinal study included 42,246 participants aged over 65 years from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The Mini-Mental State Examination (MMSE) and a self-reported scale were used to measure cognitive status and leisure activities, respectively. We examined cognitive function and leisure activities for their associations with mortality by using Cox proportional hazards models. Causal mediation analysis was used to access whether leisure activities mediate the association between cognitive function and mortality. Cognitive function and leisure activities were inversely associated with mortality. Leisure activities accounted for 28.3% (95% CI: 25.6 - 31.1%) of the total effect (TE) of cognitive function and mortality. A higher mediated proportion (PM) of physical leisure activities (PM = 20.1%, 95% CI: 18.0 - 22.3%) was observed than that of social leisure activities (PM = 17.7%, 95% CI: 15.7 - 19.7%). The mediating effect is higher among participants at younger ages (PM = 41.5%, 95% CI: 21.3 - 65.4%), with higher education levels (PM = 30.5%, 95% CI: 25.3 - 36.2%), and rural residents (PM = 42.5%, 95% CI: 25.4 - 62.5%). Cognitive function was associated with inverse mortality. Leisure activities significantly mediated this association. Participation in leisure activities, at the early stages of mild cognitive impairment, could reduce the risk of mortality, which has a major impact on interventional strategies for healthy ageing.