Chain mediation effect of activity of daily living and self-rated health between depression and life satisfaction in Chinese older adults: evidence from CHARLS 2018

Depression is an important risk factor for life satisfaction in the elderly, but the underlying mechanism remains to be further explored. Depression is an important risk factor for life satisfaction in the elderly, but the underlying mechanism of depression affecting life satisfaction remains to be further explored. Existing research has found that activity of daily living (ADL) and self-rated health (SRH) are respectively associated with depression and life satisfaction. Based on these findings, activity of daily living may mediate the relationship between depression and life satisfaction; meanwhile, self-rated health may also serve as a key factor linking the two. This study aims to examine the associations among depression, activity of daily living, self-rated health, and life satisfaction, as well as the hypothesized mediating and chain-mediating roles of activity of daily living and self-rated health in this association. To explore the chain mediating effect of activity of daily living and self-rated health on the relationship between depression and life satisfaction in the elderly in China. A cross-sectional design was used in this study. Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS), including 4731 elderly aged 60 years and above (mean age: 68.2 years). Depression was measured using the Center for Epidemiologic Studies Depression Scale (CES-D-10), and the participants were divided into depression group and non-depression group according to the cut-off value. Activity of daily living was assessed by 12 items of daily activities such as dressing, bathing, and cooking. Self-rated health was measured by self-assessment of health status. Life satisfaction was measured by an assessment of overall life satisfaction. SPSS 27.0 was used for data cleaning and descriptive statistics. Model 6 in the PROCESS macro program was used to test the chain mediation effect, and the confidence interval of the indirect effect was estimated by the Bootstrap method (5 000 samples). Among the 4731 participants, 41.5% had depressive symptoms. Correlation analysis showed that depression, activity of daily living, self-rated health and life satisfaction were all correlated ( P <0.001). The mediation analysis showed that depression had a significant direct association with life satisfaction (coefficient =-0.0411, 95% CI: -0.0446~-0.0376). Among the three mediating pathways, the independent mediating effect of self-rated health was significant (effect size proportion: 10.06%), the chain mediating effect of activity of daily living and self-rated health was significant (effect size proportion: 2.14%), and the independent mediating effect of activity of daily living was not significant. Depression has a direct association with life satisfaction. At the same time, depression had an indirect association on life satisfaction through the following paths: the single mediating path of self-rated health, and the chain mediating path of activity of daily living→self-rated health. Therefore, improving the subjective health perception of the elderly and delaying the decline of activity of daily living may be an effective intervention path to address the negative association between depression on life satisfaction.