The longitudinal relationship between physical function, activities of daily living impairment, and depressive symptoms in middle-aged and older adults in China: the mediating role of self-rated health.

Objective To investigate the longitudinal relationship between physical function, impairment in activities of daily living, and depressive symptoms among middle-aged and older adults in China, as well as to explore the mediating role of self-rated health. Methods Data from the China Health and Retirement Longitudinal Study (CHARLS) national cohort from 2013 to 2020 were analyzed, including 7 899 participants aged 45 and older. The Cox proportional hazards regression model was employed to analyze the longitudinal association between impairment and depressive symptoms. The Process macro model 4 was used to construct the model, examining the mediating effect of self-rated health, with the Bootstrap method applied to test the significance of the mediation effect. Results After adjusting for confounding factors, the Cox proportional hazards regression results indicated that the risk of depressive symptoms for individuals with only physical function impairment, only activities of daily living impairment, and dual impairment was 1.408 times (95%CI: 1.284-1.543), 1.447 times (95%C/: 1.166-1.795), and 1.825 times (95%C7: 1.636-2.034) higher, respectively, compared to those without impairment (P<0.001). Self-rated health played a significant partial mediating role in the relationship between the two, with the effect size being the largest in the group with only physical function impairment at 24.29%, followed by the dual impairment group at 17.02%, and the group with only activities of daily living impairment at 12.15%. Conclusion There is a longitudinal relationship between physical function, activities of daily living impairment, and depressive symptoms among middle-aged and older adults. Additionally, self-rated health serves as a partial mediator in this relationship. Implementing targeted interventions to delay the aging of physical functions and improve self-rated health can effectively control the occurrence and progression of depression in this population, facilitating a shift towards preventive measures. [ABSTRACT FROM AUTHOR]