Basic Medical Insurance Type and Depressive Symptoms in Middle-Aged and Older Adults with Multimorbidity: A Cross-Sectional Study Based on CHARLS 2020

<title>Abstract</title> <p>Background Multimorbidity is common among middle-aged and older adults in China and is strongly associated with depression. China's two main public insurance schemes differ substantially in coverage and reimbursement rates: the Urban Employee Basic Medical Insurance (UEBMI) provides higher reimbursement and broader benefits than the Urban and Rural Resident Basic Medical Insurance (URRBMI), yet whether this gap translates into differences in mental health outcomes among people with multimorbidity remains poorly understood. Methods We analyzed data from the 2020 wave of the China Health and Retirement Longitudinal Study (CHARLS). Participants aged 45 years or older with two or more chronic physical conditions who were enrolled in either UEBMI or URRBMI were included (n = 9,142). Depressive symptoms were assessed using the 10-item Center for Epidemiologic Studies Depression Scale (CES-D-10), with a cutoff score of ≥ 10. We estimated the association between insurance type and depressive symptoms using four nested multivariable logistic regression models. To address baseline confounding between the two insurance groups, we applied 1:1 propensity score matching (PSM) with a caliper of 0.02. Subgroup and sensitivity analyses were conducted to assess effect modification and result stability. Results The overall prevalence of depressive symptoms was 45.6%: 48.9% among URRBMI enrollees versus 27.7% among UEBMI enrollees (χ² = 221.73, P &lt; 0.001). After adjusting for demographic, socioeconomic, health status, behavioral, and healthcare utilization covariates, UEBMI enrollment remained associated with significantly lower odds of depressive symptoms (OR = 0.684, 95% CI: 0.586–0.799, P &lt; 0.001). PSM produced 1,078 matched pairs with excellent covariate balance (all standardized mean differences &lt; 0.1), and the association persisted in the matched sample (adjusted OR = 0.679, 95% CI: 0.558–0.825, P &lt; 0.001). The protective direction of UEBMI was consistent across all subgroups, with no statistically significant interaction terms. Sensitivity analyses using alternative CES-D-10 cutoffs, continuous outcome modeling, and varied PSM parameters all yielded concordant results. Conclusions Among middle-aged and older adults with multimorbidity, UEBMI enrollment was associated with substantially lower odds of depressive symptoms compared with URRBMI enrollment, and this association held consistently across multiple analytical strategies. These findings suggest that the benefit disparity between the two insurance schemes may have measurable consequences for mental health in this population. Narrowing coverage gaps, integrating mental health services into chronic disease management pathways, and strengthening psychosocial support, with priority given to rural areas, warrant policy attention.</p>