Analysis of the Impact of Comorbid Depression on Healthcare Expenditures among Middle-Aged and Elderly Patients with Digestive System Diseases

Background: To examine how comorbid depression influences healthcare expenditures in middle-aged and elderly patients with digestive system diseases, thereby providing evidence for the government’s optimal allocation of health resources and the development of integrated prevention and treatment strategies for digestive disorders. Methods: We used the 2018 China Health and Retirement Longitudinal Study (CHARLS). Depression status and overall health in patients aged 45 years and older with diagnosed digestive system diseases were assessed via the 10-item Center for Epidemiologic Studies Depression Scale (CES-D‑10). A Tobit regression model was fitted to identify key drivers of medical costs, and stratified analyses were conducted to reveal subgroup differences by age group, geographic region, and urban versus rural residence. Results: Comorbid depression was significantly associated with increased total healthcare expenditures among middle-aged and elderly patients with digestive system diseases, with the largest rise observed in inpatient costs (p < 0.05). The presence of additional chronic conditions further intensified this economic burden. Regionally, total medical expenditures were markedly higher in western China compared to eastern China, and the effect of comorbid depression was significantly stronger among rural residents than urban dwellers. Additionally, illiterate patients and those without a spouse experienced disproportionately greater medical cost burdens. Conclusion: Depression exacerbates the complexity of managing digestive system diseases in middle-aged and elderly patients and substantially increases their healthcare expenditures. We recommend routine depression screening and the implementation of comprehensive management plans tailored to this population to alleviate their financial burden.