Effect of Community-based integrated care for patients with diabetes and depression in China: interim analysis of a pragmatic cluster-randomized trial

Background: There remains a significant gap in our understanding of how to effectively identify and manage patients with both mental and physical multimorbidity within primary healthcare settings in LMICs. To address this gap, we have developed a care model called Community-based Integrated Care for Patients with Diabetes and Depression (CIC-PDD). In this study, we present the results of a prespecified interim analysis of the CIC-PDD intervention. Methods: In this pragmatic cluster-randomized trial conducted in community health centers (CHCs) in China, we initially allocated these centers into two groups: the enhanced usual care group (comprising 4 CHCs) and the intervention group (comprising 4 CHCs). The allocation process involved computer-generated randomization, with stratification by counties. In the intervention group, a comprehensive care plan was developed based on the CIC-PDD model, primarily involving a multidisciplinary team consisting of specialists, case managers, and health communicators. This team delivered a range of services, including scheduled follow-ups led by case managers, collaborative meetings, both online and offline active services, and self-management enhancement strategies. We recruited individuals aged 18 years or older with diabetes and depression (PHQ-9 ≥ 10). The primary outcome was change of depressive symptoms (assessed with SCL-20) and HbA1c after a 6-month follow-up period. This trial is registered with ClinicalTrials.gov (registration number ChiCTR2200065608). Findings: Between October, 2021 and May 2022, we enrolled a total of 630 individuals in this study, with 275 participants in the intervention group (4 CHCs) and 355 participants in the control group (4 CHCs). At the 6-months, we observed significant improvements in patients' depressive symptoms, indicating a group difference of -0.17 (p=0.019). However, HbA1c levels did not show a significant change, with a group difference of -0.2 ( p=0.345). In terms of secondary outcomes, there was a significant enhancement in mental-related quality of life, with a group difference of 4.98 (p<0.001). Conversely, physical-related quality of life did not exhibit significant changes, showing a group difference of -0.62 (p=0.355). Despite the lack of significant improvement in physical health, patients demonstrated improved self-management skills, particularly in medication adherence (adjusted difference in means 0.86 (p<0.001) and diabetes self-care activities (adjusted difference in means 0·68; p=0.002). Furthermore, our process outcome analysis revealed a significant enhancement in the person-centered care experience within the intervention group compared to the control group, indicating a group difference of 0.47 (p=0.003). In heterogeneous analysis, we found that rural patients benefited more from CIC-PDD intervention in terms of self-health management compared to urban patients. Interpretation: This study represents the largest intervention trial to date, focusing on the optimal management of patients with diabetes and depression through an integrated care model. The implementation strategy developed here can serve as a valuable blueprint not only for China but also for other LMICs in improving the identification and management of patients with physical and mental multimorbidity in primary healthcare settings. Furthermore, it provides a pathway to address the complex healthcare needs of patient with multimorbidity in resource-constrained settings.