Long-term effectiveness of a disease management program to prevent diabetic nephropathy: a propensity score matching analysis using administrative data in Japan

Background: Existing reviews indicated that disease management for patients with diabetes may be effective in achieving better health outcomes with less resource utilization in the short term. However, the long-term results were inconsistent because of the heterogeneous nature of the study designs. In the present study, we evaluated the 5-year follow-up results of a local disease management program focused on diabetic nephropathy prevention under the universal public health insurance scheme in Japan. Methods: Patients diagnosed with type 2 diabetes who had stage 3 or 4 diabetic kidney disease and were aged between 20 and 75 years were invited to join a disease management program to support self-management and receive a recommended treatment protocol between 2011 and 2013. Follow-up data were collected from an electronic claims database for the public insurance scheme. Considering the non-random selection process, we prepared two control groups matched by estimated propensity scores to compare the incidence of diabetes-related complications, death, and resource utilization. Results: The treatment group was more likely to receive clinical management in accordance with the guideline-recommended medication. After propensity score matching, the treatment group had lower incidence of diabetic nephropathy and emergency care use than the control group selected from a beneficiary pool mainly under primary care. Comparisons between the treatment group and the control group with more selected clinical conditions did not show differences in the incidence rate and resource utilization. Conclusions: The present results demonstrated limited effectiveness of the program for reducing complication incidence and resource utilization during the 5-year follow-up. Further research on the long-term effectiveness of co-management by primary care physicians, subspecialists in endocrinology and nephrology, and nurse educators is required for effective management of diabetes-related nephropathy.