diabetic nephropathy and emergency care use than the control group selected from a benefciary pool mainly under primary care. Comparisons between the treatment group and the control group with more selected clinical conditions did not show diferences in the incidence rate and resource utilization. Conclusions: The present results demonstrated limited efectiveness of the program for reducing complication incidence and resource utilization during the 5-year follow-up. Further research on the long-term efectiveness of co-management by primary care physicians, subspecialists in endocrinology and nephrology, and nurse educators is required for efective management of diabetes-related nephropathy. © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativeco mmons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Open Access *Correspondence: morimich@hiroshima-u.ac.jp 1 Chronic Care and Family Nursing, Division of Nursing Science, Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-Ku, Hiroshima 734-8553, Japan Full list of author information is available at the end of the article Watanabe et al. BMC Endocrine Disorders (2022) 22:135 Page 2 of 9 Background Te increasing prevalence of diabetes mellitus has become a signifcant global health policy issue because of its impact on population disease burden and related healthcare cost [1–3]. In particular, diabetic kidney disease, a frequent complication of diabetes, can lead to end-stage renal disease that requires extremely highcost treatment and reduces the quality of life of afected patients [4, 5]. To respond to the demand for fnancial efciency and improved prognosis with better quality of life, disease management has been implemented as a promising program for this purpose [6, 7]. Tis evidence-based approach emphasizes comprehensive care integrated across healthcare delivery systems along the continuum of the disease trajectory [8]. Disease management includes patient education, especially self-management, consecutive data monitoring, and care coordination with multi-disciplinary health professionals. Although several systematic reviews indicated that disease management for patients with diabetes may be efective in achieving better health outcomes (e.g., reduced morbidity and disability), more appropriate processes (e.g., adherence to guidelines), less utilization of health services (e.g., hospitalization), and improved quality of life, the results remain controversial because of the heterogeneous nature of the study designs [6–10]. A long-term evaluation study in Hong Kong found a reduction in diabetes-related events, but little improvement in laboratory data for patients with severe comorbidities [11]. Another study reported a reduced incidence of stroke among patients with diabetes after an 8-year follow-up, but sufered from a low followup rate [12]. Te study also failed to exhibit efects for other diabetes-related complications. Finally, the cost efciency of the disease program for diabetes control was inconclusive. In previous studies, we took advantage of the universal public health insurance scheme in Japan to overcome attrition and data quality limitations through the use of electronic administrative records [13–15]. In preliminary analyses, we found improvement of hemoglobin A1c, maintenance of renal function, and modifcation of patient behavior during a mean 1-year follow-up [13, 14]. We also found reduced cost during a mean 2-year follow-up that was attributable to amended treatment processes and improved prognosis of the disease [15]. However, the majority of the previous studies including ours had a short-term design, with an evaluation period of less than 3 years. We believe that evaluation of the long-term clinical efectiveness and cost efciency of this type of disease management program is critically important for diabetes control because of the long-term impact on patient health and healthcare cost. Te present study aimed to examine the long-term efects of a local disease management program focused on diabetic nephropathy prevention using administrative data under the universal public health insurance scheme in Japan to extend our previous fndings. Methods Study setting and disease management program Tis study took advantage of a public health insurance scheme, the National Community-based