Evaluation of a program designed to prevent diabetic nephropathy aggravation: A retrospective cohort study using health checkups and claims data in Japanese municipalities.

AIMS

Japan started the Diabetic Nephropathy Aggravation Prevention Program. Its early impact was assessed in this study.

METHODS

This study used the Kokuho Database of patients with type 2 diabetes from program-implementing and non-implementing municipalities (fiscal years [FYs] 2015-2021). Implementing municipalities facilitated clinic visits and provided education to eligible patients. Average treatment effects on the treated in FYs 2016 and 2018 were evaluated using the inverse probability of treatment weighting. Comparison included intervened vs. non-intervened patients in program-implementing municipalities (Comparison A), intervened patients in program-implementing vs. eligible patients in non-implementing municipalities (Comparison B), and eligible patients in implementing and non-implementing municipalities (Comparison C).

RESULTS

Overall, 89,611/89,685 patients from FY 2016/2018 were eligible. Among 68,125/68,170 patients in program-implementing municipalities, 1,470/1,819 were intervened. In Comparison A, the estimated effect of the program on ΔeGFR at 3 years were -0.4 (95 % confidence interval; -1.0, 0.2)/-0.4 (-0.9, 0.1) mL/min/1.73 m in FY 2016/2018. Comparisons B and C demonstrated similar tendency; distribution of %change in eGFR varied between municipalities.

CONCLUSIONS

Early in the program, renal function did not improve in the intervened patients or program-implementing municipalities. Diverse eGFR changes across municipalities highlighted diverse intervention outcomes, emphasizing the need of program refinement.