Factors associated with the degree of glycemic deterioration among patients with type 2 diabetes who dropped out of diabetes care: A longitudinal analysis using medical claims and health checkup data in Japan

AIMS/INTRODUCTION: To identify factors associated with worsening glycemic control after discontinuing diabetes care among patients with type 2 diabetes. MATERIALS AND METHODS: This retrospective cohort study combined medical claims and health checkup data between January 2005 and April 2018. Adult Japanese workers with type 2 diabetes who had dropped out from diabetes care for ≥4 months after receiving ≥18 months of non‐intermittent care and had health checkup information both before and after the dropout were included. Factors associated with changes in HbA1c during the dropout period were identified using multiple linear regression analyses and depicting restricted cubic spline (RCS) curves. RESULTS: A total of 1,125 patients (mean age: 51.2 years, baseline HbA1c: 6.8%, and number of males: 93.7%) whose follow‐up HbA1c increased to 7.6% after a mean 9.3‐month dropout period were included. Deterioration in HbA1c was associated with higher baseline HbA1c and sulfonylurea or insulin use. The RCS curves illustrated that patients without antidiabetic medication had small changes in HbA1c (+0.5% from a baseline HbA1c of 7.0%), whereas those using sulfonylureas or insulin had an approximately 2% or more increase in HbA1c even when maintaining reasonable glycemic control before dropping out. CONCLUSIONS: Overall in this study, glycemic control worsened during treatment interruptions among patients who were mainly male employees. However, changes in HbA1c greatly varied based on baseline HbA1c and antidiabetic medication type. Caring for patients at risk of worsening glycemic control due to treatment dropout, especially those using sulfonylurea and insulin, is imperative.