Purpose: To describe the extent of delays in insulin initiation, analyze its impact on glycemic control, and explore factors influencing delayed insulin initiation among Chinese type 2 diabetes mellitus (T2DM) patients.
Methods: A real-world, retrospective cohort study with regional electronic health records from Fuzhou, southeast China was conducted among T2DM patients. Adult patients uncontrolled with oral antidiabetic drugs (OADs; HbA_1c ≥ 7%) and initiated on insulin treatment were included. Time to insulin initiation was described. After propensity-score matching, Wilcoxon rank-sum test and chi-square test were used to compare follow-up HbA_1c (first HbA_1c 3 months after insulin initiation) between timely (initiated insulin within 6 months after OAD failure) and delayed (initiated after 6 months) insulin-initiation groups. Sensitivity analysis was also performed by linear and logistic regression. Factors associated with delayed insulin initiation were explored using logistic regression.
Results: A total of 940 patients were included, with mean±SD age 66.3± 11.9 years. In sum, 328 had HbA_1c recorded 3 months after insulin initiation. After propensity-score matching (1:1 matching), 184 patients were included for further analysis. Median follow-up HbA_1c was lower in the timely-initiation group than the delayed-initiation group (7.25% vs 8.25%, P =0.009). Patients in the timely initiation group also had higher odds of achieving HbA_1c < 7% (OR=3.15, P =0.001). Results were confirmed by logistic regression. Hypertension, coronary artery disease, baseline HbA_1c, and hospital level at insulin initiation were associated with delays in insulin initiation.
Conclusion: Timely insulin initiation after OAD failure is associated with better glycemic control.
Keywords: type 2 diabetes mellitus, therapeutic inertia, delayed insulin initiation, glycemic control, HbA_1c