Benchmarking Insulin Treatment Persistence Among Patients with Type 2 Diabetes Across Different U.S. Payer Segments

Treatment persistence with basal insulins is crucial to achieving sustained glycemic control, which is associated with a reduced risk of microvascular disease and other complications of type 2 diabetes (T2D). However, studies suggest that persistence with basal insulin treatment is often poor.

To measure and benchmark real-world basal insulin treatment persistence among patients with T2D across different payer segments in the United States.

This was a retrospective observational study of data from a national pharmacy database (Walgreen Co., Deerfield, IL). The analysis included patients with T2D aged ≥ 18 years who filled ≥ 1 prescription for basal insulins between January 2013 and June 2013 (the index prescription) and who had also filled prescriptions for ≥ 1 oral antidiabetes drug in the database. Patients with claims for premixed insulin were excluded. Treatment persistence was defined as remaining on the study medication(s) during the 1-year follow-up period. Patients were stratified according to treatment history (existing basal insulin users vs. new insulin users), payer segments (commercially insured, Medicare, Medicaid, or cash-pay), type of basal insulin (insulin glargine, insulin detemir, or neutral protamine Hagedorn insulin [NPH]), and device for insulin administration (pen or vial/syringe).

A total of 274,102 patients were included in this analysis, 82% of whom were existing insulin users. In terms of payer segments, 45.3% of patients were commercially insured, 47.8% had Medicare, 5.9% had Medicaid, and 1.1% were cash-pay. At the 1-year follow-up, basal insulin treatment persistence rate was 66.8% overall, 61.7% for new users, and 67.9% for existing users. In general, for both existing and new basal insulin users, higher persistence rate and duration were associated with Medicare versus cash-pay patients, use of insulin pens versus vial/syringe, and use of insulin glargine versus NPH.

This large-scale study provides a benchmark of basal insulin treatment persistence across different payers in the United States. Findings indicate that basal insulin persistence patterns are significantly different across different payers, basal insulin types, and devices. This information may be useful in developing targeted approaches to improve T2D patients' persistence with insulin treatment for better glycemic control.

This study was funded by Sanofi U.S. through a grant provided to Walgreens for research services. Matusik, Jiang, and Lou are employed by Walgreen Co. Wei and Ganguli were employed by Sanofi U.S. at the time of this study. Study concept and design were contributed by Wei, Ganguli, and Matusik, with assistance from Lou. Jiang took the lead in data collection, along with Lou, and data interpretation was performed by Wei, Lou, and Jiang, along with Ganguli and Matusik. The manuscript was written by Wei and Jiang, along with Ganguli and Matusik, and revised by Wei and Ganguli, along with the other authors.