Does Pen Help? A Real-World Outcomes Study of Switching from Vial to Disposable Pen Among Insulin Glargine-Treated Patients with Type 2 Diabetes Mellitus

Abstract

Objective: The study was designed to evaluate real-world data on clinical and economic outcome differences between patients with type 2 diabetes mellitus (T2DM) who use insulin glargine with vial-and-syringe delivery and those who switch to pen administration. Subjects and Methods: This retrospective study analyzed medical and pharmacy claims information from the national managed-care IMPACT? database (Ingenix Inc., Salt Lake City, UT). Adults with T2DM treated with insulin glargine were evaluated. Clinical and economic outcomes over 1 year were compared between individuals who had converted from administering glargine via vial-and-syringe to the SoloSTAR? (sanofi-aventis U.S., Bridgewater, NJ) pen (Switchers) and patients who continued to use vial-and-syringe administration (Continuers). Patients from each cohort were matched using propensity score matching for a comparison sample. Results: In total, 3,893 eligible patients were identified (665 Switchers and 3,228 Continuers), with a matched cohort with 603 patients in each group. Baseline characteristics were similar between groups. One-year treatment persistence was significantly higher with Switchers versus Continuers (65.3% vs. 49.8%; P<0.0001). Medication possession ratio was also significantly higher among Switchers (0.79 vs. 0.76; P=0.0173). Insulin use and glycemic control were similar between groups. Healthcare utilization and total costs were also similar between groups. Higher prescription costs among Switchers were offset by lower overall and diabetes-related outpatient and inpatient costs. Conclusions: Switching from insulin glargine vial-and-syringe administration to pen delivery resulted in improved treatment adherence and persistence, with comparable clinical and economic outcomes.