Aim: To assess adherence and discontinuation of injectable glucagon-like peptide-1 receptor agonists (GLP-1 RA) at 12 and 24 months among adult type 2 diabetes mellitus (T2DM) patients in the United States initiating GLP-1 RA using the administrative claims-based database, Optum Clinformatics® Data Mart 7.1.
Method: A retrospective study was conducted from 2009-01 to 2017-12. Patients were required to be continuously enrolled for 12 months prior to their first GLP-1 RA prescription. Proportion of days covered (PDC) from prescription claims ≥0.80 defined adherence. Discontinuation was defined as a ≥90-day gap from the last date of GLP-1 RA supply to the first date of subsequent prescription claim.
Results: A total of 4,791 T2DM patients had ≥1 and 3,907 had ≥2 GLP-1 RA prescription claims. 50.9% and 47.4% of patients were adherent at 12 and 24 months, respectively. Adherence was statistically-significantly higher among patients on weekly vs daily doses (p < 0.001). Median time to discontinuation was 13 months. The discontinuation rate was 47.7% and 70.1% at 12 and 24 months, respectively, with differences at 24 months for age and dosing frequency (p < 0.001 for both).
Conclusion: Over half of T2DM patients initiating GLP-1 RA were non-adherent and the majority (70.1%) discontinued therapy by 24 months. Reasons for non-adherence and discontinuation merit further research.