Comparing Medication Adherence and Persistence Among Patients with Type 2 Diabetes Using Sodium-Glucose Cotransporter 2 Inhibitors or Sulfonylureas.

BACKGROUND Patients with type 2 diabetes treated with pharmacotherapy should be adherent to and persistent with their medications to experience glycemic control and prevent associated complications. OBJECTIVE To compare medication adherence and persistence among patients with type 2 diabetes who are newly initiating a sodium-glucose cotransporter 2 (SGLT-2) inhibitor or a sulfonylurea. METHODS This was a retrospective, observational cohort study using the MarketScan claims databases. The patients who were selected for the study had newly initiated treatment with an SGLT-2 inhibitor or a sulfonylurea between January 1, 2015, and December 31, 2015 (index date; class of earliest medication is defined as the index class); were aged ≥18 years on the index date; were continuously enrolled with health insurance for 12 months before and 6 months after (ie, follow-up) the index date; and had ≥1 baseline diagnoses of type 2 diabetes. Study exclusions were type 1 diabetes, pregnancy, and gestational diabetes. Medication adherence was measured by the proportion of days covered (PDC) with the index class during the follow-up period and dichotomized as adherent (PDC ≥80%) or nonadherent. Persistence was defined as the number of days from the index date until a >60-day continuous gap in days without the index drug class (ie, discontinuation) or the end of follow-up. A propensity score model was used to match patients receiving an SGLT-2 inhibitor to patients receiving a sulfonylurea in a 1:1 ratio based on patient characteristics. Logistic (ie, adherence) and Cox (ie, persistence) regression models were fit to the matched samples. RESULTS Initially, the study included 17,724 patients who received an SGLT-2 inhibitor and 25,490 patients who received a sulfonylurea. After propensity score matching, 13,657 patients remained in each cohort. Compared with patients receiving a sulfonylurea, a statistically significantly greater percentage of patients receiving an SGLT-2 inhibitor were adherent to therapy (61.4% vs 53.9%, respectively; odds ratio of adherence, 1.364; 95% confidence interval [CI], 1.30-1.43; P <.001) and persistent (76.1% vs 68.9%, respectively; hazard ratio of discontinuation, 0.746; 95% CI, 0.71-0.78; P <.001). CONCLUSION Maintaining adherence to and persistence with antidiabetes medication is vital to glycemic control among patients with type 2 diabetes. In this real-world study, patients who newly initiated treatment with SGLT-2 inhibitors were more likely to adhere to treatment and persist with the initiated therapy than similar patients who newly initiated treatment with sulfonylureas.