Real-World Clinical and Economic Outcomes of Liraglutide Versus Sitagliptin in Patients with Type 2 Diabetes Mellitus in the United States

INTRODUCTION The objective of this study was to compare the clinical effectiveness of liraglutide with sitagliptin and assess the associated economic outcomes in patients with type 2 diabetes mellitus (T2DM) treated in real-world practice in the United States (US). METHODS This retrospective cohort study used a large US claims database to identify patients with T2DM who initiated liraglutide or sitagliptin between January 2010 and December 2012. Adults (≥18 years old) with persistent use of therapy for ≥3 months were included. Changes in glycated hemoglobin A1c (A1C) and the proportion of patients achieving A1C targets (≤6.5% and <7%) were examined at 6-month follow-up. Diabetes-related total, medical, and pharmacy costs over the follow-up period were assessed. Multivariable regression models were used to estimate the outcomes associated with liraglutide relative to sitagliptin, adjusting for differences in patient demographics and clinical characteristics. RESULTS The study included 1,465 patients with T2DM who initiated liraglutide (N = 376) or sitagliptin (N = 1,089) (mean age [standard deviation (SD)]: 54 [8.9] vs. 58 [10.8] years; 43.9% vs. 61.8% males; both P < 0.01). After controlling for confounding factors, liraglutide patients experienced 0.31% points greater reduction in A1C (0.95% vs. 0.63% points; P < 0.01) at 6-month follow-up than sitagliptin patients and were more likely to reach A1C targets of ≤6.5% (odds ratio [OR]: 2.00; P < 0.01) and <7% (OR: 1.55; P < 0.01). Liraglutide patients had $994 lower mean diabetes-related medical costs ($1,241 vs. $2,235; P < 0.01), but $544 higher diabetes-related pharmacy costs ($2,100 vs. $1,556; P < 0.01) during the follow-up. No difference was found in the total mean diabetes-related costs between the two cohorts. CONCLUSION Liraglutide showed greater improvement in glycemic outcomes than sitagliptin among adult patients with T2DM in real-world clinical practice. Although diabetes-related pharmacy costs for patients using liraglutide were higher compared with sitagliptin, these were offset by significantly lower diabetes-related medical costs, resulting in similar total diabetes-related costs between the two treatment groups.