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.