Characteristics of Elderly Patients Initiating Sitagliptin or Non-DPP-4-Inhibitor Oral Antihyperglycemic Agents: Analysis of a Cross-Sectional US Claims Database

INTRODUCTION: Previous analyses concluded that patients initiating treatment with sitagliptin are older and have more comorbidities than patients initiating treatment with other oral antihyperglycemic agents (OAHAs). However, these studies focused on the general population or subjects ≤ 65 years of age. We sought to compare differences in baseline characteristics of elderly patients (≥ 65 years of age) with T2DM initiating sitagliptin vs. non-DPP-4 inhibitor (non-DPP-4i) OAHA in the MarketScan(®) Medicare Supplemental Database. METHODS: Relevant patients were identified in the MarketScan(®) Medicare Supplemental Database and categorized according to the complexity of their antihyperglycemic treatment: initiating monotherapy, escalating to dual combination therapy, or escalating to triple combination therapy. Within each category, the comparison between patients initiating use of sitagliptin or non-DPP-4i OAHA was made within three age groups: 65–74, 75–84, and ≥ 85 years. Gender and comorbidity recorded within the 12 months prior to the index date (date of initiation/escalation of treatment) were assessed as baseline characteristics in each group. Between-treatment group differences in each covariate were compared using standardized differences. RESULTS: Patients with T2DM who initiated treatment with sitagliptin tended to be older and were more likely to have a pre-treatment history of arrhythmia, congestive heart failure, peripheral vascular disease, renal failure, and stroke than those initiating non-DPP-4i OAHAs, with the most pronounced differences observed between patients initiating monotherapy in all three age groups. As treatment complexity advanced to dual combination therapy, the differences were attenuated and mostly observed in the 75–84 and ≥ 85 age groups. In patients aged 65–74 years initiating triple therapy, no differences were observed between groups. CONCLUSION: Patients ≥ 65 years with T2DM initiating sitagliptin tend to be older and have more comorbidities than those prescribed other classes of OAHA. Appropriate adjustment is required to minimize the impact of potential confounding and channeling bias in any comparative analyses including users of sitagliptin. FUNDING: Merck & Co., Inc., Kenilworth, NJ, USA.