Resource utilization and costs associated with using insulin therapy within a newly diagnosed type 2 diabetes...

Although oral antidiabetic medications are the mainstay for managing type 2 diabetes mellitus (T2DM), patients often require insulin therapy to achieve optimal glycemic control. Given the prevalence of insulin use among patients with T2DM, this study evaluated the economic impact of this treatment modality in patients treated in a managed care setting.

To estimate costs and resource utilization associated with using insulin therapy among patients with newly diagnosed T2DM who were initially treated with other noninsulin antidiabetic (NIAD) medications.

An observational, retrospective study design was implemented using integrated medical and pharmacy claims data. Adults with a diagnosis of T2DM from July 1, 2003, through March 31, 2008, were identified. The date of first diagnosis was deemed the index date. The 24-month period after the index date was used to assess treatment patterns. Based on the treatment patterns, the following 2 cohorts were selected: NIAD-only cohort, users who received greater than 1 NIAD class medication but never received insulin, and insulin-use cohort, NIAD users who switched to/added on insulin therapy (duration ≥ 60 days). Patients were matched in a 1:3 (insulin-use:NIAD-only) ratio based on propensity scores and other key covariates of interest. Hypoglycemia rates, monthly costs, and resource use during the outcome assessment period were compared between cohorts.

After matching, 1,400 patients (350 insulin users and 1,050 NIAD-only users) were included in the analysis (42% women; mean age, 56 years). After controlling for covariates, the insulin-use cohort incurred $71 per patient per month higher total T2DM-specific costs than the NIAD-only cohort ($241/month vs. $170/month, P = 0.0003). Pharmacy costs and utilization of physician visits were drivers of cost differences between cohorts. The rate of hypoglycemic events was 10.2 per 100 person-years for the insulin-use cohort versus 2.9 per 100 person-years in the NIAD-only cohort (P  less than  0.0001).

Use of insulin therapy is associated with increased hypoglycemic events, increased pharmacy and medical costs, and greater utilization of T2DM-specific health care services.