OBJECTIVES:  To evaluate, in a US managed care setting, health outcomes among patients with type 2 diabetes mellitus (T2DM) initiating basal insulin therapy via disposable pen with insulin glargine (GLA-P) or insulin detemir (DET-P). METHODS:  Using the claim database from a US health plan (InVision™), T2DM patients initiating GLA-P or DET-P were included if they were ≥18 years, had continuous health plan coverage for 6 months before (baseline) and 1-year after initiation (follow-up), with ≥1 prescription for oral antidiabetic drugs (OADs) and/or exenatide, but no insulin use, during baseline. To minimize selection bias, stringent 1:1 propensity score matching was used to balance baseline characteristics of the two cohorts. Outcomes measures included 1-year treatment persistence and adherence, hemoglobin A1c (A1C), hypoglycemia-related events, healthcare utilization and costs. RESULTS:  A totla of 5828 matched patients were included (n=2914 in each cohort; female 44.4%, baseline mean age 54.4 years; Charlson comorbidity index 0.55; number of OADs 2.60). During 1-year follow-up, patients initiating GLA-P, compared with DET-P, were more persistent (58.8 vs. 44.1%, P<0.001) and adherent (adjusted medication possession ratio 0.68 vs. 0.66, P=0.002) with treatment, had lower daily insulin doses (DACON) (29.2 vs. 32.5 units/day, P=0.012), similar rates of hypoglycemia-related events (5.9 vs. 6.6%, P=0.281), lower diabetes prescription costs (mean $3,142 vs. $3,372, P=0.043) and marginally lower total health care costs (mean $30,364 vs. $33,109, P=0.086). Among patients with A1C data available (GLA-P n=356, DET-P n=332), A1C at 1-year follow-up was 8.14% in GLA-P vs. 8.50% in DET-P (P=0.007), reflecting A1C reduction from baseline of −1.03 vs.−0.86% (P=0.260). CONCLUSIONS: This real-world comparative study suggested that among T2DM patients initiating basal analog insulins using disposable pen, compared with DET-P, GLA-P might be associated with increased treatment persistence and adherence, similar rates of hypoglycemia, lower DACON and healthcare costs during 1-year follow-up. This, however, should be confirmed in future pragmatic randomized clinical trials.