Clinical and Economic Outcomes Associated with the Timing of Initiation of Basal Insulin in Patients with Type 2 Diabetes Mellitus Previously Treated with Oral Antidiabetes Drugs

Purpose In patients with type 2 diabetes mellitus (T2DM) not achieving glycemic targets using oral antidiabetes drugs (OADs), studies suggest that timely insulin initiation has clinical benefits. Insulin initiation at the early versus late stage of disease progression has not been explored in detail. This retrospective database analysis investigated clinical and economic outcomes associated with the timing of insulin initiation in patients with T2DM treated with ≥1 OAD in a real-world US setting. Methods This study linked data from the Truven Health MarketScan^® Commercial database, Medicare Supplemental database, and Quintiles Electronic Medical Records database. A total of 1830 patients with T2DM were included. Patients were grouped according to their OAD use before basal insulin initiation (1, 2, or ≥3 OADs) as a proxy for the timing of insulin initiation. Clinical and economic outcomes were evaluated over 1 year of follow-up. Findings During follow-up the 1 OAD group, compared with the 2 and ≥3 OADs groups, had a greater reduction in glycosylated hemoglobin A_1c (-1.7% vs -1.0% vs -0.9%, respectively; P < 0.0001), greater achievement of glycemic target (38.2% vs 26.7% vs 19.6%, respectively; P < 0.0001), and a lower incidence of hypoglycemia (2.7% vs 6.6% vs 5.0%, respectively; P = 0.0002), with no difference in total health care costs ($21,167 vs $21,060 vs $20,133, respectively). Implications This study shows that early insulin initiation (represented by the 1 OAD group) may be clinically beneficial to patients with T2DM not controlled with OADs, without adding to costs. This supports the call for timely initiation of individualized insulin therapy in this population.