Slow Titration and Delayed Intensification of Basal Insulin Among Patients with Type 2 Diabetes

BACKGROUND: Clinical inertia in type 2 diabetes mellitus (T2DM) refers to the failure of clinicians to intensify therapy when indicated. Many T2DM patients remain suboptimally controlled after initiating basal insulin. OBJECTIVE: To examine the prevalence of patients treated with basal insulin but in poor glycemic control (hemoglobin A1c [A1c] ≥ 7%) after initiation and subsequent treatment intensification patterns and glycemic outcomes in a real-world setting. METHODS: Adults diagnosed with T2DM newly initiating a basal insulin analog (insulin glargine or detemir) from January 2010 to September 2014 were identified in the QuintilesIMS Real-World Data Adjudicated Claims linked to the QuintilesIMS Real-World Data Electronic Medical Records. Patients were previously naive to insulin and glucagon-like peptide-1 receptor agonists (GLP-1 RAs), were persistent on therapy for ≥ 6 months, and had ≥ 12 months of continuous health plan enrollment after initiation. First treatment intensification (increase in basal insulin dose [of ≥ 10%], addition of bolus insulin, GLP-1 RA, or a new oral antidiabetic drug [OAD]) was assessed among patients in poor glycemic control at 6 months after initiation over the available (minimum ≥ 12-month) follow-up. Subsequent glycemic outcomes and treatment intensification were assessed. Kaplan-Meier (KM) analysis evaluated time-to-treatment intensification and time to A1c goal. RESULTS: Of 427 eligible patients with A1c available at 6 months, 59.3% were male; mean age was 53.9 years; mean follow-up was 29.4 months; and mean dose of the initiated prescription was 29.6 insulin units (U) (median 24U). Six months after initiating basal insulin, 81.0% of patients (n = 346) remained in poor glycemic control, and mean basal insulin dose was 31.0U (median 25U). Most (88.4%; n = 306) of these uncontrolled patients subsequently intensified treatment over the available follow-up. Using KM analysis, these patients intensified treatment in a median of 58 days (range: 17.5 days [GLP-1 RA addition] to 52 days [increase in basal insulin dose]) from the first elevated A1c measurement taken after 6 months, and 72.5% (GLP-1 RA addition) to 91.1% (OAD addition) of patients continued to remain in poor glycemic control at 12 months after intensification. Most patients (66.8%; n = 231/346) first intensified treatment by increasing their basal insulin dose, and mean dose increased to 61.7U (median 38U) at intensification. Six months following basal insulin increase, almost all patients remained on basal insulin therapy and among those with available A1c, 92.1% (140 of 152) were in poor glycemic control. In the subsequent 12 months, only a third (34%) of uncontrolled patients added another antihyperglycemic agent. CONCLUSIONS: The vast majority of patients remained uncontrolled in the 6 months following basal insulin initiation. Basal insulin up-titration was slow and insufficient in the 6 months after initiation, indicating treatment inertia. Subsequently, most patients failed to achieve glycemic targets despite intensification with basal insulin. This finding suggests a substantial unmet need for effective treatment intensification among T2DM patients treated with basal insulin who remain uncontrolled. Improved provider education and guidelines on appropriate intensification are warranted.