Non-adherence to basal insulin among patients with type 2 diabetes in a US managed care population: Results from a patient survey

The aim of this study was to assess insulin non-adherence among patients with type 2 diabetes (T2DM) to better understand relationships between adherence, basal insulin (BI) usage, and patient experiences. A cross-sectional survey of patients with T2DM using BI was conducted. Adherence was measured by the Morisky Medication Adherence Scale 8-Items (MMAS-8). Low adherence (LA) was defined as MMAS-8 score < 6, high adherence (HA) as MMAS-8 score = 8, and medium adherence as MMAS-8 score = 6 to < 8. Patients with MMAS-8 scores = 6 to < 8 were excluded from the analysis. Of 400 completed surveys, 395 patients (98.8%) completed all MMAS-8 items, 112 with LA, 134 with HA. Compared with HA patients, greater proportions of LA patients followed more complex BI dosing patterns (57.1% vs. 39.5%, P = 0.014), had some difficulty calculating their correct BI dose (40.2% vs. 6.8%, P < 0.001), reported having missed >= 1 dose per month (79.3% vs. 12.6%, P < 0.001), and temporarily stopped BI in the past year (23.2% vs. 0.7%, P < 0.001). In conclusion, understanding patients' experiences with BI therapy can help formulate strategies to improve adherence.