Depression in Patients with Type 2 Diabetes: Impact on Adherence to Oral Hypoglycemic Agents

Background:Adherence to oral hypoglycemic agents (OHAs) is important for adequate glycemic control and prevention of future complications in patients with type 2 diabetes.Objective:To examine the impact of depression on adherence to OHAs in patients newly diagnosed with type 2 diabetes.Methods:Patients newly diagnosed with type 2 diabetes during a 4 year period were identified from a Medicaid claims database. Presence of preexisting depression was determined on the basis of ICD-9-CM codes. Adherence to OHAs was computed using prescription refill data for a 12 month follow-up period from the date of the index OHA prescription. Two separate adherence indices (Medication Possession Ratio-1 [MPR-1], Medication Possession Ratio-2 [MPR-2]) were computed. The impact of depression on adherence was assessed after controlling for confounders such as demographics, comorbidity, provider interaction, complexity of regimen, and diabetes severity.Results:A total of 1326 newly diagnosed patients with type 2 diabetes were...