Factors associated with non-adherence to insulin and non-insulin medications in patients with poorly controlled diabetes.

Objectives: To evaluate differences in factors associated with self-reported medication non-adherence to insulin and non-insulin medications in patients with uncontrolled type 2 diabetes.

Methods: In this secondary analysis of a randomized trial in patients with obesity and uncontrolled type 2 diabetes, multivariable logistic regression was used to evaluate associations between several clinical factors (measured with survey questionnaires at study baseline) and self-reported non-adherence to insulin and non-insulin medications.

Results: Among 263 patients, reported non-adherence was 62% (52% for insulin, 55% for non-insulin medications). Reported non-adherence to non-insulin medications was less likely in white versus non-white patients (odds ratio (OR) = 0.42; 95%CI: 0.22,0.80) and with each additional medication taken (OR = 0.75; 95%CI: 0.61,0.93). Non-adherence to non-insulin medications was more likely with each point increase in a measure of diabetes medication intensity (OR = 1.43; 95%CI: 1.01,2.03), the Problem Areas in Diabetes (PAID) score (OR = 1.06; 95%CI: 1.02,1.12), and in men versus women (OR = 3.03; 95%CI: 1.06,8.65). For insulin, reporting non-adherence was more likely (OR = 1.02; 95%CI: 1.00,1.04) with each point increase in the PAID.

Discussion: Despite similar overall rates of reported non-adherence to insulin and non-insulin medications, factors associated with reported non-adherence to each medication type differed. These findings may help tailor approaches to supporting adherence in patients using different types of diabetes medications.