Aims: Medication non-adherence is particularly common in patients with Type 2 diabetes. We constructed a discrete-choice experiment to examine the relative importance of oral glucose-lowering medication features and to estimate the likely effect of effectiveness and side effects on medication adherence in patients with Type 2 diabetes in the UK and the USA.
Methods: Preferences were elicited using a cross-sectional, web-enabled survey. Patients with a self-reported physician-made diagnosis of Type 2 diabetes, who were currently taking oral glucose-lowering medications were recruited through an existing online chronic-disease panel. In each discrete-choice question, patients were asked to choose between two hypothetical medication alternatives, each defined by improvement in glycated haemoglobin, frequency of mild-to-moderate hypoglycaemia, water retention, weight gain, mild stomach upset and medication-related cardiovascular risk. Patients were also asked to indicate how likely they would be to miss or skip doses of each hypothetical medication.
Results: Two hundred and four patients in the UK and 203 patients in the USA completed the survey. Preferences did not differ between the two countries. Overall, glucose control was the most important medication feature, followed by medication-related cardiovascular risk and weight gain, respectively. Water retention was not important to patients. Weight gain and cardiovascular risk had significant negative effects on likely medication adherence.
Conclusions: While patients with Type 2 diabetes believe glucose control is important, medication side effects and risks influence patients' treatment choices. Medication-related weight gain and cardiovascular risk are significant predictors of likely medication non-adherence.