Introduction: Although cost-utility analyses are frequently used to estimate treatment outcomes for type 2 diabetes, utilities are not available for key medication-related attributes. The purpose of this study was to identify the utility or disutility of diabetes medication-related attributes (weight change, gastrointestinal side effects, fear of hypoglycemia) that may influence patient preference.
Methods: Patients with type 2 diabetes in Scotland and England completed standard gamble (SG) interviews to assess utility of hypothetical health states and their own current health state. The EQ-5D, PGWB, and Appraisal of Diabetes Symptoms were administered. Construct validity and differences among health states were examined with correlations, t-tests, and ANOVAs.
Results: A total of 129 patients (51 Scotland; 78 England) completed interviews. Mean utility of diabetes without complications was 0.89. Greater body weight was associated with disutility, and lower body weight with added utility (e.g., 3% higher = -0.04; 3% lower = +0.02). Gastrointestinal side effects and fear of hypoglycemia were associated with significant disutility (p < 0.001). SG utility of current health (mean = 0.87) demonstrated construct validity through correlations with patient-reported outcome measures (r = 0.08-0.31).
Discussion: The vignette-based approach was feasible and useful for assessing added utility or disutility of medication-related attributes.