Estimating Quality of Life Decrements Due to Diabetes Complications in the United States: The Health Utility Index (HUI) Diabetes Complication Equation

ObjectiveHealth utility decrements associated with diabetes mellitus complications are essential for calculating quality-adjusted life-years (QALYs) in patients for use in economic evaluation of diabetes interventions. Previous studies mostly focused on assessing the impact of complications on health utility at event year based on cross-sectional data. This study aimed to separately estimate health utility decrements associated with current and previous diabetes complications.Research Design and MethodsThe Health Utilities Index Mark 3 (HUI-3) was used to measure heath utility in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial (N=8713). Five macrovascular complications (myocardial infarction [MI], congestive heart failure [CHF], stroke, angina, and revascularization surgery [RS]) and three microvascular complications (nephropathy [renal failure], retinopathy [severe vision loss], and neuropathy [severe pressure sensation loss]) were included in a set of alternative modelling approaches including the ordinary least squares (OLS) model, fixed effects model, and random effects model to estimate the complication-related health utility decrements.ResultsAll macrovascular complications were associated with decrements of HUI-3 scores: MI (event year: -0.042, successive years: -0.011), CHF (event year: -0.089, successive years: -0.041), stroke (event year: -0.204, successive years: -0.101), angina (event year: -0.010, successive years: -0.032), and revascularization (event year: -0.038, successive years: -0.016) (all p<0.05). For microvascular complications, severe vision loss (-0.057), and severe pressure sensation loss (-0.066) were significantly associated with decrements of HUI-3 scores (both p<0.05). Hypoglycemia (both severe and symptomatic) was found to be associated with a 0.036 decrement of health utility at event year, and a 0.033 decrement of health utility at successive years. Results from an OLS model are preferred for supporting a microsimulation model while a fixed effects model is preferred to describe direct health impacts from complications.ConclusionsMacrovascular and microvascular complications caused QALY decrements in patients with type 2 diabetes. While only part of the total impaired QALY is experienced during the event year, further QALY decrements for successive years were quite substantial.