Objectives: Cost-effectiveness models for diabetes link glycated hemoglobin (HbA1c) to diabetes-related complications. Independent of diabetes-related complications, there is little known on the association between HbA1c and health utility scores. This link can alter the cost effectiveness of interventions designed to improve HbA1c. The cross-sectional relationship between HbA1c and health utility scores in adult type 1 diabetes patients was estimated after adjusting for diabetes-related complications.
Methods: The EuroQoL-5 dimension (EQ-5D) questionnaire and an ad hoc survey requesting demographic information and adherence to glucose monitoring therapies was administered to adult type 1 diabetes patients during a clinic visit and combined with clinical medical record data. Health utility scores were derived using the US time-tradeoff valuation of the EQ-5D. Linear regression was used to estimate the relationship between HbA1c and utility, adjusting for treatments, demographics, and diabetes-related complications.
Results: Among 176 patients, mean (standard deviation [SD]) age was 38 (12.2) years, duration of disease was 22 (12.1) years, and number of chronic conditions other than type 1 diabetes was 2.7 (2.0). Unadjusted mean (SD) utility was 0.94 (0.09) for those with HbA1c levels <7 % (n = 54), 0.89 (0.15) for those with HbA1c ≥ 7 % (n = 122), and 0.91 (0.14) for all patients. After adjustment, a 1 % absolute increase in HbA1c was associated with a disutility of -0.03 (95 % confidence interval [CI] -0.049, -0.006).
Conclusions: Findings suggest that, after adjusting for diabetes-related complications, higher HbA1c levels are associated with a significant health disutility. Pending additional data from longitudinal studies, these findings could be used in cost-effectiveness evaluations of type 1 diabetes interventions that impact HbA1c.