A meta-analysis of health state valuations for people with diabetes: explaining the variation across methods and implications for economic evaluation.

PURPOSE: To review published studies on the effect of diabetes and its complications on utility scores to establish whether there is systematic variation across studies and to examine the implications for the estimation of quality-adjusted life years (QALYs).
METHODS: A systematic review was performed using studies reporting QALY measures elicited from people with diabetes including those with a history of complications. Meta-analysis was used to obtain the average utility, and meta-regression was employed to examine the impact of study characteristics and elicitation methods on these values. The effect of different utility scores on QALYs was examined using diabetes simulation models.
RESULTS: In the meta-analysis based on 45 studies reporting 66 values, the average utility score was 0.76 (95% CI 0.75-0.77). A meta-regression showed significant variation due to age, method of elicitation and the proportion of males. The average utility score for individual complications ranged from 0.48 (95% CI 0.25, 0.71) for chronic renal disease to 0.75 (95% CI 0.73, 0.78) for myocardial infarction, and these differences produced meaningful changes in simulated QALYs. There was significant heterogeneity between studies.
CONCLUSIONS: We provide summary utility scores for diabetes and its major complications that could help inform economic evaluation and policy analysis.