OBJECTIVES: Many treatments for rare paediatric diseases are currently under development or are being reviewed by decision makers like NICE. However utility data for the estimation of QALYs in cost-effectiveness analysis is commonly not collected in these trials. Few methods exist for addressing this gap and so this project was designed to make recommendations for methods.

METHODS: Recent health technology assessment (HTA) submissions for orphan drugs were reviewed to record how utilities were captured for each model. This included submissions in Duchenne Muscular Dystrophy, Spinal Muscular Atrophy and Fabry disease. The methodologies were summarised and then presented in interviews with HTA experts. These experts (n=5) were asked for their opinion on the appropriateness of each approach and the possible limitations of each. A proposed hierarchy of acceptable methods was also presented and discussed.

RESULTS: The review of HTA submissions revealed that very few submissions included utility data collected using standardised measures in clinical trials. The methods for collecting these data included patient surveys, vignette methodologies, discrete choice experiment surveys, and structured forms of expert elicitation. Each method had limitations. These included a lack of validated utility measures, poor mapping functions, unvalidated vignettes and methods based on substantial assumptions. There was no clear agreement among experts in terms of the most appropriate approach.

CONCLUSIONS: The opportunity costs associated with many of the new treatments for rare diseases are very high because of the high acquisition costs and uncertainty regarding outcomes. More work including an expert Task Force may provide a better set of methods for estimating utilities in rare disease.