The EuroQoL EQ-5D questionnaire is a brief utility index designed to measure health-related quality of life and health preferences. The Panel on CostEffectiveness in Health and Medicine recommends the use of societal or community preferences to calculate quality-adjusted life years (QALYs) for the reference case analysis in cost-effectiveness analyses. Preference-based health state classification systems, or ‘utility indices,’ represent a class of survey instruments recommended as suitable for providing these community preferences for reference-case analyses. While the mechanisms for creating scoring functions vary for different utility indices, these indices all consist of a descriptive health survey on which the respondent describes his or her state of health on multiple domains. The survey is then scored to produce a summary measure, which represents an average preference score ...