The goal of this study was to appraise the extent of unique content on disease-specific preference-based measures (DSPMs) when contrasted with the EQ-5D using published studies and to inform whether EQ-5D could be inadequate as a utility measure in its content coverage for a given disease-specific application.
A structured search of published literature was performed using PubMed and EMBASE/Medline database from Jan 1, 1990 to Mar 31, 2011. Articles were eligible for inclusion if algorithms were developed to convert components from disease-specific measures into utility scores.
Of 1,029 articles identified, 50 studies satisfied the inclusion criteria. The most frequent conditions where DSPMs were developed included cancer (12 studies), coronary artery disease (4 studies), osteoarthritis, rheumatoid arthritis (3 studies of each), obesity, and stroke (2 studies of each). Most studies involved mapping items or scores from disease-specific non-preference-based measures onto a preference-based measure of health such as the EQ-5D. A substantial number of DSPMs appeared to include unique content not covered by EQ-5D dimensions.
Several conditions were identified as potential areas where the richness of the EQ-5D descriptive system could be enhanced. It is yet unclear whether added dimension(s) would contribute unique explained variance to a utility score. Given the resources required to rigorously develop a utility measure, the need for such measures should be carefully vetted.