Published Apr 15, 2015

Oxford, UK  -  Generic preference-based measures of health are commonly used to evaluate the impact of diseases and their treatments on overall health related quality of life by weighting their dimensions using people’s value judgements. However, these measures, including the EQ-5D, may miss key dimensions of health for some conditions. A team of researchers from Oxford University, Brunel University, and Sheffield University explored the potential solution of adding extra dimensions to the EQ-5D, a practice known as a ‘bolt-on’ approach. They developed three dimensions describing hearing impairment, vision impairment, and tiredness to add separately to the five core dimensions of the EQ-5D. Interviews were undertaken among 300 members of the UK general public to elicit people’s preferences for the health states with and without the extra dimensions, and data were analysed to examine the magnitude and direction of impact on health state values of the extra dimensions. Study co-author, Dr. Yaling Yang, PhD, from the University of Oxford concluded, “Each of the bolt-on dimensions had a significant impact on values for EQ-5D health states. The extent and direction of the impact of the bolt-on varied according to the level of severity of the bolt-on dimension and the severity of the state to which it was added. The results of this research suggest that simple valuation of these bolt-on items may not be possible; however, further research is required to confirm this exploratory finding.” The full study, “An Exploratory Study to Test the Impact on Three “Bolt-On” Items to the EQ-5D,” is available Open Access in Value in Health.