title: Response-Scale Heterogeneity in the EQ-5D.
abstract: This paper discusses two types of response-scale heterogeneity, which may impact upon the EQ-5D. Response-scale heterogeneity in reporting occurs when individuals systematically differ in their use of response scales when responding to self-assessments. This type of heterogeneity is widely observed in relation to other self-assessed measures but is often overlooked with regard to the EQ-5D. Analogous to this, preference elicitation involving the EQ-5D could be subject to a similar type of heterogeneity, where variations across respondents may occur in the interpretations of the levels (response categories) being valued. This response-scale heterogeneity in preference elicitation may differ from variations in preferences for health states, which have been observed in the literature. This paper explores what these forms of response-scale heterogeneity may mean for the EQ-5D and the potential implications for researchers who rely on the instrument as a measure of health and quality of life. We identify situations where they are likely to be problematic and present potential avenues for overcoming these issues. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Centre for Health Economics, Monash Business School, Monash University, Melbourne, Australia.
authors.forename: Rachel J
authors.initials: RJ
authors.lastname: Knott
authors.affiliation: Centre for Health Economics, Monash Business School, Monash University, Melbourne, Australia.
authors.forename: Nicole
authors.initials: N
authors.lastname: Black
authors.affiliation: Division of Health Research, Lancaster University, Lancaster, UK.
authors.forename: Bruce
authors.initials: B
authors.lastname: Hollingsworth
authors.affiliation: Centre for Health Economics, Monash Business School, Monash University, Melbourne, Australia.
authors.forename: Paula K
authors.initials: PK
authors.lastname: Lorgelly
mesh_terms: D006304:Health Status; D006801:Humans; D015233:Models, Statistical; D019057:Quality-Adjusted Life Years; D012647:Self-Assessment; D011795:Surveys and Questionnaires
keywords: EQ-5D; anchoring vignettes; differential item functioning; multi-attribute utility instruments; preference heterogeneity; reporting heterogeneity; response-scale heterogeneity