Understanding health state valuations: a qualitative analysis of respondents' comments.

Self-completed questionnaires (usually distributed by post) and visual analogue scales (VAS) are common means for collecting valuations for hypothetical EQ-5D health states. Although opportunities for respondents to comment on aspects of the exercise are often included, these data have rarely been the focus of analyses. This paper, therefore, reports on solicited and unsolicited written comments received in a New Zealand survey in 1999 to which 1360 people responded of whom approximately 50% made comments. The comments were systematically analysed via an inductive process that allowed principal themes to emerge with respect to understanding the peculiarities of respondents' valuations, particularly common 'data problems', and their perceptions as to the adequacy or otherwise of the EQ-5D classification system. From our findings we conclude that the valuation exercise imposes a substantial cognitive burden on respondents and many do not understand it (for a variety of reasons documented in the paper). Also, although there is some evidence for expanding the EQ-5D (generic) health-related quality of life dimensions, more research as to whether this holds for a larger sample and across cultural settings is needed. We offer recommendations for future research into understanding respondents' cognitive processes and possible revisions to the design and administration of the EQ-5D.