Guidelines for value sets in economic and non-economic studies using EQ-5D

Values play a critical role in influencing all aspects of the planning and delivery of health care. The term ‘values’ is taken here to embrace a variety of forms of preference, sometimes but not always formally codified, sometimes held privately by individuals and otherwise pooled with others, sometimes represented in a quantitative numeric form and elsewhere represented descriptively or in an ordinal form. Our own private preferences shape the way that we respond to our own health experiences as patients. Health care workers are not insulated from the contaminating effects of their private values on the judgements that they make in the course of their professional activities. Politicians and policy makers too, will be aware of these same tensions. It is the usual state of affairs that such preferences remain largely obscured and the rules by which they are manipulated and traded are undocumented. The emergence of standardised measures of health status such as EQ-5D promises to introduce a degree of order to this otherwise confused information void. The strength of such measures lies partly in their capacity to generate numeric data in terms of a single index. In this, its most sophisticated form, EQ-5D explicitly incorporates information on preferences derived from one or other of its many potential sources. However, there are simpler methods of treating the data generated by EQ-5D but even these less complex formats rely in part upon the exercise of preferences. As with all generic measures of HRQoL ‘values’ form a consistent theme in the collection, processing, analysis and presentation of EQ-5D. This chapter is intended as a guide to the use of EQ-5D in its several formats and in the different types of application for which it was designed or has proven to be of value.