A qualitative analysis of the lottery equivalents method

Numerous instruments have been developed to elicit numerical values that represent the strength of preference for different health states. However, relatively few studies have attempted to analyse the reasoning processes that people employ when they are asked to answer questions based on these elicitation methods. The lottery equivalents method is a preference elicitation instrument that has recently received some attention in the literature. This study attempts a qualitative analysis of the use of this instrument on a group of 25 relatively highly educated respondents. For each of three health states considered in the study, a substantial number of respondents refused to trade the chance of survival for a possible improvement in the health state. Therefore, many respondents violated an assumption that is necessary for the lottery equivalents instrument to generate cardinal health state values. These findings place a question mark against the usefulness of the lottery equivalents method, and add weight to the suspicion that ‘preferences’ are constructed according to how questions are framed