Using the person trade-off approach to examine differences between individual and social values

Health state valuations, elicited by methods such as the standard gamble and the time trade-off, give an indication of the value that an individual attaches to particular health states. As measures of individual values, it has been argued that such valuations serve as poor proxies for social preferences, which, it is suggested, are a function of other factors, such as the initial severity of the patient's health state. The person trade-off (PTO) method has been proposed as a technique which takes account of many of these other factors. This paper reports on a study using the PTO to investigate whether an individual's preferences over treatments for themselves differ from their preferences when they are asked to think about the treatment of other people. The results suggest that there is indeed a difference, although qualitative data suggests that health gain is an important determinant of social value. This latter finding runs counter to those of a number of other studies which suggest that concerns about pre-treatment severity are as, if not more, important. Possible explanations for the differences are put forward.