Are health states "timeless"? The case of the standard gamble method

The standard gamble method, as currently recommended for use in health care program evaluation, provides an individual's preference score or "utility weight" for living in a given health state for the rest of the individual's life. Many researchers interpret this value as a time-independent or "time less" one and order health states on a scale of zero (death) to one (full h ealth), regardless of the time spent in the health state. This article exam ines whether preference scores for a severe pain health state are "timeless ," or in other words whether the utility independence assumption is satisfi ed. Our study results suggest that for the majority of respondents, the pre ference scores are not independent of time. J CLIN EPIDEMIOL 52;11:1047-105 3, 1999. (C) 1999 Elsevier Science Inc.