COMPARING 3 VERSIONS OF THE TIME TRADEOFF - TIME FOR A CHANGE

This paper reports a comparative study of three formulations of the ti me-tradeoff (TTO) method of health valuation. One asks people to consi der giving up time each day in exchange for better health. The second asks people to consider giving up time during a 12-month interval. The third is the more conventional TTO in which people are asked to conte mplate a reduction in life expectancy. Questionnaires were sent to 4,0 87 adults selected at random from the population of Scotland. Each res pondent provided a description of his or her health, and was asked to value an improvement in that health, using all three formulations of t he TTO. The daily TTO appeared to be an improvement on the conventiona l formulation, correlating more strongly with health, eliciting respon ses that appeared to be more precise, and obtaining information about the value of health from a far greater number of respondents. The perf ormance of the annual TTO appeared to be only slightly inferior to tha t of the daily TTO.