Time preference, duration and health state valuations.

There is increasing interest in health status measurement and the relative weights that people attach to different states of health and illness. One important issue which has been raised is the effect that the time spent in a health state may have on the way that state is perceived. Previous studies have suggested that the worse a state is, the more intolerable it becomes as it lasts longer. However, for most of these studies, it is impossible to determine how much of what was observed is attributable to the time spent in the state and how much is attributable to when it was occurring. This paper reports on a pilot study designed to test the feasibility of using the Time Trade-Off (TTO) method to isolate the effect of pure time preference from the effect of duration per se. Interviews were conducted with 39 members of the general population who were asked to rate 5 health states for durations of one month, one year and ten years. In aggregate, rates of time preference were very close to zero which suggests that the implicit assumption of the TTO method that there is no discounting may be a valid one. However, that more respondents had negative (rather than positive) rates, casts some doubt on the axions of discounted utility theory. In addition, implied valuations for states lasting for short periods were often counter-intuitive which questions the feasibility of using the TTO method to measure preferences for temporary health states.

[1]  G. Torrance,et al.  The utility of different health states as perceived by the general public. , 1978, Journal of chronic diseases.

[2]  Baruch Fischhoff,et al.  Measuring values: A conceptual framework for interpreting transactions with special reference to contingent valuation of visibility , 1988 .

[3]  A. Tversky,et al.  The framing of decisions and the psychology of choice. , 1981, Science.

[4]  Victor R. Fuchs,et al.  Economic Aspects of Health , 1983 .

[5]  M. Parsonage,et al.  Discounting and health benefits. , 1992, Health economics.

[6]  N. Boyd,et al.  Attitudes Toward Quality of Survival , 1982, Medical decision making : an international journal of the Society for Medical Decision Making.

[7]  J. Christensen-Szalanski Discount Functions and the Measurement of Patients' Values , 1984, Medical decision making : an international journal of the Society for Medical Decision Making.

[8]  J. Cairns Health, wealth and time preference , 1992 .

[9]  M. Weinstein,et al.  Foundations of cost-effectiveness analysis for health and medical practices. , 1977, The New England journal of medicine.

[10]  C. C. Perkins,et al.  Immediate vs. delayed shock in T-maze performance. , 1959, Journal of experimental psychology.

[11]  G. Loewenstein Anticipation and the Valuation of Delayed Consumption , 1987 .

[12]  D A Redelmeier,et al.  Time Preference in Medical Decision Making and Cost - Effectiveness Analysis , 1993, Medical decision making : an international journal of the Society for Medical Decision Making.

[13]  M. Weinstein Time-preference Studies in the Health Care Context , 1993, Medical decision making : an international journal of the Society for Medical Decision Making.

[14]  J Lipscomb,et al.  Time Preference for Health in Cost-Effectiveness Analysis , 1989, Medical care.

[15]  P. Dolan,et al.  Modelling valuations for health states: the effect of duration. , 1996, Health policy.

[16]  George W. Torrance,et al.  Social preferences for health states: An empirical evaluation of three measurement techniques , 1976 .