LIFE EXPECTANCY AND THE DISCOUNTING OF HEALTH OUTCOMES
Author(s)
Stant A, Groen H, Post W, TenVergert E, University Hospital Groningen, Groningen, Groningen, Netherlands
OBJECTIVES: The topic of discounting health outcomes in economic evaluations has led to much debate in the field of health technology assessment. In practice, health outcomes are mainly discounted by means of the controversial discounted utility (DU) model. When adopting an individual perspective, as recommended by new welfare economic theory, the main reason for discounting health is uncertainty of the individual about the future. This uncertainty is directly related to future health and, ultimately, the occurrence and timing of death. The purpose of this study is to examine the relevance of explicitly including life expectancy in models of discounting. METHODS: Aspects and assumptions that are relevant for life expectancy and discounting health: (a) the future is not fully uncertain and individuals are aware of their life expectancy; (b) trade-offs among benefits occurring at different points in time will result in choosing to receive health benefits before the moment with a high probability of being dead; and (c) when the life expectancy of a (patient) population is known, it is possible to identify (time) cut-off points for individuals at which the probability of being alive is high, or at which the probability of being dead is high. These points in time distinctively influence the level of discounting. RESULTS: The standard DU model, which is insensitive to variation in life expectancy, was compared with an alternative model of discounting that explicitly includes life expectancy. In the current example, focusing on patients with a life expectancy of 10 years, the alternative model led to higher present values of future health outcomes when the time horizon was less than 8 years. CONCLUSIONS: Explicitly including life expectancy in models of discounting seems to address some of the controversy surrounding the discounting of health outcomes. Empirical studies are needed to further explore the influence of life expectancy on individual time preferences.
Conference/Value in Health Info
2003-11, ISPOR Europe 2003, Barcelona, Spain
Value in Health, Vol. 6, No. 6 (November/December 2003)
Code
PMD21
Topic
Economic Evaluation
Topic Subcategory
Cost/Cost of Illness/Resource Use Studies
Disease
Multiple Diseases