Reviewing and piloting methods for decreasing discount rates; someone, somewhere in time.

There has been substantial debate on the need for decreasing discounting for monetary and health gains in economic evaluations. Next to the discussion on differential discounting, a way to identify the need for such discounting strategies is through eliciting the time preferences for monetary and health outcomes. In this article, the authors investigate the perceived time preference for money and health gains through a pilot survey on Dutch university students using methods on functional forms previously suggested. Formal objectives of the study were to review such existing methods and to pilot them on a convenience sample using a questionnaire designed for this specific purpose. Indeed, a negative relation between the time of delay and the variance of the discounting rate for all models was observed. This study was intended as a pilot for a large-scale population-based investigation using the findings from this pilot on wording of the questionnaire, interpretation, scope and analytic framework.

On discounting of health gains from human papillomavirus vaccination: effects of different approaches.

OBJECTIVES: Discounting has long been a matter of controversy in the field of health economic evaluations. How to weigh future health effects has resulted in ongoing discussions. These discussions are imminently relevant for health care interventions with current costs but future benefits. Different approaches to discount health effects have been proposed. In this study, we estimated the impact of different approaches for discounting health benefits of human papillomavirus (HPV) vaccination. METHODS: An HPV model was used to estimate the impact of different discounting approaches on the present value of health effects. For the constant discount approaches, we varied the discount rate for health effects ranging from 0% to 4%. Next, the impact of relevant alternative discounting approaches was estimated, including hyperbolic, proportional, stepwise, and time-shifted discounting. RESULTS: The present value of health effects gained through HPV vaccination varied strongly when varying discount rates and approaches. The application of the current Dutch guidelines resulted in a present value of health effects that was eight or two times higher than that produced when using the proportional discounting approach or when using the internationally more common 4% discount rate for health effects, respectively. Obviously, such differences translate into large variations in corresponding incremental cost-effectiveness ratios. CONCLUSION: The exact discount rate and approach chosen in an economic evaluation importantly impact the projected value of health benefits of HPV vaccination. Investigating alternative discounting approaches in health-economic analysis is important, especially for vaccination programs yielding health effects far into the future. Our study underlines the relevance of ongoing discussions on how and at what rates to discount.