Discounting of health benefits in the pharmacoeconomic analysis of drug therapies: an issue for debate?

In most economic evaluations, future monetary costs and benefits and future health benefits are discounted at the same rate. The purpose of this article is to question such current practice. The primary reason behind discounting costs and benefits is to allow for individuals' preferences over the timing of such events, i.e. to represent social time preference. We argue that the social time preference rate for health benefits is unlikely to be the same as that for monetary costs and benefits. The results of a sensitivity analysis of pharmacoeconomic analyses of drug treatments for hypertension illustrate how the choice of discount rate can affect the conclusions. As no definite conclusions can be drawn regarding the magnitude of the discount rate for health benefits, we recommend that analysts conduct sensitivity analyses employing differential discount rates for health benefits as well as monetary costs and benefits.