Abstract

Objectives

Health technology assessment (HTA) guidance often recommends a 3% real annual discount rate, the appropriateness of which has received limited attention. This article seeks to identify an appropriate rate for high-income countries because it can influence projected cost-effectiveness and hence resource allocation recommendations.

Methods

The author conducted 2 Pubmed.gov searches. The first sought articles on the theory for selecting a rate. The second sought HTA guidance documents.

Results

The first search yielded 21 articles describing 2 approaches. The “Ramsey Equation” sums contributions by 4 factors: pure time preference, catastrophic risk, wealth effect, and macroeconomic risk. The first 3 factors increase the discount rate because they indicate future impacts are less important, whereas the last, suggesting greater future need, decreases the discount rate. A fifth factor—project-specific risk—increases the discount rate but does not appear in the Ramsey Equation. Market interest rates represent a second approach for identifying a discount rate because they represent competing investment returns and hence opportunity costs.

Conclusions

Declining consumption growth and real interest rates imply HTA guidance should reduce recommended discount rates to 1.5 to 2+%. This change will improve projected cost-effectiveness for therapies with long-term benefits and increase the impact of accounting for long-term drug price dynamics, including reduced prices attending loss of market exclusivity.