Methodological and applied concerns surrounding age-related weighting within health economic evaluation.

Economic evaluations that measure the benefits of health interventions in terms of units of health gain inevitably require decision-makers to make judgments about the 'value for money' of those health gains. Decision-making bodies have also commonly returned to the position that a unit of health gain, such as an additional quality-adjusted life year, is of equal value regardless of the characteristics of the recipient. This paper focuses on whether and how health gains in economic evaluation should be differentially weighted by age of recipient. The paper presents a structured overview of evidence from the revealed preference and stated preference literature in this area. It discusses a number of methodological issues raised by differential weighting of health gains by age of recipient. These include identifying appropriate samples for the derivation of age-related weights, methodological issues surrounding the application of the quality-adjusted life year measure, the relative merits of alternative valuation techniques for weighting exercises, the impact of context and design effects on derived values and operational concerns surrounding the application of age-related weights within economic evaluation. The paper ends with pointers for potential future research in this area.