The use of consensus methods and expert panels in pharmacoeconomic studies. Practical applications and methodological shortcomings.

The use of expert opinion in pharmacoeconomic studies is widespread. A review of the relevant literature has shown that expert opinion is frequently used in decision analysis, Markov models and disease management, with estimates of potential values derived from Delphi panels, modified Delphi panels and expert round tables. These consensus-gathering methods are often applied as if potential drawbacks to their application were absent. This article reviews and summarises the use of these techniques in pharmacoeconomic research and evaluates the potential shortcomings of the methodology employed. In particular, several areas of concern are noted: the provision of baseline information or seed algorithms to panellists, the high attrition rate of panels, the criteria for selecting experts and the definition of consensus. This article offers recommendations for the future application of these techniques and concludes that expert opinion can still play a valuable role in pharmacoeconomic research.