Using the Delphi technique in economic evaluation: time to revisit the oracle?

Summary Background and objective:  Although the Delphi technique has been commonly used as a data source in medical and health services research, its application in economic evaluation of medicines has been more limited. The aim of this study was to describe the methodology of the Delphi technique, to present a case for using the technique in economic evaluation, and to provide recommendations to improve such use. Methods:  The literature was accessed through MEDLINE focusing on studies discussing the methodology of the Delphi technique and economic evaluations of medicines using the Delphi technique. Results and discussion:  The Delphi technique can be used to provide estimates of health care resources required and to modify such estimates when making inter‐country comparisons. The Delphi technique can also contribute to mapping the treatment process under investigation, to identifying the appropriate comparator to be used, and to ensuring that the economic evaluation estimates cost‐effectiveness rather than cost‐efficacy. Conclusion:  Ideally, economic evaluations of medicines should be based on real‐patient data. In the absence of such data, evaluations need to incorporate the best evidence available by employing approaches such as the Delphi technique. Evaluations based on this approach should state the limitations, and explore the impact of the associated uncertainty in the results.