Extrapolating Clinical Evidence Within Economic Evaluations

Extrapolation is a fundamental part of many economic evaluations, though there are numerous methods of extrapolating the same dataset. The method that is most appropriate for the decision problem is contingent on several factors. From the literature, recommendations for best practices when it comes to the extrapolation of clinical data have been identified. These pertain to validation of output, use of external evidence, treatment waning, proportional hazards, characterization of uncertainty, reporting of results, and choice of decision model. Gaps remain in the literature that require further research regarding what is the minimum amount of data to extrapolate reliably and how to robustly extrapolate relative effects for multiple treatment comparisons.