Welfarism versus extra-welfarism: can the choice of economic evaluation approach impact on the adoption decisions recommended by economic evaluation studies?

A long-running debate surrounds the equivalence of the welfarist and extra-welfarist approaches to economic evaluation. There is a growing belief that the extra-welfarist approach may not necessarily provide all the information that decisionmakers require in certain contexts, e.g. evaluation of complex interventions. As the number of these interventions being evaluated increases, it is crucial that the most appropriate economic evaluation approach is used to enable decisionmakers to be confident in their adoption decisions. We conducted a literature review to evaluate the potential for the choice of economic evaluation approach to impact on the adoption decisions recommended by economic evaluation studies. We found that for every five studies applying both approaches, one shows limited or no concordance in economic evaluation results: the different approaches suggest conflicting adoption decisions, and there is no pattern to which approach provides the most convincing adoption evidence. Only one study in ten indicates which results will best inform adoption decisions. We conclude that the choice of approach can significantly impact on the adoption decisions recommended by economic evaluation studies, with conflicting results creating confusion over whether or not interventions provide good value for money. Health economists rarely provide sufficient guidance to decisionmakers to alleviate this confusion.