Does Health Technology Assessment guidance give adequate consideration to decisions about less costly and less effective alternatives?

Cost-effectiveness analysis (CEA) plays a key role informing decision-making in healthcare and, consequently, the interpretation of its results is discussed in formal guidance from health technology assessment (HTA) organisations. A body of research indicates different willingness to pay for more effective interventions than willingness to accept less effective interventions, which some suggest supports application of different cost-effectiveness thresholds depending on whether an intervention is considered more or less effective than the comparator. We review the theoretical basis for the use of differential thresholds within HTA organisations, and question whether they are compatible with coherent decisions and social values. The National Institute for Health and Care Excellence (NICE) is one such organisation, providing recommendations on which healthcare interventions to adopt in the United Kingdom. NICE guidance describes the decision rules it employs, including comparing CEA results to a cost-effectiveness threshold that defines the boundaries beyond which an intervention is no longer considered to provide value for money. Our review of NICE guidance finds that it describes a common threshold range for all alternatives, in line with the theoretical basis for a supply-side threshold. However, we also find that the guidance focuses on the application of the threshold as a decision rule for more effective and more expensive treatments, with less guidance provided on less effective and less expensive treatments. We make suggestions for how HTA organisations can better support application of decision rules to interventions that are less effective and less expensive.