Research suggests a different willingness to pay for more effective interventions than willingness to accept (WTA) for less effective interventions which has prompted debate as to whether the threshold in the southwest (SW) quadrant should be kinked to reflect this disparity. Acceptance of less costly, less effective interventions with incremental cost-effectiveness ratios (ICERs) in the SW-quadrant presents an opportunity for resource-constrained healthcare systems by releasing resources for other purposes, which is of particular importance during a pandemic. The National Institute for Health and Care Excellence (NICE)’s methods guide suggests the threshold for decision-making for SW-quadrant interventions be the same as for more expensive, more effective interventions. To assess NICE’s WTA less effective treatments, the objective was to review the outcomes and decision drivers for interventions presenting SW-quadrant ICERs.

A review of NICE health technology appraisals (HTAs) containing SW-quadrant ICERs identified from 2015-2021 was conducted. Appraisal details were extracted and analyzed to identify trends in the WTA and decision drivers.

The HTA review identified twenty-one submissions containing SW-quadrant ICERs in the base-case/scenario analysis. Eighty-one percent received a positive recommendation, with ICERs ranging from GBP 30,000-GBP 4.2m (EUR 35,264-EUR 5m) compared to a range of GBP 789-GBP 50,905 (EUR 927-EUR 59,837) for negative recommendations. The HTAs covered a wide range of therapeutic areas including psoriasis, multiple sclerosis and multiple oncology indications. Decision drivers identified that may have had a positive influence on final outcomes included a high net monetary benefit, a small QALY difference, clinical unmet need, poor tolerability of existing treatments, and oral administration route.

The analysis suggests that there is a high rate of acceptance of interventions with ICERs in the SW-quadrant, however, the threshold for acceptance is unclear. The high frequency of HTAs with SW-quadrant ICERs identified in this review indicates the need for further guidance on such interventions in the NICE reference case.