Objectives: A typical health technology assessment (HTA) submission presents a novel treatment with better effect and higher cost than the comparators, considered cost-effective if the resulting incremental cost-effectiveness ratio (ICER) is below the willingness to pay (WTP) threshold. Treatments that provide cost-savings, but less health gain, fall in the south-west (SW) quadrant of the cost-effectiveness acceptability plane (CEAP) where the threshold relates to the willingness to accept (WTA) a loss in QALY. The ICERs in SW quadrant is positive (-/-) and higher ICERs are better than lower ICERs. The WTP for a gain in health is generally less than WTA a loss in health which implies that the slope of the WTA curve is steeper than in the WTP curve. Since it is not clear how HTA authorities views ICERs in the SW quadrant, the objective of this study was to estimate the threshold for WTA for a QALY in Sweden.
Methods: A review of all reimbursement decisions published by the Dental and Pharmaceutical Benefit’s Agency (TLV) from 2013-2016 was conducted. The subset of submissions with both negative incremental costs and negative incremental QALYs were further reviewed for TLVs perspective on cost-effectiveness.
Results: Two evaluations were found: pasireotide in the acromegaly indication. The analysis resulting in a SW quadrant result equal to 6.2 million SEK was a scenario analysis conducted by TLV, which was deemed cost-effective. In the 2014 assessment of vandetanib TLV wrote a general statement that SW quadrant results should be interpreted as cost savings per QALY lost, and that SW quadrant evaluations are not as straight-forward but that the potential cost-effectiveness will depend on the WTA.
Conclusions: There are few published TLV evaluations of the cost-effectiveness of SW quadrant ICERs, and no evidence that TLV considers the SW quadrant differently from the typical submission.