Eliciting a Willingness-To-Pay Threshold in Denmark: Analysis of Published Reimbursement Decisions

Since the introduction of incremental cost-effectiveness ratios (ICERs) and cost-effectiveness assessments for new inpatient medicines in Denmark, no willingness-to-pay (WTP) threshold has been officially published. The objective of this study was to elicit such a threshold through a quantitative analysis of publicly available assessment reports.

The assessment reports were obtained from the Danish Medicines Council database. In the primary analysis, we used a logistic regression model to identify the impact of the ICERs on the reimbursement decision. The Youden's index identified the optimal probability cutoff point that maximized sensitivity and specificity of the model. The implicit WTP threshold was then defined as the ICER value corresponding to such an optimal probability cutoff point. Secondary analyses explored WTP thresholds by disease area (oncology vs other disease areas) and the impact of the size of the patient population.

The primary analysis showed a statistically significant effect of the ICER on the reimbursement decision and resulted in an elicited WTP threshold of €116 122. The secondary analysis showed different WTP thresholds for oncology and other indications, although the impact of the ICER on the recommendation decision was not statistically significant. Finally, an increase in the number of patients was associated with a declining WTP threshold.

To the best of our knowledge, this is the first study to assess an implicit WTP threshold in Denmark. Through an open-access use case, we provide a quantitative approach that can be repeated as more data become available and applied in different settings.