Willingness to Pay for a Quality-Adjusted Life-Year: The Individual Perspective

Objective: The aim of this study was to elicit the individual willingness to pay (WTP) for a quality-adjusted life-year (QALY). Methods: In a Web-based questionnaire containing contingent valuation exercises, respondents valued health changes in five scenarios. In each scenario, the respondents first valued two health states on a visual analog scale (VAS) and expressed their WTP for avoiding a decline in health from the better health state to the worse, using a payment scale followed by a bounded open contingent valuation question. Analysis: WTP per QALY was calculated for QALY gains calculated using VAS valuations, as well as the Dutch EQ-5D tariffs, the two steps in the WTP estimations and each scenario. Heterogeneity in WTP per QALY ratios was examined from the perspective of: 1) household income; and 2) the level of certainty in WTP indicated by respondents. Theoretical validity was analyzed using clustered multivariate regressions. Results: A total of 1091 respondents, representative of the Dutch population, participated in the survey. Mean WTP per QALY was 12,900 based on VAS valuations, and 24,500 based on the Dutch EuroQoL tariffs. WTP per QALY was strongly associated with income, varying from 5000 in the lowest to 75,400 in the highest income group. Respondents indicating higher certainty exhibited marginally higher WTP. Regression analyses confirmed expected relations between WTP per QALY, income, and other personal characteristics. Conclusion: Individual WTP per QALY values elicited in this study are similar to those found in comparable studies. The use of individual valuations in social decision-making deserves attention, however.