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.