Willingness to pay for a quality-adjusted life year: an evaluation of attitudes towards risk and preferences

BACKGROUND: This paper examines the Willingness to Pay (WTP) for a quality-adjusted life year (QALY) expressed by people who attended the healthcare system as well as the association of attitude towards risk and other personal characteristics with their response. METHODS: Health-state preferences, measured by EuroQol (EQ-5D-3L), were combined with WTP for recovering a perfect health state. WTP was assessed using close-ended, iterative bidding, contingent valuation method. Data on demographic and socioeconomic characteristics, as well as usage of health services by the subjects were collected. The attitude towards risk was evaluated by collecting risky behaviors data, by the subject's self-evaluation, and through lottery games. RESULTS: Six hundred and sixty two subjects participated and 449 stated a utility inferior to 1. WTP/QALY ratios varied significantly when payments with personal money (mean €10,119; median €673) or through taxes (mean €28,187; median €915) were suggested. Family income, area income, higher education level, greater use of healthcare services, and the number of co-inhabitants were associated with greater WTP/QALY ratios. Age and female gender were associated with lower WTP/QALY ratios. Risk inclination was independently associated with a greater WTP/QALY when "out of pocket" payments were suggested. Clear discrepancies were demonstrated between linearity and neutrality towards risk assumptions and experimental results. CONCLUSIONS: WTP/QALY ratios vary noticeably based on demographic and socioeconomic characteristics of the subject, but also on their attitude towards risk. Knowing the expression of preferences by patients from this outcome measurement can be of interest for health service planning.The field work of this study has been financed by the funds for research projects in the field of Primary Care health outcomes, established by order 472/2010 of the Consejería de Sanidad (Community of Madrid, Spain), on September 16, 2010.S