Abstract
Within the framework of economic evaluation of healthcare interventions, Contingent Valuation Method constitutes a technique used in order to elicit values related to people’s preferences, such as the maximum willingness-to-pay (WTP) for an intervention, and assign a monetary value to Quality-Adjusted Life-Years (QALYs), setting a cost-effectiveness threshold for accepting or rejecting interventions in a healthcare system. The present doctoral thesis aims at: a) developing, assessing and implementing a research tool for defining, using the Contingent Valuation Method, the monetary value attributed to a QALY (WTP per QALY) by Greek citizens, and examining determining factors and motives that might affect it, b) eliciting the WTP per QALY estimate for the general Greek population, c) investigating the impact of a number of determining factors on WTP per QALY and WTP probability, and d) examining the impact of motives on WTP per QALY and unwillingness to pay for a health improvement. The ...
Within the framework of economic evaluation of healthcare interventions, Contingent Valuation Method constitutes a technique used in order to elicit values related to people’s preferences, such as the maximum willingness-to-pay (WTP) for an intervention, and assign a monetary value to Quality-Adjusted Life-Years (QALYs), setting a cost-effectiveness threshold for accepting or rejecting interventions in a healthcare system. The present doctoral thesis aims at: a) developing, assessing and implementing a research tool for defining, using the Contingent Valuation Method, the monetary value attributed to a QALY (WTP per QALY) by Greek citizens, and examining determining factors and motives that might affect it, b) eliciting the WTP per QALY estimate for the general Greek population, c) investigating the impact of a number of determining factors on WTP per QALY and WTP probability, and d) examining the impact of motives on WTP per QALY and unwillingness to pay for a health improvement. The research tool (questionnaire) developed consisted of four parts: a) current health state assessment using the EuroQoL-5D-3L tool, b) WTP elicitation using the iterative bidding technique, followed by assessment of participants’ motives through pre-defined statements, c) assessment of WTP per QALY determining factors, and d) collection of information regarding participants’ demographic characteristics. WTP per QALY was estimated as the ratio of the annual stated WTP over utility improvement from individual’s current health to perfect health. Multiple linear regression and logistic regression were conducted to assess the effect of demographic characteristics on WTP per QALY and WTP probability, respectively. ANOVA, chi-square test, Kruskal-Wallis H and Mann-Whitney U tests were employed to investigate the relationships of motives and other determinants in question with WTP per QALY and WTP probability. Prior to main research, a pilot test was conducted in order to assess the reliability of the research tool using the test-retest approach. Intraclass-correlation coefficients (ICCs) revealed a reliable research tool with respect to WTP elicitation (ICC>0.6) and the pre-defined statements assessing participants’ motives (ICC>0.8) and WTP per QALY determining factors (ICC>0.8). A random sample, representative of the general Greek population with respect to gender, age and geographical region of residence, was employed in the main research (N=1,342). Computer-Assissted Telepohone-Interview (CATI) method was adopted to ensure random sampling. Analysis revealed that the general Greek population is willing to pay on average €26.280 for a QALY. Regarding the determining factors assessed, income, access to healthcare services funded by the state or compulsory social security, experience with severe disease and exercise frequency affected WTP per QALY positively. Moreover, professional and marital status had, also, an impact on WTP per QALY. With respect to motives, analysis showed that individuals strongly considering inability to cover basic household needs or tax claims as motives guiding the size of their WTP for a health improvement, reported lower WTP per QALY values compared to those not viewing these aspects as motives. For individuals not willing to pay for a health improvement, their negative attitude was primarily explained by their inability to pay for the examined treatment and their belief that treatment cost should be covered by sick funds or the government, instead of them. Finally, educational level, household income and age were proven to be predictors of willingness-to-pay probability for a health improvement. In conclusion, the present thesis contributes to the understanding of willingness-to-pay for a QALY, in the context of Greek economic evaluations and reimbursement decision-making, by eliciting its estimate and clarifying the determining factors and motives influencing it.
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