RESUMEN
BACKGROUND: The preferences of citizens are a basic element to incorporate into the decision-making process when planning health policies. Contingent valuation (CV) is a common method for calculating the value for citizens that new technologies, interventions, and the provision of services or policies have. However, choosing the correct CV tool may not be a neutral decision. This work aims to assess the substitution of a healthcare service by comparing valuation differences between the willingness to pay (WTP) for the maintenance of the service versus the willingness to accept compensation (WTA) for its substitution, both of which are related to subject characteristics, with a particular focus on trust in institutions and risk aversion. METHODS: A CV study was designed to study Dutch population preferences when physician assistants replace anaesthesiologists. Differences between the distributions of WTA and WTP were compared through full decomposition methods, and conditional quantile regression was performed. RESULTS: Nearly two-thirds of surveyed citizens expressed null values for WTA and WTP. The other third systematically reported a value of WTA higher than that of WTP, which increased further with lower income and the possible presence of a strategic bias. In contrast, being more than 65 years old, having trust in government, and preferring anaesthesiologists decreased the WTA-WTP difference. Risk aversion had no clear association with the WTA-WTP gap. CONCLUSIONS: Known differences between the perceived value of health services from the perspective of gains and losses could be related to people's characteristics. Trust in government but not aversion to risk was related to the WTA-WTP differences. Identifying a profile of citizens who are averse to losing health services should be considered when designing and implementing health services or interventions or making disinvestment decisions.
RESUMEN
RATIONALE AND OBJECTIVES: Economic theory classifies an intervention as socially beneficial if the total Willingness to Pay (WTP) of those who gain exceeds the total Willingness to accept (WTA) of those who are harmed. This paper examines the differences in health system users' valuation of a health care service in primary care setting based on the WTP and WTA perspectives, discussing the impact of personal and service variables, including risk attitudes, on these disparities. METHOD: Six hundred and sixty two subjects who asked for care in health centres in the Region of Madrid (Spain) were interviewed, using the contingent valuation method to estimate WTP and WTA. Patient sociodemographic characteristics, health needs, satisfaction with the service and risk attitude and behaviour under risk (measured by self-reported scales and lottery games respectively) were collected. Generalised Linear Models were used to estimate the association between the explanatory variables and the WTA/WTP ratio. RESULTS: We obtained the WTA/WTP ratio for 570 subjects (mean 1.66 CI 95%: 1.53-1.79; median 1, interquartile range 1-2). People with higher education or in high social groups expressed WTA values closest to WTP. The opposite occurred in patients with the greatest health needs or who were born abroad. Self-reported expression of risk aversion appeared also related to increases in the WTA/WTP ratio. Satisfaction with the service evaluated was the most influential factor in the WTA/WTP ratio. CONCLUSION: Health need, difficulty in obtaining substitutes and satisfaction with the service could serve for profiling people averse to loss for health care services in primary care setting. Self-reported expression of risk aversion could also be related to increases in the WTA/WTP ratio. This would mean that these characteristics should be taken into account both in the design and implementation of new healthcare interventions, as in the making decision for disinvestment.
