Differences between willingness to pay and willingness to accept for visits by a family physician: A contingent valuation study

BACKGROUND The economic value attributed by users of health services in public health systems can be useful in planning and evaluation. This value can differ from the perspectives of Willingness to Pay (WTP) and Willingness to Accept [Compensation] (WTA).Our objective was to study the perceptions of the patient about the service provided by the family physician by means of the WTA/WTP ratio. METHODS An economic evaluation study by the Contingent Valuation Method was designed. Interviews were conducted with 451 subjects at six health centres (four urban and two rural) in areas with different socioeconomic characteristics. A payment card was used to measure the WTP and WTA. Other characteristics of the subject or service that could influence these responses were collected. An explicative model was constructed to study the WTA/WTP relationship. RESULTS Four hundred and four subjects (89.6%) expressed a WTP and WTA different from zero. The WTA/WTP quotient showed a median of 1.55 (interquartile range 1-3.08) and a mean of 3.30 (IC 95%: 2.84-3.75). The WTA/WTP ratio increases with age and in low-income areas. It decreases in professional groups with more specialized activities, with growing family income, and in the chronically ill. Other characteristics related to the perception of state of health, accessibility to the service, satisfaction, or perception of risk were not explicative. CONCLUSIONS Subjects who were older and had a less favourable socioeconomic situation expressed a higher WTA/WTP ratio when valuing the visit to the family physician. These characteristics could identify a profile of "aversion to loss" with respect to this service.