Defining monetary values for quality of life improvements: an exploratory study

QOL improvements, which can in many cases reflect the overall effect of a health intervention, are frequently measured. It would therefore be useful to define the monetary value of QOL improvements in order to subsequently estimate the value of a given intervention on the basis of its impact on QOL.

To explore the feasibility of assessing the monetary value of an intervention by translating the improvement in QOL it produces into willingness to pay (WTP) amounts.

Seven different hypothetical health state descriptions were developed. Five hundred and forty-five subjects randomly selected among the staff of the University of Montreal, Canada were sent a self-administered questionnaire asking them to evaluate the QOL corresponding to various hypothetical health states and indicate the amount they would be willing to pay for interventions that would enable them to move from these health states to perfect health.

The response rate was 55% (n = 294). A significant correlation was found between the WTP amount and the anticipated QOL improvement, and between the WTP amount and the respondent's family income. A regression equation for WTP amounts was derived from a step-wise model including the anticipated QOL improvement and the respondent income. While the model could only account for about 20% of the WTP variance (R(2) = 0.2), the mean predicted WTP amounts were very close to the mean WTP amounts observed in the sample.

This study indicates that a definite correlation exists between willingness to pay for an intervention and the improvement in QOL it produces.