Benefit evaluation of mass screening for prostate cancer: willingness-to-pay measurement using contingent valuation

Cancer screening exists to save lives. However, the mortality-reducing effect of prostate cancer screening has not yet been sufficiently demonstrated. Therefore, screening should only be performed in men well informed about the disease. We hypothesized that having sufficient information will reduce men's desire for screening. To verify this hypothesis, we measured the willingness to pay (WTP) for prostate-specific antigen screening using the contingent valuation method.

A computer-based questionnaire was implemented through the Internet for 137 men in Japan aged 40 to 59 years. Participants were randomly assigned to two subgroups: 69 subjects were provided with information about the detection rate, and 68 were provided with additional information such as the failure to demonstrate the mortality-reducing effect of prostate-specific antigen screening to date. All were asked about their WTP by a payment cards approach.

The mean WTP for prostate-specific antigen screening was 18.90 dollars. Categorical regression analysis suggested that annual income, age, and hospitalization history were factors affecting the WTP. Unexpectedly, the difference in the mean WTP between the ill-informed and well-informed groups was not statistically significant.

The contingent valuation method can quantify comprehensive benefits, including not only health outcomes, but also non-health outcomes such as reassurance value. The subjects were not so concerned about the long-term effectiveness of saving lives. Their greatest concern was the detection rate. Their WTP may have reflected their desire for the reassurance that could be obtained by confirming that they had no physical sign of cancer.