Web Comparison of Three Contingent Valuation Techniques in Women of Childbearing Age: The Case of Ovulation Induction in Quebec.

BACKGROUND

In Canada, 11.5% to 15.7% of couples suffer from infertility. Anovulation, or failed ovulation, is one of the main causes of infertility in women. In Quebec, the treatment for ovulation induction and other services related to assisted reproductive technology (ART) have been partially reimbursed by the government since 2010.

OBJECTIVE

This study aimed to compare the willingness to pay (WTP) of women of childbearing age to receive drug treatment in the event of failed ovulation according to 3 different contingent valuation methods.

METHODS

The following elicitation techniques were used: simple bid price dichotomous choice (DC), followed by an open-ended question (DC-OE), and a simplified multiple-bounded discrete choice (MBDC). Each participant was randomly assigned to 1 of 3 elicitation techniques. Bid prices ranged from Can $200 to Can $5000. Of the 7 bid prices, 1 was randomly proposed to each participant in the DC and DC-OE groups. For the DC-OE group, if the answer to the DC bid price was no, respondents were asked what was the maximum amount they were willing to pay. For the MBDC group, each respondent was offered an initial bid price of Can $1500, and the subsequent bid price offer increased or decreased according to the answer provided. "Do not know" responses were considered as a "no", and each individual was questioned as to their certainty after each choice. WTP values were estimated using probit and bivariate models; the Welsh and Poe model was also performed for the MBDC group.

RESULTS

The survey was conducted from 2009 to 2010 with a total sample of 680 women. Analyses were performed on 610 respondents (199 DC, 230 DC-OE, and 181 MBDC). Of the 70 respondents who were excluded, 6 did not meet the age criterion, 45 had an annual income less than Can $2500, and 19 did not respond to the WTP question. Mean WTP values were Can $4033.26, Can $1857.90, and Can $1630.63 for DC, DC-OE, and MBDC, respectively. The WTP for MBDC "definitely yes" and "probably yes" values were Can $1516.73 and Can $1871.22, respectively. The 3 elicitation techniques provided WTP value differences that were statistically significant (P<.01). The MBDC was the most accurate method, with a lower confidence interval (Can $557) and a lower (CI/mean) ratio (0.34).

CONCLUSIONS

A positive WTP for ovulation induction was found in Quebec. Adding a follow-up question resulted in more accurate WTP values. The MBDC technique provided a more accurate estimate of the WTP with a smaller and, therefore, more efficient confidence interval. To help decision making and improve the effectiveness of the fiscal policy related to the ART program, the WTP value elicited with the MBDC technique should be used.