Factors associated with the intention and cost for ECS
Unexpectedly, the chi-square test (Table S1) and multivariate logistic regression analysis (data not shown) showed that sociodemographic factors were not significantly associated with the intention of ECS (p>0.05). More than a third of the participants in our survey (n=311) had heard about ECS, a reflection of prior knowledge or awareness of this test. Participants whose first reaction was of interests or who had prior awareness of the test were nearly three times more likely to have intention for taking ECS, compared with those who had no interest in ECS or never heard of this test, respectively (OR=2.73, 95% CI 1.57 to 4.75, p=5.03E-04; OR=2.91, 95% CI 1.34 to 6.33, p=0.007). Meanwhile, those who perceived the benefits for their future offspring were five times more likely to take the test (OR=5.57, 95% CI 1.55 to 20.00, p=0.008, Table 3).
Moreover, we also explored association between sociodemographic factors and the amount that participants were willing to pay. As shown in Table 4, the chi-square analysis showed that participants with bachelor’s or above degrees and those with the household income more than 150,000 CNY were more willing to pay 1,000 CNY and greater for ECS (p=0.017, p=2.10E-06). Besides, participants with household income greater than or equal to 150,000 CNY were more likely to pay for ECS at the price of 1,000 CNY or greater (OR:1.34, 95%CI 1.40 to 2.57, 3.58E-05, Table 4).