Table 4. The mixed-logit model of main effects.

Attributes	Level	Coefficient	SE	WTP (CNY)	95% CI of WTP
ASC§§		−6.680***	1.079
Preventive service time	Workday*†
	Vacation‡	0.907***	0.080	87***	68 to 106
Preventive effectiveness	Low§†
	General¶	1.766***	0.105	170***	138 to 202
	High**	2.775***	0.486	267***	165 to 369
	Very high††	4.249***	0.488	409***	295 to 522
Distance‡‡	≥50 min†
	25–50 min	0.327***	0.056	31***	20 to 43
	10–25 min	0.873***	0.334	84***	20 to 148
	≤10 min	0.841***	0.334	81***	17 to 145
OOP service cost (CNY)		−0.010***	0.001
AIC	7290.543
BIC	7431.716
Log-likelihood	−3627.272

Note:*p<0.05, **p<0.01, ***p<0.001.

^*Non vacation

^† reference.

^‡ Usually weekends and statutory holidays

^§ The probability of reduction in caries is 60%-70%

^¶ The probability of reduction in caries is 70%-80%

^**The probability of reduction in caries is 80%-90%

^††The probability of reduction in caries is higher than 90%

^‡‡The driving time to the healthcare institution by public transport, including bus, subway, etc.

^§§The utility of choosing ”neither” option

AICAkaike information criterionBICBayesian information criterionCNYChinese yuanWTPwillingness to pay