Table 2.

Factors associated with WTP^a in the included studies.

Study	Demographics					Socioeconomic income		Health service distance to preferred health facility
	Gender (female)	Age	Married	Ethnicity
Bradford et al [30]	+b	−−c	−d	−	+		++e
Bettiga et al [33]	N/Af	N/A	N/A	N/A	N/A		N/A
Fletcher et al [36]	N/A	N/A	N/A	N/A	N/A		N/A
Losiouk et al [29]	N/A	N/A	N/A	N/A	N/A		N/A
Park et al [37]	N/A	−−	N/A	N/A	N/A		N/A
Snoswell et al [34]	N/A	N/A	N/A	N/A	N/A		N/A
Bergmo and Wangberg [38]	N/A	++	N/A	N/A	+		N/A
Scherrenberg et al [39]	N/A	N/A	N/A	N/A	N/A		N/A
Ramchandran et al [31]	N/A	N/A	N/A	N/A	N/A		N/A
Spinks et al [35]	N/A	N/A	N/A	N/A	N/A		N/A
Bradford et al [32]	+	−−	−	+	+		++

^aWTP: willingness to pay.

^bThe effect of the variable is positive and nonsignificant.

^cThe effect of the variable is negative and significant.

^dThe effect of the variable is negative and nonsignificant.

^eThe effect of the variable is positive and significant.

^fN/A: not applicable; the effect of the variable is not applicable to this study.