China’s community-based strategy of universal preconception care in rural areas at a population level using a novel risk classification system for stratifying couples´ preconception health status

Table 2 Socio-demographic characteristics of women in different preconception risk factor classification categories

		No risk factors	A	B	C	D	X
Age	≤25	24.7%	21.6%	26.3%	22.4%	14.7%	21.3%
	25–30	46.3%	47.4%	46.7%	44.1%	38.5%	46.0%
	30–35	19.5%	21.2%	18.2%	20.9%	27.1%^*	20.1%
	≥35	9.6%	9.8%	8.7%	12.6%	19.8%^*	12.6%^*
Area	Rural area	93.9%	89.6%	94.0%	94.0%	94.3%	92.2%
Race	Han	92.7%	91.6%	92.5%	88.7%	84.0%^*	84.2%^*
Education	Secondary school or lower	71.5%	64.8%^*	69.4%	71.8%	77.4%	75.5%
	High school	18.7%	19.7%	18.7%	17.1%	13.8%^*	16.6%
	College or higher	9.8%	15.5%^*	11.8%	11.1%	8.8%	8.0%