Maternal age and educational level modify the association between chronic hepatitis B infection and preterm labor

Table 2 Incidence of preterm labor with respect to HBsAg status in pregnant women, stratified by maternal age, education level

Factors	PT (%)		OR(95% CI)	P-values^a	P _mul
Factors	HBsAg +	HBsAg -	OR(95% CI)	P-values^a	P _mul
Age
< 30	4.3(55/1271)	2.7(34/1271)	1.65(1.07–2.54)	0.023	0.039
≥ 30	6.8(53/779)	8.0(62/779)	0.84(0.58–1.24)	0.023	0.039
Education
Low educational level	9.0(31/344)	3.7(17/461)	2.59(1.41–4.76)	0.002	0.003
High educational level	4.5(77/1706)	5.0(79/1589)	0.90(0.66–1.24)	0.002	0.003

P _mul for multiplicative interaction between each risk factor and HBsAg status on PT, adjusting age, education level, pre-pregnancy BMI, GWG, HBsAg status
Abbreviation: PT Preterm labor, OR Odds ratio, CI Confidence interval
^aP-values for interaction effect between each risk factor and HBsAg status on PT

ISSN: 1471-2393