Table 3.

Socioeconomic and environmental factors regarding habitual snoring by multivariate logistical regression models (N = 21,052)

Variables	Model I		Model II		Model III
	Adjusted OR (95% CI)	P value	Adjusted OR (95% CI)	P value	Adjusted OR (95% CI)	P value
Socioeconomic characteristics
Family income		< .001		< .001		< .001
< 800 vs. ≥ 2500	1.35 (1.18-1.54)	< .001	1.43 (1.23-1.67)	< .001	1.46 (1.23-1.75)	< .001
800-2500 vs. ≥ 2500	1.12 (0.99-1.26)	.072	1.16 (1.02-1.32)	.024	1.12 (0.96-1.30)	.142
Mather's education level
Low vs. High	NS		NS		NS
Medium vs. High	NS		NS		NS
Father's education level				.007		< .001
Low vs. High	NS		1.22 (1.08-1.38)	.002	1.38 (1.20-1.60)	< .001
Medium vs. High	NS		1.04 (0.94-1.16)	.427	1.14 (1.01-1.29)	.034
Environmental exposures
Delivery
Caesarean section vs. Vaginal Birth	1.21 (1.11-1.33)	< .001	1.19 (1.08-1.31)	< .001	NS
Feeding patterns during the first four months
Mixed/bottle feeding vs. Breastfeeding	1.16 (1.06-1.27)	.001	NS
Breastfeeding
<6 months vs. ≥ 6 months	1.19 (1.09-1.29)	< .001	1.14 (1.05-1.25)	.003	1.17 (1.08-1.28)	< .001
Pregnancy maternal smoking
Yes vs. No	1.81 (1.42-2.38)	< .001	1.68 (1.28-2.21)	< .001	1.51 (1.07-2.13)	.019
Household passive smoking
Yes vs. No	1.18 (1.07-1.30)	.001	1.16 (1.05-1.29)	.003	NS

Family income was expressed in RMB(yuan)/person/month

OR: odds ratio; CI: confidence interval

Model I adjusted for age and gender;

Model II adjusted for age, gender, and all socioeconomic and environmental factors

Model III adjusted for age, gender, all socioeconomic and environmental factors, and all health problems and family history simultaneously.