Prevalence and risk factors of congenital heart defects among live births: a population-based cross-sectional survey in Shaanxi province, Northwestern China

Table 3 Predictors of any CHD among infants alive in Shaanxi province using a poisson regression

Predictors^c	Univariate analysis^a	Multivariate analysis^b
Predictors^c	PRR (95% CI)	PRR (95% CI)
Infant Gender
Male	Reference	Reference
Female	0.9 (0.7, 1.1)	0.9 (0.7, 1.2)
Fetal number
Singleton	Reference	Reference
Twin and Multi-fetal	4.3 (2.4, 7.9)*	3.1 (1.6, 6.1)*
Mother's education
College and above	Reference	Reference
Senior high school	0.9 (0.6, 1.3)	0.8 (0.5, 1.3)
Junior high school	0.9 (0.7, 1.3)	0.7 (0.5, 1.2)
Primary school	0.8 (0.5, 1.3)	0.6 (0.3, 1.1)
No education	1.3 (0.6, 3.0)	1.1 (0.4, 2.8)
Mother's age, year
<25	Reference	Reference
25-29	1.2 (0.9, 1.8)	1.2 (0.8, 1.8)
≥30	1.6 (1.1, 2.4)*	1.6 (1.1, 2.5)*
Parity*
1	Reference	Reference
2	1.1 (0.9, 1.5)	1.1 (0.8, 1.6)
≥3	2.6 (1.6, 4.3)*	2.2 (1.2, 4.2)*
Wealth index
Poor	Reference	Reference
Medium	0.9 (0.6, 1.2)	0.9 (0.6, 1.3)
Rich	0.8 (0.6, 1.1)	0.9 (0.6, 1.3)
Family history of CHD*
No	Reference	Reference
Yes	10.9 (6.2, 19.1)*	9.8 (5.3, 18.1)*
Residence during the pregnancy
Permanent	Reference	Reference
Floating	0.6 (0.4, 0.8)*	0.6 (0.4, 0.9)*
Household registration
Urban	Reference	Reference
Rural	0.9 (0.7, 1.3)	0.9 (0.6, 1.4)
Areas*
Southern area	Reference	Reference
Central area	0.7 (0.5, 0.9)*	0.5 (0.4, 0.7)*
Northern area	0.5 (0.3, 0.7)*	0.4 (0.3, 0.6)*
Number of ultrasound examination	1.1 (0.9, 1.3)	1.1 (0.6, 1.4)

^aOnly one variable is entered into the poisson regression model
^bAll possible risk factors are entered into the poisson regression model
^cPrevalence Rate Ratio (PRR) and 95% confidence interval are given to indicate the magnitude of change
*P < 0.05

ISSN: 1471-2431