Table 3

Multivariable logistic regression models showing associations between covariates of interest and risk of low birth weight among non-Arab white mothers in Michigan between 2000 and 2005

	Dearborn				48126
	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI
Dearborn
No (reference)
Yes	0.90	0.79 to 1.02	0.93	0.82 to 1.06
48126 zip code
No (reference)
Yes					0.89	0.69 to 1.15	0.88	0.68 to 1.14
Parity
0 (reference)
1			0.79	0.77 to 0.81			0.79	0.77 to 0.81
2			0.82	0.80 to 0.85			0.82	0.80 to 0.85
3+			0.96	0.93 to 1.00			0.96	0.93 to 1.00
Unknown			1.27	1.07 to 1.51			1.27	1.07 to 1.51
Marital status
Unmarried (reference)
Married			0.82	0.80 to 0.85			0.82	0.80 to 0.85
Maternal age^†
<20			1.03	0.98 to 1.07			1.03	0.98 to 1.07
20–25 (reference)
26–30			1.11	1.07 to 1.14			1.11	1.07 to 1.14
31–35			1.24	1.20 to 1.29			1.24	1.20 to 1.29
36–40			1.50	1.44 to 1.56			1.50	1.44 to 1.56
41+			1.86	1.74 to 1.98			1.86	1.74 to 1.98
Education
<11 years			1.21	1.15 to 1.27			1.21	1.15 to 1.27
GED^* or equivalent			1.06	1.02 to 1.10			1.06	1.02 to 1.10
College			0.98	0.95 to 1.02			0.98	0.95 to 1.02
Masters or above (reference)
Unknown			1.34	1.23 to 1.45			1.34	1.23 to 1.45
Place of birth
Foreign			0.88	0.85 to 0.92			0.88	0.85 to 0.92
USA (reference)
Tobacco use
None (reference)
Yes			1.60	1.56 to 1.64			1.6	1.56 to 1.64

↵* The General Educational Development examination is a five-part examination that certifies that the taker has academic skills commensurate with a high school graduate in the USA or Canada.
↵† Analyses were also adjusted for unknown maternal age.