Table 2.

Hierarchical logistic regression models of SGA^a births and tract-level and individual-level predictors (N=173 tracts, N=8,082)

	Empty Model	Model 1	Model 2^b

	OR (95% CI)	OR (95% CI)	OR (95% CI)
Individual-level variables
Age (years)			1.01 (0.99, 1.03)
Education			1.01 (0.91, 1.12)
Medicaid (no=ref)			1.04(0.75, 1.45)
Total cigarettes smoked during pregnancy			1.01 (1.00, 1.02) ^*
Number of previous live births			0.84 (0.76, 0.92) ^*
Race (White=ref)			1.84 (1.46, 2.32) ^*
Tract-level variables
Domestic violence rate		1.11 (1.08, 1.15) ^*	1.04 (1.01, 1.08) ^*
Random effects
Variance between neighborhoods	0.14	0.07	0.03
Variance between individuals	3.29	3.29	3.29
Intraclass correlation coefficient (ICC)^c	4.0%	2.0%	0.54%
Median odds ratio (MOR)^d	1.4	1.3	1.2
−2 Res Log Likelihood	39847.0	39984.1	40125.7
Akaike information criterion (AIC)		1963.57	1954.65
Moran’s I	0.13^*	0.04	0.02
R-squared		0.12	0.22

Note. p-value (two-sided):

p<0.05.

SGA, Small for Gestational Age.

Models adjusted for propensity score calculated on living in a high violent crime area.

ICC, intraclass correlation coefficient calculated using the formula of Snijders and Boskers.³²

Because of limitations of the ICC for non-linear outcomes, the median odds ratio (MOR) was calculated.³³