Do measures matter? Comparing surface-density-derived and census-tract-derived measures of racial residential segregation

Table 4 Association of neighborhood racial composition and very preterm birth among Black and White

mothers, Atlanta, GA
	Main effect of segregation			Main effect of race			Segregation × Race Interaction			Model Fit (Deviance)
	OR	95% CI		OR	95% CI		OR	95% CI
BASELINE				2.84	2.70	2.99				62845
Continuous
Tract % black	1.75	1.35	2.24	2.45	2.28	2.64	0.69	0.53	0.90	62813
500-m % black	1.59	1.30	1.95	2.43	2.26	2.62	0.75	0.60	0.94	62813
4000-m % black	1.68	1.34	2.09	2.47	2.30	2.65	0.71	0.56	0.91	62814
Tract-500-m^†	1.68	1.34	2.08	2.45	2.28	2.63	0.71	0.56	0.91	62811
Trichotomous
Tract % black
< 0.3	1.00	--	--	2.75	2.55	2.96	1.00	--	--	62818
0.3-0.7	1.27	1.11	1.44				0.80	0.69	0.94
> 0.7	1.22	0.85	1.67				0.93	0.67	1.34
500-m % black
< 0.3	1.00	--	--	2.75	2.53	2.99	1.00	--	--	62811
0.3-0.7	1.25	1.10	1.42				0.81	0.69	0.95
> 0.7	1.50	1.20	1.85				0.74	0.59	0.94
4000-m % black
< 0.3	1.00	--	--	2.69	2.48	2.92	1.00	--	--	62814
0.3-0.7	1.23	1.10	1.38				0.87	0.76	1.01
> 0.7	1.43	1.10	1.82				0.81	0.62	1.06
Tract-500-m^†
< 0.3	1.00	--	--	2.80	2.59	3.03	1.00	--	--	62811
0.3-0.7	1.31	1.16	1.47				0.76	0.66	0.88
> 0.7	1.27	0.96	1.64				0.88	0.67	1.17

NOTE: Race is coded Black = 1, White = 0, and all continuous segregation indices are mean-centered so that the main effect of segregation is the effect for white women only, and the main effect of race is the excess relative risk for black as compared with white women at average segregation levels (e.g. mean-centered segregation equals zero for an neighborhood with average racial composition). The interaction term is then the excess relative risk for black women in the most compared with the least segregated neighborhoods.
†Tract-500-m are obtained by taking a population-weighted average of the racial composition in the 500-meter vicinity of each grid point within a census tract, thus approximating the average spatial isolation experienced by residents of each tract.
Data source: Georgia Department of Community Health, Office of Health Indicators for Planning; all singleton live births to non-Hispanic black and non-Hispanic white mothers in Atlanta MSA, 2000-2002

ISSN: 1476-072X