Table 3.

Adjusted ^a odds ratios and 95% confidence intervals of the associations of neighborhood racial composition (% Black residents), income incongruity, and relative household income with preterm birth, Black Women’s Health Study, 1995–2003

	All preterm birth				Spontaneous preterm birth			Medically indicated preterm birth
	No. term	No. preterm	OR	95% CI	No. preterm	OR	95% CI	No. preterm	OR	95% CI
Neighborhood racial composition
<14.4% Black residents	1359	243	1.08	0.91, 1.28	128	1.08	0.86, 1.35	115	1.08	0.85, 1.37
14.4 – 82.7% Black residents	2734	472	1.00	Referent	245	1.00	Referent	227	1.00	Referent
> 82.7% Black residents	1357	245	1.03	0.87, 1.22	134	1.10	0.88, 1.37	111	0.97	0.76, 1.24
Income incongruity
Positive incongruity	728	122	0.92	0.75, 1.14	73	1.07	0.81, 1.40	49	0.78	0.57, 1.06
No incongruity	3839	698	1.00	Referent	357	1.00	Referent	341	1.00	Referent
Negative incongruity	745	125	0.92	0.75, 1.12	69	0.99	0.76, 1.30	56	0.84	0.63, 1.13
Relative household income
Higher income	2786	477	1.01	0.84, 1.22	251	1.01	0.79, 1.30	226	1.00	0.77, 1.31
Similar income	994	173	1.00	Referent	90	1.00	Referent	83	1.00	Referent
Lower income	628	124	1.09	0.84, 1.41	61	1.02	0.72, 1.45	63	1.17	0.82, 1.66

^aAdjusted for age, education, marital status, body mass index, and smoked cigarettes during pregnancy.