Table 3. Comparison of the proportion of mothers from low- and high-income areas giving birth to premature babies in New Mexico.

Year	Low Income		Higher Income		Fisher's Exact p	OR	(95% CI)
	%	Total births	%	Total births
1989	10.59	8479	7.72	803	0.01	1.41	(1.08,1.84)
1990	11.08	8785	7.35	830	0.00	1.56	(1.19, 2.04)
1991	4.64	8971	4.92	833	0.67	0.93	(0.67, 1.29)
1992	4.60	9135	4.57	788	1.00	0.99	(0.70, 1.41)
1993	4.44	9002	5.34	787	0.24	0.82	(0.59, 1.13)
1994	4.72	8695	4.66	880	1.00	1.00	(0.72, 1.39)
1995	5.03	8369	5.75	1008	0.32	0.86	(0.65, 1.14)
1996	4.89	8613	6.03	879	0.14	0.79	(0.59, 1.06)
1997	4.85	8104	3.52	1022	0.06	1.38	(0.98, 1.95)
1998	5.00	7960	6.07	1433	0.09	0.81	(0.64, 1.03)
1999	4.94	7891	4.87	1539	0.95	1.01	(0.78, 1.30)

OR refers to Odds Ratio.