TABLE 3.

Multivariable Logistic Regression of Breastfeeding Initiation and Cox Proportional Hazard Model of Breastfeeding Discontinuation

Characteristic	Breastfeeding Initiation (n = 1235)			Breastfeeding Discontinuation (n = 962)
	Logistic Regression Model			Cox Proportional Hazards Model
	OR	95% CI	P	HR	95% CI	P
Country of birth and education
MX-MX (reference)	1.00	—	—	1.00	—	—
MX-US	0.54	0.38–0.77	<.001	1.30	1.11–1.51	<.001
US-US	0.16	0.09–0.27	.001	1.69	1.38–2.06	.001
Age at delivery, y
18–24 (reference)	1.00	—	—	1.00	—	—
25–29	1.86	1.13–3.06	.02	0.71	0.56–0.90	.005
30–34	2.02	0.96–4.24	.06	0.75	0.59–0.97	.025
35+	1.68	1.21–2.33	.002	0.80	0.56–1.15	.22
Mother’s education level at baseline
Less than high school (reference)	1.00	—	—	1.00	—	—
High school graduate	1.03	0.70–1.51	.89	0.91	0.82–1.02	.12
More than high school	1.30	0.78–2.16	.32	0.76	0.63–0.92	.004
No. children
1 (reference)	1.00	—	—	1.00	—	—
2	0.43	0.23–0.81	.009	1.06	0.94–1.20	.31
3	0.18	0.07–0.43	<.001	0.93	0.73–1.18	.54
4+	0.24	0.12–0.45	<.001	0.80	0.65–0.98	.04
Newborn in NICU	0.45	0.19–1.08	.08	1.05	0.73–1.53	.77
Type of delivery
Vaginal (reference)	1.00	—	—	1.00	—	—
Cesarean delivery	0.68	0.50–0.92	.01	1.08	0.90–1.30	.40
Introduced formula within 1 wk	—	—	—	1.77	1.55–2.02	<.001
Cigarette smoking (time varying)	—	—	—	2.00	1.52–2.62	<.001
Working (time varying)	—	—	—	1.14	1.03–1.26	.009
Constant	54.39	22.46–131.71	<.001	—	—	—

P values are obtained through 2-tailed tests. CI, confidence interval; HR, hazard ratio; OR, odds ratio; —, not applicable.