Table 1

Demographic characteristics of the infant feeding groups

Characteristic	Category	Breastfed						P values
		<1 month		≥1 to <4 months		≥4 months
		%	n	%	n	%	n
Sex	All	19.2	151	49.6	390	31.2	245	–
	Male	44.4	67	45.9	179	50.6	124
	Female	55.6	84	54.1	211	49.4	121	0.389
Race/ethnicity	Non-Hispanic White	55.0	83	60.0	234	79.2	194
	Hispanic White	26.5	40	26.9	105	13.1	32
	Other	18.5	28	13.1	51	7.8	19	<0.001
Maternal
Asthma	No	94.6	141	88.2	337	87.7	214
Asthma	Yes	5.4	8	11.8	45	12.3	30	0.063
Smoking	No	78.8	119	84.1	328	90.6	222
Smoking	Yes	21.2	32	15.9	62	9.4	23	0.004
Education	≤12 years	43.1	65	23.6	92	13.1	32
Education	>12 years	57.0	86	76.4	297	86.9	213	<0.001
Age	≤28 years	62.3	94	62.6	244	53.9	132
Age	>28 years	37.7	57	37.4	146	46.1	113	0.075
Paternal
Asthma	No	83.3	115	87.4	320	89.1	213
Asthma	Yes	16.7	23	12.6	46	10.9	26	0.265
Smoking	No	60.1	89	72.4	278	80.0	196
Smoking	Yes	39.9	59	27.6	106	20.0	49	<0.001
Education	≤12 years	37.2	54	23.0	88	14.3	35
Education	>12 years	62.8	91	77.0	294	85.7	210	<0.001
Age	≤28 years	46.0	68	46.0	174	34.3	84
Age	>28 years	54.0	80	54.0	208	65.7	161	0.012

Proportions compared by Χ².