TABLE 1.
Participant characteristics
| Characteristics | In analysis n = 1290 | Excluded subjects1n = 838 | P |
|---|---|---|---|
| Child’s sex | |||
| Male [n (%)] | 658 (51.0) | 438 (52.3) | 0.57 |
| Female [n (%)] | 632 (49.0) | 400 (47.7) | |
| Birthweight (kg) | 3.53 ± 0.512 | 3.35 ± 0.68 | < 0.0001 |
| Race-ethnicity | |||
| White [n (%)] | 975 (75.6) | 424 (52.0) | |
| Black [n (%)] | 134 (10.4) | 214 (26.3) | |
| Hispanic [n (%)] | 69 (5.4) | 85 (10.4) | < 0.0001 |
| Asian [n (%)] | 63 (4.9) | 57 (7.0) | |
| Other [n (%)] | 48 (3.7) | 35 (4.3) | |
| Number of other children in the home younger than 12 y | |||
| >1 [n (%)] | 675 (53.9) | 256 (50.8) | 0.24 |
| Breastfeeding duration | |||
| None [n (%)] | 139 (11.6) | 84 (23.1) | |
| >0 to <4 mo [n (%)] | 269 (22.5) | 152 (41.9) | < 0.0001 |
| 4 to <10 mo [n (%)] | 387 (32.3) | 90 (24.8) | |
| >10 mo [n (%)] | 402 (33.6) | 37 (10.2) | |
| Multivitamin intake in the first year | |||
| Yes [n (%)] | 239 (19.1) | 60 (11.9) | 0.0003 |
| Eczema in the first 2 y of life3 | |||
| Yes [n (%)] | 410 (31.9) | —4 | |
| No [n (%)] | 875 (68.1) | ||
| Any wheezing at 2 y5 | |||
| Yes [n (%)] | 376 (32.4) | —3 | |
| No [n (%)] | 785 (67.6) | ||
| Recurrent wheezing at 2 y4 | |||
| Yes [n (%)] | 136 (13.1) | —3 | |
| No [n (%)] | 902 (86.9) | ||
| Lower respiratory tract infection at 2 y5 | |||
| Yes [n (%)] | 327 (25.7) | —3 | |
| No [n (%)] | 944 (74.3) | ||
| Maternal age (y) | 32.6 ± 4.8 | 30.6 ± 5.6 | < 0.0001 |
| Maternal prepregnancy BMI (kg/m2) | 24.5 ± 5.1 | 25.5 ± 6.2 | < 0.0001 |
| Highest educational level | |||
| High school or some college [n (%)] | 346 (26.8) | 398 (48.8) | |
| College graduate [n (%)] | 491 (38.1) | 252 (30.9) | < 0.0001 |
| Postgraduate degree [n (%)] | 452 (35.1) | 165 (20.3) | |
| Maternal smoking during pregnancy [n (%)] | 122 (9.5) | 133 (15.9) | < 0.0001 |
| Passive smoke exposure in the home (h/w) | 0.26 ± 1.31 | 0.20 ± 1.02 | 0.32 |
| Household income | |||
| ≤$40 000 [n (%)] | 139 (10.8) | 153 (18.3) | |
| >$40 000 to $70 000 [n (%)] | 278 (21.6) | 156 (18.6) | < 0.0001 |
| >$70 000 [n (%)] | 807 (62.6) | 337 (40.2) | |
| Missing | 66 (5.1) | 192 (22.9) | |
| Maternal asthma | |||
| Yes [n (%)] | 211 (16.4) | 137 (16.4) | |
| No [n (%)] | 1079 (83.6) | 701 (83.7) | 0.996 |
| Maternal eczema | |||
| Yes [n (%)] | 253 (19.6) | 116 (13.8) | 0.0006 |
| No [n (%)] | 1037 (80.4) | 722 (86.2) | |
| Paternal asthma | |||
| Yes [n (%)] | 187 (14.5) | 102 (12.2) | 0.13 |
| No [n (%)] | 1103 (85.5) | 736 (87.8) | |
| Paternal eczema | |||
| Yes [n (%)] | 184 (14.3) | 50 (6.0) | < 0.0001 |
| No [n (%)] | 1106 (85.7) | 788 (94.0) |
1
Numbers do not always add up to 838 because of varied numbers of missing data for each variable.
2
x̄ ± SD (all such values).
3
There were not enough numbers with information to make valid comparisons. Most had missing information for these variables.
4
For the recurrent wheezing variable, children who wheezed in either the first year only or the second year only were excluded from the analyses.
5
Numbers do not add up to 1290 because of missing data.