Table 1.
Characteristics of Participating Children
| Variable | At baseline $ (n=498) | At 9 years of follow-up $ (n=432) | Children with assessment of allergen sensitization $ (n=271) |
|---|---|---|---|
| Number, (percentage) | Number, (percentage) | Number, (percentage) | |
| Female sex | 230 (46.2) | 195 (45) | 116 (43) |
| Household income <$30,000 | 45 (9.3) | 24 (5.7)* | 13 (5)* |
| Ethnicity | |||
| White | 375 (75.3) | 344 (79.6)* | 219 (81)* |
| Black | 60 (12.1) | 37 (8.6)* | 23 (9)* |
| Hispanic | 28 (5.6) | 19 (4.4) | 11 (4) |
| Asian and other | 35 (7.0) | 32 (7.4) | 18 (7) |
| Caesarean delivery | 114 (22.9) | 102 (23.6) | 65 (24.0) |
| -Scheduled | 27 (5.4) | 24 (5.6) | 16 (5.9) |
| -Nonscheduled | 86 (17.3) | 77 (17.9) | 48 (17.8) |
| Quartiles of birth weight (kg) | |||
| 1.84 to <3.18 | 125 (25.2) | 106 (24.6) | 67 (24.7) |
| 3.18 to <3.46 | 126 (25.4) | 108 (25.1) | 65 (24.0)) |
| 3.46 to <3.79 | 122 (24.6) | 108 (25.1) | 68 (25.1) |
| 3.79 to <4.91 | 124 (25.0) | 109 (25.3) | 71 (26.2) |
| Season of birth | |||
| Spring | 144 (28.9) | 127 (29.4) | 86 (31.7)* |
| Summer | 110 (22.1) | 94 (21.8) | 58 (21.4)) |
| Fall | 120 (24.1) | 106 (24.5) | 68 (25.1) |
| Winter | 124 (24.9) | 105 (24.3) | 59 (21.8) |
| Gestational Age <38.5 weeks | 104 (20.9) | 87 (20.1) | 60 (22.14) |
| Maternal history of asthma | 152 (30.5) | 125 (28.9) * | 76 (28.0) |
| Number of siblings in the child’s home | |||
| 0 | 228 (45.8) | 215 (49.8)* | 136 (50.2)* |
| 1 | 176 (35.4) | 147 (34.0) | 93 (34.3) |
| 2 or more | 94 (18.9) | 70 (16.2)* | 42 (15.5)* |
| >= 3 episodes of nasal catarrh in the first year of life | 421 (84.5) | 365 (84.5) | 229 (84.5) |
| Physician-diagnosed bronchiolitis in the first year of life | 65 (13.1) | 52 (12.0) | 35 (12.9) |
| Physician-diagnosed croup in the first year of life | 57 (11.5) | 47 (10.9) | 30 (11.1) |
| Quartiles of endotoxin (EU/mg) | |||
| 2.14–52.5 | 100 (24.9) | 84 (24.1) | 50 (22.6) |
| 52.5–79.9 | 100 (24.9) | 90 (25.8) | 53 (24.0) |
| 80.48–125.59 | 101 (25.2) | 88 (25.2) | 60 (27.2) |
| 125.6–713.2 | 100 (24.9) | 87 (24.9) | 58 (26.2) |
| Dust mite allergen, μg/g (tertiles of detectable levels) | |||
| <0.0523 (non-detectable) | 192 (44.4) | 192 (44.4) | 124 (46.1) |
| >=0.0523 <0.685 | 80 (18.5) | 80 (18.5) | 49 (18.2) |
| >=0.685 <2.725 | 80 (19) | 80 (19) | 44 (16.4) |
| >=2.725 | 80 (19) | 80 (19) | 52 (19.3) |
*
P <0.05 for comparison with children at baseline.
$
Numbers and percentages reflect missing information on some variables.