| | Asthma | | | | No | Yes | Total | | | % | | % | | | | Num | Row | Column | Num | Row | Column | Num | % |
| Total | 59,975 | 74.6 | 100.0 | 20,473 | 25.4 | 100.0 | 80,448 | 100.0 |
| Birth year | | | | | | | | | 1989 | 3,823 | 65.1 | 6.4 | 2,051 | 34.9 | 10.0 | 5,874 | 7.3 | 1990 | 5,816 | 66.5 | 9.7 | 2,931 | 33.5 | 14.3 | 8,747 | 10.9 | 1991 | 5,671 | 67.2 | 9.5 | 2,773 | 32.8 | 13.5 | 8,444 | 10.5 | 1992 | 6,020 | 71.7 | 10.0 | 2,374 | 28.3 | 11.6 | 8,394 | 10.4 | 1993 | 6,135 | 74.0 | 10.2 | 2,152 | 26.0 | 10.5 | 8,287 | 10.3 | 1994 | 6,524 | 75.9 | 10.9 | 2,067 | 24.1 | 10.1 | 8,591 | 10.7 | 1995 | 6,503 | 77.4 | 10.8 | 1,896 | 22.6 | 9.3 | 8,399 | 10.4 | 1996 | 6,793 | 80.7 | 11.3 | 1,629 | 19.3 | 8.0 | 8,422 | 10.5 | 1997 | 6,465 | 81.8 | 10.8 | 1,440 | 18.2 | 7.0 | 7,905 | 9.8 | 1998 | 6,225 | 84.3 | 10.4 | 1,160 | 15.7 | 5.7 | 7,385 | 9.2 |
| Antenatal steroid exposure | 773 | 68.1 | 1.3 | 362 | 31.9 | 1.8 | 1,135 | 1.4 |
| Number of siblings | | | | | | | | | 0 | 25,916 | 72.2 | 43.2 | 9,972 | 27.8 | 48.7 | 35,888 | 44.6 | 1 | 21,753 | 75.1 | 36.3 | 7,199 | 24.9 | 35.2 | 28,952 | 36.0 | 2 | 8,691 | 78.1 | 14.5 | 2,435 | 21.9 | 11.9 | 11,126 | 13.8 | 3+ | 3,608 | 80.7 | 6.0 | 864 | 19.3 | 4.2 | 4,472 | 5.6 |
| Preterm birth (<37 weeks) | 2,534 | 68.1 | 4.2 | 1,189 | 31.9 | 5.8 | 3,723 | 4.6 |
| Caesarean section | 10,873 | 71.9 | 18.1 | 4,253 | 28.1 | 20.8 | 15,126 | 18.8 |
| Income | | | | | | | | | Quintile 1 | 12,693 | 73.6 | 21.5 | 4,547 | 26.4 | 22.7 | 17,240 | 21.4 | Quintile 2 | 12,619 | 74.3 | 21.4 | 4,359 | 25.7 | 21.7 | 16,978 | 21.1 | Quintile 3 | 11,368 | 75.2 | 19.3 | 3,749 | 24.8 | 18.7 | 15,117 | 18.8 | Quintile 4 | 12,435 | 74.6 | 21.1 | 4,235 | 25.4 | 21.1 | 16,670 | 20.7 | Quintile 5 | 9,873 | 75.7 | 16.7 | 3,174 | 24.3 | 15.8 | 13,047 | 16.2 |
| Surfactant administration | 139 | 59.9 | 0.2 | 93 | 40.1 | 0.5 | 232 | 0.3 |
| 1 Minute Apgar score | | | | | | | | | 0–3 | 1,309 | 70.4 | 2.2 | 550 | 29.6 | 2.7 | 1,859 | 2.3 | 4–6 | 4,375 | 71.9 | 7.3 | 1,712 | 28.1 | 8.4 | 6,087 | 7.6 | 7–10 | 54,070 | 74.9 | 90.5 | 18,137 | 25.1 | 88.9 | 72,207 | 89.8 |
| Maternal smoking | 16,421 | 72.6 | 27.4 | 6,211 | 27.4 | 30.3 | 22,632 | 28.1 | Married/Common law | 42,671 | 74.6 | 71.1 | 14,566 | 25.4 | 71.1 | 57,237 | 71.1 | Hyaline membrane disease | 672 | 62.3 | 1.1 | 406 | 37.7 | 2.0 | 1,078 | 1.3 | Bronchopulmonary dysplasia | 97 | 54.2 | 0.2 | 82 | 45.8 | 0.4 | 179 | 0.2 | Duration: weeks (mean, SD) | 512.3 | 155.3 | | 287.2 | 116.6 | | 455.0 | 176.2 | Birth weight: grams (mean, SD) | 3,487.4 | 554.7 | | 3,444.3 | 592.1 | | 3,476.5 | 564.7 | Gestational age: weeks (mean, SD) | 39.5 | 1.7 | | 39.3 | 1.9 | | 39.4 | 1.7 | Maternal age: years (mean, SD) | 26.7 | 5.3 | | 26.4 | 5.2 | | 26.6 | 5.3 |
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