Table 2. Characteristics of the children at enrollment and onset of childhood asthma at age 3 to 10 years.
| HAI group | Control group | |||
|---|---|---|---|---|
| Total | Bronchiolitis | Other HAI | ||
| At enrollment (0–2 years old) | ||||
| Case no. | 3264 | 1981 | 1283 | 18527 |
| Age (months, mean ± SD) | 12.9 ± 9.6 | 9.5 ± 7.7 a c | 18.2 ± 9.9 a | 12.5 ± 9.4 |
| Male (% of total) | 1891 (57.9) | 1184 (59.8) | 707 (55.1) b | 11026 (59.5) |
| Female (% of total) | 1373 (42.1) | 797 (40.2) | 576 (44.9) b | 7501 (40.5) |
| Onset of childhood asthma (3–10 years old) | ||||
| Case number | ||||
| 3–10 y (% of enrolled case)* | 530 (16.2) a | 351 (17.7) a | 179 (14.0) b | 2159 (11.7) |
| 3–5 y (% of total) | 411 (77.5) | 272 (77.5) | 139 (77.7) | 1487 (68.9) |
| 6–10 y (% of total) | 119 (22.5) | 79 (22.5) | 40 (22.3) | 672 (31.1) |
| Age | ||||
| (months, mean ± SD) | 59.1 ± 19.2 a | 59.6 ±19.5 a | 58.2 ± 18.7 a | 64.8 ± 20.1 |
| (years, mean ± SD) | 4.9 ± 1.6 a | 5.0 ± 1.6 a | 4.8 ± 1.6 a | 5.4 ± 1.7 |
| Gender | ||||
| Male (% of total) | 322 (60.8) | 219 (62.4) | 103 (57.5) b | 1404 (65.0) |
| Female (% of total) | 208 (39.2) | 132 (37.6) | 76 (42.5) b | 755 (35.0) |
Abbreviations: HAI, hospitalized airway infection; y, years old.
*% of enrolled children with early childhood airway disease (0–2 years old).
a p < 0.001 vs. control group;
b p < 0.05 vs. control group,
c p < 0.001 vs. other HAI subgroup.