Characteristics of the two study groups
| Undiagnosed asthma | Diagnosed asthma | |
| Subjects n | 70 | 29 |
| Sex | ||
| Male | 30 (43) | 19 (66) |
| Female | 40 (57) | 10 (35) |
| Age yrs | 9.3±0.8 | 9.4±0.8 |
| Mother asthma ever | 10 (17) | 3 (10) |
| Father asthma ever | 3 (6) | 3 (12) |
| Mother or father current smoker | 19 (27) | 8 (28) |
| Mother's education | ||
| Low | 7 (12) | 6 (21) |
| Moderate | 28 (46) | 12 (45) |
| High | 25 (42) | 10 (34) |
| Father's education | ||
| Low | 7 (13) | 5 (19) |
| Moderate | 22 (42) | 10 (38) |
| High | 24 (45) | 11 (41) |
Data are presented as n (%) or mean±sd, unless otherwise stated.