Description of the study cohort
| Frequency | ||
| n/N | Prevalence % | |
| Variable | ||
| Age of 1 yr | ||
| 258/1722 | 15.0 | |
| Cough w/o infection | 151/1655 | 9.1 |
| Dry cough at night | 123/1737 | 7.1 |
| Doctor diagnosed bronchial asthma | 6/1731 | 0.4 |
| Doctor diagnosed asthmoid/spast./obstr. bronchitis | 196/1735 | 11.3 |
| Doctor diagnosed respiratory infections | 1212/1728 | 70.1 |
| Sneezing, running/stuffed nose w/o a cold | 254/1743 | 14.6 |
| Age of 2 yrs* | ||
| Wheezing | 416/1627 | 25.6 |
| Dry cough at night | 228/1614 | 14.1 |
| Doctor diagnosed bronchial asthma | 16/1600 | 1.0 |
| Doctor diagnosed asthmoid/spast./obstr. bronchitis | 303/1616 | 8.8 |
| Doctor diagnosed respiratory infections | 1528/1695 | 90.2 |
| Sneezing, running/stuffed nose w/o a cold | 354/1638 | 21.6 |
| Confounding variables | ||
| Female sex | 832/1756 | 47.4 |
| Parental atopy | 935/1756 | 53.3 |
| ETS at home | 398/1704 | 23.4 |
| Maternal education | ||
| <12 grades | 633/1751 | 36.1 |
| >12 grades | 1118/1751 | 63.9 |
| Siblings | 700/1712 | 40.9 |
| Use of gas for cooking | 221/1731 | 12.8 |
| Home dampness | 115/1731 | 6.6 |
| Indoor moulds | 534/1735 | 30.8 |
| Keeping of pets | 318/1739 | 18.3 |
| Cat | 159/1735 | 9.2 |
| Dog | 70/1735 | 4.0 |
n/N: number of subjects/total number of subjects
ETS: environmental tobacco smoke
Obstr.: obstructive
Spast: spastic
w/o: without
*: lifetime prevalence