Table 1.
Comparison of children with a follow-up at age 10 and the subset used in the analysis
| Numbers at age 10 (%) | Numbers used in the analysis (%) | χ2 p value | ||
| Variable | Total | 1,373 | 791 | |
| Wheeze Phenotype | Early-onset persistent* | 139 (12.7) | 105 (13.3) | 0.60 |
| Late-onset persistent† | 81 (7.4) | 70 (8.9) | ||
| Early transient‡ | 259 (23.6) | 190 (23.9) | ||
| Non-wheezer§ | 617 (56.3) | 426 (53.9) | ||
| Missing | 277 | 0 | ||
| Birth weight | ≥2500 grams | 1287 (96.3) | 736 (96.0) | 0.75 |
| <2500 grams | 49 (3.7) | 31 (4.0) | ||
| Missing | 37 | 24 | ||
| Exposure to tobacco smoke | ETS-0 | 617 (45.2) | 381 (48.2) | 0.22 |
| ETS-1 | 430 (31.5) | 249 (31.5) | ||
| ETS-2 | 319 (23.3) | 161 (20.3) | ||
| Missing | 7 | 0 | ||
| Gender | Girl Boy | 676 (49.2) | 388 (49.3) | 0.98 |
| 697 (50.8) | 399 (50.7) | |||
| Breast fed | ≥3 months | 470 (41.7) | 322 (42.8) | 0.67 |
| <3 months | 657 (58.3) | 430 (57.2) | ||
| Missing | 246 | 39 | ||
| Household cat during pregnancy | Yes | 453 (33.2) | 269 (34.0) | 0.68 |
| No | 912 (66.8) | 521 (66.0) | ||
| Missing | 8 | 1 | ||
| Household dog during pregnancy | Yes | 395 (28.9) | 240 (30.4) | 0.48 |
| No | 970 (71.1) | 550 (69.6) | ||
| Missing | 8 | 1 | ||
* Onset of wheeze in the first 4 years, still present at age 10.
† Onset of wheeze after age 4 years, still present at age 10.
‡ Wheeze only in the first 4 years.
§ No wheeze up to age 10.
ETS-0, mothers did not smoke during pregnancy and children not exposed to household ETS; ETS-1, mothers did not smoke during pregnancy, but children were exposed to household ETS; ETS-2, mothers smoked during pregnancy and children were exposed to household ETS