Multivariate logistic regression analysis of risk factors for BO
| Variable | OR | 95% CI | p value |
|---|---|---|---|
| ETS, environmental tobacco smoke. | |||
| Age (<6 v ⩾6 months) | 1.4 | 0.4 to 5.4 | 0.6 |
| Sex (male v female) | 0.8 | 0.2 to 2.6 | 0.7 |
| ETS at present | 1.4 | 0.4 to 4.5 | 0.5 |
| ETS during pregnancy | 0.4 | 0.1 to 3.2 | 0.4 |
| Adenovirus infection | 49 | 12 to 199 | <0.001 |
| Mechanical ventilation | 11 | 2.6 to 45 | 0.001 |