TABLE 3.
CIGARETTE SMOKING AND RISK OF NEWLY DIAGNOSED ASTHMA, RELATIVE RISK AND 95% CONFIDENCE INTERVAL, CHILDREN'S HEALTH STUDY 1993–2003
| Relative Risk | 95% Confidence Interval | p Value for Trend | |
|---|---|---|---|
| Any smoking in year of diagnosis | 1.3 | 0.9–2.0 | — |
| Regular smoking | |||
| Amount smoked weekly | |||
| None | 1 | — | 0.0005 |
| 1–6 cigarettes | 1.8 | 0.9–3.6 | |
| 7+ cigarettes | 3.1 | 1.5–6.2 | |
| Amount smoked yearly | |||
| None | 1 | — | 0.0009 |
| 1–99 cigarettes | 1.1 | 0.7–1.7 | |
| 100–299 cigarettes | 1.8 | 0.6–5.0 | |
| 300+ cigarettes | 3.9 | 1.7–8.5 |
Relative risk (Hazard ratio) and corresponding 95% confidence intervals from Cox's proportional hazard model for concurrent smoking with stratified baseline hazard for sex and age (in 1-yr intervals) at study entry. All models are adjusted for race/ethnicity and community of residence.