Adjusted risks of wheeze by multivariate analysis in subjects aged 16–52 years.

Multivariate odds ratios (OR) with 95% confidence intervals (CI) were calculated for any wheeze (models 1–3) and asthmatic wheeze (models 4–6). Interaction with sex was tested separately for each category of smoking: ever smoking (adjusted for pack-years) in models 1 and 4; current smoking (adjusted for pack-years) in models 2 and 5; and number of pack-years in models 3 and 6.*All factors significantly associated with the respective wheeze outcomes in univariate analysis were entered into the model, and then removed stepwise if p>0.2, yielding the final models presented below.**Models 1–3 included female sex, BMI (30; vs. 20–24.9); secondary schooling; perceived irritation from outdoor air (sometimes; daily; vs never); minutes of daily traffic exposure (30–60; >60; vs. ***Models 4–6 included female sex, BMI (30; vs. 20–24.9); secondary schooling; perceived irritation from outdoor air (sometimes; daily; vs never); work exposure to vapors, gas, dust and fumes; chronic rhinosinusitis, and smoking as listed.