Table 3—

Logistic regression analysis of airway responsiveness: provocative concentration causing a 20% fall in forced expiratory volume in one second (FEV1, PD20) <6400 µg methacholine

Odds ratio95% Confidence intervalp-value
Atopy per positive allergen2.051.71–2.46<0.001
Sex female versus male2.431.84–3.22<0.001
Smoking status yes versus no2.261.68–3.03<0.001
Baseline FEV1 per % less than pred0.940.93–0.95<0.001
Survey 1998–1999 versus 1992–19930.770.58–1.01 NS
  • ns: nonsignificant; pred: predicted