Fig. 4

Receiver operating curves (ROC) describing the relationship between sensitivity and specificity of percent changes obtained at the corresponding provocation dose levels, PD_-40sGeff for a 40% fall in effective specific conductance, PD_-20FEV₁ for a 20% fall in forced expiratory volume in one second, and PD_-20FEF₅₀ for a 20% fall in forced expiratory flow at 50% vital capacity during methacholine challenge represented by methacholine