Fig. 3
Receiver operating characteristics (ROC) curve for model combining forced expiratory flow at 50% of FVC, FEF50% %predicted, angle β and forced expiratory flow at 25–75% of FVC, FEF25–75% %predicted as a predictor of methacholine responsiveness in the derivation cohort. AUC = Area under the curve. Line of unity is represented by a grey line, corresponding to AUC = 0.5