Fig. 4
ROC curves for the model of ΔFEV1 combined with FeNO in predicting the diagnosis of asthma. ROC, receiver operating characteristic; ΔFEV1, post-bronchodilator forced expiratory volume in 1 s response; FeNO, fractional exhaled nitric oxide; BDT, bronchodilation test. \({\text{AUC}}_{{\text{FeNO}}+\Delta{\text{FEV}}_1} = 0.774\) (95% CI 0.72–0.83); AUCFeNO = 0.613 (95% CI 0.55–0.68); \({\text{AUC}}_{\Delta{\text{FEV}}_1} = 0.765\) (95% CI 0.71–0.82)