Fig. 3From: Contribution of small airway inflammation to the development of COPDArea under the curve of exhaled NO in COPD. The area under the ROC curve of FeNO50 is 0.742, FeNO200 is 0.841, CaNOdual is 0.707, and FnNO is 0.590 in COPD at the studyCOPD, chronic obstructive pulmonary disease; NO, nitric oxide; ROC, receiver operating curveBack to article page