Fig. 4

The receiver operating characteristic analysis of biomarkers to detect the diagnosis of asthma-COPD overlap. The area under the curve was 0.666 for blood eosinophil count, 0.665 for total immunoglobulin E (IgE), and 0.703 for fraction of exhaled nitric oxide (FeNO). The best cutoff value was 234 count/μL for blood eosinophils (sensitivity 0.618, specificity 0.786), 158 IU/mL for serum total IgE (sensitivity 0.677, specificity 0.662), and 31.0 ppb for FeNO (sensitivity 0.546, specificity 0.881)