Table 2

Sensitivity, specificity, PPV and NPV of different surrogate markers using alternative cut-points to diagnose eosinophilic airway inflammation (less than, more than or equal to 3% sputum eosinophils)

Blood eosinophils>0.22×109/L86796093
Blood eosinophils≥0.25×109/L79846491
Blood eosinophils≥0.27×109/L78917991
FENO level>20 ppb74574087
FENO level≥24 ppb74634287
FENO level≥42 ppb63927489
FENO level>50 ppb56926784
Serum periostin (in-house)>26 ng/mL54572977
  • NPV, negative predictive value; PPV, positive predictive value.