Abstract
The utility of fractional exhaled nitric oxide (FeNO) was evaluated alongside blood eosinophils in phenotyping mild asthma. Inclusion of FeNO improved classification accuracy and calibration in an adapted ISAR-based model; however, its predictive improvement was modest and its susceptibility to transient elevations suggests limited added value for routine clinical classification. Simplified algorithms may offer more accurate phenotyping in population-based settings with real-world constraints.