FIGURE 3.

A prototype nomogram to interpret the strength of the fractional exhaled nitric oxide (FeNO) (‘magnet’) versus eosinophil (‘bomb’) signals: The line linking two biomarker values identifies bomb‐ versus magnet‐predominant asthma. Dashed grey line (—): Example of the nomogram result for a patient with an FeNO of 60 ppb and a blood eosinophil count (Eos) of 0.3 × 10⁹/L, suggesting a magnet‐driven asthma; see Table 1 for other phenotypic characteristics that may influence case interpretations. The cut‐off points and their positions on the nomogram are based on the fact that (a) clinical cut‐off points are 0.15–0.3 × 10⁹/L for blood eosinophils and 20–40 ppb for FeNO, ¹⁴ (b) the predictive value of these biomarkers are approximately linear up 0.6 × 10⁹/L and 60 ppb, respectively, in the placebo arms of severe asthma trials ¹⁵ and (c) upper values are logarithmically distributed.