Fig. 2

Correlation between biomarkers and objective tests. A Scatter plot showing the correlation between FeNO levels and the B-Eos count in asthmatic patients (n = 824). B Scatter plot showing the correlation between FeNO and the B-Eos count in non-asthmatic patients (n = 1525). C Violin plots showing the FeNO levels in different BPT subgroups. D Violin plots showing the B-Eos counts in different BPT subgroups. E Violin plots showing the FeNO levels in different BDT subgroups. F Violin plots showing the B-Eos counts in different BDT subgroups. rs, Spearman’s ρ. Notes: The positive BPT results are presented as follows: + / − indicates that the PD₂₀-FEV₁ of methacholine was 1.076–2.500 mg; + indicates that it was 0.294–1.075 mg; ++ indicates that it was 0.035–0.293 mg; +++ indicates that it was < 0.035 mg. The BDT results are presented as follows: − indicates that FEV₁ increased less than 12% or 200 ml above baseline after inhalation of 400 μg salbutamol sulfate aerosol; + indicates that FEV₁ increased by 12–25% and its absolute value increased by 200 ml; ++ indicates that FEV₁ increased by 25–40% and its absolute value increased by 200 ml; +++ indicates that FEV₁ increased > 40% and its absolute value increased by 200 ml. *Data were analyzed by Spearman’s rank correlation coefficients