Table 5.

Table of results of the multivariate analyses performed to determine the independent associations between the variables

Independent Predictor	Dependent Variable
	FeNO	Sputum TCC	Sputum Neutrophil TCC	Sputum Neutrophil %	Sputum Eosinophil TCC	Sputum Eosinophil %	Sputum IL8
FeNO	N/A	NS	NS	P < 0.0001 R = -0.6	P < 0.0001 R = 0.7	P < 0.0001 R = 0.62	NS
Sputum IL8	NS	NS	P = 0.002 R = 0.57	P < 0.0001 R = -0.6	NS	NS	N/A
Plasma TNFα	NS	NS	P < 0.0001 R = 0.57	NS	NS	NS	P = 0.01 R = 0.44
Smoking	P < 0.0001 R = 0.72 (lower in smokers)	NS	NS	NS	NS	NS	NS
Reversibility	NS	NS	NS	P = 0.01 R = -0.6	P = 0.02 R = 0.7	NS	NS
Gender	P = 0.04 R = 0.7 (lower in females)	NS	NS	NS	NS	NS	NS

FEV₁, IC, BMI, Bronchodilator reversibility, plasma CRP, ICS usage and smoking pack years did not predict any of the variables marking airway inflammation.

P and R values were determined by linear regression multivariate analysis.

NS : No significant association.

TNFα; tumour necrosis factor-alpha, TCC; total cell count.