Table 2.

Correlations of clinical outcomes with NE levels in sputum

	R value	P value
Post-bronchodilator FEV1 (L)	0.04	0.81
FEV/FVC ratio, %	−0.02	0.94
Chronic respiratory disease questionnaire, units	0.09	0.63
Total visual analogue scale, mm	0.11	0.58

FEV₁ – Forced expiratory volume in 1 s; FVC - Forced vital capacity; Chronic Respiratory Disease Questionnaire, scores range between 1 to 7 with higher score representing better health quality; Visual Analogue Scale, performed on 100 mm line from ‘no symptoms’ to ‘worst symptoms’, higher scores represent worse symptoms (total score addition of measured domains: cough, dyspnoea, sputum production and sputum purulence)