TABLE 3

Relationship between multiple-breath washout (MBW) test outcomes with inflammation and structural lung disease in children with cystic fibrosis when MBW outcomes were calculated from all trials obtained compared with the first two trials obtained in visits with three or more acceptable trials

	Lung clearance index		First moment ratio		Second moment ratio
	All trials	First two trials	All trials	First two trials	All trials	First two trials
MBW outcomes	8.19±1.50	8.19±1.46	1.81±0.31	1.80±0.30	7.11±2.83	7.04±2.84
Pulmonary inflammation
Total cell count	0.35 (−0.04–0.75)	0.40 (−0.01–0.80)	0.06 (−0.02–0.14)	0.08 (−0.01–0.17)	0.50 (−0.21–1.22)	0.65 (−0.11–1.41)
Neutrophil cells	0.38 (0.12–0.63)*	0.40 (0.14–0.66)*	0.07 (0.01–0.12)*	0.07 (0.01–0.13)*	0.55 (0.07–1.03)*	0.58 (0.06–1.10)*
Neutrophil elastase concentration	0.28 (0.04–0.53)*	0.29 (0.04–0.54)*	0.06 (0.01–0.11)*	0.07 (0.01–0.12)*	0.49 (0.05–0.93)*	0.56 (0.08–1.03)*
Interleukin-8 concentration	0.31 (0.08–0.53)*	0.32 (0.09–0.55)*	0.05 (0.01–0.10)*	0.06 (0.01–0.11)*	0.45 (0.04–0.87)*	0.48 (0.04–0.93)*
Structural lung disease
%Dis	0.08 (−0.06–0.23)	0.07 (−0.08–0.22)	0.02 (−0.01–0.05)	0.02 (−0.02–0.05)	0.13 (−0.14–0.39)	0.12 (−0.17–0.41)
%Bx	0.07 (−0.09–0.23)	0.06 (−0.10–0.22)	0.01 (−0.02–0.04)	0.01 (−0.02–0.05)	0.10 (−0.19–0.39)	0.08 (−0.23–0.40)
%TA	0.03 (−0.02–0.08)	0.04 (−0.01–0.09)	0.01 (−0.01–0.01)	0.01 (−0.01–0.02)	0.05 (−0.04–0.14)	0.06 (−0.03–0.16)

The raw MBW outcomes are presented, and the coefficients for the linear mixed effects model (adjusted for test centre) for associations with markers of pulmonary inflammation and structural lung disease are presented with 95% confidence intervals. %Dis: volume proportion of the lung with airway disease; %Bx: volume proportion of the lung with bronchiectasis; %TA: volume proportion of the lung with trapped air. *: p<0.05.