Table 4.

Factors Associated with LCI Values in Patients with CF

	CF [LCI units/year (95% Confidence Interval)]
Time-independent factors
Baseline LCI	0.71 (0.62 to 0.80)
Hypertonic saline at enrollment
No	Reference
Yes	0.18 (−0.53 to 0.89)
Dornase alfa at enrollment
No	Reference
Yes	−0.09 (−0.81 to 0.63)
Chronic inhaled antibiotics at enrollment
No	Reference
Yes	0.99 (0.17 to 1.81)
Positive microbiology culture during the study compared with reference group (negative culture)
Pseudomonas aeruginosa	0.5 (−0.7 to 1.7)
Staphylococcus aureus	0.8 (0.04 to 1.6)
Methicillin-resistant S. aureus	−0.6 (−1.2 to 0.9)
Stenotrophomonas maltophilia	−0.4 (−1.3 to 5.2)
Stenotrophomonas influenza	2.0 (−1.1 to 5.2)
Burkholderia cepacia complex*	3.1 (0.002 to 6.2)
Aspergillus fumigatus	2.2 (−0.8 to 5.2)
Time-dependent factors
Increasing height-for-age z score	−0.23 (−0.58 to 0.12)
Increasing weight-for-age z score	-0.41 (−0.77 to −0.05)
Increasing BMI-for-age z score	−0.27 (−0.59 to 0.06)
Symptoms
Pulmonary exacerbations
No	Reference
Yes	1.05 (0.62 to 1.48)
Cough
No	Reference
Yes	0.51 (0.13 to 0.89)
Nasal congestion
No	Reference
Yes	0.12 (−0.27 to 0.51)

Definition of abbreviations: BMI = body mass index; CF = cystic fibrosis; LCI = Lung Clearance Index.

Coefficients are derived from a univariable generalized mixed effects regression analysis and represent the difference in LCI values (95% confidence interval) relative to the reference group. A positive coefficient indicates higher (worse) LCI, whereas a negative coefficient represents lower (better) LCI relative to the reference. Bold represents values that are significantly different from 0 at a significance level of P < 0.05.

^*Based on two observations in this category.