Overall variability in lung function during the study
| Total population | Individuals with no PEX | Individuals with at least one PEX | |
| Patients | 90 | 67 | 23 |
| LCI meas. (n) | 430 | 265 | 165 |
| LCI; CR | 4.25 units (60.4%) | 3.79 units (53.8%) | 4.83 units (68.6%) |
| LCI; ICC | 0.75 (0.68 to 0.81) | 0.76 (0.67 to 0.83) | 0.77 (0.61 to 0.88) |
| LCI; CV% | 11.6 [6.5–15.6] ‡ | 10.9 [6.3–15.5] | 12.4 [9.8–16.7] |
| FEV1 meas. (n) | 427 | 266 | 161 |
| FEV1; CR | 2.41 z-score (29.2%) | 2.08 z-score (25.1%) | 2.82 z-score (34.3%) |
| FEV1; ICC | 0.68 (0.59 to 0.75) | 0.67 (0.56 to 0.77) | 0.66 (0.50 to 0.79) |
| FEV1; CV% | 8.2 [5.3–14.2] ‡ | 6.7 [4.4–13.4] † | 10.3 [7.6–16.3] † |
CV: intervisit coefficient of variation—within-subject SD×100/within-subject mean displayed as median [IQR]. ICC: intraclass correlation coefficient displayed as mean (95% CI) derived from a random-effects model. CR: coefficient of repeatability—1.96×SD of absolute or relative differences between consecutive measurements.
*p=0.382.
†p=0.029 derived from a Wilcoxon rank-sum test.
‡p=0.043 derived from a Wilcoxon signed-rank test.
FEV1, forced expiratory volume in 1 s; LCI, lung clearance index; Meas. (n), number of measurements; PEX, pulmonary exacerbation.