Imaging-based measurements across the groups

CF IS (n=26)CR (n=16)HC (n=12)CF HS (n=26)p-valuep-value
(CF vs HC)
(CF vs CR)
(CR vs HC)
(CF HS vs CF IS)
 Whole lung38 (26–49)36 (30–43)36 (26–47)55 (35–70)0.970.491.000.830.0001
 Peripheral lung36 (16–43)35 (31–39)35 (28–43)54 (35–62)0.810.840.630.44<0.0001
 Whole lung21 (8–26)13 (7–24)6 (0–13)18 (6–25)
 Peripheral lung20 (11–32)17 (5–22)7 (0–18)14 (8–25)
Cen%51 (47–57)52 (48–57)49 (46–51)52 (48–56)

Data are presented as median (interquartile range), unless otherwise stated. CF: cystic fibrosis; IS: isotonic saline; CR: single CF transmembrane conductance regulator mutation carrier; HC: healthy control; HS: hypertonic saline; MCC: mucociliary clearance rate; ABS: technetium-99m-DTPA absorption rate; Cen%: percentage of radioactive counts deposited in the central lung zone (see supplementary material). All groups inhaled IS during the MCC/ABS scan. CF subjects performed an additional study day where they inhaled 7% HS during the scan. Data are presented graphically in supplementary figures S4 and S5 (CF HS versus CF IS). p-values comparing all groups by Kruskal–Wallis (nonparametric). Group comparisons by Dunn's test with Holm adjustment (nonparametric, multiple comparisons). HS versus IS comparison for CF group by Wilcoxon matched-pairs signed-ranks test (nonparametric, paired).