Table 1 Agreement between LCI, FEV1 and FEF75 and structural lung changes classified as abnormal or normal
BronchiectasisHRCT scoreAir trapping
YesNo>5%⩽5%>30%⩽30%
LCI
    Abnormal2292561516
    Normal49211112
p = 0.033p<0.001p = 0.027
FEV1
    Abnormal527043
    Normal211620171225
p = 0.761p = 0.062p = 0.413
FEF75
    Abnormal163172127
    Normal10151015421
p = 0.008p = 0.003p = 0.004

  • LCI, lung clearance index; FEV1, forced expiratory volume in 1 s; FEF75, maximal expiratory flow when 75% of forced vital capacity was expired; HRCT, high-resolution CT.

  • HRCT score >5% is defined as abnormal and >30% air trapping is defined as abnormal.

  • p Values refer to the Yates corrected χ2 test.