Multivariate models testing the association between the quantitative CT measurements and annual change in FEV1%predicted
| Estimate (95% CI) | p Value | |
| Model 1*: Lung overinflation | ||
| %overinflation | −0.04 (−0.08 to −0.02) | 0.04 |
| Cluster analysis | −0.49 (−11.34 to 10.35) | 0.93 |
| Upper zone predominant | 0.02 (−0.10 to 0.14) | 0.74 |
| Model 2*: Emphysema | ||
| %LAA (−950 HU) | −0.13 (−0.47 to 0.21) | 0.46 |
| Cluster analysis | −0.61 (−2.68 to 1.45) | 0.56 |
| Upper zone predominant | 0.11 (−1.38 to 1.59) | 0.89 |
| Model 3*: Airway dimensions | ||
| Ai (mm2) | 0.17 (−0.40 to 0.73) | 0.56 |
| WA % | 0.00 (−0.53 to 0.53) | 0.99 |
| √Aaw at Pi10 (mm) | 1.4 (−4.45 to 7.25) | 0.64 |
*Models were adjusted for sex, age, body mass index, smoking status, pack years, FEV1%predicted and FEV1/FVC at baseline.
Aaw, airway wall area; Ai, lumen area; LAA, low attenuation lung area; Pi, lumen perimeter; WA %, wall area expressed as the percentage of the total airway area.
%overinflation, (volume of overinflated lung/volume of total lung) × 100%; %LAA (−950 HU), (volume of lung areas with x ray attenuation lower than −950 HU/volume of total lung) × 100%; WA %, (airway wall area/(airway wall area + lumen area)) × 100%; √Aaw at Pi10 (mm), √Aaw for a standardised airway with an internal perimeter (Pi) of 10 mm.