Table 3. Multivariate analysis of mean (95% confidence interval) differences in structural CT changes (emphysema. airway wall thickening and gas trapping) according to classification of airflow limitation correcting for age, height, BMI, packyears and respiratory symptoms.
FEV1/FVC <70%, but>LLN | FEV1/FVC <70%, and <LLN | ||
15th percentile | −8.1 (−10.9–−5.3)# | 15th percentile | −16.45 (−19.36–−13.5) # |
log950% | 0.58 (0.43–0.73)# | log950% | 1.37 (1.25–1.56)# |
E/I-ratio% | 3.25 (2.32–4.27)# | E/I-ratio% | 6.27 (5.32–7.22)# |
Pi10 [millimeters] | 0.22 (0.14–0.29)# | Pi10 [millimeters] | 0.51 (0.43–0.59)# |
The group FEV1/FVC >70% was used as reference. # p<0.001 Log950% = log-transformed percentage of voxels below HU -950. E/I-ratio% = expiratory mean lung density in HU divided by the inspiratory mean lung density in HU expressed as a percentage. Pi10 = the square root of wall area for a theoretical airway with 10 mm lumen perimeter.