. Author manuscript; available in PMC: 2015 Aug 1.

Published in final edited form as: Eur Respir J. 2014 May 29;44(2):341–350. doi: 10.1183/09031936.00216013

Table 3.

Chest CT scan features of the COPD-asthma population compared to COPD alone.

	COPD	COPD & Asthma	Beta (se)*	P Value
Log Emphysema (%)	1.91 (1.4)	1.44 (1.6)	−0.23 (0.07)	<0.001
Pi10 (mm)	3.71 (0.14)	3.78 (0.16)	0.06 (0.01)	<0.001
Segmental airway wall area percent	62.8 (3.0)	63.6 (3.3)	0.61 (0.16)	<0.001
Subsegmental airway wall area percent	65.6 (2.3)	66.4 (2.7)	0.66 (0.20)	0.001
Gas trapping (%)	39.7 (20.7)	35.6 (21.5)	0.88 (1.5)	0.55

Regression models are adjusted for age, gender, pack-years, BMI, and CT scanner type. Emphysema analysis additionally adjusted for current smoking status. Gas trapping additionally adjusted for clinical center. Beta refers to effect size for COPD and asthma group.