Table 2.

Quantitative computed tomographic characteristics by report of exposure to vapors, gas, dust, or fumes in longest job

	Nonsmoking Control Subjects	Current and Former Smokers	Current and Former Smokers without VGDF Exposure in Longest Job	Current and Former Smokers with VGDF Exposure in Longest Job	P Value
	(n = 202)	(n = 2,736)	(n = 1,390)	(n = 1,346)
Emphysema
% emphysema, median (IQR)	1.0 (1.4)	3.2 (9.8)	2.9 (8.7)	3.5 (11.2)	0.002
% emphysema, 95th percentile	4.5
Large airway
Pi10, mean (SD), mm	3.67 (0.08)	3.71 (0.08)	3.71 (0.08)	3.72 (0.08)	<0.001
Pi10, 95th percentile	3.80
Wall area %, mean (SD)
Segmental	57.5 (4.1)	60.6 (4.7)	60.4 (4.8)	60.8 (4.7)	<0.001
Subsegmental	61.4 (3.8)	64.1 (4.6)	64.0 (4.8)	64.1 (4.5)	0.06
Wall area %, 95th percentile
Segmental	65.0
Subsegmental	68.5
Airway lumen area, median (IQR), mm2
Segmental	24.5 (10.8)	20.4 (11.6)	20.0 (11.4)	20.7 (11.6)	<0.001
Subsegmental	14.5 (6.4)	11.1 (7.9)	11.0 (7.8)	11.3 (8.1)	0.002
Airway wall area, mean (SD), mm2
Segmental	37.8 (8.9)	32.8 (9.9)	32.1 (9.6)	33.6 (10.1)	<0.001
Subsegmental	26.1 (8.4)	21.7 (9.1)	21.4 (9.3)	22.0 (8.8)	<0.001
Small airway
% gas trapping, median (IQR)	3.4 (7.1)	18.3 (33.2)	17.9 (31.9)	18.7 (34.8)	0.10
% gas trapping, 95th percentile	21.6
% PRM fSAD, median (IQR)	3.8 (8.0)	18.1 (25.0)	17.6 (24.8)	18.3 (25.1)	0.38
% PRM fSAD, 95th percentile	24.4

Definition of abbreviations: IQR =  interquartile range; Pi10 = estimated square-root wall area of a single hypothetical airway with internal perimeter of 10 mm; PRM fSAD = parametric response mapping of functional small-airway abnormality; SD = standard deviation; VGDF = vapors, gas, dust, or fumes.

Boldface entries indicate a statistically significant association with P < 0.005.