Respiratory effects of particulate air pollution episodes in former smokers with and without chronic obstructive pulmonary disease: a panel study

Table 3 Comparison of variables on pollution vs. clean air quality days

Variable	Group	Estimate^a	95 % CI	P value
Nitrite + nitrate (NOx)	COPD	3.15	(1.41, 7.04)	0.007
Nitrite + nitrate (NOx)	Control	0.49	(0.14, 1.65)	0.23
8-Isoprostane	COPD	0.44	(0.05, 3.61)	0.43
8-Isoprostane	Control	2.34	(0.18, 29.73)	0.49
FEV1 (L)	COPD	0.01	(-0.10, 0.12)	0.85
FEV1 (L)	Control	0.01	(-0.10, 0.11)	0.90
FVC (L)	COPD	−0.17	(-0.37, 0.03)	0.09
FVC (L)	Control	−0.01	(-0.12, 0.09)	0.80
Aggregate symptom score	COPD	3.47	(1.01, 5.93)	0.008
Aggregate symptom score	Control	2.02	(-0.92, 4.95)	0.16

^a Displayed are estimated ratios of geometric mean levels (with 95 % CIs and p-values) of 8-isoprostane and NOx between pollution and clean air days, as well as estimated mean differences (with 95 % CIs and p-values) in FEV1, FVC, and aggregate symptom score between pollution and clean air days in a) COPD patients and b) Control group participants

ISSN: 2054-9040