Table 2

Change in lung function, as measured every 3 months, patients with COPD and the comparator groups

Spirometric variable	Visit (months)	NSC	SC	Patients with COPD	p Values
Spirometric variable	Visit (months)	NSC	SC	Patients with COPD	NSC vs SC	NCS vs patients with COPD	SC vs patients with COPD
Post-bronchodilator FEV₁ change (litres)	0	0.08 (0.14)	0.14 (0.15)	0.12 (0.15)	<0.001	<0.001	0.110
	3	0.09 (0.16)	0.11 (0.22)	0.12 (0.14)	0.059	<0.001	0.308
	6	0.08 (0.14)	0.12 (0.13)	0.13 (0.15)	0.002	<0.001	0.893
	12	0.07 (0.17)	0.11 (0.14)	0.12 (0.14)	0.002	<0.001	0.201
Post-bronchodilator FVC change (litres)	0	–0.00 (0.20)	0.01 (0.22)	0.25 (0.34)	0.656	<0.001	<0.001
	3	–0.01 (0.22)	0.01 (0.31)	0.25 (0.32)	0.464	<0.001	<0.001
	6	–0.01 (0.20)	0.03 (0.19)	0.24 (0.32)	0.111	<0.001	<0.001
	12	–0.02 (0.19)	0.02 (0.17)	0.23 (0.31)	0.197	<0.001	<0.001
Post-bronchodilator FEV₁/FVC change (%)	0	2.13 (3.46)	2.98 (4.25)	0.29 (4.35)	0.025	<0.001	<0.001
	3	2.29 (3.93)	2.51 (3.41)	0.35 (4.15)	0.542	<0.001	<0.001
	6	2.42 (3.20)	2.45 (3.29)	0.61 (4.43)	0.923	<0.001	<0.001
	12	1.93 (4.20)	2.31 (3.59)	0.71 (4.13)	0.291	<0.001	<0.001

Data are given as mean (SD).
COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; NCS, non-smoker control; SC, smoker control.