Table 4.

Comparison of pulmonary function in the three groups.

	Patients with COPD and pulmonary infection	Patients with COPD without pulmonary infection	Healthy controls	F	P
FEV1 (L)	1.22 ± 0.41	1.77 ± 0.42	3.04 ± 0.51	338.56	<0.001
FEV%pred (%)	49.98 ± 13.41	57.68 ± 10.27	85.50 ± 10.05	215.59	<0.001
FEV1%FVC (%)	48.54 ± 14.01	57.68 ± 10.27	85.50 ± 10.05	215.19	<0.001

Data are shown as mean  ±  standard deviation.

FEV1, forced expiratory volume in 1 s; FEV1%pred, FEV1 % predicted; FEV1%FVC, FEV1/forced vital capacity.