3.

COPD合并肺癌组患者与单纯COPD组患者肺功能主要指标的比较（Mean±SD, %）

Comparison of the main indicators of lung function between COPD patients with primary bronchopulmonary carcinoma and simple COPD patients (Mean±SD, %)

Lung function index	COPD with bronchopulmonary carcinoma (n=118)	Simple COPD (n=120)	t	P
FEV1: forced expiratory volume in one second; FVC: forced vital capacity; TLC: total lung capacity; RV: residual volume; DLCO: diffusing capacity of carbon monoxide.
FEV1/FVC	48.76±11.03	50.18±12.42	1.54	0.11
FEV1% pre	45.18±15.44	48.31±17.23	1.18	0.12
TLC	79.36±9.72	82.76±11.75	2.97	0.08
RV/TLC	48.38±9.42	51.36±8.72	3.46	0.07
DLCO	63.38±10.78	70.48±10.57	6.75	< 0.05