Table 4. Subjects by COPD classification, ^a Week 0.

	Smokers	Never smokers	All
Intent-to-treat sample
No COPD b	117	30	147
COPD c	13	2	15
COPD classification
Mild	10	1	11
Moderate	3	1	4
Severe	0	0	0
Per-protocol sample
No COPD b	79	30	109
COPD c	9	2	11
COPD classification
Mild d	6	1	7
Moderate e	3	1	4
Severe f	0	0	0

COPD, chronic obstructive pulmonary disease; FEV1_post, forced expiratory volume, post-bronchodilator; FVC_post, forced vital capacity, post-bronchodilator. FER_post=100 × FEV1_post/FVC_post.

^aAmerican Thoracic Society (Ferris, 1978); data for one subject was unknown.

^bForced expiratory ratio, post-bronchodilator (FER_post) ≥ 70%.

^cFER_post <70%.

^dFER_post <70% and FEV1_post ratio ≥80%.

^eFER_post <70% and 50%≤FEV1_post ratio <80%.

^fFER_post <70% and 30%≤FEV1_post ratio <50%.