TABLE 3

Annual decline in forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) before and after bronchodilator use after withdrawing tiotropium in early chronic obstructive pulmonary disease (COPD)^#

	Decline per year			p-value
	Placebo	Tiotropium	Difference (95% CI)^¶	p-value
Subjects n	126	136
FEV₁ mL
Before bronchodilator use	31±21	21±20	10 (−47–67)	0.73
After bronchodilator use	68±16	48±16	20 (−24–64)	0.37
FVC mL
Before bronchodilator use	40±35	26±33	14 (−80–107)	0.77
After bronchodilator use	59±31	23±29	36 (−46–118)	0.39

Data are presented as mean±se, unless otherwise stated. ^#: values were measured from month 36 until the end of the study (follow-up from 36 to 60 months after withdrawing tiotropium in early COPD). Multiple linear regression was adopted for each follow-up. For each follow-up visit, the measured value was the dependent variable, and covariates included the individual baseline value, baseline smoking status, treatment allocation and participating centre. Additionally, for 36–60 months, the p-value was computed by using the individual baseline value, smoking status across the whole follow-up, bronchiectasis status, treatment allocation and participating centre as covariates; ^¶: the difference was calculated as the value in the placebo group minus the value in the tiotropium group.