Table 2.

Mean change from baseline in SGRQ total score at study end according to COPD severity, reversibility at baseline, and ICS use during the trial

	Tiotropium		Placebo
	Number of patients	Mean (SE) Δ from baseline	Number of patients	Mean (SE) Δ from baseline	Difference (SE)	95% CI	p value
COPD severity
FEV1 > 50% predicted	105	−8.85 ± 1.37	93	−7.38 ± 1.44	−1.47 (1.99)	−5.37, 2.44	0.4604
FEV1 ≤ 50% predicted	140	−8.18 ± 1.18	150	−2.18 ± 1.14	−6.00 (1.64)	−9.21, −2.78	0.0003
ICS use
Not receiving ICS	154	−9.22 ± 1.13	156	−4.81 ± 1.13	−4.41 (1.60)	−7.55, −1.27	0.0061
Receiving ICS	93	−7.32 ± 1.46	89	−3.45 ± 1.49	−3.87 (2.09)	−7.97, 0.24	0.0648
Reversibilitya
Yes	101	−8.78 ± 1.40	100	−4.20 ± 1.41	−4.58 (1.99)	−8.49, −0.68	0.0215
No	143	−8.25 ± 1.18	144	−4.48 ± 1.17	−3.76 (1.66)	−7.02, −0.50	0.0239
Exacerbation
Yes	95	−7.21 ± 1.44	119	−2.15 ± 1.28	−5.06 ± 1.92	−8.84, −1.28	0.0089
No	152	−9.33 ± 1.14	126	−6.35 ± 1.25	−2.98 ± 1.69	−6.30, 0.35	0.0791

Lower SGRQ total scores indicate an improvement.

Means are adjusted for baseline SGRQ total scores using the following analysis of covariance model: Change from baseline of SGRQ total score = treatment + subgroup + subgroup-by-treatment interaction + baseline.

^aReversibility to a short-acting β₂-agonist.

Full analysis set was analyzed. Number of patients with available data may differ in each subgroup.

The interaction of treatment and subgroup was not significant with p values of 0.0787, 0.8364, 0.7510, and 0.4177, respectively for severity of the illness, ICS use, reversibility, and exacerbation on treatment.