Table 1 Baseline characteristics of patients in the tiotropium and control groups

Male, %

75.4

73.9

Age, years^a

64.5 ± 8.4

64.5 ± 8.5

Body mass index^a

26.0 ± 5.1

25.9 ± 5.1

Smoking status

Current smoker, %

29.3

29.9

Smoking history, pack-years^a

49.0 ± 28.0

48.4 ± 27.9

SGRQ total score, units^a

45.7 ± 17.0

46.0 ± 17.2

Respiratory medications, %

Short-acting inhaled anticholinergics^b

44.9

44.1

Long-acting inhaled anticholinergics

2.0

1.6

Short-acting inhaled β₂-agonists^b

68.5

68.1

Long-acting inhaled β₂-agonists^b

60.1

60.1

Inhaled corticosteroids^b

61.6

61.9

Oral steroids

8.4

8.3

Theophylline compounds

28.4

28.5

Mucolytics

7.4

6.9

Leukotriene receptor antagonists

3.3

3.1

Supplemental oxygen

2.3

1.9