Demographics and baseline characteristics of the randomized patients
| Tiotropium | Placebo | |
| Patients n | 550 | 371 |
| Sex male/female | 366/184 | 233/138 |
| Age yrs | 65±9 | 65±9 |
| Height cm | 171.1±9.6 | 170.5±9.5 |
| Weight kg | 76.9±17.7 | 75.5±17.5 |
| Smoking history pack-yrs | 63±31 | 59±30 |
| Duration of disease yrs | 8.6±7.4 | 8.1±6.8 |
| FEV1 L | 1.04±0.41 | 1.00±0.44 |
| FEV1 % pred | 39.1±13.7 | 38.1±14.1 |
| FVC L | 2.31±0.79 | 2.23±0.78 |
| FEV1/FVC % | 45.8±11.6 | 45.5±11.6 |
| Prestudy medication for COPD | ||
| Anticholinergics | 302 (55) | 217 (59) |
| β2-agonist, inhaled | 546 (99) | 368 (99) |
| Inhaled steroids | 239 (44) | 149 (40) |
| Oral steroids | 31 (6) | 33 (9) |
| Theophylline | 123 (22) | 94 (25) |
Data are presented as mean±sd unless otherwise indicated
No significant differences were seen between the two groups
FEV1: forced expiratory volume in one second
FVC: forced vital capacity
COPD: chronic obstructive pulmonary disease
% pred: percentage of the predicted value