Drop out rate (%) in the active and placebo groups in major COPD studies
| Study | Duration (years) | Reference | Active | Placebo | No randomised |
|---|---|---|---|---|---|
| EUROSCOP | 3 | Pauwels et al1 | 27% | 30% | 1277 |
| ISOLDE | 3 | Burge et al3 | 43% | 53% | 751 |
| Copenhagen | 3 | Vestbo et al2 | 25% | 35% | 290 |
| City Lung Study | |||||
| LHS II | 3 | LHS Group4 | Not reported | Not reported | 1116 |
| TRISTAN | 1 | Calverley et al8 | 29% | 38% | 1465 |
| Symbicort | 1 | Szafranski et al7 | 30% | 44% | 812 |
| 1 | Calverley et al8 | 37% | 41% | 1022 | |
| Tiotropium | 1 | Vincken et al5 | 15% | 21% | 535 |
| 1 | Casaburi et al6 | 19% | 28% | 921 | |
| BRONCUS | 3 | Decramer et al33 | 27% | 37% | 573 |
| Average | 27% | 37% |