Table 1.
Characteristics of approved clinical trials with drugs
| Commercial sponsored clinical trials (n = 651) | Noncommercial sponsored clinical trials (n = 127) | P | Total (n = 778) | ||
|---|---|---|---|---|---|
| Participating sites | Multicentre international | 599 (92.0%) | 33 (26.0%) | 632 (81.2%) | |
| Multicentre national | 37 (5.7%) | 76 (59.8%) | P < 0.001 | 113 (14.5%) | |
| Single‐centre study | 15 (2.3%) | 18 (14.2%) | 33 (4.3%) | ||
| Design | Controlled | 493 (75.7%) | 92 (72.4%) | P = 0.501 | 585 (75.2%) |
| Uncontrolled | 158 (24.3%) | 35 (27.6%) | 193 (24.8%) | ||
| Masking of controlled clinical trials | Unmasked | 122 (24.7%) | 51 (55.4%) | 173 (29.6%) | |
| Double blind | 359 (72.8%) | 35 (38.0%) | P < 0.001 | 394 (67.4%) | |
| Simple blind | 5 (1.0%) | 1 (1.1%) | 6 (1.0%) | ||
| Observer blind | 7 (1.4%) | 5 (5.4%) | 12 (2.1%) | ||
| Phase of clinical trials | Phase I | 56 (8.6%) | 6 (4.7%) | 62 (8.0%) | |
| Phase II | 196 (30.1%) | 24 (18.9%) | P < 0.001 | 220 (28.3%) | |
| Phase III | 307 (47.2%) | 17 (13.4%) | 324 (41.6%) | ||
| Phase IV | 92 (14.1%) | 80 (63.0%) | 172 (22.1%) |