Table 4 Study design of the pivotal studies (n = 108)
From: Clinical evidence for orphan medicinal products-a cause for concern?
| Â | Number of pivotal studies (%) |
|---|---|
Control arm | |
No control | 34 (31.5%) |
Controlled | 74 (68.5%) |
  Historical control | 2 (1.9%) |
  Different dosages of the OMP | 11 (10.2%) |
  Placebo | 49 (45.4%) |
  Active comparator (or standard of care) | 17 (15.7%) |
Similarity at baseline | |
  Yes, statistically verified | 13 (12.0%) |
  Likely, but not statistically verifiable | 41 (38.0%) |
  Not likely, but not statistically verifiable | 4 (3.7%) |
  No, statistically verified | 1 (0.9%) |
  Not reported | 15 (13.9%) |
Randomized allocation | |
No | 38 (35.2%) |
Yes | 70 (64.8%) |
  Valid method of randomization | 25 (23.1%) |
  Invalid method of randomization | 2 (1.9%) |
  Not reported | 43 (39.8%) |
Blinding | |
No (open-label) | 44 (40.7%) |
No, but justified | 10 (9.3%) |
Yes | 54 (50.0%) |
  Blinding of the care provider | 53 (49.1%) |
  Blinding of the outcomes assessor | 12 (11.1%) |
  Blinding of the patient | 54 (50.0%) |