Table 1.
Characteristics of cohort of studies with no results posted at ClinicalTrials.gov and randomly selected trials. Values are numbers (percentages) unless stated otherwise
| Characteristics | Whole cohort (n=379) | Random selection of trials receiving intervention (n=190) | Control group (no intervention) (n=189) |
|---|---|---|---|
| No (interquartile range) of patients | 42 (20-100) | 40 (20-90) | 48 (22-100) |
| Randomized controlled trial | 256 (68) | 122 (64) | 134 (71) |
| Study objectives* | |||
| Efficacy | 137/313 (44) | 69/158 (44) | 68/155 (44) |
| Safety | 24/313 (8) | 12/158 (8) | 12/155 (8) |
| Efficacy or safety | 119/313 (38) | 60/158 (38) | 59/155 (38) |
| Other | 33/313 (10) | 17/158 (11) | 16/155 (10) |
| Trial intervention: | |||
| Drugs | 305 (80) | 157 (83) | 148 (78) |
| Devices | 67 (18) | 30 (16) | 37 (20) |
| Biologics | 7 (2) | 3 (2) | 4 (2) |
| Funding source: | |||
| Industry | 91 (24) | 43 (23) | 48 (25) |
| Not industry | 159 (42) | 89 (47) | 70 (37) |
| Mixed | 129 (34) | 58 (31) | 71 (38) |
| Masking: | |||
| Double blind | 145 (38) | 67 (35) | 78 (41) |
| Single blind | 50 (13) | 26 (14) | 24 (13) |
| Open label | 184 (48) | 97 (51) | 87 (46) |
| Publication in peer reviewed journal | 32 (8) | 23 (12) | 9 (5) |
*66 had missing data.