Baseline characteristics of included trials
| Trial characteristic | N (%) | ||
| All trials n=192 | Financial ties present* n=130 | Financial ties absent n=62 | |
| Study phase | |||
| Phase II | 50 (26) | 38 (29) | 12 (19) |
| Phase III | 102 (53) | 81 (62) | 21 (34) |
| Phase IV | 16 (8) | 7 (5) | 9 (15) |
| Other | 24 (13) | 4 (3) | 20 (32) |
| Blinding | |||
| Double blind | 146 (76) | 101 (78) | 45 (73) |
| Single blind | 7 (4) | 5 (4) | 2 (3) |
| Open label | 37 (19) | 22 (17) | 15 (24) |
| Unknown | 2 (1) | 2 (2) | 0 (0) |
| Sample size | |||
| <100 participants | 40 (21) | 17 (13) | 23 (37) |
| 100–299 participants | 55 (29) | 36 (28) | 19 (31) |
| 300–499 participants | 45 (23) | 31 (24) | 14 (23) |
| ≥500 participants | 52 (27) | 46 (35) | 6 (10) |
| Funding source | |||
| Any industry funding | 134 (70) | 113 (87) | 21 (34) |
| Any government funding | 56 (29) | 23 (18) | 33 (53) |
| Non-profit | 32 (17) | 14 (11) | 18 (29) |
| No funding reported | 6 (3) | 1 (1) | 5 (8) |
| First author continent | |||
| North America | 87 (45) | 69 (53) | 18 (29) |
| Europe | 68 (35) | 46 (35) | 22 (35) |
| Asia | 28 (15) | 8 (6) | 20 (32) |
| Beginning of enrolment† | |||
| Prior to 2006 | 37 (19) | 17 (13) | 20 (32) |
| 2006–2007 | 45 (23) | 31 (24) | 14 (23) |
| 2008–2009 | 63 (33) | 49 (38) | 14 (23) |
| 2010 or later | 46 (24) | 33 (25) | 13 (21) |
*Direct financial relationship present between first or last study author and drug manufacturer.
†Start date not reported for one trial.