Characteristics of included trials
| Short message and protocol (n=45) | Long message (n=43) | |
| Number of authors randomised | 36 | 40 |
| Trials per author* | ||
| 1 | 30 (83%) | 37 (93%) |
| 2 | 4 (11%) | 3 (8%) |
| 3 | 1 (3%) | 0 (0%) |
| 4 | 1 (3%) | 0 (0%) |
| Year of main trial publication | ||
| 1990–2000 | 5 (11%) | 2 (5%) |
| 2001–2005 | 7 (16%) | 3 (7%) |
| 2006–2010 | 11 (24%) | 11 (26%) |
| 2011–2015 | 19 (42%) | 22 (51%) |
| 2016–2017 | 3 (7%) | 5 (12%) |
| Patients randomised | ||
| Mean [SD] | 3910.8 [5593.4] | 3755.7 [5154.8] |
| Median [25th, 75th centile] | 1224 [439, 5170] | 1809 [500, 4576] |
| Min, max | 74, 20 332 | 48, 21 105 |
| Type of trial | ||
| Primary prevention | 20 (44%) | 16 (37%) |
| Secondary prevention | 19 (42%) | 21 (49%) |
| Acute stroke | 6 (13%) | 6 (14%) |
| Setting | ||
| 1 continent | 30 (67%) | 17 (40%) |
| >1 continent | 14 (31%) | 23 (53%) |
| Not found | 1 (2%) | 3 (7%) |
| Number of centres | ||
| Mean [SD] | 212.8 [286.7] | 165.5 [293.4] |
| Median [25th, 75th centile] | 67 [27, 260] | 85 [32, 141] |
| Min, max | 1, 1034 | 4, 1393 |
| Study design | ||
| Parallel† | 44 (98%) | 41 (95%) |
| Factorial | 1 (2%) | 2 (5%) |
| Intervention | ||
| Drug | 30 (67%) | 31 (72%) |
| Surgery/procedure | 12 (27%) | 11 (26%) |
| Device | 2 (4%) | 1 (2%) |
| Diet | 1 (2%) | 0 (0%) |
| Comparator | ||
| Placebo | 6 (13%) | 10 (23%) |
| Standard care | 28 (62%) | 24 (56%) |
| Active treatment | 8 (18%) | 6 (14%) |
| Surgery/procedure | 3 (7%) | 3 (7%) |
| Number of intervention groups | ||
| 2 | 39 (87%) | 38 (88%) |
| 3 | 4 (9%) | 3 (7%) |
| 4 | 1 (2%) | 1 (2%) |
| >4 | 1 (2%) | 1 (2%) |
| Primary contact | ||
| First author | 32 (71%) | 30 (70%) |
| Second author | 2 (4%) | 3 (7%) |
| Last author | 4 (9%) | 5 (12%) |
| Other | 7 (16%) | 5 (12%) |
| Corresponding author | 32 (71%) | 37 (86%) |
| Secondary contact | ||
| First author | 5 (11%) | 7 (16%) |
| Second author | 8 (18%) | 9 (21%) |
| Last author | 18 (40%) | 17 (40%) |
| Other | 14 (31%) | 10 (23%) |
| Corresponding author | 4 (9%) | 3 (7%) |