Table 1 Characteristics of preprint–article RCTs
Characteristics | Preprint–Article RCTs n = 109 (%) | RCTs with consistent data n = 81 (%) | RCTs with added/ deleted outcomes n = 20* (%) | RCTs with change in effect estimate n = 9* (%) | |
|---|---|---|---|---|---|
Sample size, median (IQR) | 150 (71–464) | 149 (66–420) | 129 (85–663) | 606 (240–1225) | |
Delay†, median (IQR) | 121 (73–187) | 128 (79–187) | 91 (27–153) | 127 (99–210) | |
Registration timing, n (%) | Prospective | 83 (76) | 62 (77) | 14 (70) | 8 (89) |
Retrospective | 25 (23) | 18 (22) | 6 (30) | 1 (11) | |
Not reported/unclear | 1 (1) | 1 (1) | 0 | 0 | |
Funding type, n (%) | Industry/mixed | 65 (60) | 45 (56) | 16 (80) | 5 (56) |
Public | 34 (31) | 28 (35) | 1 (5) | 4 (44) | |
Others | 10 (9) | 8 (10) | 3 (15) | 0 | |
Study centers, n (%) | Single | 30 (28) | 28 (35) | 2 (10) | 0 |
Multicenter | 79 (72) | 53 (65) | 18 (90) | 9 (100) | |
Overall risk of bias⁑, n (%) | Low | 13 (12) | 7 (9) | 6 (30) | 1 (11) |
Some concerns | 87 (80) | 66 (81) | 13 (65) | 8 (89) | |
High | 9 (8) | 8 (10) | 1 (5) | 0 | |
Setting, n (%) | Hospital | 93 (85) | 67 (83) | 18 (90) | 8 (89) |
Outpatient clinic | 16 (15) | 14 (17) | 2 (10) | 1 (11) | |
Geographical location‡, n (%) | High-income countries | 42 (39) | 30 (37) | 8 (40) | 5 (56) |
Low-/middle-income countries | 49 (45) | 39 (48) | 7 (35) | 3 (33) | |
Countries of different income levels | 18 (17) | 12 (15) | 5 (25) | 1 (11) | |
Preprint post§, n (%) | < 6 months | 21 (19) | 14 (17) | 6 (30) | 1 (11) |
6–12 months | 45 (41) | 32 (40) | 10 (50) | 3 (33) | |
> 12 months | 43 (39) | 35 (43) | 4 (20) | 5 (56) | |