All journals | IF 0.01–2.0 | IF 2.01–4.0 | IF>4.01 | |
n=55 (100%) | n=30 (100%) | n=18 (100%) | n=7 (100%) | |
Direct reference to trial registration | 20 (36.4) | 8 (26.7) | 7 (38.9) | 5 (71.43) |
Required | 18 (90) | 6 (75) | 7 (100) | 5 (100) |
Recommended | 2 (10) | 2 (25) | – | – |
Indirect reference to trial registration | 6 (10.9) | 3 (10) | 2 (11.1) | 1 (14.29) |
Any advice about trial registration | 26 (47.3) | 11 (36.7) | 9 (50) | 6 (85.72) |
IF, impact factor.