Levels of Evidence JBJS in instruction for Authors | Cochrane Item | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Level | Description | A | B | C | D | E | F | G | H | I | J | K | L |
I | High-quality randomised controlled trial with statistically significant difference or no statistically significant difference but narrow confidence intervals | 2 | X | 2 | x | 2 | 2 | x | x | x | x | x | 2 |
II | Lesser-quality randomised controlled trial (e.g., <80% follow-up, no blinding, or improper randomisation) | 0 | X | 0 | x | 0 | 0 | x | x | x | x | x | 0 |