Table 2 Level of evidence rating criteria
Level | Rating | Criteria |
|---|---|---|
Strong | + or − | Consistent findings in multiple studies of good methodological quality OR in one study of excellent methodological quality |
Moderate | + or − | Consistent findings in multiple studies of fair methodological quality OR in one study of good methodological quality |
Limited | + or − | One study of fair methodological quality |
Conflicting | + or − | Conflicting findings |
Unknown | ? | Only studies of poor methodological quality or no studies |