Table 4 Levels of evidence for the overall quality of a measurement property [16]
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 | +/− | Conflicting findings |
Unknown | ? | Only studies of poor methodological quality |