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 |
+positive rating, ? indeterminate rating, −negative rating.