Table 2 Levels of evidence for the overall quality of a measurement property
From: Measurement properties of asthma-specific quality-of-life measures: protocol for a systematic review
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 methological quality |