Table 2 Levels of evidence approach [22]

Strong

Consistent^a findings from 3 or more high-quality studies

Moderate

Consistent^a findings from at least 1 high-quality and 1 low-quality study

Limited

Consistent^a findings in > 1 low-quality study or only one study available

Conflicting

Inconsistent evidence in multiple studies irrespective of study quality

No evidence

No studies found