TableĀ 3

Methods for ranking included studies by risk of bias in systematic reviews

Numbers of reviews% of category total
Simple summary score (criteria met added together)414
Cut-off threshold score (summary score dichotomised on the basis of a cut-off)414
Weighted score (criteria added together, with some factors given greater weighting as deemed more important)14
Specific domains prioritised (some risk of bias domains, such as allocation concealment or blinding, deemed more important)518
All criteria required518
Unclear621
Only one criterion difference between included studies14
Combination of score and domain prioritisation27