Table 5

Summaries of risk of bias conducted by systematic reviews

Number of reviews% of category total
Was a summary of risk of bias presented at the study level?
 No risk of bias assessment at the study level2645
 Review studying a single outcome which presents risk of bias at the study level712
 Review studying multiple outcomes which summarise the risk of bias at the study level but does not assess the risk of bias separately for each outcome1221
 Review studying multiple outcomes which summarise the risk of bias separately for each outcome1322
Was a summary of the risk of bias presented for each outcome across studies?
 Yes3052
 No2848
Was a review-level summary risk of bias provided?
 Yes1933
 No3967
How was the risk of bias summarised at the review level?*
 GRADE1158
 Cochrane risk of bias table737
 Narrative statement (in text)421
  • *Denominator is the number of reviews providing a review-level summary risk of bias. Note that the total adds up to more than 100% because some reviews used multiple methods for summarising bias at the review level.

  • GRADE, Grading of Recommendations Assessment, Development and Evaluation.