Table 5

Incorporating risk of bias assessment findings into review findings

Quantitatively incorporating risk of bias assessment findings when undertaking a meta-analysisSensitivity analyses can evaluate whether effect estimates change if only studies at ‘low’ risk of bias are included in meta-analysis compared with all included studies.34
Meta-regression is a secondary analysis that assesses the quantitative influence of overall risk of bias judgements (eg, ‘low’, ‘some concerns’ or ‘high’) of studies on the meta-analytic effect estimates.43
Qualitative description (descriptive information when there is no meta-analysis)A detailed discussion can speculate about the extent to which included studies, at ‘some concerns’ or at ‘high’ risk of bias, may underestimate or overestimate review findings compared with studies at ‘low’ risk of bias.19
Excluding studies at a prespecified risk of bias judgement from the evidence synthesis offers an addition to a simple descriptive synthesis. For example, systematic review authors might decide to include only studies at ‘low’ risk in specific bias domains. By excluding studies at ‘some concerns’ and ‘high’ risk of bias from the synthesis, review authors may plausibly reduce the extent to which review findings are exposed to biased study-level data. Another approach to account for risk of bias is to visually present study findings according to risk of bias assessment findings.