TableĀ 2

Risk of bias (summary) of the included studies assessed by Cochrane's risk of bias tool

AuthorSequence generationAllocation concealmentBlinding participants and personnelBlinding of outcome assessorsIncomplete outcome dataSelective outcome reporting
Agnew et al18High riskLow riskHigh riskUnclear riskUnclear riskLow risk
Everitt et al22Low riskLow riskHigh riskHigh riskLow riskLow risk
Francis et al17Low riskLow riskHigh riskLow riskLow riskLow risk
Gauld et al23Unclear riskUnclear riskHigh riskLow riskLow riskLow risk
Little et al19Low riskLow riskHigh riskHigh riskLow riskLow risk
Macfarlane et al20Unclear riskLow riskHigh riskUnclear riskLow riskLow risk
Macfarlane et al21Unclear riskLow riskHigh riskHigh riskLow riskLow risk
Sustersic et al24Low riskLow riskHigh riskUnclear riskLow riskLow risk