Table 5

Assessment of risk of bias using the Cochrane Risk of Bias Tool12

Risk of bias domain
Selection biasPerformance biasDetection biasAttrition biasReporting biasOther bias
Richardson59 2007HighHighHighHighLowHigh
Gardner63 2011LowLowHighLowLowLow
Marshall60 2013HighHighHighHighLowLow
Bouchard61 2013HighHighHighLowLowHigh
Rider64 2014HighHighLowLowLowHigh
Mansfield65 2016LowLowLowHighLowLow
Barreira66 2016HighLowLowHighLowHigh
Slaght62 2017HighHighHighLowLowHigh
  • Domains of bias as per Cochrane Risk of Bias tool:

  • Selection bias—random sequence generation, allocation concealment.

  • Performance bias—blinding of participants and personnel to intervention group allocation.

  • Detection bias—blinding of outcome assessors from knowledge of which intervention a participant received.

  • Attrition bias—incomplete outcome data, including information regarding attrition and exclusions from analyses.

  • Reporting bias—selective outcome reporting.

  • Other bias—other sources of bias.