Table 1B

Risk of bias assessment: non-randomised observational studies (Risk of Bias Assessment tool for Non-randomized Studies)

StudyConfoundingParticipant selectionBlinding of outcome assessorsMissing dataExposure measurementSelective outcome reportingOverall
Bak et al 60 LowLowLowLowLowLowLow
Beischer et al 61 LowLowLowHighLowLowLow
Bourke et al 62 LowLowLowLowLowLowLow
Cordasco et al 53 LowHighUnclearLowLowLowHigh
Dekker et al 63 LowLowLowHighLowLowLow
Demange et al 54 LowHighUnclearLowHighLowHigh
Geffroy et al 56 LowLowUnclearLowHighLowHigh
Graziano et al 57 LowHighLowLowUnclearLowHigh
Gupta et al 58 LowLowUnclearLowLowHighHigh
Heath et al 65 LowLowLowLowLowLowLow
Kamath et al 67 LowLowLowLowLowLowLow
Laboute et al 59 HighLowUnclearHighHighHighHigh
Paterno et al 30 LowLowLowLowHighLowLow
Shelbourne et al 38 LowLowLowLowLowLowLow
Webster et al 69 LowLowLowLowLowLowLow