Table 2:

Risk-of-bias review of included studies

StudyRandom sequence generation (selection bias)Allocation concealment (selection bias)Blinding (performance bias and detection bias)Incomplete outcome data (attrition bias)Selective reporting (reporting bias)Other bias
Al-Nakib et al.26UnclearUnclearLowLowHighHigh
Douglas et al.27UnclearUnclearLowHighUnclearHigh
Eby et al.28UnclearUnclearLowHighLowHigh
Farr et al. (A)29LowUnclearLowUnclearHighUnclear
Farr et al. (B)29LowUnclearLowUnclearUnclearUnclear
Godfrey et al.30LowLowLowHighUnclearUnclear
Kurugöl et al.31LowUnclearLowLowLowLow
Kurugöl et al.32LowLowLowLowLowLow
Macknin et al.33LowLowLowLowLowLow
Mossad et al.34LowLowLowLowLowUnclear
Petrus et al.34UnclearUnclearLowLowUnclearUnclear
Prasad et al.36LowLowLowLowLowLow
Prasad et al.37LowLowLowLowLowLow
Smith et al.38UnclearUnclearLowHighHighUnclear
Turner et al. (A)24UnclearUnclearLowHighLowUnclear
Turner et al. (B)24UnclearUnclearLowHighLowUnclear
Weismann et al.39UnclearUnclearLowHighHighUnclear