Table 1: Methodological quality of all included studies.

StudiesRandom allocationAllocation concealmentBlindingIncomplete outcomeSelective reportingOther biasQuality level

Lu et al. 2015+?+B
Suen et al. 2007??++++A
Wang 2015+++B
Xia et al. 2011?++B
Yeh et al. 2013+++++A
Yeh et al. 2014++++++A
Yeh et al. 2015++++++A

“+” = criteria “met”; “−” = criteria “unmet”; “?” = criteria “unclear.”