Table 2.

Risk of bias assessment of randomized controlled trials

Risk of bias assessment	Lian 2013 [19]	Benegas 2014 [20]	Kim 2015 [21]	Esmailiejah 2015 [22]
Random sequence generation	Low	Low	Low	Low
Allocation concealment	Unclear	Low	Unclear	Unclear
Blinding of participants and personnel	High	High	High	High
Blinding of outcome assessment	Unclear	Low	Low	Unclear
Incomplete outcome data addressed	Low	Low	Low	Low
Selective reporting	Low	Low	Low	Low
Other bias	Unclear	Unclear	Unclear	Unclear