Table 3.

Cochrane Collaboration tool risk of bias assessment

Study	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Data integrity	Selective reporting	Other sources of bias	Risk of bias
Mall et al. [17]	Low risk	Low risk	High risk	Low risk	High risk	Low risk	Low risk	High
Goel et al. [16]	Unclear risk	Unclear risk	Unclear risk	Unclear risk	Low risk	Low risk	Low risk	Unclear
Qin et al. [13]	Unclear risk	Unclear risk	Unclear risk	Unclear risk	Low risk	Low risk	Low risk	Unclear