Table 1.

Risk of bias assessment. *①Random sequence generation (selection bias); ②Allocation concealment (selection bias); ③Blinding of participants and personal (performance bias); ④Blinding of outcome assessment (detection bias); ⑤Incomplete outcome data (attrition bias);⑥Selection reporting (reporting bias); ⑦Other bias

Study	①*	②*	③*	④*	⑤*	⑥*	⑦*
Kalem (2020)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Huang (2020)	Low risk	Low risk	Unclear risk	Low risk	Unclear risk	Low risk	Unclear risk
Scarpellini (2019)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Arefi (2018)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Tanha (2016)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Aleyasin (2016)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Obidniak (2016)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Maryam (2016)	Low risk	Low risk	Unclear risk	Low risk	Unclear risk	Low risk	Unclear risk
Abedi (2015)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk