Table 4.

Risk of bias in included studies

Bias	Baskurt et al. (2011)	Bernardsson et al. (2011)	Sturyf et al. (2013)	Moezy et al. (2014)	Shankar et al. (2016)	Turgut et al. (2017)	Hotta et al. (2017)
Selection of participants	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	High risk
Allocation concealment	Low risk	High risk	Low risk	Low risk	High risk	Low risk	High risk
Blinding of participants	Unclear	Unclear	Unclear	Low risk	High risk	Unclear	Unclear
Assessor blinding	Unclear	Low risk	Low risk	Low risk	High risk	Unclear	Unclear
Incomplete data	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Selective reporting	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Other Bias	Unclear	Unclear	Unclear	Unclear	Unclear	Unclear	Low risk