Table 3.

Risk of bias assessment of the studies included in this meta-analysis.

Study (Year)	Random Sequence Generation	Allocation Concealment	Selective Outcome Reporting	Other Sources of Bias	Blinding of Participants Personnel	Blinding of Outcome Assessors	Incomplete Outcome Data
Modaghegh et al., 2008 [37]	L	U	L	H	L	U	L
Fadai et al., 2014 [38]	L	U	H	H	L	L	L
Azimi et al., 2016 [44]	L	U	L	L	H	H	L
Kermani et al., 2017 [39]	L	U	L	H	L	U	L
Kermani et al., 2018 [40]	L	U	L	H	L	U	L
Ebrahimi et al., 2019 [45]	L	U	L	L	L	U	L
Zilaee et al., 2019 [42]	L	U	L	L	L	U	L
Behrouz et al., 2020 [43]	L	U	L	L	L	U	L

Abbreviations: U; unclear risk of bias, L; low risk of bias, H; high risk of bias.