Table 2.

Risks of bias for the randomized controlled trials included in this study.

Author	Year	Risk of bias assessment					Overall bias
		Randomization process	Deviations from intended interventions	Measurement of the outcome	Missing outcome data	Selection of the reported result
Li et al [24]	2020	Some concerns	High risk	Low risk	Some concerns	Some concerns	Some concerns
Liang et al [34]	2020	Some concerns	High risk	Low risk	Some concerns	Some concerns	Some concerns
Lin et al [33]	2021	Some concerns	High risk	Low risk	Some concerns	Some concerns	Some concerns
Liu and Wan [32]	2020	Some concerns	High risk	Low risk	Some concerns	Some concerns	Some concerns
Wu et al [25]	2020	Some concerns	High risk	Low risk	Some concerns	Some concerns	Some concerns
Akin et al [23]	2021	Low risk	High risk	Low risk	Some concerns	Low risk	Some concerns
Ebrahimian and Rahmani Bilandi [31]	2021	Some concerns	High risk	Low risk	Some concerns	Low risk	Some concerns
Gür and Apay [29]	2020	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Momenyan et al [28]	2021	Low risk	High risk	Low risk	Some concerns	Low risk	Some concerns
Frey et al [30]	2019	Low risk	High risk	Low risk	Some concerns	Low risk	Some concerns
Noben et al [27]	2019	Low risk	High risk	Low risk	Some concerns	Low risk	Some concerns
Wong et al [26]	2021	Low risk	High risk	Low risk	Some concerns	Low risk	Some concerns