Table 2. Quality assessment of RCT using the Cochrane risk-of-bias tool.

RCT	Selection bias	Reporting bias	Performance bias	Detection bias	Attrition bias
1- Khedr et al. [16]	Low risk	Low risk	High risk	Low risk	Unclear
2- Passard et al. [9]	Low risk	Low risk	low risk	Unclear	Low
3- Carretero et al. [17]	Unclear	Low	High	Low	Low
4- Borckardt et al. [11]	Low	Low	Low	Low	Low
5- Fregni et al. [18]	Low risk	High	Low	Unclear	Unclear
6- Ahmed et al. [19]	High	Low	Low	High	Low
7- Andre-Obadia et al. [20]	Low	Low	Low	Unclear	Low
8- Avery et al. [21]	Low	Low	Low	Low	Low
9- Hosomi et al. [22]	Low risk	High risk	Low risk	Low risk	Low risk
10- Conforto et al. [23]	High	Low	Low	High	Low
11- Shimizu et al. [24]	Low	Unclear	Low	Low	Low
12- Andre-Obadia et al. [25]	Low	Unclear	High risk	Low risk	Low