Table 1.

Risk of Bias Assessment with the Cochrane Tool.

	Random Sequence Generation (Selection Bias)	Allocation Concealment (Selection Bias)	Blinding of Participants and Personnel (Performance Bias)	Blinding of Outcome Assessment (Detection Bias)	Incomplete Outcome Data (Attrition Bias)	Selective Reporting (Reporting Bias)	Other Bias
Aslan et al. [12]									Low risk of bias
Cramer et al. [21]
Cramer et al. [22]									Unclear risk of bias
Marek et al. [24]
Wakefield et al. [25]									High risk of bias
Wallmann et al. [23]
Young et al. [26]
Zakas et al. [27]