Table 3.

Quality Assessment of Included Studies^a

	Selection Bias		Performance Bias	Detection Bias	Attrition Bias	Reporting Bias	Other Bias
Study	Random Sequence Generation	Allocation Concealment	Blinding of Participants and Personnel	Blinding of Outcome Assessment	Incomplete Outcome Data	Selective Reporting	Other Bias
Betrosian et al [5]	+	?	-	-	+	+	+
Cisneros et al [6]	+	+	-	-	+	+	+
Khalili et al [7]	+	?	-	-	+	+	+
Mosaed et al [8]	+	?	-	-	?	+	+
Motsch et al [9]	+	+	+	+	+	+	?

^a+, low risk of bias; “?” Unclear risk of bias; “-” high risk of bias.