Table 3

Cochrane tool to assess risk of bias for randomised controlled trials

	Vahidi et al32	Aurilio et al36	Aurilio et al28	Mitchell and Fallon33	Persson et al34
Random sequence generation (selection bias)	+	+	?	+	+
Allocation concealment (selection bias)	+	+	?	+	+
Blinding (performance bias and detection bias) All outcomes	+	−	−	+	+
Incomplete outcome data (attrition bias) All outcomes	+	+	+	−	+
Selective reporting (reporting bias)	+	+	+	+	+
Other bias	+	+	+	+	−