Table 3.

Evaluation of the Risk of Bias of Studies.

Criteria	Alavi vd.,2017	Cenkçi, 2017	Hamdamian vd.,2018	Tanvisut vd.,2018	Yazdkhasti & Pirak, 2016	Esmaelzadeh vd., 2018	Vakilian vd., 2018	Janula ve Singh, 2014	Janula ve Singh, 2015	Joseph ve Fernandes, 2013	Kaviani vd.,2014 (a)	Kaviani vd.,2014 (b)	Lamadah ve Nomani, 2016	Namazi vd.,2014
Risk of bias arising from the randomization process	?	+	+	+	+	+	+	?	?	?	?	?	?	?
Risk of bias due to deviations from intended interventions (impact of assignment on intervention)	+	+	+	+	+	+	+	+	+	+	+	+	+	+
Risk of bias due to deviations from intended interventions (effect of adherence to the intervention)	+	+	+	+	+	+	+	+	+	+	+	+	+	+
Risk of bias due to missing outcome data	?	?	+	?	?	+	+	+	?	+	+	+	+	+
Risk of bias in measuring outcome	?	?	?	?	?	?	?	?	?	?	?	?	?	?
Risk of bias in selection of the reported outcome	+	+	+	+	+	+	+	+	+	+	+	+	+	+

+ Low risk of bias ? Suspicious bias risk -High risk of bias