Table 5. Evaluation of risk of bias.

Authors/ reference	1. Inclusion /exclusion varies between groups	2. Recruitment varies between groups	3. Sample size sufficiently large	4. Description of the intervention or exposure	5. Outcome assessor blinded	6. Valid and reliable measures	7. Differential follow-up	8. Impact of highloss to follow-up	9. Missing outcomes	10. Missing harm or adverse event data	11. Results believable	12. Balance of allocation between groups	13. Confounding addressed appropriately
Al-Qahtani et al. [28]	+	+	?	?	?	+	?	?	+	?	+	?	Part
Cha et al. [29]	+	?	?	?	?	+	+	?	+	?	+	?	Part
Chalfin et al. [30]	+	+	+	?	?	+	?	?	+	?	+	?	Part
Hsieh et al. [31]	+	+	?	?	?	?	?	?	+	?	+	?	Part
Gilligan et al. [32]	+	?	?	?	?	?	?	?	+	?	+	?	-
Junhasavasdikul et al. [33]	+	?	?	?	?	+	?	?	+	?	+	?	-
Singer et al. [34]	+	?	?	?	?	+	?	?	+	?	+	?	+
Augustin et al. [35]	+	?	?	?	?	+	?	?	+	?	+	?	Part
Lord et al. [36]	+	+	?	?	?	+	?	?	+	?	+	?	+
Reznek et al. [37]	+	+	?	+	?	+	+	?	+	?	+	?	Part
Al-Khathaami et al. [38]	+	?	-	?	?	-	?	?	+	?	+	?	Part
Hong et al. [39]	+	+	+	?	?	?	+	?	+	?	+	?	Part

+ Study met criteria,—Study did not meet criteria, ? Not applicable, Part: partially met criteria