Table 2.

Quality and Bias Assessment of included trials

	Mittal et al. 2011	Abid et al. 2011	Alvares-da-Silva et al. 2014	Varakanahalli et al. 2018	Higuera-de la Tijera et al. 2018	Bai et al. 2014
A. Jadad Score
Randomization	2	1	2	2	2	2
Blinding	0	1	1	2	2	2
Dropouts	1	1	1	1	1	1
Total score	3	3	4	5	5	5
B. Cochrane Score
Selection bias (randomization)	L	L	L	L	L	L
Selection bias (blinding)	L	L	L	L	L	L
Performance Bias	H	L	L	L	L	L
Detection bias	H	UC	L	L	L	L
Reporting bias	L	L	L	L	L	L
Overall bias	UC	L	L	L	L	L

Trial quality is indicated by a score of 1–5 on the Jadad scale; scores of 3 or above indicate high quality. Assessment of risk of bias due to randomization, blinding, detection and attrition using the Cochrane tool for risk of bias assessment as described in Methods. L low, H high, UC unclear