Table 1.

Risk of bias assessment of included SRs with the SIGN checklist.

First author and year published	Items on SIGN checklista
	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	#11	#12	Total	Qualityb
Liddle, 201576	1	1	1	1	0	1	1	1	1	1	1	1	11	H
Franke, 201778	1	1	1	1	0	1	1	1	1	1	1	1	11	H
Ruffini, 201377	1	1	1	1	0	1	1	1	1	1	1	1	11	H
Hall, 201618	1	1	1	1	1	1	1	1	1	1	1	1	12	H
Gutke, 201570	1	1	0	1	0	1	1	1	1	0	1	1	9	A
Sharma, 201479	1	1	1	1	0	0	1	1	1	1	0	0	8	A
Majchrzyki, 201580	0	0	0	0	0	0	0	0	0	0	0	0	0	U
Posadaski, 201181	0	0	0	0	0	0	0	0	0	0	0	0	0	U

SIGN = Scottish Intercollegiate Guideline Network

^a,bSee Figure 2 for Quality assessment SIGN checklist items^a and scoring^b for SRs