Checklist adapted from DARE criteria22 and CASP tool23	Little 200077	Long 200175	Maetzel 199737	McAlindon 200069	McCarthy 200668	Osiri 200064	Patrella 200049	Pelland 200452	Poolsup 200571	Reichebach 200773	Reilly 200580	Richy 200370	Rintelen 200674	Robinson 200165	Roddy 200553	Srikanth 200543	Towheed 200572	Towheed 200634	Towheed 200633	Van Baar48	Van Dijk 200644	Vignon 200645	Walsh 200654	Wang 200459	Wegman 200430	White 200778	Zhang 200431
Well-defined review question
1. Were inclusion/exclusion criteria reported separately to review questions?	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	–	+	+	+	+	+
2. Did inclusion/exclusion criteria relate to study design of interest?	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	–	+	+	+	+	+
3. Did inclusion/exclusion criteria relate to participants of interest?	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+
4. Did inclusion/exclusion criteria relate to intervention of interest?	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	N/A	+	+	+	+	–	+	+	+	+	+	+
5. Did inclusion/exclusion criteria relate to outcomes of interest?	+	+	+	+	+	+	+	+	+	+	–	+	–	+	+	+	+	+	+	+	+	–	+	+	+	+	+
6. Were inclusion/exclusion criteria valid?	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	–	+	+	+	+	+
Comprehensive literature search
7. Was there evidence of a comprehensive search of the literature?	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	–	+	+	+	+	+	+	+	+	+	+	+
8. Did search include attempt to identify unpublished studies?	+	+	–	+	+	+	–	–	–	+	+	+	+	–	–	+	–	+	–	–	–	+	–	–	–	+	+
9. Was grey literature searched?	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
10. Were non-English language studies considered?	+	+	+	+	–	–	+	+	–	+	+	+	+	+	–	–	+	+	–	+	+	+	–	–	+	+	–
Systematic process for decision on retrieval and relevance
11. Did more than one reviewer assess references for relevancy?	–	–	+	?	?	+	?	+	?	+	?	–	+	+	?	–	+	–	+	+	+	–	+	+	?	+	–
12. If no did more than one reviewer assess a sample of the references?	–	?	N/A	?	?	N/A	?	N/A	?	N/A	?	?	N/A	N/A	?	–	N/A	–	N/A	N/A	N/A	–	N/A	N/A	?	N/A	–
13. Did more than one reviewer assess retrieved studies for inclusion?	+	+	+	?	?	+	?	+	?	+	?	+	+	+	?	–	+	–	+	+	+	–	+	+	?	+	–
14. If no, did more than one independent reviewer assess a sample?	N/A	N/A	N/A	?	?	N/A	?	N/A	?	N/A	?	N/A	N/A	N/A	?	–	N/A	–	N/A	N/A	N/A	–	N/A	N/A	?	N/A	–
Quality assessment
15. Was validity systematically assessed using a checklist ?	+	+	+	+	+	+	?	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+
16. Were validity criteria applied by more than one reviewer?	+	?	+	+	+	+	?	+	?	+	+	+	+	+	+	–	+	–	+	+	+	+	+	+	+	+	+
17. Was validity taken into account in synthesis?	–	–	–	+	–	+	?	–	–	+	–	–	+	–	+	–	–	–	+	+	+	+	+	+	+	+	+
Systematic data extraction
18. Were data extracted using standardised format?	+	+	+	+	?	+	?	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+
19. Was data extraction performed by more than one reviewer?	+	–	+	+	?	+	?	+	+	+	+	+	+	+	+	+	+	–	+	+	+	+	+	+	?	+	+
20. If no, was data extraction checked by second independent reviewer?	N/A	+	N/A	N/A	?	N/A	?	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	–	N/A	N/A	N/A	N/A	N/A	N/A	?	N/A	N/A
Appropriate synthesis
21. Are primary studies presented in sufficient detail?	+	+	+	+	+	+	+	+	+	+	+	+	+	+	–	+	+	+	+	–	–	+	+	+	+	+	+
22. Have the primary studies been synthesised appropriately?	+	–	–	+	+	+	+	–	+	+	–	+	+	–	+	+	–	+	+	?	+	+	+	+	+	+	+
23. Has meta-analysis been performed?	+	–	–	+	+	+	–	–	+	+	–	+	+	–	+	+	–	+	+	+	–	–	–	+	+	+	+
24. If yes, has heterogeneity been formally assessed?	+	N/A	N/A	+	+	+	N/A	N/A	+	+	–	+	–	N/A	+	+	N/A	+	+	+	N/A	N/A	N/A	+	+	+	+

Key: + item properly addressed; — item not properly addressed; ? insufficient information; N/A not applicable.