Table 1.

Quality of included papers

Author	Aims scope	Ethical dimension	Study design	Rigour	Analysis procedure	Depth/detail	Credibility	Relevance transferability	Contribution to knowledge	Overall quality
Andersen et al. (a) and (b)	VG	VG	VG	G	VG	G	VG	VG	VG	VG
Apps et al.	VG	VG	VG	VG	VG	VG	G	VG	VG	VG
Boeckxstaens et al.	VG	VG	VG	VG	VG	G	VG	VG	VG	VG
Brandt	G	VG	VG	VG	VG	L	L	G	G	G
Brien et al.	VG	VG	G	G	G	G	G	G	G	G
Chang et al.	VG	G	G	G	VG	G	G	G	G	G
Chen et al. (a) and (b)	VG	VG	G	VG	VG	VG	L	VG	VG	VG
Cicutto et al.	VG	VG	VG	VG	VG	VG	VG	VG	VG	VG
Duangpaeng et al.	VG	G	G	G	G	G	L	G	G	G
Ehrlich et al.	VG	VG	VG	VG	VG	VG	G	VG	VG	VG
Fotokain et al.	G	VG	G	VG	VG	G	G	G	G	G
Gysels and Higginson	VG	VG	VG	VG	VG	VG	VG	VG	VG	VG
Harris et al.	VG	G	VG	VG	VG	VG	VG	VG	VG	VG
Harrison et al.	VG	VG	VG	VG	VG	VG	VG	VG	VG	VG
Hillebregt et al.	G	VG	VG	VG	VG	G	G	VG	VG	VG
Hyde et al.	VG	G	VG	VG	VG	VG	G	VG	VG	VG
Johnston et al. (a)	VG	VG	VG	VG	VG	G	G	VG	VG	VG
Johnston et al. (b)	VG	G	VG	VG	G	VG	VG	VG	VG	VG
Kayyali et al.	VG	G	G	G	G	G	L	G	G	G
McCabe et al.	VG	G	VG	G	G	G	G	VG	VG	G
Ogunbayo et al.	VG	VG	G	VG	VG	G	VG	VG	VG	VG
Panos et al.	VG	G	VG	VG	VG	VG	G	VG	VG	VG
Robinson et al.	VG	VG	G	VG	VG	G	VG	VG	VG	VG
Sheridan et al.	VG	VG	VG	G	L	VG	VG	VG	VG	VG
Stellefson et al.	VG	VG	VG	VG	VG	VG	VG	G	G	VG
Summers et al.	VG	VG	G	VG	VG	G	VG	VG	VG	VG
Verbrugge et al.	VG	G	VG	VG	VG	VG	VG	VG	VG	VG
Wong et al.	VG	VG	VG	G	G	VG	G	VG	VG	VG
Wortz et al.	VG	VG	G	G	G	VG	VG	VG	VG	VG
Young et al.	VG	VG	VG	G	G	VG	G	VG	VG	VG
Zakrisson and Hagglund	VG	G	G	G	G	VG	G	VG	VG	G

L low, G good, VG very good