Table 2

 Quality assessment of all studies

ReferenceABCDEFGHIJKLMNOPQOverall rating (see appendix 1)
Results A–Q are quality criteria (see Appendix 1).
Abenhaim et al20+++++++++++++++15
Andersson et al21++++++++?+9
Burdorf et al22++++++++++++12
Butterfield et al23++++++??+++++11
Fransen et al24+++++++++++++13
Gatchel et al25,26++++++++++++12
Gluck et al and Oleinick et al27,28++++++++++++12
Goertz29+++++?+++8
Hagen and Thune30+++?+++?++?+9
Dasinger et al and Krause et al31,32++++++++++?++?+13
Nordin et al33++??+??+++++8
Schultz et al34+++++++++++11
van der Weide et al35,36++++++++++++++14
van Doorn37++++–++++++++++14