Unfortunately, the original version of this article [1] contained an error in abstract S1. The corresponding author for the abstract ‘Gabriele Meyer’ was included in the 'Correspondence' section but accidentally omitted from the author list. The correct author list should be as below:

Gabriele Meyer1*, Sascha Köpke2, Jane Noyes3, Jackie Chandler4

1Martin Luther University Halle-Wittenberg, Magdeburger Str. 8, D-06112 Halle (Saale), Germany

2University of Lübeck, Germany

3Bangor University, UK

4Cochrane Collaboration, Oxford, UK

Correspondence: Gabriele Meyer (Gabriele.Meyer@medizin.uni-halle.de) – Martin Luther University Halle-Wittenberg, Magdeburger Str. 8, D-06112 Halle (Saale), Germany