1. Institute for Evidence in Medicine Medical Center - Faculty of Medicine; University of Freiburg; Freiburg Germany
2. Cochrane Germany Foundation; Cochrane Germany; Freiburg Germany
3. Department of Anesthesiology; University Heart Center Freiburg, Bad Krozingen; Freiburg Germany
4. Cochrane Hungary, Clinical Center of the University of Pécs, Medical School; University of Pécs; Pécs Hungary