1. Cochrane Germany; Medical Center - University of Freiburg; Faculty of Medicine; University of Freiburg; Freiburg Germany
2. AWMF-Institute for Medical Knowledge Management (IMWi); Marburg Germany
3. Department of Anesthesiology and Critical Care; University Heart Center Freiburg-Bad Krozingen; Medical Center - University of Freiburg; Freiburg Germany
4. Institute for Medical Biometry and Statistics; Faculty of Medicine and Medical Center - University of Freiburg; Freiburg Germany