1. Faculty of Medicine Carl Gustav Carus, TU Dresden; Center for Evidence-Based Healthcare; Fetscherstr. 74 Dresden Saxony Germany 01307
2. German Diabetes Center, Leibniz Institute for Diabetes Research at Heinrich Heine University Düsseldorf; Institute for Biometry and Epidemiology; Auf´m Hennekamp 65 Düsseldorf Germany 40225
3. University Hospital Carl Gustav Carus; Centre for Orthopaedic and Trauma Surgery; Fetscherstr. 74 Dresden Saxony Germany 01307
4. Faculty of Medicine Carl Gustav Carus, Technischen Universität (TU) Dresden; Center for Evidence-Based Healthcare; Fetscherstr. 74 Dresden Germany 01307