1. Department of Medical Biometry Institute for Quality and Efficiency in Health Care (IQWiG) Cologne Germany
2. Department of Medical Statistics University Medical Center Göttingen Göttingen Germany
3. Institute for Biostatistics Hannover Medical School Hannover Germany
4. Institute for Biometrics and Epidemiology, German Diabetes Center Leibniz Institute for Diabetes Research, Heinrich Heine University Düsseldorf Germany
5. Institute of Medical Statistics, Computer Sciences and Documentation Jena University Hospital, Friedrich Schiller University Jena Jena Germany
6. Institute for Medical Biometry and Statistics, Faculty of Medicine and Medical Center University of Freiburg Freiburg Germany