1. Institute of Epidemiology and Medical Biometry, Ulm, Germany
2. Department of Internal Medicine I, University Hospital Ulm, Ulm, Germany
3. Department of Mathematics, Natural Sciences and Economic Sciences (Biostatisitcs), University of Applied Sciences Ulm, Ulm, Germany
4. Department of Internal Medicine II, University Hospital Ulm, Ulm, Germany
5. Department of Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany
6. Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Ohio, USA