1. Institute for Epidemiology; Social Medicine and Health Systems Research; Hannover Medical School; Hannover Germany
2. Department of Internal Medicine; Krankenhaus Nordwest; Frankfurt/M Germany
3. Factum - Company for Statistics; Scientific Information and Communication mbH; Offenbach Germany
4. Virology; Roche Pharma AG; Grenzach-Wyhlen Germany
5. Center of Gastroenterology; Herne Germany
6. Center for HIV and Hepatogastroenterology; Duesseldorf Germany