[1] University of Saarland,Department of Internal Medicine II, Division of Gastroenterology
[2] University of the Saarland,Institute of Medical Biometrics, Epidemiology, and Medical Informatics
[3] St.Michael Hospital,Department of Internal Medicine I, Charité
[4] Hospital of the Miner's Guild,undefined
[5] St.Elisabeth Hospital,undefined
[6] The Saarland Cancer Registry,undefined
[7] Campus Benjamin Franklin,undefined