[1] Univ Duisburg Essen, Univ Hosp Essen, Dept Neurol, Hufelandstr 55, D-45147 Essen, Germany
[2] Univ Duisburg Essen, Univ Hosp Essen, Nursing Headquarters, Essen, Germany
[3] Alfried Krupp Hosp Essen, Dept Nephrol Geriatr & Internal Med, Essen, Germany
[4] Univ Duisburg Essen, Univ Hosp Essen, Dept Nephrol, Essen, Germany
[5] Univ Duisburg Essen, Univ Hosp Essen, Dept Gastroenterol & Hepatol, Fac Med, Essen, Germany
[6] Univ Witten Herdecke, Fac Hlth, Dept Med, Witten, Germany
[7] Univ Hosp Essen, Dept Geriatr, Essen, Germany