[1] Essen Univ Hosp, Dept Otorhinolaryngol, Essen, Germany
[2] German HHT Self Help Grp, Morbus Osler Selbsthilfe, Niederkruchten, Germany
[3] Univ Saarland, Hosp Saarland, Dept Otorhinolaryngol, Formerly of Otorhinolaryngol, Homburg, Germany
[4] Med Practice Haemostaseol & Transfus Med, Saarbrucken, Germany
[5] Univ Saarland, Hosp Saarland, Dept Haemostaseol & Transfus Med, Formerly of Haemostaseol & Transfus Med, Homburg, Germany
[6] BAD Gesundheitsvorsorge & Sicherheitstech GmbH, Munich, Germany
[7] Med Practice Dr Rolf Kubler, Stuttgart, Germany
[8] Klinikum Braunschweig, Dept Anaesthesiol, Braunschweig, Germany
[9] Heidelberg Univ, Dept Otorhinolaryngol, D-69115 Heidelberg, Germany
[10] Johannes Gutenberg Univ Mainz, Univ Med Ctr, Div Med Biometry, Inst Med Biostat Epidemiol & Informat, Mainz, Germany
[11] Univ Saarland, Inst Med Biostat Epidemiol & Informat, Formerly of Med Biostatist Epidemiol & Info, Homburg, Germany