[1] Tech Univ Munich, Klinikum Rechts Isar, Competence Ctr Complementary Med & Naturopathy, 9 Kaiserstr, D-80801 Munich, Germany
[2] Univ Zurich, Univ Zurich Hosp, Inst Complementary & Integrat Med, Zurich, Switzerland
[3] Med Practice Internal Med, Treuchtlingen, Germany
[4] Deggendorf Inst Technol, Fac Appl Hlth Care Sci, Deggendorf, Germany
[5] Tech Univ Munich, Munich Trial Ctr, Inst Med Stat & Epidemiol, Klinikum Rechts Isar, Munich, Germany