[1] Univ Hosp Bonn, Dept Oncol Haematol Rheumatol & Clin Immunol, Clin Internal Med 3, Bonn, Germany
[2] Med Univ Graz, Dept Rheumatol, Graz, Austria
[3] Paracelsus Med Univ, Teaching Hosp, Hosp Bruneck ASAA SABES, Dept Rheumatol, Brunico, Italy
[4] Univ Hosp Bonn, Inst Med Biometry Informat & Epidemiol, Bonn, Germany
[5] Univ Hosp Bonn, Dept Oncol Haematol Rheumatol & Clin Immunol, Clin Internal Med 3, Venusberg Campus 1, D-53127 Bonn, Germany