[1] Ruhr Univ Bochum, Rheumazentrum Ruhrgebiet, D-4690 Herne, Germany
[2] Practising Rheumatol, Erfurt, Germany
[3] Practising Rheumatol, Essen, Germany
[4] Practising Rheumatol, Halle, Germany
[5] Practising Rheumatol, Hildesheim, Germany
[6] Practising Rheumatol, Goslar, Germany
[7] Practising Rheumatol, Cologne, Germany
[8] Medac, Wedel, Germany