1. Department of Rheumatology & Immunology, Medical University of Graz, Auenbruggerplatz 2/4, A-8036 Graz, Austria
2. Department of Internal Medicine, Bezirkskrankenhaus Kufstein, Endach 27, A-6330 Kufstein, Austria
3. Department of Rheumatology, Southend University Hospital, Essex, UK
4. Division of Rheumatology & Division of Epidemiology, Departments of Internal Medicine & Health Sciences Research Mayo Clinic College of Medicine, Rochester, MN, USA
5. Department of Internal Medicine I, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria.