1. First Department of Propaedeutic Internal Medicine, National and Kapodistrian University of Athens, “Laiko” General Hospital, Athens, Greece
2. Department of Rheumatology, Faculty of Medicine, Patras University Hospital, University of Patras Medical School, Patras, Greece
3. Fourth Department of Internal Medicine, Hippokration University Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
4. Arthritis Research UK, Centre for Epidemiology, University of Manchester, Manchester, UK