1. Rheumatology Unit, Department of Medical Sciences, University of Ferrara and Azienda Ospedaliero-Universitaria S. Anna, Cona, Ferrara, Italy.
2. Rheumatology Unit, Department of Medicine, University of Verona, Policlinico G. B. Rossi, Verona, Italy.
3. Chair and Division of Rheumatology, University of Pavia, IRCCS Policlinico San Matteo Foundation, Pavia, Italy.
4. Rheumatology Division, Multispecialist Medical Department, ASST Grande Ospedale Metropolitano Niguarda, Milan, and Epidemiology Unit, Italian Society for Rheumatology, Milan, Italy.
5. Rheumatology Unit, Department of Medical Sciences, University of Ferrara and Azienda Ospedaliero-Universitaria S. Anna, Cona, Ferrara; and Epidemiology Unit, Italian Society for Rheumatology, Milan, Italy. scrcll@unife.it
6. Department of Rheumatology, Leiden University Medical Centre, The Netherlands.