1. Rheumatology Unit, San Camillo – Forlanini Hospital, Rome, Italy
2. Rheumatology Unit, “Sapienza” University of Rome, Rome, Italy
3. Rheumatology Unit, University of Perugia, Perugia, Italy
4. Rheumatology Unit, University of Ferrara e AOU S. Anna, Ferrara, Italy
5. Unit of Immunology, Rheumatology, Allergy and Rare Diseases, IRCCS Ospedale San Raffaele, Milan, Italy
6. Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome “Tor Vergata”, Rome, Italy
7. Rheumatology Unit, AOU Città della Salute e della Scienza di Torino, Turin, Italy
8. Dipartimento di Medicina Clinica e Sperimentale, University of Firenze, Firenze, Italy
9. Dipartimento di Scienze Cliniche e Sperimentali, Unit of Rheumatology and Clinical Immunology, ASST Spedali Civili, University of Brescia, Brescia, Italy
10. Rheumatology Unit, University of Padova, Padova, Italy
11. Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
12. Rheumatology Unit, Scafati, Salerno, Italy
13. Epidemiology Unit, Italian Society of Rheumatology, Milan, Italy
14. Department of Statistics and Quantitative Methods, Division of Biostatistics, Epidemiology and Public Health, University of Milano-Bicocca, Milan, Italy