[1] Univ Siena, Dept Med Surg & Neurosci, Clin Diag Management Hand Osteoarthritis, Rheumatol Unit, Viale Bracci 1, I-53100 Siena, Italy
[2] Univ Liege, WHO Collaborating Ctr Publ Hlth Aspects Musculosk, Div Publ Hlth Epidemiol & Hlth Econ, Liege, Belgium
[3] Azienda Osped Univ Senese, Dept Med Surg & Neurosci, Clin Diag & Management Hand Osteoarthritis, Rheumatol Unit, Siena, Italy
[4] Univ Palermo, Dept Internal Med & Geriatr, Geriatr Unit, Palermo, Italy