[1] Diakonhjemmet Hosp, Dept Rheumatol, Oslo, Norway
[2] Diakonhjemmet Hosp, Oslo, Norway
[3] Helse More & Romsdal HF, Alesund Hosp, Dept Rheumatol, Alesund, Norway
[4] Haukeland Hosp, Dept Rheumatol, N-5021 Bergen, Norway
[5] Vestre Viken Hosp, Dept Rheumatol, Drammen, Norway
[6] Martina Hansens Hosp, Dept Rheumatol, Baerum, Norway
[7] St Olavs Hosp, Dept Rheumatol, Trondheim, Norway
[8] Hosp Ostfold HF, Dept Rheumatol, Moss, Norway
[9] Haugesund Rheumatism Hosp, Haugesund, Norway
[10] Rheumatol Clin Dovland Bendvold, Kristiansand, Norway
[11] Sorlandet Hosp, Dept Rheumatol, Kristiansand, Norway
[12] Univ Hosp Northern Norway, Dept Rheumatol, Tromso, Norway
[13] Univ Hosp North Norway, Inst Clin Med, Tromso, Norway
[14] Leiden Univ, Med Ctr, Dept Rheumatol, Leiden, Netherlands