[1] Rigshosp, Copenhagen Univ Hosp, Copenhagen Res Ctr Autoimmune Connect Tissue Dis, Copenhagen, Denmark
[2] Stanford Univ Sch Med, Dept Epidemiol Populat Hlth, Stanford, CA USA
[3] Rigshosp, Copenhagen Univ Hosp, Copenhagen Res Ctr Autoimmune Connect Tissue Dis, Ctr Rheumatol & Spine Dis, Copenhagen, Denmark