[1] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Div Rheumatol Allergy & Immunol, Boston, MA USA
[2] Boston Univ, Sch Med, Boston, MA 02118 USA
[3] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Rheumatol Allergy & Immunol, Boston, MA USA
[4] Boston Univ, Sch Med, Clin Epidemiol Unit, Boston, MA 02118 USA
[5] Boston VA HealthCare Syst, Rheumatol, Boston, MA USA
[6] Univ British Columbia, Expt Med, Vancouver, BC V5Z 1M9, Canada
[7] Univ British Columbia, Arthrit Res Canada, Vancouver, BC V5Z 1M9, Canada