[1] Univ Manitoba, Rheumatol, Winnipeg, MB, Canada
[2] Boston Univ, Psychol, Boston, MA 02215 USA
[3] Boston Univ, Rheumatol, Boston, MA 02215 USA
[4] Boston Univ, Sch Med, Clin Epidemiol Unit, Boston, MA 02118 USA
[5] Univ Pittsburgh, Sch Med, Div Rheumatol & Clin Immunol, Pittsburgh, PA USA