[1] Laval Univ, Ctr Hosp Univ Laval, Montreal, PQ, Canada
[2] McGill Univ, Fac Med, Montreal, PQ, Canada
[3] JSS Med Res Inc, Montreal, PQ, Canada
[4] Inst Rhumatol Montreal, Montreal, PQ, Canada
[5] McGill Univ, Dept Pediat, Montreal, PQ, Canada
[6] Bristol Myers Squibb, Montreal, PQ, Canada
[7] Western Univ, Dept Med, Div Rheumatol, London, ON, Canada
[8] Western Univ, Dept Med, Div Epidemiol, London, ON, Canada
[9] Western Univ, Dept Med, Div Biostat, London, ON, Canada