[1] Univ Queensland, Royal Brisbane Hosp, CONROD, St Lucia, Qld 4067, Australia
[2] Univ Toronto, Sunnybrook & Womens Coll, Hlth Sci Ctr, Toronto, ON, Canada
[3] McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4L8, Canada
[4] Univ Montreal, Montreal Inst Rheumatol, Montreal, PQ H3C 3J7, Canada
[5] Univ Ottawa, Inst Populat Hlth, Ctr Global Hlth, Ottawa, ON K1N 6N5, Canada
[6] Genzyme Corp, Clin Res Biosurg, Cambridge, MA USA