[1] Mem Univ Newfoundland, Hlth Sci Ctr, Patient Res Unit, St John, NF A1B 3V6, Canada
[2] McGill Univ, Royal Victoria Hosp, Montreal, PQ H3A 1A1, Canada
[3] Univ Alberta, Hlth Sci Ctr, Edmonton, AB, Canada
[4] Univ Montreal, Hop Sacre Coeur, Montreal, PQ, Canada
[5] Univ Ottawa, Loeb Hlth Res Unit, Clin Epidemiol Unit, Ottawa, ON, Canada
[6] Univ Manitoba, St Boniface Gen Hosp, Winnipeg, MB, Canada
[7] Dalhousie Univ, Hlth Sci Ctr, St John, NB, Canada
[8] Univ Quebec, Hop Hotel Dieu, Quebec City, PQ, Canada
[9] Janssen Ortho Inc, Toronto, ON, Canada
[10] Univ British Columbia, St Pauls Hosp, Vancouver, BC V5Z 1M9, Canada
[11] Univ Toronto, Toronto Hosp, Toronto, ON, Canada
[12] Univ Western Ontario, Hlth Sci Ctr, London, ON N6A 5C1, Canada
[13] Univ Calgary, Foothills Hosp, Calgary, AB, Canada
[14] Univ Ottawa, Ottawa Hosp, Ottawa, ON, Canada