[1] Univ Toronto, Dept Surg, Toronto, ON, Canada
[2] Univ Toronto, Dept Hlth Policy Management & Evaluat, Toronto, ON, Canada
[3] Univ Toronto, Inst Med Sci, Fac Med, Toronto, ON M5S 1A1, Canada
[4] McMaster Univ, Dept Clin Epidemiol & Biostat, Dept Oncol, Hamilton, ON, Canada
[5] Univ Toronto, Dept Med, Guidelines Advisory Comm, Ctr Effect Practice, Toronto, ON, Canada
[6] Univ Ottawa, Dept Med, Ctr Best Practices, Inst Populat Hlth, Ottawa, ON, Canada