[1] British Columbia Canc Agcy, Vancouver Isl Canc Ctr, Dept Med Oncol, Victoria, BC V8R 6V5, Canada
[2] Univ British Columbia, Sch Populat & Publ Hlth, Vancouver, BC V5Z 1M9, Canada
[3] McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON, Canada
[4] Program Evidence Based Care, Toronto, ON, Canada