[1] McMaster Univ, Juravinski Canc Ctr, Div Med Oncol, Hamilton, ON L8V 5C2, Canada
[2] McMaster Univ, Program Evidence Based Care, Ontario Hlth Canc Care Ontario, Dept Oncol, Hamilton, ON L8V 1C3, Canada
[3] McMaster Univ, Dept Hlth Res Methods Evidence & Impact, Hamilton, ON L8S 4L8, Canada
[4] Univ Toronto, Princess Margaret Hosp, Dept Obstet & Gynecol, Toronto, ON M5G 2C1, Canada
[5] Queens Univ, Canc Ctr Southeastern Ontario, Div Canc Care & Epidemiol, Canc Res Inst,Dept Oncol & Med, Kingston, ON K7L 3N6, Canada
[6] McMaster Univ, Juravinski Canc Ctr, Dept Obstet & Gynecol, Hamilton, ON L8V 5C2, Canada