[1] ICES, Toronto, ON M4N 3M5, Canada
[2] Univ Toronto, Dept Surg, Toronto, ON, Canada
[3] Univ Toronto, Dept Publ Hlth Sci, Toronto, ON, Canada
[4] Univ Toronto, Dept Med, Toronto, ON, Canada
[5] Toronto Gen Hosp, Div Vasc Surg, Toronto, ON, Canada
[6] Sunnybrook & Womens Coll, Hlth Sci Ctr, Clin Epidemiol & Hlth Care Res Program, Toronto, ON, Canada
[7] Sunnybrook & Womens Coll, Hlth Sci Ctr, Div Gen Internal Med, Toronto, ON, Canada