作者单位:McGill Univ, Dept Epidemiol Biostat & Occupat Hlth, Purvis Hall,1020 Pine Ave West, Montreal, PQ[1]Canc Care Ontario, Aboriginal Canc Care Unit, Toronto, ON, Canada[2]Stat Canada, Ottawa, ON, Canada[3]Univ Toronto, Dalla Lana Sch Publ Hlth, Toronto, ON, Canada[4]