[1] Univ British Columbia, Sch Populat & Publ Hlth, Vancouver, BC, Canada
[2] Univ British Columbia, Ctr Clin Epidemiol & Evaluat, Vancouver, BC, Canada
[3] Vancouver Prostate Ctr, Vancouver, BC, Canada
[4] Univ British Columbia, Dept Urol Sci, Vancouver, BC, Canada
[5] Univ Washington, Fred Hutchinson Canc Res, Seattle, WA 98195 USA