[1] British Columbia Ctr Subst Use, 400-1045 Howe St, Vancouver, BC V6Z 2A9, Canada
[2] St Michaels Hosp, Li Ka Shing Knowledge Inst, Ctr Drug Policy Evaluat, Toronto, ON, Canada
[3] Univ Victoria, Canadian Inst Subst Use Res, Victoria, BC, Canada
[4] Univ Calif San Diego, Div Infect Dis & Global Publ Hlth, La Jolla, CA USA
[5] Drexel Univ, Dornsife Sch Publ Hlth, Dept Epidemiol & Biostat, Philadelphia, PA USA
[6] St Michaels Hosp, MAP Ctr Urban Solut, Toronto, ON, Canada
[7] St Michaels Hosp, Ctr Drug Policy Evaluat, 209 Victoria St, Toronto, ON M5B 1T8, Canada