[1] Univ Alberta, Fac Med & Dent, Edmonton, AB, Canada
[2] Univ Alberta, Sch Publ Hlth, Nashville, TN USA
[3] Univ Victoria, Sch Nursing, Victoria, BC, Canada
[4] Univ Calgary, Dept Sociol, Calgary, AB, Canada
[5] Univ British Columbia, Okanagan Sch Social Work, British Columbia Ctr Subst Use, Vancouver, BC, Canada
[6] Univ Alberta, Sch Publ Hlth, Edmonton, AB, Canada
[7] St Marys Univ, Dept Criminol, Halifax, NS, Canada
[8] Univ Calgary, Dept Community Hlth Sci, Calgary, AB, Canada
[9] Univ Alberta, Sch Publ Hlth, Vancouver, BC, Canada
[10] Univ Victoria, Sch Publ Hlth & Social Policy, Victoria, BC, Canada
[11] St Michaels Hosp, Ctr Drug Policy Evaluat, MAP Ctr Urban Hlth Solut, Toronto, ON, Canada
[12] Univ Calif San Diego, Div Infect Dis & Global Publ Hlth, La Jolla, CA 92093 USA