[1] British Columbia Ctr Subst Use, 1045 Howe St, Vancouver, BC V6Z 2A9, Canada
[2] Columbia Univ, Mailman Sch Publ Hlth, 722 W 168th St, New York, NY 10032 USA
[3] Univ British Columbia, St Pauls Hosp, Dept Med, 608-1081 Burrard St, Vancouver, BC V6Z 1Y6, Canada
[4] Univ Coll Dublin, UCD Sch Med, Dublin 4, Ireland
[5] Univ Geneva, Inst Global Hlth, CH-1205 Geneva, Switzerland
[6] Univ Coll Dublin, Sch Med, Primary Care Res Grp, Catherine McAuley Ctr, Dublin 4, Ireland