1. British Columbia Centre on Substance Use, St. Paul’s Hospital, Vancouver, British Columbia, Canada
2. Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
3. Health Economic Research Unit, British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
4. Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
5. Vancouver Area Network of Drug Users, Vancouver, British Columbia, Canada