1. Centre for Addictions Research of British Columbia, University of Victoria, Victoria, BC, Canada; Canadian AIDS Society, Ottawa, ON, Canada
2. Centre for Addictions Research of British Columbia, University of Victoria, Victoria, BC, Canada; Department of Sociology, University of Victoria, Victoria, BC, Canada
3. Centre for Addictions Research of British Columbia, University of Victoria, Victoria, BC, Canada; Department of Nursing, University of Victoria, Victoria, BC, Canada