1. British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada;
2. School of Population & Public Health, University of British Columbia, Vancouver, BC, Canada;
3. Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada;
4. British Columbia Centre for Disease Control, Provincial Health Services Authority, Vancouver, BC, Canada;
5. Division of AIDS, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada