1. British Columbia Centre for Disease Control, Vancouver, BC, Canada
2. Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
3. School of Population and Public Health, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
4. Division of Addiction Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
5. Department of Family and Community Practice, Vancouver Coastal Health, Vancouver, BC, Canada
6. Department of Family Practice, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
7. Faculty of Health Sciences, Simon Fraser University, Vancouver, BC, Canada