1. British Columbia Centre for Disease Control, Vancouver, BC V5Z 4R4, Canada
2. School of Population and Public Health, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
3. Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
4. Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
5. Centre for Health Evaluation and Outcome Sciences, St Paul’s Hospital, Vancouver, BC V6Z 1Y6, Canada