1 School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada.
2 Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
3 Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; British Columbia Centre for Disease Control, Vancouver, BC, Canada. Electronic address: hsamji@sfu.ca.