1. BC 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. Department of Public Health, University of Turku, 20014 Turku, Finland
4. Sauder School of Business, University of British Columbia, Vancouver, BC V6T 1Z2, Canada
5. School of Psychology and Public Health, La Trobe University, Bundoora, VIC 3086, Australia