1 Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia. Electronic address: karen.hobday@menzies.edu.au.
2 Bixby Center for Population, Health and Sustainability, School of Public Health, University of California, Berkeley, CA, USA.
3 Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada; Department of Emergency Medicine, University Health Network, University of Toronto, Toronto, ON, Canada.