1. Asthma Research Unit, Kingston Health Sciences Centre, Department of Medicine, Queen’s University, Kingston, Canada
2. Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
3. The Lung Association-Ontario, Toronto, Ontario, Canada
4. Departments of Pediatrics and Emergency Medicine, University of Ottawa, Ottawa, Southern Ontario, Canada
5. Dalla Lana Graduate School of Public Health, University of Toronto, Toronto, Ontario, Canada