1. Department of Epidemiology, Biostatistics and Occupational Health, Faculty of Medicine, McGill University, Canada
2. Respiratory Epidemiology and Clinical Research Unit, Montreal Chest Institute, Canada
3. Department of Pediatrics, Montreal Children’s Hospital of the McGill University Health Centre, Canada
4. Faculty of Medicine, McGill University, Canada
5. Research Centre, Centre hospitalier universitaire Sainte-Justine and Department of Pediatrics, University of Montreal, Montreal, Quebec, Canada