1. School of Kinesiology and Health Studies, Queen's University, 28 Division Street Room 310-F, Kingston, ON, Canada K7L 3N6
2. Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada H2W 1V1
3. Department of Epidemiology, Biostatistics, and Occupational Health, Faculty of Medicine, McGill University, Montréal, Canada H3A 1A2
4. School of Health Sciences, University of South Australia, SA 5001 Adelaide, Australia
5. Department of Social Medicine, University of Bristol, BS82PS Bristol, UK