1. Department of Research and Clinical Epidemiology, Canadian College of Naturopathic Medicine, Toronto, ON M2K 1E2, Canada
2. Department of Research and Clinical Epidemiology, Canadian College of Naturopathic Medicine, Vancouver, BC V3L 5N8, Canada
3. NCCO Rehabilitation, Toronto, ON M4J 3S2, Canada
4. School of Public Health, University of Technology Sydney, Sydney, Ultimo 2007, Australia
5. National Centre for Naturopathic Medicine, Southern Cross University, Lismore 2480, Australia
6. Department of Human Biology, University of Toronto, Toronto, ON M5S 3J6, Canada