1. Clinical Epidemiology Unit, Division of Community Health and Humanities, Faculty of Medicine, Memorial University, St. John’s, Canada
2. Canadian Centre for Health and Safety in Agriculture (CCHSA), University of Saskatchewan, Saskatoon, Canada
3. Department of Medicine, University of Colorado, Denver, CO, USA
4. Department of Medicine, University of Alberta, Edmonton, Canada
5. School of Public Health, University of Alberta, Edmonton, Canada