1. Center for Clinical Epidemiology & Population Health, Marshfield Clinic Research Institute, Marshfield, WI, USA
2. Communicable Disease Prevention and Control Services, British Columbia Centre for Disease Control, Vancouver, BC, Canada
3. University of Minnesota School of Public Health, Minneapolis, MN, USA
4. Institut National de Sante Publique du Quebec [National Institute of Health of Quebec], Quebec, Canada
5. Department of Social and Preventive Medicine, Laval University, Quebec, Canada