1. Centre for Clinical Epidemiology & Evaluation, Vancouver Coastal Health Research Institute, University of British Columbia, Canada; Centre for Health Promotion Studies, School of Public Health, University of Alberta, Canada
2. Centre for Clinical Epidemiology & Evaluation, Vancouver Coastal Health Research Institute, Canada; School of Population and Public Health, University of British Columbia, Canada
3. Faculty of Health and Social Development, University of British Columbia, Canada
4. Health Services Management Centre, School of Social Policy, University of Birmingham, UK