1. Institute for Clinical Evaluative Sciences; Toronto Ontario Canada
2. Institute of Health Management, Policy and Evaluation; University of Toronto; Toronto Ontario Canada
3. Schulich Heart Research Program; Sunnybrook Research Institute; Toronto Ontario Canada
4. Atlantic Veterinary College; University of Prince Edward Island; Charlottetown Prince Edward Island Canada
5. Centre for Multilevel Modelling; University of Bristol; Bristol UK
6. Unit for Social Epidemiology, Faculty of Medicine; Lund University; Malmö Sweden
7. Center for Primary Health Care Research; Region Skåne; Malmö Sweden