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 Canada
4. Unit for Social Epidemiology, Faculty of Medicine; Lund University; Malmö Sweden
5. Centre for Clinical Research Västmanland; Uppsala University; Uppsala Sweden
6. Center for Primary Health Care Research, Region Skåne; Malmö Sweden