1. Department of Anesthesia and Pain Medicine University of Toronto Toronto Western Hospital Toronto ON Canada
2. Institute of Health Policy Management and Evaluation University of Toronto Toronto ON Canada
3. Division of Pain Medicine Department of Anesthesiology and Critical Care Medicine Johns Hopkins University Baltimore MD USA
4. Department of Anesthesia and Pain Medicine University of TorontoMount Sinai Hospital Toronto ON Canada
5. Department of Anesthesiology and Intensive Care Medicine Università Cattolica del Sacro CuoreFondazione Policlinico Universitario Agostino Gemelli Rome Italy