1 Division of Hematology, Department of Medicine, University of British Columbia, Vancouver, BC V6H 2M9, Canada. Electronic address: matthew.seftel@blood.ca.
2 Department of Biostatistics and Epidemiology, Hudson College of Public Health, Health Sciences Center, University of Oklahoma, Oklahoma City, OK, USA.
3 Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
4 Department of Medicine, University of Toronto, Toronto, ON, Canada.
5 Department of Medicine, McMaster University, Hamilton, ON, Canada.