1. Thrombosis Research Group (B.B.), Brigham and Women’s Hospital, Harvard Medical School, Boston, MA.
2. Cardiovascular Medicine Division (B.B.), Brigham and Women’s Hospital, Harvard Medical School, Boston, MA.
3. Yale New Haven Hospital/Yale Center for Outcomes Research and Evaluation, CT (B.B.).
4. Population Health Research Institute, Hamilton Health Sciences, McMaster University, Canada (J.W.E.).