1. Division of General Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan.
2. Patient Safety Enhancement Program, VA Medical Center and University of Michigan Health System, Ann Arbor, Michigan.
3. Transfusion Medicine Unit, Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York.
4. Hematology-Oncology Unit, Department of Medicine, University of Rochester, Rochester, New York.
5. Cardiac Surgery Unit, Department of Surgery, University of Rochester, Rochester, New York.