1. Formerly of Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114
2. Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115 (e-mail: )
3. MIT, 100 Main Street, Cambridge, MA 02142 (e-mail: )
4. Armstrong Institute for Patient Safety and Quality, Johns Hopkins University School of Medicine, 750 E Pratt Street, 15th Floor, Baltimore, MD 21202 (e-mail: )