1. Cardiovascular Engineering, Inc., Norwood, MA
2. Department of Biostatistics, Boston University School of Public Health, Boston, MA
3. Framingham Heart Study, Framingham, MA
4. Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA
5. Veterans Administration Hospital, West Roxbury, MA
6. Department of Epidemiology, Boston University School of Public Health, Boston, MA
7. Preventive Medicine and Cardiology Sections, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
8. Evans Department of Medicine, Boston University School of Medicine, Boston, MA