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