1. Dana-Farber Cancer Institute, Boston, Massachusetts,
2. Dana-Farber Cancer Institute, Boston, Massachusetts, and Harvard School of Public Health, Department of Society, Human Development and Health, Boston, Massachusetts
3. Dana-Farber Cancer Institute, Boston, Massachusetts
4. New England Research Institute, Watertown, Massachusetts
5. Harvard University, John F. Kennedy School of Government, Cambridge, Massachusetts
6. Brown Medical School, Providence, Rhode Island