1. Tobacco Research and Treatment Center, Massachusetts General Hospital, Boston2Mongan Institute for Health Policy, Massachusetts General Hospital, Boston
2. Center for Statistical Sciences, Brown University School of Public Health, Providence, Rhode Island4Department of Epidemiology, Brown University School of Public Health, Providence, Rhode Island
3. National Center for PTSD, Veterans Affairs Boston Healthcare System, Boston, Massachusetts
4. Massachusetts General Hospital Cancer Center, Boston
5. Center for Statistical Sciences, Brown University School of Public Health, Providence, Rhode Island
6. Tobacco Research and Treatment Center, Massachusetts General Hospital, Boston7Division of General Internal Medicine, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston