1. Department of Health Sciences and Epidemiology, Northeastern University, Boston, Massachusetts
2. Department of Health Policy and Management, Harvard School of Public Health, Harvard University, Boston, Massachusetts
3. Massachusetts Veterans Epidemiology Research and Information Center, Veterans Affairs Boston Healthcare System, Boston4Department of Biostatistics, School of Public Health, Boston University, Boston, Massachusetts
4. Massachusetts Veterans Epidemiology Research and Information Center, Veterans Affairs Boston Healthcare System, Boston5Department of Medicine, School of Medicine, Boston University, Boston, Massachusetts
5. Massachusetts Veterans Epidemiology Research and Information Center, Veterans Affairs Boston Healthcare System, Boston6Department of Medicine, Harvard Medical School, Harvard University, Boston, Massachusetts