1. Division of General Internal Medicine, Department of Medicine, Massachusetts General Hospital, Boston
2. Harvard Medical School, Boston, Massachusetts
3. Munn Center for Nursing Research, Massachusetts General Hospital, Boston
4. Institute for Research, Quality, and Policy in Homeless Health Care, Boston Health Care for the Homeless Program, Boston, Massachusetts
5. Section of General Internal Medicine, Boston University School of Medicine, Boston, Massachusetts
6. University of Miami School of Medicine, Miami, Florida