1. Division of General Internal Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts
2. Division of General Internal Medicine, Massachusetts General Hospital; Harvard Medical School; and Institute for Research, Quality, and Policy in Homeless Health Care, Boston Health Care for the Homeless Program, Boston, Massachusetts
3. Division of General Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts
4. Harvard Medical School and Division of General Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts