1. Department of Emergency Medicine, Boston University School of Medicine and Boston Medical Center, Boston, Massachusetts, USA
2. Beth Israel Deaconess Medical Center, Department of Medicine, Section of Infectious Diseases, Boston, Massachusetts, USA
3. Section of Infectious Diseases, Department of Medicine, VA Boston Healthcare System, Boston, Massachusetts, USA
4. Harvard Medical School, Boston, Massachusetts, USA
5. VA Boston Center for Healthcare Organization and Implementation Research, Boston, Massachusetts, USA