1. Department of General Internal Medicine, Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts 02118, USA; Duke Global Health Institute, Duke University, Durham, NC 27710, USA; Department of Emergency Medicine, Boston VA Healthcare System, Jamaica Plain, MA 02130, USA
2. Department of General Internal Medicine, Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts 02118, USA; Department of Emergency Medicine, Boston VA Healthcare System, Jamaica Plain, MA 02130, USA
3. College of Computer and Information Science, Northeastern University, Boston, MA, USA