1. a Division of Infectious Diseases, Department of Medicine , Vanderbilt University School of Medicine , Nashville , TN , USA
2. b Division of Infectious Diseases , Meharry Medical College , Nashville , TN , USA
3. c Vanderbilt Institute for Global Health , Vanderbilt University School of Medicine , Nashville , TN , USA
4. d Division of Epidemiology, Department of Medicine , Vanderbilt University School of Medicine , Nashville , TN , USA
5. e Department of Biostatistics , Vanderbilt University School of Medicine , Nashville , TN , USA
6. f Center for Health Services Research, Department of Medicine , Vanderbilt University School of Medicine , Nashville , TN , USA