1. Division of Infectious Diseases; Department of Medicine, Perelman School of Medicine; University of Pennsylvania; Philadelphia PA USA
2. Department of Biostatistics and Epidemiology; Center for Clinical Epidemiology and Biostatistics; Perelman School of Medicine; University of Pennsylvania; Philadelphia PA USA
3. Medicine Service; Philadelphia Veterans Affairs Medical Center; Philadelphia PA USA
4. Division of Infectious Diseases; Department of Medicine; Emory School of Medicine; Atlanta GA USA
5. Department of Medicine; Penn Presbyterian Medical Center; Philadelphia PA USA
6. Department of Medicine; Pennsylvania Hospital; Philadelphia PA USA
7. Division of Infectious Diseases; Department of Medicine; Cooper University Hospital; Camden NJ USA
8. Jonathan Lax Treatment Center; Philadelphia Field Initiating Group for HIV Trials; Philadelphia PA USA
9. Division of Gastroenterology; Department of Medicine; Perelman School of Medicine; University of Pennsylvania; Philadelphia PA USA