1. Department of Medicine; Massachusetts General Hospital; Boston MA
2. Liver Center, Division of Gastroenterology, Department of Medicine; Massachusetts General Hospital; Boston MA
3. VA Pittsburgh Healthcare System; Pittsburgh PA
4. Division of Infectious Diseases; Icahn School of Medicine at Mount Sinai; New York NY
5. Center for Clinical Epidemiology and Biostatistics, Department of Biostatistics and Epidemiology, Perelman School of Medicine; University of Pennsylvania; Philadelphia PA
6. Hamad Medical Corporation; Doha Qatar
7. Weill Cornell Medical College; Doha, Qatar and New York NY