[1] Hosp Univ Penn, Dept Surg, Div Transplant, 3400 Spruce St, Philadelphia, PA 19104 USA
[2] Temple Univ, Sch Med, Philadelphia, PA 19122 USA
[3] Univ Penn, Perelman Sch Med, Dept Med Eth & Hlth Policy, Philadelphia, PA 19104 USA
[4] Univ Penn, Dept Med, Perelman Sch Med, Div Gastroenterol, Philadelphia, PA 19104 USA
[5] Univ Penn, Perelman Sch Med, Dept Biostat & Epidemiol, Ctr Clin Epidemiol & Biostat, Philadelphia, PA 19104 USA
[6] Weill Cornell Med Coll, Dept Surg, Div Liver Transplantat & Hepatobiliary Surg, New York, NY USA
[7] Yale Univ, Sch Med, Dept Surg, New Haven, CT 06510 USA