[1] Mayo Clin, Div Gastroenterol & Hepatol, Rochester, MN 55905 USA
[2] Stanford Univ, Div Gastroenterol & Hepatol, Stanford, CA 94305 USA
[3] Mayo Clin, Div Biomed Stat & Informat, Rochester, MN USA
[4] Mayo Clin, Div Transplant Surg, Rochester, MN USA
[5] Mayo Clin, Div Nephrol & Hypertens, Rochester, MN USA