[1] Mahidol Univ, Siriraj Hosp, Fac Med, Clin Epidemiol Unit,Dept Res & Dev, 3rd Floor,SIMR Bldg, Bangkok 10700, Thailand
[2] Mayo Clin, Dept Med, Div Gastroenterol & Hepatol, Jacksonville, FL 32224 USA
[3] Univ Mississippi, Med Ctr, Dept Med, Div Nephrol, Jackson, MS 39216 USA
[4] Mayo Clin, Dept Med, Div Nephrol, Rochester, MN USA