[1] Yonsei Univ, Div Gastroenterol & Hepatol, Dept Internal Med, Wonju Coll Med, Wonju 220701, Gangwon Do, South Korea
[2] Yonsei Univ, Dept Pathol, Wonju Coll Med, Wonju 220701, Gangwon Do, South Korea
[3] Chung Ang Univ, Dept Appl Stat, Seoul 156756, South Korea