[1] Wonkwang Univ, Coll Med, Dept Internal Med, Iksan, South Korea
[2] Inst Wonkwang Med Sci, Iksan, South Korea
[3] Chonnam Natl Univ, Med Sch, Dept Internal Med, Gwangju, South Korea
[4] Univ Ulsan, Coll Med, Dept Internal Med, Seoul, South Korea
[5] Seoul Natl Univ, Boramae Med Ctr, Dept Internal Med, Seoul Metropolitan Govt, Seoul, South Korea
[6] Chungnam Natl Univ, Coll Med, Dept Internal Med, Daejeon, South Korea
[7] Soonchunhyang Univ, Sch Med, Dept Internal Med, Bucheon, South Korea
[8] Inje Univ, Ilsan Paik Hosp, Coll Med, Dept Internal Med, Goyang, South Korea
[9] Inje Univ, Sanggye Paik Hosp, Coll Med, Dept Internal Med, Seoul, South Korea
[10] Keimyung Univ, Dongsan Med Ctr, Sch Med, Dept Internal Med, Daegu, South Korea
[11] Kyungpook Natl Univ, Chilgok Hosp, Sch Med, Dept Internal Med, Daegu, South Korea
[12] Inha Univ, Sch Med, Dept Internal Med, Incheon, South Korea
[13] Catholic Univ Korea, Eunpyeong St Marys Hosp, Coll Med, Dept Internal Med, Seoul, South Korea
[14] Eulji Univ, Uijeongbu Eulji Med Ctr, Sch Med, Dept Internal Med, Uijongbu, South Korea
[15] Hallym Univ, Dongtan Sacred Heart Hosp, Coll Med, Dept Internal Med,Div Gastroenterol, Hwaseong, South Korea
[16] Natl Evidence based Healthcare Collaborating Agcy, Seoul, South Korea
[17] Shihwa Med Ctr, Dept Internal Med, Shihung, South Korea
[18] Soonchunhyang Univ, Coll Med, Seoul Hosp, Dept Internal Med,Div Gastroenterol, Seoul, South Korea