[1] Korea Univ, Coll Med, Dept Internal Med, Seoul, South Korea
[2] Korea Univ Guro Hosp, Internal Med, Seoul, South Korea
[3] Korea Univ Anam Hosp, Dept Internal Med, Seoul, South Korea
[4] Seoul Natl Univ, Seoul Metropolitan Govt, Coll Med, Dept Internal Med,Boramae Med Ctr, Seoul, South Korea
[5] Soonchunhyang Univ Seoul Hosp, Dept Internal Med, Seoul, South Korea
[6] Soonchunhyang Univ, Cheonan Hosp, Coll Med, Dept Internal Med, Cheonan, South Korea
[7] Gachon Univ, Gil Med Ctr, Dept Internal Med, Seongnam, South Korea
[8] Catholic Univ Korea, Uijeongbu St Marys Hosp, Coll Med, Dept Internal Med, Seoul, South Korea
[9] Hallym Univ, Kangdong Sacred Heart Hosp, Med Ctr, Internal Med, Chunchon, South Korea
[10] Kyunghee Univ Hosp, Dept Internal Med, Gangdong, South Korea
[11] Wonkwang Univ, Coll Med, Dept Internal Med, Iksan, South Korea
[12] Jeonbuk Natl Univ Hosp, Dept Internal Med, Jeonju, South Korea
[13] Chungnam Natl Univ Hosp, Dept Gastroenterol, 282 Munhwa Ro, Daejeon 35015, South Korea
[14] Seoul Natl Univ Hosp, Dept Internal Med, Seoul, South Korea
[15] Daegu Catholic Univ, Med Ctr, Dept Internal Med, Gyongsan, South Korea
[16] Catholic Univ Korea, Seoul St Marys Hosp, Dept Internal Med, Seoul, South Korea
[17] Gangnam Severance Hosp, Dept Internal Med, Seoul, South Korea
[18] Catholic Univ Korea, Incheon St Marys Hosp, Dept Internal Med, Seoul, South Korea
[19] Yonsei Univ, Wonju Sevrance Christian Hosp, Wonju Coll Med, Dept Internal Med, Seoul, South Korea
[20] Catholic Univ Korea, St Vincents Hosp, Dept Internal Med, Seoul, South Korea
[21] Yeungnam Univ, Coll Med, Dept Internal Med, Daegu, South Korea
[22] Inje Univ, Sanggye Paik Hosp, Dept Internal Med, Gimhae, South Korea