[1] Soonchunhyang Univ, Coll Med, Bucheon Hosp, Ctr Digest Dis, Bucheon, South Korea
[2] Soonchunhyang Univ, Coll Med, Bucheon Hosp, Res Inst,Dept Internal Med, Bucheon, South Korea
[3] Soonchunhyang Univ, Coll Med, Cheonan Hosp, Dept Internal Med, Bucheon, South Korea
[4] Soonchunhyang Univ, Seoul Hosp, Dept Internal Med, Coll Med, Bucheon, South Korea
[5] Univ Ulsan, Coll Med, Dept Internal Med, Gangneung Asan Hosp, Kangnung, South Korea
[6] Soonchunhyang Univ, Dept Biostat Consulting, Bucheon Hosp, Bucheon, South Korea