[1] Seoul Natl Univ, Boramae Med Ctr, Seoul, South Korea
[2] Korea Univ, Anam Hosp, Seoul, South Korea
[3] Chonnam Natl Univ Hosp, Gwangju, South Korea
[4] Gachon Med Sch, Gil Med Ctr, Incheon, South Korea
[5] Hallym Univ, Med Ctr, Chunchon, South Korea
[6] Ewha Womans Univ Hosp, Seoul, South Korea