[1] Ajou Univ, Sch Med, Ctr Hlth Promot, Dept Family Practice & Community Hlth, Suwon 443380, Gyeonggi Do, South Korea
[2] Ajou Univ, Sch Med, Dept Gastroenterol, Suwon 443380, Gyeonggi Do, South Korea
[3] Ajou Univ, Sch Med, Dept Anesthesiol, Suwon 443380, Gyeonggi Do, South Korea
[4] Ajou Univ, Sch Med, Dept Surg, Suwon 443380, Gyeonggi Do, South Korea