[1] Korea Univ, Coll Med, Dept Prevent Med, Seoul 136705, South Korea
[2] Korea Hlth Insurance Review Agcy, Seoul, South Korea
[3] Chungbuk Natl Univ, Coll Med, Dept Thorac & Cardiovasc Surg, Cheongju, South Korea
[4] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Urol, Seoul, South Korea
[5] Ewha Womans Univ, Coll Med, Dept Anat, Seoul, South Korea