1. Department of Urology, School of Medicine, Kyung Hee University, Seoul, Korea.
2. Department of Preventive Medicine, School of Medicine, Kyung Hee University, Seoul, Korea.
3. Departments of Urology, Wonkwang University School of Medicine, Iksan, Korea.
4. Department of Urology, Chungnam National University College of Medicine, Daejeon, Korea.
5. School of Medical Welfare, Aichi Shukutoku University, Aichi, Japan.