1. Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, South Korea
2. Biostatistics Collaboration Unit, Department of Biomedical Systems Informatics, Yonsei University College of Medicine, Seoul, South Korea
3. Department of Urology, Inha University School of Medicine, Incheon, South Korea
4. Department of Urology, Wonju Yonsei University College of Medicine, Wonju, South Korea