1. Deparment of Internal Medicine, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea.
2. Namgu Public Health Center, Busan, Korea.
3. Deparment of Internal Medicine, Dong-A University College of Medicine, Busan, Korea.
4. Deparment of Internal Medicine, Busan Paik Hospital, Inje Uiniversity College of Medicine, Busan, Korea.
5. Deparment of Internal Medicine, Kosin University College of Medicine, Busan, Korea.