1. Department of Family Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, 93-6 Jungbu-daero, Paldal-gu, Suwon 442-723, Republic of Korea
2. Department of Internal Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, 93-6 Jungbu-daero, Paldal-gu, Suwon 442-723, Republic of Korea