Department of Internal Medicine, Bucheon St. Mary's Hospital, Bucheon, South Korea; College of Medicine, The Catholic University of Korea, Seoul, South Korea. Department of Internal Medicine, Seoul St. Mary's Hospital, Seoul, South Korea; College of Medicine, The Catholic University of Korea, Seoul, South Korea. Department of Internal Medicine, Uijeongbu St. Mary's Hospital, Uijeongbu, South Korea; College of Medicine, The Catholic University of Korea, Seoul, South Korea. Department of Internal Medicine, St. Vincent's Hospital, Suwon, South Korea; College of Medicine, The Catholic University of Korea, Seoul, South Korea. Department of Internal Medicine, Ansan Hospital, Korea University, Ansan, South Korea. Department of Internal Medicine, Bundang Hospital, College of Medicine, Seoul National University, Seongnam, South Korea. Department of Internal Medicine, Dong-A University Hospital, Busan, South Korea. Department of Internal Medicine, Chonnam National University Hospital, Gwangju, South Korea. Department of Internal Medicine, National Health Insurance Service, Ilsan Hospital, Goyang, South Korea. Department of Internal Medicine, Kangwon National University Hospital, Kangwon National University, Chuncheon, South Korea. Department of Internal Medicine, Cheju Halla General Hospital, Jeju, South Korea. Department of Internal Medicine, Inha University Hospital, Incheon, South Korea. Department of Internal Medicine, Daegu Catholic University Medical Center, Daegu, South Korea. Department of Internal Medicine, Kyunghee University Medical Center, Seoul, South Korea. Department of Internal Medicine, College of Medicine, Yonsei University, Seoul, South Korea. Department of Internal Medicine, Nowon Eulji Medical Center, Eulji University, Seoul, South Korea. Department of Internal Medicine, Seoul Medical Center, Seoul, South Korea. Department of Internal Medicine, Seoul National University Hospital, College of Medicine, Seoul National University, Seoul, South Korea. Department of Internal Medicine, Kangnam Sacred Heart Hospital, Hallym University, Seoul, South Korea. Department of Internal Medicine, Wonju Severance Christian Hospital, Wonju, South Korea. Department of Internal Medicine, Ajou University Hospital, Suwon, South Korea. Department of Internal Medicine, Dongsan Hospital, Keimyung University, Daegu, South Korea. Department of Internal Medicine, Seoul St. Mary's Hospital, Seoul, South Korea; College of Medicine, The Catholic University of Korea, Seoul, South Korea. Electronic address: kbseung0217@gmail.com.