1. Department of Internal Medicine, College of Medicine, Hallym University , Seoul , Republic of Korea
2. Department of Internal Medicine, Guri Hospital, College of Medicine, Hanyang University , 153, Gyeongchun-ro, Guri-si, Gyeonggi-do 11923 , Republic of Korea
3. Department of Statistics and Actuarial Science, Soongsil University , 369, Sangdo-ro, Dongjak-gu, Seoul 06978 , Republic of Korea
4. Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine , 29 Saemunan-ro, Jongno-gu, Seoul 03181 , Republic of Korea