1 Yon-In Severance Hospital, Department of Family Medicine, Yonsei University College of Medicine, Yong-In, Republic of Korea Department of Medicine, Graduate School of Yonsei University College of Medicine, Seoul, Republic of Korea Chungbuk National University College of Medicine, Department of Family Medicine, Cheongju, Republic of Korea Department of Medicine, Graduate School of Yonsei University College of Medicine, Seoul, Republic of Korea.