[1] Seoul Natl Univ Hosp, Dept Internal Med, 101 Daehak Ro, Seoul 03080, South Korea
[2] Seoul Natl Univ, Dept Internal Med, Coll Med, Seoul, South Korea
[3] Catholic Univ Korea, Coll Med, Dept Med Stat, Seoul, South Korea
[4] Soongsil Univ, Dept Stat & Actuarial Sci, Seoul, South Korea
[5] Univ Liverpool, Liverpool Ctr Cardiovasc Sci, Liverpool, Merseyside, England
[6] Liverpool Chest & Heart Hosp, Liverpool, Merseyside, England
[7] Aalborg Univ, Dept Clin Med, Aalborg, Denmark