[1] Kyungpook Natl Univ, Dept Internal Med, Sch Med, Taegu, South Korea
[2] Keimyung Univ, Dept Internal Med, Sch Med, Taegu, South Korea
[3] Kyungpook Natl Univ, WCU Program, Sch Med, Taegu, South Korea
[4] Kyungpook Natl Univ, Dept Prevent Med, Sch Med, Taegu, South Korea