1. Department of Internal Medicine College of Medicine St. Vincent's Hospital The Catholic University of Korea Seoul Korea
2. Department of Statistics and Actuarial Science Soongsil University Seoul Korea
3. Department of Epidemiology Fay W. Boozman College of Public Health University of Arkansas for Medical Sciences Little Rock AZ USA
4. Department of Internal Medicine Daegu Dongsan Hospital Keimyung University Daegu Korea
5. Department of Internal Medicine Severance Hospital Yonsei University College of Medicine Seoul Korea