1. Total Healthcare Center Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine Seoul Korea
2. Department of Internal Medicine Yonsei University College of Medicine Seoul Korea
3. Department of Family Medicine/Supportive Care Center Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul Korea
4. Department of Biostatistics Soongsil University Seoul Korea
5. Department of Family Medicine CHA Gumi Medical Center, CHA University Gumi Korea
6. Department of Family Medicine, Healthcare System Gangnam Center Seoul National University Hospital Seoul Korea