1. Division of Hematology & Medical Oncology, Department of Internal Medicine, Dongguk University Ilsan Hospital, Goyang, Korea.
2. Division of Oncology/Hematology, Department of Internal Medicine, Korea University, Seoul, Korea.
3. Department of Statistics, Korea University, Seoul, Korea.
4. Research Institute, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
5. Division of Oncology-Hematology, Department of Internal Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea.