1. Center for Palliative Care and Clinical Ethics, Seoul National University Hospital, Seoul, Korea.
2. Public Healthcare Center, Seoul National University Hospital, Seoul, Korea.
3. Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
4. Department of Psychiatry, Seoul National University College of Medicine, Seoul, Korea.
5. Division of Hematology and Medical Oncology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
6. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.