Affiliation: | 1. Department of Anaesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea;2. Anaesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea;3. Department of Surgery, Yonsei University College of Medicine, Seoul, Korea;4. Department of Research Affairs, Biostatistics Collaboration Unit, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea |