1. Department of Nursing, Yonsei University Graduate School, Seoul, Korea.
2. Mo-Im Kim Nursing Research Institute, College of Nursing, Yonsei University, Seoul, Korea.
3. Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Neurosurgery, Spine and Spinal Cord Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.