1. Department of Nursing Science, Gachon University, Incheon, Korea.
2. The Health Insurance Review and Assessment Service, Seoul, Korea.
3. Department of Neurosurgery, Korea University Hospital, Seoul, Korea.
4. Department of Family Medicine, Hallym University Kangdong Sacred Heart Hospital, Seoul, Korea.
5. Department of Orthopedic Surgery, Ewha Womans University Hospital, Seoul, Korea.