1. Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan
2. Department of Anesthesiology, Kansai Medical University Hospital, Osaka, Japan
3. Department of Orthopedics, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
4. Department of Orthopedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
5. Department of Anesthesiology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
6. Health Policy Research Center, Taipei Medical University Hospital, Taipei, Taiwan
7. Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan