1. Department of Anesthesiology and Pain Medicine Daegu Catholic University Medical Center School of Medicine Daegu Catholic University Daegu Korea
2. Department of Anesthesiology and Pain Medicine School of Medicine Kyungpook National University Chilgok Hospital Kyungpook National University Daegu Korea
3. Department of Psychiatry School of Medicine Catholic University of Daegu Daegu Korea
4. Department of Anesthesiology and Pain Medicine Hanyang University Medical Center Seoul Korea
5. Biostatistical Consulting and Research Lab Medical Research Collaborating Center Hanyang University Seoul Korea
6. Department of Anesthesiology and Pain Medicine Hanyang University Medical Center College of Medicine Hanyang University Seoul Korea