1 Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan; Health Policy Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing St., Taipei, 11031, Taiwan. Electronic address: nekota@tmu.edu.tw.
2 Department of Anesthesiology, Cathay General Hospital, #280, Renai Road, Section 4, Taipei, 10630, Taiwan.