title: Validation of the confusion assessment method in detecting postoperative delirium in cardiac surgery patients.
abstract: BACKGROUND
  Early detection, prevention, and treatment of delirium after cardiac surgery are important for quick postoperative recovery. The Confusion Assessment Method (CAM) may be an easy-to-use instrument for detecting delirium in clinical practice.
  
  
  OBJECTIVE
  To compare the congruent validity of the CAM with the results from repeated assessments by using a combination of the Organic Brain Syndrome Scale and the Mini-Mental State Examination according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) criteria for delirium.
  
  
  METHODS
  Patients aged 70 years or older undergoing cardiac surgery were assessed on postoperative days 1 and 4, and the 2 diagnostic methods were compared. The sensitivity and specificity of the CAM were examined. The reference method allowed categorization of delirium into subgroups of psychomotor activities and psychiatric symptom profiles, which were compared with the CAM results.
  
  
  RESULTS
  Postoperative delirium was diagnosed in 78 of 141 patients (55.3%). According to the CAM, 59 patients (41.8%) were categorized as delirious, 53 correctly. Thus, the sensitivity was 68% and the specificity was 90%, indicating false-negative rather than false-positive observations.
  
  
  CONCLUSIONS
  Patients with psychomotor hyperactivity and mixed psychotic-emotional symptoms were more likely to have delirium detected via the CAM than were patients with less obvious clinical manifestations of delirium. Repetitive cognitive testing and psychogeriatric experience are probably necessary to improve the results obtained with the CAM.
authors.affiliation: Nina Smulter is a registered nurse and lecturer, Department of Nursing and Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division Umeå University, Umeå, Sweden. Helena Claesson Lingehall is a registered nurse and doctoral student at Department of Nursing, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University, and a nurse anesthetist in the Heart Center, University Hospital of Umeå, Västerbotten, Sweden. Yngve Gustafson is a professor, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University. Birgitta Olofsson is an associate professor, Department of Nursing, Umeå University. Karl Gunnar Engström is a professor, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University. nina.smulter@umu.se.
authors.forename: Nina
authors.initials: N
authors.lastname: Smulter
authors.affiliation: Nina Smulter is a registered nurse and lecturer, Department of Nursing and Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division Umeå University, Umeå, Sweden. Helena Claesson Lingehall is a registered nurse and doctoral student at Department of Nursing, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University, and a nurse anesthetist in the Heart Center, University Hospital of Umeå, Västerbotten, Sweden. Yngve Gustafson is a professor, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University. Birgitta Olofsson is an associate professor, Department of Nursing, Umeå University. Karl Gunnar Engström is a professor, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University.
authors.forename: Helena Claesson
authors.initials: HC
authors.lastname: Lingehall
authors.affiliation: Nina Smulter is a registered nurse and lecturer, Department of Nursing and Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division Umeå University, Umeå, Sweden. Helena Claesson Lingehall is a registered nurse and doctoral student at Department of Nursing, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University, and a nurse anesthetist in the Heart Center, University Hospital of Umeå, Västerbotten, Sweden. Yngve Gustafson is a professor, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University. Birgitta Olofsson is an associate professor, Department of Nursing, Umeå University. Karl Gunnar Engström is a professor, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University.
authors.forename: Yngve
authors.initials: Y
authors.lastname: Gustafson
authors.affiliation: Nina Smulter is a registered nurse and lecturer, Department of Nursing and Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division Umeå University, Umeå, Sweden. Helena Claesson Lingehall is a registered nurse and doctoral student at Department of Nursing, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University, and a nurse anesthetist in the Heart Center, University Hospital of Umeå, Västerbotten, Sweden. Yngve Gustafson is a professor, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University. Birgitta Olofsson is an associate professor, Department of Nursing, Umeå University. Karl Gunnar Engström is a professor, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University.
authors.forename: Birgitta
authors.initials: B
authors.lastname: Olofsson
authors.affiliation: Nina Smulter is a registered nurse and lecturer, Department of Nursing and Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division Umeå University, Umeå, Sweden. Helena Claesson Lingehall is a registered nurse and doctoral student at Department of Nursing, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University, and a nurse anesthetist in the Heart Center, University Hospital of Umeå, Västerbotten, Sweden. Yngve Gustafson is a professor, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University. Birgitta Olofsson is an associate professor, Department of Nursing, Umeå University. Karl Gunnar Engström is a professor, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University.
authors.forename: Karl Gunnar
authors.initials: KG
authors.lastname: Engström
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003221:Confusion / Q000175:diagnosis*; D003693:Delirium / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests / Q000592:standards*; D011183:Postoperative Complications / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity