title: Evaluation of a summary score of cognitive performance for use in trials in perioperative and critical care.
abstract: OBJECTIVE
  Cognitive dysfunction after medical treatment is increasingly being recognized. Studies on this topic require repeated cognitive testing within a short time. However, with repeated testing, practice effects must be expected. We quantified practice effects in a demographically corrected summary score of a neuropsychological test battery repeatedly administered to healthy elderly volunteers.
  
  
  METHODS
  The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Neuropsychological Assessment Battery (for which a demographically corrected summary score was developed), phonemic fluency tests, and trail-making tests were administered in healthy volunteers aged 65 years or older on days 0, 7, and 90. This battery allows calculation of a demographically adjusted continuous summary score.
  
  
  RESULTS
  Significant practice effects were observed in the CERAD total score and in the word list (learning and recall) subtest. Based on these volunteer data, we developed a threshold for diagnosis of postoperative cognitive dysfunction (POCD) with the CERAD total score.
  
  
  CONCLUSIONS
  Practice effects with repeated administration of neuropsychological tests must be accounted for in the interpretation of such tests. Ignoring practice effects may lead to an underestimation of POCD. The usefulness of the proposed demographically adjusted continuous score for cognitive function will have to be tested prospectively in patients.
authors.affiliation: Department of Anesthesia and Intensive Care Medicine, University Hospital Basel, Basel, Switzerland. cburkhart@uhbs.ch
authors.forename: Christoph S
authors.initials: CS
authors.lastname: Burkhart
authors.forename: Dagmar
authors.initials: D
authors.lastname: Birkner-Binder
authors.forename: Alexa
authors.initials: A
authors.lastname: Gagneux
authors.forename: Manfred
authors.initials: M
authors.lastname: Berres
authors.forename: Stephan P
authors.initials: SP
authors.lastname: Strebel
authors.forename: Andreas U
authors.initials: AU
authors.lastname: Monsch
authors.forename: Luzius A
authors.initials: LA
authors.lastname: Steiner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001288:Attention; D003071:Cognition; D003422:Critical Care / Q000523:psychology*; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall; D009483:Neuropsychological Tests; D019990:Perioperative Care; D011597:Psychomotor Performance; D014705:Verbal Behavior