title: Understanding of informed consent by demented individuals.
abstract: BACKGROUND
  The informed consent process is central to the conduct of research but may be difficult for cognitively impaired participants to understand. The authors developed a brief test addressing the elements of informed consent for a specific minimum-risk nontreatment research protocol.
  
  
  OBJECTIVE
  To evaluate and document understanding of informed consent by elderly research participants across a range of dementia severity.
  
  
  METHODS
  The elements of informed consent regarding participation in a longitudinal study of healthy aging and dementia were reviewed with both demented (n = 250) and nondemented (n = 165) participants who then completed a short test requiring yes-no responses to assess understanding of these elements. Demented participants had very mild, mild, or moderate dementia as staged by the Clinical Dementia Rating.
  
  
  RESULTS
  After adjusting for education, performance on the test varied with dementia severity in mean differences and by correlation. All nondemented and very mildly demented participants and 92% of mildly demented participants provided correct answers for at least 8 of 10 true-false items, whereas only 67% of the moderately demented participants achieved this level of accuracy.
  
  
  CONCLUSIONS
  Demented individuals, very mild and mild, understood informed consent information for this nontreatment research study. Understanding notably declined in the moderate stage of dementia. Brief tests may be useful as one method to assess understanding of the consent process for specific studies.
authors.affiliation: Department of Neurology, Washington University School of Medicine, USA. bucklesv@abraxas.wustl.edu
authors.forename: V D
authors.initials: VD
authors.lastname: Buckles
authors.forename: K K
authors.initials: KK
authors.lastname: Powlishta
authors.forename: J L
authors.initials: JL
authors.lastname: Palmer
authors.forename: M
authors.initials: M
authors.lastname: Coats
authors.forename: T
authors.initials: T
authors.lastname: Hosto
authors.forename: A
authors.initials: A
authors.lastname: Buckley
authors.forename: J C
authors.initials: JC
authors.lastname: Morris
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D032882:Comprehension / Q000941:ethics*; D032962:Consent Forms / Q000941:ethics; D003704:Dementia / Q000175:diagnosis* / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D007258:Informed Consent / Q000941:ethics* / Q000706:statistics & numerical data; D008137:Longitudinal Studies; D008297:Male; D016743:Mental Competency; D009483:Neuropsychological Tests / Q000592:standards* / Q000706:statistics & numerical data