Interpreting the clinical significance of capacity scores for informed consent in alzheimer disease clinical trials

Jason Karlawish, Scott Y H Kim, David S Knopman, Christopher H. Van Dyck, Bryan D. James, M. Bioethics, Daniel Marson

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

Objective: Among Alzheimer disease (AD) patients enrolled in a clinical trial, the authors assessed the ability of a standardized capacity assessment procedure to identify persons who are capable of giving their own informed consent. Design: Cross-sectional interview. Setting: Thirteen sites participating in a randomized and placebo controlled study of simvastatin for the treatment of mild to moderate AD. Participants: Persons with mild to moderate AD and their study partners enrolled in the simvastatin clinical trial. Measurements: Interviews to assess decision-making capacity using the MacArthur Competency Assessment Tool for Clinical Research (MacCAT-CR). Results: Judges blinded to the subject's clinical status had a high rate of agreement on patients capable of giving their own informed consent (κ = 0.73). The understanding subscale had the best receiver operator characteristic and an analysis of positive and negative predictive values over a range of hypothetical prevalences of incapacity to consent demonstrated the value of a range of understanding cut-points. Conclusion: Among mild to moderate AD patients, enrolled in an actual clinical trial, these results suggest evidence based guidelines for using the MacCAT-CR understanding subscale to help guide judgments about whether a patient has the capacity to consent.

Original languageEnglish (US)
Pages (from-to)568-574
Number of pages7
JournalAmerican Journal of Geriatric Psychiatry
Volume16
Issue number7
DOIs
StatePublished - Jul 2008

Fingerprint

Informed Consent
Alzheimer Disease
Clinical Trials
Simvastatin
Interviews
Aptitude
Research
Decision Making
Placebos
Guidelines
Therapeutics

Keywords

  • Alzheimer disease
  • Decision making capacity
  • Informed consent

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Geriatrics and Gerontology
  • Medicine(all)

Cite this

Interpreting the clinical significance of capacity scores for informed consent in alzheimer disease clinical trials. / Karlawish, Jason; Kim, Scott Y H; Knopman, David S; Van Dyck, Christopher H.; James, Bryan D.; Bioethics, M.; Marson, Daniel.

In: American Journal of Geriatric Psychiatry, Vol. 16, No. 7, 07.2008, p. 568-574.

Research output: Contribution to journalArticle

Karlawish, Jason ; Kim, Scott Y H ; Knopman, David S ; Van Dyck, Christopher H. ; James, Bryan D. ; Bioethics, M. ; Marson, Daniel. / Interpreting the clinical significance of capacity scores for informed consent in alzheimer disease clinical trials. In: American Journal of Geriatric Psychiatry. 2008 ; Vol. 16, No. 7. pp. 568-574.
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