Alzheimer's Disease Patients' and Caregivers' Capacity, Competency, and Reasons to Enroll in an Early-Phase Alzheimer's Disease Clinical Trial

Authors

  • Jason H. T. Karlawish MD,

    1. Department of Medicine, Division of Geriatrics, University of Pennsylvania, Philadelphia, Pennsylvania;
    2. Alzheimer's Disease Center, Philadelphia, Pennsylvania;
    3. Center for Bioethics, Philadelphia, Pennsylvania;
    4. Leonard Davis Institute for Health Economics, Philadelphia, Pennsylvania; and
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  • David J. Casarett MD,

    1. Department of Medicine, Division of Geriatrics, University of Pennsylvania, Philadelphia, Pennsylvania;
    2. Leonard Davis Institute for Health Economics, Philadelphia, Pennsylvania; and
    3. Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
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  • Bryan D. James MBioethics

    1. Department of Medicine, Division of Geriatrics, University of Pennsylvania, Philadelphia, Pennsylvania;
    2. Center for Bioethics, Philadelphia, Pennsylvania;
    3. Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
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Address correspondence to Jason Karlawish, MD, 3615 Chestnut St., Philadelphia, PA 19104. E-mail: jasonkar@mail.med.upenn.edu

Abstract

OBJECTIVES: To examine the capacity, competency, and reasons for enrolling of patients with Alzheimer's disease (AD) and of their caregivers in an early phase AD clinical trial.

DESIGN: Interviews were conducted with patients with AD, nondemented older persons, and caregivers.

SETTING: Participants' homes.

PARTICIPANTS: Fifteen patients with mild to moderate AD, 15 age- and education-matched nondemented older persons, and 15 patient caregivers.

MEASUREMENTS: Capacity was measured using the MacArthur Competency Assessment Tool for Clinical Research (MacCAT-CR); a study coordinator who reviewed audiotapes of the capacity interviews judged competency, and the reasons for a decision were determined by coding the capacity interviews.

RESULTS: On all measures except the ability to make a choice, patients performed worse than controls (understanding: z = 3.2, P = .001; appreciation: z = 2.8, P = .005; reasoning: z = 3.5, P = .0005), and caregivers (understanding: z = 3.8, P = .0002; appreciation: z = 3.0, P = .003; reasoning: z = 3.6, P = .0003). Using the controls' performance to set psychometric criteria to define capacity, the proportions of patients with adequate understanding, appreciation, and reasoning were six of 15 (40%), three of 15 (20%), and five of 15 (33%). All caregivers and nine of the 15 (60%) patients were competent. Reasons for enrolling typically featured the potential benefit to the patients' health or well-being and altruism that was expressed as a desire to help other patients and their families or a desire to contribute to scientific knowledge.

CONCLUSIONS: The MacCAT-CR, in particular its understanding scale, is a reliable and valid way to assess patient capacity and competency to enroll in an early-phase clinical trial. Although many patients have significant impairments in their capacity, some mild-stage patients are competent. Reasons for enrolling in an early-phase trial blend an expectation of therapeutic benefit and a desire to help others.

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