neurocognitive changes associated with impairment
of TCC in neurocognitive disorders such as dementia.
Findings suggest that multiple cognitive functions are
associated with the loss of consent capacity in patients
with AD. For example, deficits in conceptualization,
semantic memory, and probably verbal recall appear
to be associated with the significantly impaired capac-
ity of both mild and moderate AD patients to under-
stand a treatment situation and choices (S5). A factor
analysis of TCC in an AD population revealed a two-
factor solution comprising verbal reasoningand ver-
bal memory, which was subsequently validated using
a form of neuropsychological confirmatory analysis.
In contrast, in studies of patients with PD and demen-
tia, executive function measures have emerged as the
primary predictors of impairments of TCC.Daniel C. Marson and Katina R. HebertSee also Capacity to Consent to Treatment Instrument
(CCTI); Competency, Foundational and Decisional;
Consent to Clinical Research; End-of-Life Issues;
MacArthur Competence Assessment Tool for Clinical
Research (MacCAT–CR); MacArthur Competence
Assessment Tool for Treatment (MacCAT–T)Further Readings
Dymek, M. P., Atchison, P., Harrell, L. E., & Marson, D. C.
(2001). Competency to consent to medical treatment in
cognitively impaired patients with Parkinson’s disease.
Neurology, 56,17–24.
Grisso, T. (2003). Competence to consent to treatment. In
Evaluating civil competencies: Forensic assessment and
instruments(2nd ed., pp. 391–458). New York: Kluwer
Press.
Grisso, T., & Appelbaum, P. S. (1995). The MacArthur
Treatment Competence Study. III: Abilities of patients to
consent to psychiatric and medical treatments. Law and
Human Behavior, 19,149–169.
Grisso, T., & Appelbaum, P. S. (1998). Assessing competence to
consent to treatment. New York: Oxford University Press.
Kim, S. Y., Karlawish, J. H., & Caine, E. D. (2002). Current
state of research on decision-making competence of
cognitively impaired elderly persons. American Journal of
Geriatric Psychiatry, 10,151–165.
Marson, D. C., Chatterjee, A., Ingram, K., & Harrell, L. (1996).
Toward a neurologic model of competency: Cognitive
predictors of capacity to consent in Alzheimer’s disease
using three different legal standards. Neurology, 46,
666–672.
Marson, D. C., Dreer, L. E., Krzywanski, S., Huthwaite, J. S.,
DeVivo, M. J., & Novack, T. A. (2005). Impairment andpartial recovery of medical decision-making capacity
in traumatic brain injury: A 6-month longitudinal study.
Archives of Physical Medicine and Rehabilitation,
86,889–895.
Marson, D. C., Ingram, K., Cody, H., & Harrell, L. (1995).
Assessing the competency of Alzheimer’s disease patients
under different legal standards: A prototype instrument.
Archives of Neurology, 52(10), 949–954.
Moye, J., Karel, M. J., Azar, A. R., & Gurrera, R. J. (2004).
Capacity to consent to treatment: Empirical comparison
of three instruments in patients with and without
dementia. The Gerontologist, 44(2), 166–175.CAPACITY TO CONSENT TO
TREATMENTINSTRUMENT(CCTI)
The Capacity to Consent to Treatment Instrument
(CCTI) is a standardized psychometric instrument
designed to assess the treatment consent capacity
(TCC) of adults. The CCTI evaluates five different
consent abilities or standards and has been shown to be
a reliable and valid measure of TCC. The measure dis-
criminates well between cognitively intact adults and
persons with Alzheimer’s disease (AD), Parkinson’s
disease dementia syndrome, and traumatic brain
injury. The CCTI has application to all adult patient
populations in which issues of neurocognitive impair-
ment and consent capacity arise. Research using the
CCTI has provided insight into the relationships
between cognitive change and different thresholds of
decisional capacity.Structure and
Administration of the CCTI
The CCTI was first developed in 1992 to empirically
investigate patterns of consent capacity impairment in
patients with mild and moderate AD. The measure con-
sists of two clinical vignettes that present hypothetical
medical problems and their symptoms (brain tumor,
atherosclerotic heart disease) as well as treatment alter-
natives with the associated risks and benefits. The
CCTI is administered in a way that simulates an
informed consent dialogue between the physician and
the patient. The vignettes are presented simultaneously
in oral and written format using an uninterrupted dis-
closure method. They are written at a fifth- to sixth-
grade reading level, with low syntactic complexity and
a moderate information load.54 ———Capacity to Consent to Treatment Instrument (CCTI)C-Cutler (Encyc)-45463.qxd 11/18/2007 12:41 PM Page 54