Special Article
Current State of Research on Decision-Making Competence of Cognitively Impaired Elderly Persons

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As the number of cognitively impaired elderly persons increases, the need for evidence-based assessments of their capacity to consent to medical treatment and research participation will grow. The authors conducted an electronic and manual literature search for all English-language articles examining the decision-making capacity of elderly persons with dementia or cognitive impairment, reviewing articles in relation to key areas of methodological, clinical, and policy importance. The 32 relevant studies identified were highly heterogeneous, even in their definitions and measurements of decisional capacity. Although incapacity is common, many persons with dementia are capable of making their own medical and research decisions. In Alzheimer disease, memory and executive-function deficits predict decisional impairment. Still, at least in early stages of dementia, interventions may improve decisional abilities. Short and simple cognitive screening may be useful by identifying persons in need of more intensive evaluations. The use of expert judgment-based methods may mitigate the problem of a lack of a criterion standard for competence. Research into the decision-making competence of cognitively impaired elderly persons is a growing field. It is beginning to yield findings with practical implications for preserving the autonomy and welfare of this group of vulnerable elderly patients.

Section snippets

Definitions

The terms “decision-making capacity,” “decision-making competence,” and “decision-making abilities” are often used with varying and overlapping meanings.8 Since inconsistent definitions can lead to confusions in discussions of study findings, we adopt the following convention.

The terms “capacity” and “competence” refer to a categorical status. This does not mean that a categorical judgment about a person's capacity or competence is global in scope. It simply means that, for a particular

METHODS

We identified English-language empirical studies examining the decisional capacity or decision-making abilities of elderly persons with dementia or cognitive impairment, using MEDLINE (1966 to present), BioethicsLine (1973–2000), and PsycINFO (from 1967 to present) with keywords “mental competency” and “dementia.” Many more articles were found by examining the references of recovered articles. The final set of articles, displayed in Table 2, were included if their subjects were elderly (mean or

RESULTS

Table 2 shows that the reviewed studies were highly heterogeneous in terms of their subjects' diagnoses and degree of cognitive impairment, study setting, sample size and composition, conceptual framework, operationalization of the framework, and validation of their capacity-assessment methods. Thus, interpretation of these studies, especially the attempt to gauge their external validity, requires considerable caution. Although a thorough methodological review is not the goal of this paper, we

CONCLUSIONS

Our review is limited in a few ways. First, we used a set of inclusion criteria for selecting studies that left room for judgment. Although this was done in order to err on the side of inclusion, it is possible that this strategy may have added to the heterogeneity to the group of studies reviewed. Second, by selecting certain themes to review, we obviously neglected others. For instance, the overwhelming majority of studies used hypothetical decision-making scenarios for testing decisional

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    This work was supported in part by an American Association for Geriatric Psychiatry Eisai-Pfizer Alzheimer's Disease Research Fellowship, National Institute of Mental Health grants MH18911, and K23-MH64172 (Dr. Kim); by National Institute on Aging Alzheimer's Disease Center grants P30-AG01024 and K01-AG00931, and by a Paul Beeson Fellowship (Dr. Karlawish).

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