Research in Gerontological Nursing

Methodological Review 

Considerations of Informed Consent and Decision-Making Competence in Older Adults with Cognitive Impairment

Ann M. Mayo, DNSc, RN, CNS; Margaret I. Wallhagen, PhD, GNP-BC, AGSF, FAAN


Including older adults with cognitive impairment in research studies is necessary to ensure that interventions designed to improve care are effective for all older adults. However, issues related to capacity to consent raise many difficult questions that nurse researchers must address. Protecting vulnerable participants while simultaneously maintaining autonomy and moving important research forward can be challenging. Assessing the decision-making abilities of understanding, appreciation, reasoning, and expressing a choice is an important aspect of determining decision-making capacity. Yet although this is the prominent rational method for judging decision-making competence, it does not take into consideration the importance of culture, values, and emotions. This article focuses on the assessment of decision-making capacity to consent, recommendations for obtaining informed consent in older adults with cognitive impairment, the use of surrogate decision makers, strategies to maximize research participation, and directions for future research.


Including older adults with cognitive impairment in research studies is necessary to ensure that interventions designed to improve care are effective for all older adults. However, issues related to capacity to consent raise many difficult questions that nurse researchers must address. Protecting vulnerable participants while simultaneously maintaining autonomy and moving important research forward can be challenging. Assessing the decision-making abilities of understanding, appreciation, reasoning, and expressing a choice is an important aspect of determining decision-making capacity. Yet although this is the prominent rational method for judging decision-making competence, it does not take into consideration the importance of culture, values, and emotions. This article focuses on the assessment of decision-making capacity to consent, recommendations for obtaining informed consent in older adults with cognitive impairment, the use of surrogate decision makers, strategies to maximize research participation, and directions for future research.

Older adults with cognitive impairment represent a rapidly growing population. Their increasing numbers draw attention to the need to include them in research studies to evolve evidence-based approaches to care. However, this raises several challenges: How do we recruit these older adults into studies and then maintain their involvement when their capacity to consent is impaired?

Current approaches to informed consent are based on specific ideas surrounding autonomy and individual choice. Respect for individuals and the resulting ethical conviction that autonomy must be preserved is basic to all research involving human beings. Thus, the prominent method to judge decision-making competence and ability to consent to participate in research uses a rational approach. This approach is based on the premises that individuals should have the abilities to make a choice, understand the research, appreciate the impact of participation to them personally, and logically reason through the consequences of participating or not participating to make that choice.

This article focuses on the current method used for determining decision-making capacity and the implications for researchers who desire to include individuals with cognitive impairment in research studies. Although the issues raised can be used in consideration of research participation for older adults in general, the emphasis is on those with documented cognitive impairment. Specifically, this article reviews the method and components used in evaluating decision-making capacity for informed consent, overall limitations of this rational method, when the use of a surrogate decision maker should be considered, and related issues. Finally, recommendations are made about designing approaches for informed consent in older adults with cognitive impairment and for future research.


Including older adults in research, regardless of cognitive ability, is necessary to ensure that interventions designed to improve care are effective for all older adults. However, although nurse investigators have the obligation to advance nursing science, they also have the obligation to protect participants from harm and respect participant autonomy. Cognitive impairment makes it difficult for older adults to understand information and for the investigator to know whether their consent to volunteer for the study is valid, which makes the consent process challenging (Sachs, 2007). Further, because participation in research can involve potential risk, including older adults with cognitive impairment in research without adequate consent may increase their risk for unintended harm.

Cognitive changes can result from normal aging, common medical disorders such as depression and sleep disorders, and dementia. This article specifically focuses on older adults who experience cognitive changes resulting from dementia. An estimated 3.8 million people in the United States have dementia (Plassman et al., 2007). Its underlying pathology alters neurotransmitters in the brain compromising normal cognition and decision making (Burns & Bechara, 2007; Goodenough & Prehn, 2004). Depending on the location of the pathology and severity of the dementia, executive function, which includes attention and information processing and/or memory, may be impaired (Cummings, 2003; Foster, Cornwell, Kisley, & Davis, 2007). For example, memory is known to be impaired in early to moderate stage Alzheimer’s disease (AD), whereas executive function is impaired in frontotemporal dementia. Eventually, however, all kinds of dementia compromise decision making.

Autonomy and Informed Consent

Autonomy means that individuals are self-directed and have the freedom to make their own decisions (“Autonomy,” 2009; Rosin & van Dijk, 2005). Obtaining an informed consent supports the principle of autonomy by providing information in a context that allows voluntary choice to potential participants who are competent to decide, to affirm their understanding, and to agree to participate (National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research [National Commission], 1979; Code of Federal Regulations[CFR], 2005; Grisso & Appelbaum, 1998). The Belmont Report (National Commission, 1979) identifies three elements of informed consent: information, comprehension, and voluntarism.


Providing the kind and amount of information that a reasonable volunteer would want to know is a critical aspect of the informed consent process (National Commission, 1979). The CFR (2005) stipulates that the information provided covers the research procedure and any foreseen risks involved in participation, as well as information about compensation for risk and/or treatment for injuries, alternatives to participation, benefits for participating, how confidentiality will be handled, how participation is voluntary, and that there will be no loss of any benefits (e.g., receiving health care) the potential participant may have prior to entering the study.


Potential participants must understand the information in order to make an informed choice. Thus, the complexity of both the research and the decision involved in choosing to participate underpin what information should be provided to potential participants or whether a third party should act on behalf of the individual (National Commission, 1979; Moye & Braun, 2007).


Consent is valid only if the participant truly volunteers. There should be no coercion or undue influence to participate in research (National Commission, 1979). Relationships with clinicians (who may or may not be the investigators), powerlessness felt within settings (e.g., nursing homes), and the socioeconomic status of older adults can subtly influence decision making. Older adults with cognitive impairment may be especially vulnerable to these influences.

Although both the CFR and The Belmont Report provide the elements of informed consent, research has yet to provide evidence for just what is the right kind and amount of information for reasonable volunteers (Johnson & Nelson, 2000), let alone that needed by those with cognitive impairment. Therefore, obtaining informed consent when potential participants are cognitively impaired creates concerns for investigators, including how to determine decision-making competence.

Determining Decision-Making Competence

In 1988, Levine established that individuals with dementia were to be considered, because of their cognitive impairment, vulnerable and incapable (to varying degrees) of protecting their own interests during an informed consent process. Subsequently, the National Bioethics Advisory Commission (1998) specifically identified AD as a disorder that may affect decision-making capacity. At the same time, the American Geriatrics Society (AGS) took the position that “diagnosis of dementia does not automatically confer decisional incapacity on affected individuals” (Sachs, 2007, Position 2, Rationale section) and that, because decision making is task specific, some individuals with cognitive impairment will be able to provide a valid informed consent (Sachs, 2007). Therefore, establishing capacity is an important aspect of the consent process.

Capacity to consent is determined by assessing specific decision-making abilities, while also considering the study’s design complexity, degree of research risk, and direct benefit to the participant (Cahill & Wichman, 2000; Kim, Caine, Currier, Leibovici, & Ryan, 2001). This method uses a rational approach. Decision-making abilities important to consider in all kinds of research include understanding, appreciation, reasoning, and expressing a choice (Appelbaum & Grisso, 2001; Kim, Karlawish, & Caine, 2002; Rosin & van Dijk, 2005).

Assessing Decision-Making Abilities

Assessing decision-making abilities involves asking potential participants narrative questions that provide information about understanding, appreciation, reasoning, and expressing a choice. Depending on the particular instrument used, responses to questions that assess each ability can be scored on a matrix. Scores help establish the degree of competence possessed in each of the separate abilities (Karlawish et al., 2008a). A number of instruments, such as the Hopkins Competency Assessment Test and Capacity Assessment Tool are available to determine decision-making abilities in general and can be used for older adults with cognitive impairment in particular (Kim et al., 2002). Performance on some instruments can be determined by either specifying a priori cut-off scores or using standard deviations determined from individuals without cognitive impairment (e.g., a score of 1.5 standard deviations below the unimpaired group) (Kim et al., 2001).

The MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR) is the most common decision-making competency instrument used in research (Appelbaum & Grisso, 2001; Kim et al., 2002). Each of the four MacCAT-CR domains is described in detail throughout the following discussion.

Expressing a Choice. Expressing a choice is simply the ability to communicate the desire to participate or not participate in the study and is considered a threshold ability. If the potential participant is unable to express a choice, there is no need to assess the other abilities. The final decision does not have to appear reasonable to the investigator and others. Reasonableness is not a criterion; the only criterion is that the potential participant can express a choice (Appelbaum & Grisso, 2001; Grisso & Appelbaum, 1998).

Understanding. Understanding is the ability to grasp the nature of the research project, the primary purpose of the research, how the research project differs from ordinary care, and any benefits (in general and to potential participants), risks, and discomforts particular to the study. Potential participants should also understand that they can refuse to participate or withdraw at any time and their ongoing care will not be affected (Appelbaum & Grisso, 2001).

To assess this domain, participants are asked about their understanding of the research risks and benefits. Responses are interpreted and scored using specific a priori guidelines. For example, if the understanding of the purpose of a study was vague (e.g., “They want to see what will happen.”), a score of 1 (range = 0 to 2) would be assigned. Among the four decision-making abilities, understanding is the one that is most frequently impaired, usually because of problems with recording and storing information, attention, and awareness. In addition to dementia, causative factors can include compromised sensory integrity (e.g., hearing, seeing), medical conditions including depression, medications, and below average intellectual capacities (Appelbaum & Grisso, 2001; Grisso & Appelbaum, 1998).

Appreciation. Appreciation is the ability to acknowledge how the decision to participate in research will affect the potential participant personally and includes awareness that the goal of the research is to generate new knowledge, not optimize the participant’s care. Examples include an appreciation that one has a chance of receiving a placebo or being randomized to a control group (Appelbaum & Grisso, 2001). To assess appreciation, potential participants are asked about how they would or would not be affected by a decision to participate (Appelbaum & Grisso, 2001; Grisso & Appelbaum, 1998).

Reasoning. Reasoning involves manipulating information in a logical way. For example, expressing the potential consequences of participating in research and comparing any alternatives to participating would elucidate reasoning ability. Reasoning should involve generating the consequences of participation in relation to everyday living and describe benefits, risks, or discomforts. Finally, reasoning should be logically consistent so the potential participant’s choice to participate or not fits with the choice expressed (Appelbaum & Grisso, 2001; Grisso & Appelbaum, 1998). Deficits in reasoning appear as an inability to cope with the complexity of options (Appelbaum & Grisso, 2001; Grisso & Appelbaum, 1998).

Scoring. Each of the four MacCAT-CR domains is scored using guidelines. There are no cut-off scores for the domains. The MacCAT-CR was developed based on legal definitions of competence recognizing that “no particular level of ability is always determinative of competence or incompetence across all subjects, all disorders, and all research situations” (Appelbaum & Grisso, 2001, p. 3). Further, a total score is not calculated because a serious deficit in only one of the four abilities may be interpreted as incompetence even if the other three abilities are adequate (Appelbaum & Grisso, 2001). Thus, the ultimate judgment of whether an individual is competent to consent remains with the investigator and must be contextualized to the setting and research study.

Although the MacCAT-CR is the tool most commonly used in research, investigators in clinical settings may be more familiar with standard cognitive assessments and neuropsychological tests such as the Mini-Mental State Examination (Folstein, Folstein, & McHugh, 1975), verbal reasoning, or memory testing. While these tests may provide insight into discrete cognitive processes, they do not measure the more global decision-making abilities as described above. In fact, these tests are generally poor predictors of decision-making ability (Marson, Cody, Ingram, & Harrell, 1995). Therefore, it is important for researchers working with individuals who have cognitive impairment to become familiar with instruments that provide a more comprehensive assessment of decisional capacity.

Advantages and Limitations of Using the Rational Approach to Determine Decision-Making Competence

Decision-making requires a number of cognitive domains, such as executive function, supporting the idea that a comprehensive decision-making competence measure is required. The strength of the MacCAT-CR approach lies in its recognition that decision-making competence is not fixed across all kinds of studies. In other words, these assessments are study specific so investigators can present information from their own studies during the assessment process. In this way, study information is customized. This feature is important because by using this approach, an older adult with cognitive impairment may be assessed to have retained capacity to consent to a simple research protocol if the information is straightforward, the risks to harm are low, and there is a direct benefit to participating in the study. However, a high-risk study involving complex interventions that offers minimal benefit should raise concerns about decision-making competence for the same older adult who was determined to have the competence to decide to participate in the less complex study (Moye & Braun, 2007).

Although the information disclosed during the assessment process can be customized to any particular kind of study, there are limitations to using instruments such as the MacCAT-CR. First, there are currently no guidelines specifying just how much information or what degree of detail should be provided to potential participants during the assessment. This reflects back on the discussion above that there are minimal data about the right kind and amount of information for reasonable volunteers in general (Johnson & Nelson, 2000)—a problem that is exacerbated when working with individuals who have some degree of cognitive impairment. Unfortunately, inconsistencies in the amount of information provided when administering the instrument may disadvantage some potential participants.

Second, there are no accepted standards as to how much information or what degree of detail should be expected from potential participants to indicate they have the capacity to consent. This leads to variation across study populations, making it difficult to compare research findings.

Third, use of these instruments is based on the appropriateness of a rational approach to assessing decision-making abilities when, in fact, receipt of information, comprehension, and expressing a choice to volunteer to participate in a study are socially and person situated. Culture, personal values, and emotions play a part in the decision-making process (Grisso & Appelbaum, 1998; Nussbaum, 2001) and situate individuals’ decision-making style (Fowler, 2006). Decision-making styles are known to range from proactive and assertive, to reactive and passive, to reactive and confrontational (Fowler, 2006). These important factors are not taken into account using rational approaches for determining decision-making competency.

In summary, using a rational approach to determine decision-making competency has a number of disadvantages. Important links between the four abilities, culture, personal values, emotions, and decision-making style are not addressed using a rational approach. Research has yet to describe decisional competence from a person-situated perspective. In addition, little is known about the relationship between decisional complexity and the appropriate amount and kind of information to be provided to produce valid decisions in older adults with cognitive impairment. Research is also needed to better understand the relationship between the provision of information and decisional complexity among older adults with cognitive impairment.

Regardless of the issues noted above, current human research requirements mandate that investigators ensure that decision-making abilities are assessed for any study that involves more than minimal risk for potential participants who would be reasonably expected to have diminished decision-making capacity (National Bioethics Advisory Commission, 1998; Sachs, 2007). What is currently available to investigators is the rational approach.

Ethical Dilemmas in the Face of Decisional Incapacity

Although there are mandates regarding informed consent, limited empirically based guidance exists for addressing the conduct of research with older adults who are cognitively impaired (Sachs, 2007; Stocking et al, 2007). Therefore, researchers working with this population often need to address a number of ethical dilemmas:

  • Respecting autonomy in the face of decisional incapacity.
  • Ensuring voluntarism in the face of influential power.
  • Using a rational approach to evaluate decision-making competence while recognizing that it does not include an assessment or appreciation of culture, personal values, emotions, or decision-making style.

Autonomy Versus Protectionism

Autonomous decision making is a Western society value that is supported by social discourse that involves not only researchers, but ethicists, philosophers, and lawyers (Stocking et al., 2007) and that is subsequently operationalized through the legal system (Grisso & Appelbaum, 1998). Therefore, it is not surprising that autonomy is a major ethical conviction discussed in The Belmont Report (National Commission, 1979). Unfortunately, respecting autonomy in older adults with cognitive impairment can be difficult. In an effort to protect vulnerable older adults determined to have insufficient decision-making capacity, investigators generally believe they have only two options: not enrolling the potential participant or using a surrogate decision maker. Both options skirt the issue of autonomy of these individuals, either by avoidance or proxy.

Avoidance. Not enrolling participants is a difficult choice for most investigators. The pragmatic concern about competence assessments, right or wrong, is that for any given study, the assessments can result in more cognitively intact than cognitively impaired participants in the study. Holt, Siddiqi, and Young (2008) argued that this results in biased and underrepresentative samples, which limits the generalizability of the findings. This approach and the consequently limited development of science in some areas is a critical issue for investigators, immediately so for those who are evolving evidence-based approaches to care (Sachs, 2007).

Although it is possible to not enroll individuals deemed incapable of informed consent, the problem of maintaining autonomy remains of concern. Informed consent is an ongoing process within any research design, so participants should be informed throughout the study that ongoing participation is voluntary and their affirmation of continuation should be sought directly. In clinical practice, it is generally understood that the decision made by the participant at the time of the original decision stands as long as a valid informed consent was obtained and the participant does not dissent at a later time. However, if the investigator believes a participant no longer has sufficient decision-making competency, there are few guidelines regarding the necessity of reassessing consent capacity, reconsenting the participant, or seeking proxy confirmation that continuation in the study is appropriate.

Proxy: Use of Surrogate Decision Makers. When capacity to consent to research is compromised, other mechanisms are available to investigators and should be considered before excluding a potential participant from a study. In the strictest sense, research involvement of individuals who have been declared legally incompetent by a court of law should be approved by their legal guardians. However, many older adults with cognitive impairment have not been declared legally incompetent and do not have a designated legal guardian. In these cases, cognitively impaired individuals unable to provide informed consent require that their rights be protected by surrogate decision making (Qualls, 2007).

Surrogate decision makers make substituted decisions for individuals regarding their research participation. Who is allowed to assume this role varies. For example, the State of California (2007) has a surrogate decision-making statute requiring investigators to use a specified hierarchal model beginning with those named in advance health care directives followed by those who are guardians for health care decisions, then spouses, sons and daughters, and others. A number of AD research centers use a next-of-kin hierarchy to choose who can serve as a surrogate decision maker (Cahill & Wichman, 2000). However, because guidelines for choosing surrogate decision makers may differ from state to state, it is important for the investigator to determine who can serve in this role.

Although the use of surrogates is frequently necessary when studying individuals with cognitive impairment, there are drawbacks. Studies have documented that the wishes of older adults are not always well known by surrogates, that proxy decisions are often not accurate, and that many surrogates simply may not want to take responsibility for the enrollment decision and thus do not agree (Holt et al., 2008; Karlawish et al., 2008b). Alternately, surrogate decision makers may view participation in research as an active, potentially positive intervention. Although this belief about the research may increase the participation of cognitively impaired older adults, it may also increase their chance for harm. Like research participants themselves, surrogate decision makers must appreciate the difference between the goals of research and clinical care and be carefully informed by the investigator.

The burden research participation places on caregivers who serve as surrogate decision makers also cannot be overlooked or underestimated. Time commitments added by surrogacy to an already full schedule can be burdensome, but caregivers do not always voice these concerns. Further, the decision-making burden for all surrogate decision makers is increased when both study risks and the severity of dementia are high (Sugarman, Cain, Wallace, & Welsh-Bohmer, 2001). Research is needed to understand how to consider these burdens during the informed consent process.

Assent. As applied to children, assent refers to an affirmative agreement to participate in research. It should be noted that a lack of response from a child does not equate to agreement to participate. The assent process supports the ethical principle of respect for autonomy when an individual is unable to provide full informed consent and should be revisited at stages throughout the research process. When using a surrogate decision maker, the assent process is completed with the older adult with cognitive impairment in addition to obtaining informed consent from the surrogate (Alzheimer’s Association, 2004; Beck & Shue, 2003).

Voluntarism Versus Influential Power

The decision to participate in a given study can be influenced by the perceived need to meet the expectations of the researcher. This “influential power” is exemplified in two situations that are not uncommon when working with cognitively impaired older adults and their caregivers. First, because of a perceived imbalance of power, patients may feel that treatment or care could be withheld by the nurse researcher if they decide not to participate in a study (Holloway & Wheeler, 2002). Although the American Nurses Association’s (2005) Code of Ethics states that nurses should be aware of issues of power when conducting research with vulnerable groups such as children, students, older adults, and poor populations, no guidance is provided on how to handle such situations.

Second, role confusion can also be problematic for investigators. The nurse’s role is to preserve the patient’s health, whereas the investigator’s role is to pursue scientific knowledge. In the investigator role, the nurse will act to protect the participant from harm, but the focus is not the delivery of nursing care. These role differences may not be well understood by participants who are cognitively impaired or their caregivers and may create tensions and conflicts for the nurse. Nurse investigators need to be sensitive to this situation, be vigilant about explaining the differences in the roles throughout a study, and carefully consider how potential ethical issues raised by the study, such as how to deal with inadequate or inappropriate care that is observed, will be addressed (Holloway & Wheeler, 2002).

Rationalism Versus Culture, Values, and Emotions

Cultural differences are important because they mediate how people identify and interpret the world around them. Basic values, beliefs, and morals are important cultural factors that influence a person’s feelings and emotions, thinking, and ultimately their actions. In recent years, an awareness of cultural diversity in health care has brought to light the importance of effectively caring for diverse populations (AGS, Adler, & Kamel, 2004) and the importance of including culturally diverse populations in research (Germino, 2006).

Cultural norms affect decision making, ultimately affecting the informed consent process. For example, cultural background may determine a preferred gender role in decision making. However, patient autonomy in the United States originates from within the culture of biomedicine (Tripp-Reimer, Choi, Kelley, & Enslein, 2001), and respect for individual autonomy is based on Western bioethics principles. Many cultures do not subscribe to widely studied Western ideals, such as individualism, but would rather involve families and even communities in decision-making processes (AGS et al., 2004).

Currently, however, mandated rational decision-making assessments are individually focused. They do not accommodate cultural differences. Further, they do not indicate how to include others in the assessment process or to allow for the abdication of decision making to another, unless there is a specific advance care directive. If investigators are obligated to assess decision making using a rational, measured approach, decision making is understood only with reference to this approach. Nurses want to put each person in context, but if capacity decisions are based on rational models, then contextualizing the individual is almost impossible. Substantive research, currently completely lacking, is urgently needed to address these issues and reveal how to embed “cultural competence” into the informed consent process.

Maximizing Research Participation for Older Adults with Cognitive Impairment

Although research with cognitively impaired older adults creates challenges, there are a number of strategies available to increase their participation, while continuing to support the intent of person-centered informed consent.

Advance Consents

Advance consent to research is deemed appropriate by the AGS (Sachs, 2007) as a mechanism for allowing individuals to make their wishes known about participating in research before they become incapable of providing informed consent. The attractiveness of this mechanism is that it takes into consideration personal values, beliefs, and additional person-situated factors at a time when the person has decisional competence. Another option is to directly address research decision making in advance health care directives (Sachs, 2007).

Maximizing Decision-Making Competence

Decisional complexity is raised when research protocol information ignores any kind of comprehension requirement of the participant. Conveying information in an appropriate manner is as important as the content of that information (National Commission, 1979). Consequently, assuming there is a reasonable direct benefit to the participant in studies where risks are minimal or low, the complexity level of information can be reduced to facilitate understanding and the assessment of decisional competence (Holt et al., 2008). This strategy may allow potential participants with cognitive impairment to retain autonomous decision making about research participation.

Information complexity can be managed through the manner in which it is presented and taught. In general, it is known that age-associated changes in cognition include diminished short-term memory and concentration, slower response time in thinking and stimuli reaction time, and decreased abstract thinking ability. These changes influence information appraisal and acquisition. Teaching strategies have been identified that improve understanding among older adults with age-associated memory decline (Stanley, Blair, & Beare, 2005). Such strategies recognize values and beliefs, prior knowledge base, and readiness to learn, as well as provide motivation to take in information and learn.

Enhancing Consenting Procedures. The environment in which consent is obtained can be made conducive to the consenting process. Environmental modifications include limiting distractions and choosing an appropriate setting. Consent can be timed to be completed when the participant is ready to listen to information and has the energy to process the information, appreciate the consequences of participating, and reason through the decision.

Investigators also should target the specific decision-making abilities that are assessed as impaired. Research using the MacCAT-CR among those with AD has demonstrated that individual abilities and disabilities can be identified. In one study, 84% of the participants were compromised in at least one of the abilities (Kim et al., 2001). This can be important differentiating information for investigators who want to design supports for decision making. For example, if the understanding ability is compromised, spending more time, as recommended by the AGS (2007), may facilitate comprehension.

Other suggested practical steps for improving decision-making abilities include repeated learning trials, providing feedback, and more consumer-friendly material presentation. Investigators might consider multimedia presentations of the consenting materials. For example, content contained in a consent form could be converted into a PowerPoint® slide show and shown on a computer screen. The slide show could also be read aloud and paused to reinforce information and assess understanding, appreciation of risks and benefits, and reasoning as they finally come to a decision.

Providing Adequate Protection

As regulatory authorities, Institutional Review Boards (IRBs) ensure that investigators enrolling research participants who are vulnerable to “coercion or undue influence” have extra safeguards in place to protect such participants (CFR, 2005). IRBs do acknowledge that consenting individuals with cognitive impairment represent challenges to investigators. As such, IRBs should provide guidance in three key areas: obtaining consent from participants with cognitive impairment or authorized representatives, obtaining assent to research participation, and determination of potential participants’ decisional capacity (Cahill & Wichman, 2000). However, IRBs may not have expertise in all of these areas. IRBs should appoint geriatric health care professionals to serve on these boards to call attention to the need to include older adults with cognitive impairment in research, as well as to offer input about research protocols involving these potential participants.

Investigators may want to consider any number of alternative informed consent procedures, such as using a standardized and validated instrument tailored to their specific study or postconsent quizzes. In low-risk intervention studies, Rikkert, van den Bercken, ten Have, and Hoefnagels (1997) suggested trialing the research protocol with potential participants and then assessing their understanding. For example, following verbal consent, the participant “trials” the study for a week and then undergoes an assessment of decision-making abilities. Of course, whatever informed consent procedure is selected must be reviewed and approved by the IRB.


The increasing numbers of older adults with cognitive impairment challenge investigators to examine how to incorporate this population into research studies so appropriate and valid research findings can be translated into current practice. However, obtaining informed consent from these individuals presents challenges and ethical dilemmas, as researchers attempt to respect individual autonomy while advancing nursing science. The prominent rational-based method used to evaluate decision-making competence for participation in research has advantages and disadvantages. It provides distinct approaches to assess whether individuals have the abilities to make a choice, understand the research, appreciate the impact of participation, and logically reason, but it does not attend to more personal factors that could influence decision making, such as culture, values, and emotions.

We believe there are options to maximize participation in research for older adults with cognitive impairment. These include use of advance consents for research, strategies to compensate for identified problems in specific decision-making abilities assessed during the process of determining decisional competence, and using alternative approaches to obtaining informed consent. However, research is needed regarding how to optimize the research participation of older adults with cognitive impairment, while ensuring ethical standards are met. Future research should also address the needs to evolve assessment processes beyond a rational approach, to test innovative strategies that target participants’ comprehensive needs, to develop investigator expertise in the assessment of decision-making capacity, and to advance the role and understanding of regulatory agencies with regard to the special needs of this population.


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Dr. Mayo is Professor, Hahn School of Nursing and Health Science, University of San Diego, San Diego, and Dr. Wallhagen is Professor, Department of Physiological Nursing, and Director, John A. Hartford Center of Geriatric Nursing Excellence, University of California, San Francisco, School of Nursing, San Francisco, California.

Address correspondence to Ann M. Mayo, DNSc, RN, CNS, Professor, Hahn School of Nursing and Health Science, University of San Diego, 5998 Alcala Park, San Diego, CA 92110-2492; e-mail:


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