This study confirms the importance of seeking the assent and respecting the dissent of adults who lack consent capacity for dementia research, and it provides guidance for researchers charged with fulfilling these duties as well as for IRBs who are charged with ethical oversight of this research. Assent should be obtained explicitly from all those who lack consent capacity and have the ability to assent, but it should not be required of those who lack the ability to assent. Dissent should be respected whenever it occurs, and no reason or justification is needed for the individual’s objections to be honored. While maximizing remaining autonomy is important, it is the protective function of respecting dissent that makes it hierarchically more important from an ethical perspective than obtaining assent.
Participants in this study felt strongly that individuals who lack the ability to assent and/or dissent should not be precluded from involvement in all dementia research. To do so would place unnecessary and perhaps insurmountable barriers to the conduct of research that addresses important issues for dementia patients, particularly those in the moderate to late stages when these abilities may be lacking. They recommended that local IRBs determine whether individuals who lack one or both of these abilities can participate in a specific study and whether any protections, beyond proxy informed consent (e.g., an advance directive for research, an independent monitor), are needed for their inclusion. Investigators should be required to provide justification for the inclusion of such individuals in the protocol and should delineate the methods that will be used to ensure the well-being of these participants.
The range of remaining cognitive abilities of adults who lack consent capacity, the presence of neuropsychiatric symptoms, and changes in the individual’s temperament pose challenges when seeking assent and respecting dissent. Judgments must be based on the researcher’s observation of that individual and the situation at hand, a rigorous evaluation of the person’s abilities, probing to understand what an expression or indication really means, and addressing when possible any unrelated distress or concerns of the individual. Explicit discussion of these issues when an inability to consent is likely might reassure IRBs that adequate steps are being taken to fulfill the ethical obligations inherent in conducting dementia research. Because of the uniqueness of each situation, participants recommended that researchers should seek the assistance of caregivers in deciphering the responses of the individual who has dementia. Informants agreed that researchers must be given the flexibility to both clarify the meaning of behaviors, verbalizations, and emotional indications that potentially indicate dissent or assent and be allowed to address and resolve initial objections or indications of distress when the intent is not absolutely clear. If the response remains ambiguous, if the objection is unequivocal or sustained, or if an individual who has the ability to assent does not do so, researchers should exclude or withdraw the person from the research.
Caregivers who serve as proxy decision-makers for decisionally impaired adults are critical to the conduct of dementia research. The recommendation that researchers should seek caregivers’ assistance to understand an individual’s responses is based on the assumption that caregivers are, in most instances, family members who have known the individual for many years prior to their cognitive impairment and since then have provided care to the individual on a regular basis. Their knowledge of the individual’s prior attitudes and preferences and their caregiving experiences may enable them to provide an accurate interpretation of the individual’s responses. Conversely, researchers must be cognizant that a caregiver could misrepresent the individual’s responses. If there is any reason to doubt a caregiver’s motivations, researchers are obliged to act in what seems to be the patient’s best interests. Conflicts about research participation may arise between the proxy decision-maker and the potential study participant. If the individual who lacks consent capacity wishes to participate but the proxy does not consent, the proxy’s wishes prevail according to the doctrine of informed consent. Based on our findings, which are in line with prior recommendations (10
), if the individual expresses/indicates an unequivocal or sustained dissent, the patient’s wishes prevail over the proxy’s consent.
On the question of whether the dissent of an individual to participate in research should ever be overridden if the study provides the potential for a direct benefit available only in research, findings from this study differ from the positions taken by some previous groups (8
). The national panel concluded that superseding fundamental ethical principles and overriding dissent is unjustified and unnecessary. That is, best interest does not override dissent, even when a person cannot understand the potential benefit of research
This study has a number of limitations. First, the project focused only on persons with dementia. While some findings may be applicable to research involving adults whose lack of consent capacity is due to other disorders (e.g., focal impairment due to stroke, traumatic brain injury, intellectual disability), the guidance offered here is not directly applicable to clinical care. Second, because it is a qualitative study, the sample is small and local participants were drawn from only two geographic areas in the United States. Third, since participants were identified because of their involvement in dementia research, all would likely be favorable toward research. Finally, only a small number of focus groups were conducted.
Some issues addressed in this study require more in-depth examination. For example, how can researchers determine whether the expression or indication of a choice is meaningful (i.e., authentic)? Sugarman and colleagues (23
) highlight the challenge of determining authenticity when individuals who have dementia contribute little to the conversation in the informed consent encounter and caution that affirmative statements may only be a means of engagement rather than a deliberate cognitive act. Related to this is our finding that both assent and dissent can be expressed verbally, behaviorally, or emotionally (or some combination thereof). While others have noted that assent can be expressed verbally or indicated behaviorally (10
), an emotional indication of assent may be harder to judge. More research is needed to determine how individuals who have dementia actually respond to requests to participate in research, how researchers judge the authenticity of and consistency between an individual’s verbal, behavioral, and emotional responses, and the role that caregivers play in that encounter (25