Incapacitated Adult Research

"Respect for persons involves a recognition of the personal dignity and autonomy of individuals, and special protection of those persons with diminished autonomy." (The Belmont Report).  

In Quebec, consent to participate as a subject of health research is governed by the Civil Code of Quebec, Article 21 to safeguard the well being of individuals with transient, progressive or permanent incapacity who are subjects of research. REBs weigh the need for additional protections for vulnerable study populations that includes ensuring voluntariness of their research participation.

Adults who lack the capacity to make voluntary choices are usually recruited for research only when the knowledge to be gained cannot be obtained from competent individuals or from persons able to consent freely.  REBs strive to balance the ethical principles of Respect, Beneficence and Justice when considering a request to recruit incapacitated adults, to avoid limiting research only to those who can make informed choices. Distributive justice applied to research requires those who are to receive the benefits also to bear its burdens. In that way vulnerable members of society are not routinely denied potential benefits from participating in research.

An important ethical challenge in the informed consent discussion concerns ensuring that prospective subjects understand how participating in research differs from receiving standard medical care, to avoid the “therapeutic misconception”.  Investigators’ challenge is made more difficult when communicating such distinctions to persons with capacity impairments. It is especially critical that the informed consent discussion and the document be very clear about the differences. It is essential to address clearly if study participation would affect current efficacious care for the prospective subject. The choice of words to describe the research purpose and experimental procedures must be precise.

There is no “standard” tool, model or procedure for assessing capacity to consent to research, although the ability to assess capacity is a skill that all physicians should possess. The Investigator must determine if the person with diminished capacity has sufficient competence to consent research participation. The REB will decide whether it is appropriate that the Investigator seeking consent is also the professional who will judge the prospective subject’s capacity to consent.

The prospective subject’s level of engagement in the informed consent discussion is a key indicator of the person’s capacity to consent to research.  If following multiple attempts by the Investigator to describe the study, a subject cannot repeat back to the Investigator a simplified explanation of study participation, the person lacks capacity to consent. 

An individual not capable of providing “explicit” research consent must be asked to provide “assent” in order to participate.  Assent implies willingness; it does not imply understanding.  An interpretable statement on assent or dissent from the subject must be taken as valid regardless of the subject’s level of confusion.  Demonstrating a negative choice need not be verbal. Indications of distress such as crying or attempts to escape the situation should be taken as refusals to participate. 

Fundamental to research consent is the subject’s right to withdraw their participation.  Investigators need to be aware of verbal and non-verbal behaviour of incapacitated research subjects that may indicate their desire to participate no longer.   A clear expression to discontinue participation may be difficult to distinguish from other behaviour.  How this dilemma will be managed in context of the study should be discussed in the research protocol.

Some longitudinal studies involving progressive disorders or aging populations are designed to enroll subjects who were competent to consent at the outset of the study.  However, during the course of the research some subjects may experience progressive incapacitating effects or intermittent disorders leading to decisional impairment.  In these situations Investigators need to discuss with prospective subjects whether they should designate someone to serve as a legally authorized representative at the outset of the study; ready to step in as substitute decision-maker if the subject’s ability to assess personal needs and interests becomes compromised during the study. 

In the course of providing medical care “advance directives” in compliance with applicable law are commonly used. While advance directives concerning research participation may appear legitimate, they have no “legal standing”.  Note discussion at TCPS2, Article 3.11 about “Research Directives” to understand that Investigators and substitute decision makers must be guided by such directives during informed consent discussions.

Written documentation of explicit consent should be obtained from research subjects who were enrolled in a study while cognitively impaired, if they are still participating in the study when they regain competency. This includes subjects whose identifiable data was collected and stored in research data repositories and tissue banks.


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