Informed Consent for Dementia Research: The Study Enrollment Encounter

Article excerpt

Dementia is a major public health problem that affects about 4.5 million elders in the United States. (1) The prevalence of Alzheimer disease (AD)--one of several types of dementia--is expected to nearly quadruple in the next 40 years. (2) The need for dementia research is clear because no treatment currently exists to prevent or cure AD, and available treatments are only modestly effective. (3) Yet research involving individuals with AD and other types of dementia raises ethical and legal concerns not present in most other disease studies. While dementia has numerous causes, all are characterized by cognitive impairment that is often progressive. (4) For example, AD--the most common cause--ultimately results in permanent loss of decisional capacity because it leads to impairments in comprehension, memory, judgment, and the ability to engage in abstract thinking, thus depriving the person of the capacities needed to be informed and to give informed consent to participate in research.

Decisional capacity to perform a specific task is usually determined based on the individual's ability to 1) understand relevant information, 2) appreciate the nature of the situation and its consequences, 3) reason by manipulating information rationally, and 4) express a choice. (5) While some individuals with mild to moderate dementia retain decisional capacity, (6) there is no widely accepted method for determining whether capacity to consent to research has been lost. Also, there are no national guidelines that Institutional Review Boards (IRBs) or investigators must follow when including cognitively impaired adults in research, as there are for research with children, (7) another vulnerable population. For instance, federal regulations governing research with humans (8) require that "additional safeguards" be included in studies to protect the cognitively impaired but do not specify what they should be.

In the absence of specific federal regulations, concerned groups and individuals have made recommendations on how to provide adequate protection for cognitively impaired research participants. (9) These recommendations commonly suggest balancing the study's risks with its potential benefits; identifying an appropriate surrogate decision-maker for those who lack or may lose capacity; assessing decisional capacity; obtaining informed consent and the subject's assent; and respecting the subject's dissent at enrollment and during the study. While the empirical basis for these recommendations is limited, (10) they provide guidance for investigators recruiting individuals to participate in dementia studies.

We conducted the Consent for Dementia Research Study (CDRS) to determine what actually occurs during informed consent sessions with individuals recruited to participate in dementia studies by observing and recording the content of those sessions. The premise underlying this pilot study was that identifying strategies currently used during enrollment encounters will help determine whether recommended methods for obtaining informed consent are being followed and whether additional guidance or criteria are needed for conducting the consent process for research with cognitively impaired adults.

This report focuses on three aspects of the consent process for dementia research: 1) providing information; 2) assessing understanding and capacity to consent; and 3) obtaining assent and informed consent. For each aspect, we examined differences between drug and nondrug studies included in the CDRS. The findings of this pilot study raise questions relevant to ethical concerns and policy issues for research involving cognitively impaired adults.

Study Sample and Methods

We conducted the CDRS at two universities where dementia research is routinely conducted. We obtained a convenience sample by first asking principal investigators (PIs) of IRB-approved studies to allow studies to be included in the CDRS. …