Can a patient with dementia give informed consent?

Can a Patient with Dementia Give Consent?

Patients with dementia should be presumed to have capacity to consent unless formally established otherwise through proper assessment, and all reasonable efforts must be made to support their decision-making before resorting to surrogate consent. 1

Capacity Assessment is Decision-Specific and Progressive

The ability to provide informed consent in dementia is not an all-or-nothing determination but varies with disease severity and the complexity of the decision at hand. 1

• Persons with very mild to mild dementia typically retain capacity to consent, with studies showing that all individuals with very mild dementia and 92% with mild dementia can understand consent information for research studies. 2
• Moderate dementia significantly impairs consent capacity, with only 67% of moderately demented individuals demonstrating adequate understanding of consent elements. 2
• Cognitive testing alone (such as MMSE scores) is insufficient to determine capacity—a functional assessment of understanding, appreciation, reasoning, and ability to express a choice is required. 3

The Legal Framework for Consent

When capacity is intact, the patient with dementia retains full authority to consent. When capacity is lost, a hierarchical approach to surrogate decision-making applies:

• Healthcare proxy/agent designated via durable power of attorney takes precedence over all other decision-makers once the patient lacks capacity for that specific decision. 4
• Court-appointed guardians or conservators serve as secondary authority when no healthcare proxy exists. 4
• Default surrogates (typically family members in a statutory hierarchy: spouse, adult child, parent, sibling) may make decisions in states with default surrogacy statutes. 4
• The treating physician makes decisions based on the patient's best interests when no valid surrogate exists, considering medical factors, previously expressed values, general well-being, and spiritual/religious welfare. 4

Supporting Decision-Making Capacity

Before concluding a patient lacks capacity, clinicians must employ decision-making supports to maximize the patient's ability to participate in their own consent process. 1

Effective supports include:

• Simplifying consent forms and using visual or memory aids. 1
• Interactive or educational approaches where patients explain their understanding of consent elements, with re-explanation of misunderstood information. 1
• Involving familiar caregivers to facilitate explanation and communication. 1
• Process consent approaches where clinicians tailor consent discussions to the patient's preferred means of communication. 1

Advance Planning and Ongoing Consent

• Advance directives and designated representatives should be established early in the disease course while capacity is intact, allowing patients to express preferences about future research participation and designate decision-makers. 1
• Consent provided before loss of capacity should be respected after capacity is lost, unless the person dissents or the legally authorized representative withdraws consent. 1
• Assent and dissent must be monitored continuously—even when a surrogate provides consent, researchers and clinicians must seek affirmation of willingness from the person with dementia and respect objections to participation. 1

Common Pitfalls to Avoid

• Do not assume incapacity based on diagnosis alone—dementia is a progressive condition, and many patients retain decision-making capacity, especially in early stages. 1
• Do not rely solely on cognitive screening tools like the MMSE to determine capacity; functional assessment of the four consent elements (understanding, appreciation, reasoning, expressing choice) is required. 3
• Do not exclude patients with dementia from decision-making even when surrogates are involved—efforts should be made to include them in a manner appropriate to their level of capacity. 1
• Recognize that capacity assessment varies across disciplines—there is significant variability in how legal, medical, and ethical experts assess capacity, highlighting the need for standardized, validated procedures. 5

Risk-Proportionate Assessment

The rigor of capacity assessment should be proportionate to the risks involved:

• For minimal-risk decisions or data sharing, capacity assessment may be integrated with an interactive consent process, potentially facilitated by a family member. 1
• For higher-risk interventions, a staged approach is advisable, moving from brief screening tools to formal, rigorous assessments in cases of uncertainty. 1