How do you assess decision-making capacity in a patient?

How to Assess Decision-Making Capacity in a Patient

Assess decision-making capacity by systematically evaluating four core abilities: understanding, appreciation, reasoning, and expression of choice—using a structured clinical interview that is decision-specific and proportionate to the risk of the decision at hand. 1, 2

Presume Capacity Until Proven Otherwise

• Always begin with the legal and ethical presumption that the patient has capacity. 2, 3
• Do not assume incapacity based solely on age, diagnosis (including dementia), appearance, or because the patient makes a decision that seems unwise or eccentric. 1, 2, 3
• Capacity is decision-specific, not global—a patient may lack capacity for complex financial decisions but retain capacity for simpler medical choices. 1, 2, 4

The Four Core Abilities Framework

Evaluate each of these abilities through direct questioning during a clinical interview: 1, 2, 5

1. Understanding

• Can the patient comprehend the basic relevant information? 1, 2
• This includes understanding their medical condition, the proposed intervention, available alternatives, and the risks and benefits of each option (including no treatment). 1, 3
• Test this by asking the patient to explain back to you in their own words what you have told them. 5

2. Appreciation

• Can the patient acknowledge their medical condition and recognize how the information applies specifically to them? 1, 2
• This goes beyond mere understanding—the patient must appreciate the personal consequences of their decision. 1, 6
• Ask: "What do you believe is wrong with your health?" and "What do you think will happen if you choose this treatment (or refuse it)?" 5

3. Reasoning

• Can the patient weigh the risks and benefits of options and make a decision consistent with this evaluation? 1, 2
• The patient should demonstrate logical thought processes in comparing alternatives. 1, 6
• Ask: "How did you decide on this option?" or "What makes this choice better than the alternatives for you?" 5

4. Expression of Choice

• Can the patient clearly communicate a stable decision by any means? 1, 2
• The decision should be relatively stable over time (accounting for appropriate changes based on new information). 6, 5
• Fluctuating or rapidly changing decisions may indicate impaired capacity. 1

Structured Assessment Process

Conduct a comprehensive evaluation that includes: 1

• Direct patient interview using open-ended questions to assess the four abilities above. 6, 7
• Collateral history from family members or caregivers about baseline cognitive function and any changes. 1, 2
• Focused physical examination including cognitive screening, functional assessment, and mood evaluation. 1
• Testing to exclude reversible conditions such as delirium, medication effects, metabolic disturbances, or depression that may be temporarily impairing capacity. 1

Critical Pitfalls to Avoid

• Do not rely solely on the Mini-Mental State Examination (MMSE) or any single cognitive test—these do not assess functional decision-making abilities. 1
• Avoid vague documentation like "patient confused" without specific examples of how confusion affects the particular decision. 2
• Do not make global determinations of incapacity—specify which decisions the patient cannot make. 1, 2
• Remember that pain, illness, and premedication do not automatically render a patient incapable of providing consent. 3

Match Assessment Rigor to Decision Risk

The threshold for capacity should be proportionate to the consequences of the decision: 1, 6

• Higher-risk decisions (e.g., refusing life-saving treatment, complex surgery) require more stringent demonstration of all four abilities. 6, 7
• Lower-risk decisions (e.g., choosing between similar treatment options, appointing a healthcare proxy) require less rigorous assessment. 1
• This sliding-scale approach balances respect for autonomy against protection from harm. 6, 7

Document Thoroughly and Specifically

Your documentation must include: 2

• Specific examples of the patient's impairment or disturbance affecting decision-making (not just "confused"). 2
• Evidence of assessment of all four core abilities with the patient's actual responses. 2, 5
• The clinical reasoning that led to your determination. 2
• Consultation notes from family or other providers about baseline function. 2
• For temporary conditions, document plans for reassessment when capacity may improve. 2

When Capacity Is Lacking

If the patient lacks capacity for the specific decision: 1

• Identify and document the authorized surrogate decision-maker (healthcare proxy, power of attorney, court-appointed guardian, or next of kin per state law). 2
• Review any advance directives or previously expressed wishes. 1, 2
• Apply substituted judgment when possible—the surrogate should make the decision the patient would have made if capable, based on the patient's known values and preferences. 1
• Use best interest standard when the patient's wishes cannot be determined—decisions should reflect the patient's beliefs, values, and welfare. 1
• Document discussions with surrogates about the patient's previously expressed wishes and values. 2

Reassessment Is Essential

• Capacity is time- and context-specific—it can fluctuate, especially in patients with delirium, dementia, or acute illness. 1, 6
• Reassess capacity when the patient's condition changes, when making different decisions, or when there is reason to believe capacity may have returned. 1, 7
• For longitudinal research or treatment, ongoing reassessment may be necessary. 1

Consider Formal Tools When Needed

While no gold standard exists, structured assessment instruments can help guide your evaluation: 1, 5

• Tools should be tailored to the specific decision and validated for the context. 1, 5
• Consultation with psychiatry may be helpful in complex cases, but the final determination is made by the treating physician. 5
• Formal tools supplement but do not replace clinical judgment based on the four-abilities framework. 8, 5