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

Assessing Decision-Making Capacity

Assess decision-making capacity by evaluating four core abilities—understanding, appreciation, reasoning, and expressing a choice—through direct patient interview with open-ended questions, recognizing that capacity is decision-specific and must be 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 1, 3
• Never assume incapacity based solely on diagnosis (including dementia), age, appearance, or because a patient makes an "unwise" decision 4, 1
• Formal capacity assessment is warranted when: acute mental status changes occur, the patient refuses clearly beneficial treatment, risk factors for impaired decision-making exist, or the patient agrees too readily to risky procedures without adequate deliberation 2

The Four Core Components to Evaluate

Understanding: Can the patient comprehend basic information about their condition, the proposed treatment, alternatives, and consequences? 4, 1, 2

Appreciation: Does the patient recognize how this information applies specifically to them and acknowledge the likely consequences of their decision? 4, 1, 2

Reasoning: Can the patient weigh risks and benefits, compare options logically, and make a decision consistent with their values? 4, 1, 2

Expressing Choice: Can the patient clearly communicate their decision by any means? 4, 1, 2

Structured Assessment Approach

• Conduct a direct interview using open-ended questions to explore each of the four components 5
• Obtain detailed patient history and collateral history from family or caregivers to establish baseline cognitive function 4, 3
• Perform focused physical examination including cognitive screening 4, 1
• Exclude reversible conditions (delirium, medication effects, metabolic disturbances) that may temporarily impair capacity 4, 1

Cognitive Screening Tools (But Not Sufficient Alone)

• Use the Montreal Cognitive Assessment (MoCA) for detecting mild cognitive impairment 1
• The Mini-Mental State Examination (MMSE) can be used but has significant limitations—it cannot determine capacity by itself 4, 1
• MMSE scores below 10/30 suggest likely incapacity; scores 10-15 may allow proxy designation but not complex decisions 6
• Consider executive function tests (Stroop Test, Trail Making Test) to assess cognitive flexibility and sequencing 1

Critical caveat: Cognitive test scores alone never determine capacity—they inform but do not replace functional assessment of the four core abilities 4, 5, 7

Tailor Assessment Rigor to Decision Risk

For minimal risk decisions: Integrate capacity assessment with an interactive process, potentially involving family support 1

For moderate risk decisions: Use brief screening tools first, then proceed to formal assessment if uncertainty exists 1

For high risk decisions: Implement rigorous formal capacity assessment with higher thresholds for demonstrating all four abilities 1

This risk-stratified approach balances protection from exploitation against discrimination from overly restrictive assessments 4

Recognize That Capacity Is Decision-Specific and Fluctuating

• A patient may have capacity for some decisions (choosing a healthcare proxy) but not others (complex surgical consent) 4
• Capacity can fluctuate in the short-term (delirium) and long-term (progressive dementia) 4
• Reassess capacity when clinical status changes, when making different types of decisions, or over time in chronic conditions 4, 8
• Document plans for reassessment when temporary confusion may improve 3

Documentation Requirements

• Record specific examples of confusion or impairment and their impact on decision-making ability—avoid vague statements like "patient confused" 1, 3
• Document the clinical reasoning that led to your capacity determination 1, 3
• Specify which decisions the patient can or cannot make; never make global assessments of incapacity 1, 3
• Record consultation with family or other providers about baseline cognitive function 3
• Document any disagreements among team members or family and how they were resolved 3

When Capacity Is Lacking

• Identify the appropriate surrogate decision-maker according to state law 4, 1
• Review advance directives, durable power of attorney documents, or court-appointed guardianship orders 4, 3
• Instruct surrogates to respect the patient's known wishes and preferences from prior statements or advance planning documents 4
• When prior wishes are unknown, surrogates should make decisions based on the patient's beliefs, values, and best interests 4
• Document discussions with surrogates about the patient's previously expressed wishes 3

Common Pitfalls to Avoid

• Do not equate refusal of recommended treatment with incapacity 7
• Do not assume cognitive impairment automatically means incapacity 7
• Do not treat capacity as permanent—it can improve with treatment or worsen with disease progression 7
• Do not confuse inadequate information-giving with patient incapacity 7
• Do not rely solely on psychiatric diagnosis to determine capacity 7
• Do not assume involuntarily committed patients lack capacity 7

Who Can Assess Capacity

• Any treating physician can and should evaluate capacity—it is not exclusively a psychiatric consultation 2, 7
• Psychiatric consultation may be helpful for complex cases, psychological barriers to decision-making, or when capacity remains uncertain after initial assessment 2, 6
• The final determination of capacity rests with the treating physician, not the consultant 2

Emergency Situations

• In emergencies where delay in identifying a surrogate would increase risk of death or serious harm, physicians can provide necessary care without formal consent 2
• This exception applies only when the patient lacks capacity and obtaining surrogate consent would cause dangerous delay 2