What is the process to determine a patient's incapacity to make their own medical decisions?

Determining Patient Incapacity for Medical Decision-Making

A patient is deemed incapable of making their own medical decisions when they cannot understand, retain, use/weigh relevant information, or communicate their decision due to an impairment or disturbance in the functioning of their mind or brain. 1

Foundational Principle: Presumption of Capacity

• Always presume the patient has capacity until proven otherwise through specific assessment. 1
• Capacity cannot be assumed absent based on age, appearance, behavior, or diagnosis (including learning disabilities, dementia, or psychiatric conditions). 1
• The treating physician is responsible for determining capacity in most instances. 1, 2

The Four-Component Assessment Framework

To determine incapacity, the patient must fail one or more of these four abilities:

1. Understanding: Cannot comprehend the information relevant to the decision (diagnosis, treatment options, risks, benefits, alternatives). 1, 2

2. Retention: Cannot remember the information long enough to make the decision. 1

3. Use/Weigh: Cannot use or weigh the information as part of the decision-making process (cannot reason through risks versus benefits). 1, 2

4. Communication: Cannot communicate their decision by any means (verbal, sign language, blinking, hand squeezing). 1

Critical Two-Stage Test

Stage 1: Identify an impairment or disturbance 1

• There must be documented impairment or disturbance in the functioning of the mind or brain (temporary or permanent). 1
• Examples include delirium, dementia, intoxication, psychiatric illness, brain injury, or active hallucinations. 1, 3

Stage 2: Prove the impairment causes inability 1

• The impairment must directly cause the patient's inability to perform one or more of the four abilities above. 1
• Without this causal link, the patient retains capacity regardless of how impaired their reasoning appears. 1

Decision-Specific Nature of Capacity

• Capacity is specific to the particular decision at hand, not a global assessment. 1, 4, 2
• A patient may have capacity for simple decisions but lack it for complex ones. 1
• A patient with moderate dementia may still indicate choices and show understanding for certain decisions. 4

What Does NOT Constitute Incapacity

• Making an unwise, irrational, or poorly considered decision alone does not prove incapacity. 1
• Refusing clearly beneficial treatment does not automatically indicate incapacity. 1, 2
• Having a mental health diagnosis or cognitive impairment does not automatically mean incapacity. 1, 4

When to Formally Assess Capacity

Trigger situations requiring formal evaluation: 2, 5

• Acute change in mental status. 2, 5
• Refusal of clearly beneficial recommended treatment. 2, 5
• Consenting too hastily to risky procedures without considering risks/benefits. 2, 5
• Known risk factors for impaired decision-making (dementia, delirium, psychiatric illness, substance use). 2, 5
• Active hallucinations or responding to internal stimuli. 3

Practical Assessment Approach

Conduct a structured clinical interview: 2, 5

• Use open-ended questions to assess each of the four abilities. 4, 5
• Ask the patient to explain in their own words: their condition, proposed treatment, alternatives, risks/benefits, and consequences of refusing. 2, 5
• Perform mental status examination; patients scoring below 10 on the Mini-Mental State Examination (maximum 30) likely lack capacity. 6
• Scores 10-15 suggest ability to designate a proxy but not make complex decisions. 6

Document specific examples: 7

• Record concrete evidence of which of the four abilities are impaired and how. 7, 3
• Avoid vague statements like "patient confused" without specific examples. 7
• Document the clinical reasoning that led to the incapacity determination. 7

Critical Pitfall to Avoid

A highly irrational decision based on persistent misinterpretation of information may indicate incapacity, but determining incapacity on grounds of irrationality alone is fraught with difficulty—seek legal advice in such situations. 1

Before Declaring Incapacity

• All practicable steps must be taken to support the patient in making their own decision before treating them as lacking capacity. 1
• Optimize the environment (reduce distractions, ensure hearing aids/glasses are used). 1
• Use simple language, visual aids, and allow adequate time. 1
• Consider treating reversible causes (delirium, intoxication) and reassess. 7, 3

After Determining Incapacity

• Identify the authorized surrogate decision-maker (lasting power of attorney, court-appointed deputy, or next of kin per local law). 7
• Review any advance directives or previously expressed wishes. 1, 7
• Any intervention must be in the patient's best interests and cause the least restriction of their rights and freedom. 1
• Plan for reassessment if the incapacity may be temporary. 7, 3

Special Considerations

• For emergency treatment where the patient lacks capacity and identifying a surrogate would cause harmful delay, physicians can proceed with treatment in the patient's best interests. 1, 2
• Psychiatric consultation may be helpful for complex cases but is not required—the treating physician makes the final capacity determination. 2
• Document disagreements among healthcare team or family members and their resolution. 7