How do I assess decision‑making capacity in a hospitalized patient?

Assessing Decision-Making Capacity in Hospitalized Patients

Capacity assessment requires evaluating four specific domains: the patient's ability to understand their medical situation, appreciate the consequences of their decision, reason through treatment options, and communicate a stable choice. 1

The Four Core Domains of Capacity

Any physician can and should evaluate capacity using a structured approach focused on these determinants 1:

• Understanding: Can the patient comprehend information about their diagnosis, proposed treatment, alternatives, and risks/benefits? 1
• Appreciation: Does the patient recognize how this information applies specifically to them and acknowledge the consequences of their decision? 1
• Reasoning: Can the patient compare options, weigh risks and benefits, and explain their thought process? 1
• Communication: Can the patient clearly express and maintain a consistent choice? 1

When to Perform Formal Capacity Assessment

Capacity should be formally evaluated beyond the intuitive assessment at every encounter when specific red flags appear 1:

• Acute change in mental status 1
• Refusal of clearly beneficial recommended treatment 1
• Risk factors for impaired decision-making (delirium, dementia, psychiatric illness) 1
• Readily agreeing to invasive or risky procedures without adequately considering risks and benefits 1

Critical Recognition: Capacity is Decision-Specific

Capacity is not all-or-nothing—it varies by the specific decision being made 2. A patient may lack capacity for complex end-of-life decisions but retain capacity to name a preferred surrogate decision-maker 2. Approximately one-quarter to one-third of ICU patients retain at least partial capacity despite overall cognitive impairment 2.

Practical Assessment Approach

Document your evaluation of all four domains explicitly 3. Research shows that only 22% of psychiatric consultations for capacity assessment documented all four determinates, revealing significant gaps in standardization 3.

The assessment should include 1:

• Present the patient with information about their condition, treatment options, risks, benefits, and alternatives
• Ask the patient to explain back what you've told them (understanding)
• Ask what they believe will happen if they accept or refuse treatment (appreciation)
• Ask them to explain why they prefer one option over another (reasoning)
• Document their stated choice and verify consistency over time (communication)

Common Pitfalls to Avoid

Only 5% of primary teams document their own capacity evaluation before requesting consultation 3, leading to unnecessary delays in care. Do not reflexively defer to psychiatry—the treating physician makes the final capacity determination 1.

Additional critical errors include 2, 3:

• Failing to carefully document prior efforts to determine capacity before declaring a patient unrepresented 2
• Not recognizing that capacity may be reversible (treat delirium, pain, medication effects) 3
• Missing that patients with impaired capacity may still participate in shared decision-making to the extent possible 2
• Overlooking the patient's ability to express values, hopes, and preferences even when they cannot make complex medical decisions 2

No Gold Standard Tool Exists

There is currently no universally accepted standardized instrument for capacity assessment 4. While several formal assessment tools are available to structure the evaluation, the final determination rests with the treating physician using clinical judgment applied to the four core domains 1.

Emergency Situations

If the patient lacks capacity and identifying a surrogate will cause delay that increases risk of death or serious harm, physicians can provide emergency care without formal consent 1. However, this exception should be narrowly applied only to true emergencies.

Next Steps When Capacity is Absent

When a patient is found to lack capacity 1:

• Identify and consult a surrogate decision-maker immediately
• Document the specific reasons the patient lacks capacity
• Reassess capacity as clinical status changes
• Involve the patient in decisions to whatever extent possible 2

For unrepresented patients without available surrogates, institutions should use interprofessional, multidisciplinary committees rather than allowing ad hoc decisions by treating clinicians alone 2.