How is mental or physical capacity assessed?

Assessment of Mental and Physical Capacity

Capacity assessment should be triggered not by a specific diagnosis but by credible evidence that the individual may lack decisional capacity, and should evaluate four key abilities: understanding, appreciation, reasoning, and communication of choice specific to the decision at hand. 1

Understanding Capacity

Capacity refers to a person's ability to take in information, understand its meaning, and make an informed decision based on that information. It is:

• Decision-specific (varies by task)
• On a spectrum, not categorical
• Determined through clinical judgment
• Subject to fluctuation over time

Core Components of Capacity Assessment

1. The Four Essential Abilities

When assessing capacity, evaluate these four key domains:

1. Understanding: Can the person comprehend the relevant information about their condition, proposed treatment/decision, and alternatives?
2. Appreciation: Can they recognize how the information applies to their situation and acknowledge potential consequences?
3. Reasoning: Can they manipulate information logically, compare options using personal values, and provide rational reasons for their choice?
4. Communication: Can they clearly express a choice by any means (verbal, written, gestures)?

2. Assessment Process

1. Presume capacity first: All adults should be presumed to have capacity until proven otherwise 2
2. Tailor assessment rigor to risk: As risks increase and benefits decrease, the thoroughness of evaluation should increase 2
3. Document specific deficits: Record concrete examples of deficits in understanding, appreciation, reasoning, or communication
4. Consider decision complexity: Capacity requirements vary by task - choosing a healthcare agent differs from consenting to a complex procedure 2

Structured Assessment Approaches

For Routine Clinical Settings

1. Direct questioning techniques:

   • Ask the person to explain their understanding of their condition
   • Have them describe the proposed intervention/decision
   • Request they explain potential consequences of different choices
   • Ask them to articulate their reasoning for their decision

2. Standardized tools:

   • Aid to Capacity Evaluation (ACE): Best validated tool with good test characteristics (LR+ 8.5, LR- 0.21), freely available online with training module 3
   • Mini-Mental State Examination (MMSE): Useful only at extreme scores - scores <20 increase likelihood of incapacity (LR 6.3), scores >24 significantly lower likelihood (LR 0.14) 3

For Complex or High-Risk Decisions

For decisions with significant consequences, consider:

1. Independent evaluation: When risk is high, have someone independent of the care team perform the assessment 2
2. Multidisciplinary input: Involve relevant specialists based on the nature of potential incapacity
3. Structured interview tools: Consider using validated instruments like the MacArthur Competence Assessment Tool 2

Special Considerations

Physical vs. Cognitive Capacity

• Physical capacity: Assess functional abilities related to activities of daily living
• Cognitive capacity: Focus on executive function, memory, attention, and judgment
• Both domains: May be affected in neurological conditions, with mental comorbidities substantially increasing limitations 4

Fluctuating Capacity

For conditions with fluctuating capacity:

• Assess during periods of optimal function when possible
• Consider temporary supports during periods of diminished capacity
• Re-evaluate at appropriate intervals 2

Documentation Requirements

Document:

1. The specific decision being assessed
2. Assessment methods used
3. Findings in each of the four domains (understanding, appreciation, reasoning, communication)
4. Conclusion with supporting rationale
5. Recommendations for enhancing capacity if applicable

When Capacity is Lacking

If a person lacks capacity:

1. Identify appropriate surrogate decision-maker according to jurisdiction
2. Document grounds for determining lack of capacity
3. Ensure decisions align with previously stated preferences when available
4. Consider whether capacity might be regained with treatment or support
5. For ongoing healthcare needs, consider initiating guardianship processes 2

Common Pitfalls to Avoid

• Diagnostic overshadowing: Assuming incapacity based on diagnosis alone
• Outcome bias: Judging capacity based on the decision made rather than the decision-making process
• Inadequate assessment: Relying solely on cognitive screening without decision-specific evaluation
• Failure to enhance capacity: Not attempting to improve understanding through simplified explanations or decision aids
• All-or-nothing approach: Not recognizing that a person may have capacity for some decisions but not others

Remember that capacity assessment is ultimately about balancing respect for autonomy with protection from harm, and should be approached with careful consideration of the specific decision context.