Consent and capacity

Quick Overview

Mental capacity assessment is a legal and ethical cornerstone of UK medical practice, governed by the Mental Capacity Act 2005 (MCA). Capacity is decision-specific and time-specific-assume capacity unless proven otherwise. NICE NG108 emphasizes that all practicable steps must be taken to support decision-making before concluding someone lacks capacity.

Core Facts & Concepts

Mental Capacity Act 2005 - Five Statutory Principles:

1. Presumption of capacity until established otherwise
2. Support all practicable steps to aid decision-making
3. Unwise decisions do not prove incapacity
4. Best interests guide actions for those lacking capacity
5. Least restrictive option must be chosen

Two-Stage Capacity Test:

📌 Remember: URUC - Understand, Retain, Use/weigh, Communicate

Consent Requirements by Scenario:

• Valid consent needs: Capacity + Voluntary + Informed
• Emergency treatment: Proceed in best interests if capacity cannot be assessed (life/limb-threatening)
• Advance decisions: Legally binding if valid and applicable; must be written and witnessed for life-sustaining treatment refusal
• Lasting Power of Attorney (LPA): Health & Welfare LPA can consent/refuse treatment (only active when patient lacks capacity)
• Court of Protection: Resolves disputes; appoints deputies for ongoing decisions

Age-Specific Thresholds:

• ≥16 years: Presumed capacity (can consent; refusal may be overridden if life-threatening)
• <16 years: Gillick competence if sufficient maturity (Fraser guidelines for contraception)
• Parental responsibility: Overrides child refusal if in best interests until age 18

Problem-Solving Approach

Capacity Assessment Protocol (NICE NG108):

1. Optimize conditions: Quiet environment, appropriate timing, communication aids, involve family/advocates
2. Apply diagnostic threshold: Document impairment (delirium, dementia, learning disability, mental illness, intoxication)
3. Conduct functional test (URUC):
   • Understand: Explain in simple terms; ask patient to repeat back
   • Retain: Even brief retention sufficient (minutes acceptable)
   • Use/weigh: Can they appreciate consequences? Compare options?
   • Communicate: Any method counts (speech, writing, blinking, Makaton)
4. Document thoroughly: Record what information given, how assessed, reasons for conclusion, who consulted

Best Interests Checklist (if capacity lacking):

• Consult: Family, carers, LPA, IMCA (Independent Mental Capacity Advocate if no one available)
• Consider: Past/present wishes, beliefs, values, other relevant factors
• Encourage participation: Support patient involvement maximally
• Life-sustaining treatment: Do not assume withholding is in best interests

⚠️ Warning: Deprivation of Liberty Safeguards (DoLS) required if restricting freedom in hospital/care home-apply via supervisory body

Analysis Framework

Capacity vs Consent Scenarios:

Red Flags Suggesting Incapacity:

• 🚩 Cannot retain information even momentarily
• 🚩 Repeats same questions without incorporating answers
• 🚩 Cannot describe consequences of choices
• 🚩 Decision based on delusional beliefs directly

⭐ Clinical Pearl: Capacity can fluctuate-reassess if clinical state changes. A patient may have capacity for simple decisions (what to eat) but not complex ones (surgery consent).

Visual Aid

Capacity Assessment Documentation Template:

Key Points Summary

✓ Presume capacity for every decision unless impairment proven; capacity is decision-specific and time-specific

✓ Two-stage test: (1) Diagnostic threshold-impairment present? (2) Functional test-URUC (Understand, Retain, Use/weigh, Communicate)

✓ Valid consent requires: Capacity + Voluntary + Informed; unwise decisions ≠ incapacity

✓ Best interests: Consult widely (family, LPA, IMCA); consider patient's wishes, beliefs, values; choose least restrictive option

✓ Advance decisions: Legally binding if valid/applicable; must be written and witnessed for life-sustaining treatment refusal

✓ Age thresholds: ≥16 presumed capacity; <16 Gillick competence possible; parental responsibility until 18

✓ Emergency treatment: Proceed in best interests if capacity assessment impossible and treatment urgent-document retrospectively