Lesson 4.2 : Consent and Capacity

Lesson 4.2: Consent and Capacity

Consent and capacity questions appear in nearly every OSCE circuit. Mastering this topic earns marks across multiple station types, not just dedicated ethics stations.

Valid Consent — Three Requirements

• The patient has capacity to make this specific decision at this time.
• The patient has been given adequate information, including material risks, benefits, and alternatives.
• The decision is voluntary, no coercion, no undue pressure from family, professionals, or circumstances.

The Montgomery Ruling (2015) — Material Risks

A risk is 'material' if a reasonable person in the patient's position would want to know about it, OR if the doctor knows this particular patient would consider it significant. Doctors must disclose all material risks, not just the ones they judge to be clinically important.

In practice: take the patient's individual circumstances, values, and concerns seriously when deciding what to disclose. A professional athlete asking about knee surgery has different material risks from a sedentary 80-year-old.

The Mental Capacity Act 2005 — Five Principles

1. Presume capacity — every adult is presumed to have capacity unless proved otherwise.
2. Support decision-making — take all practicable steps to help someone decide before concluding they lack capacity.
3. Unwise decisions are permitted — a decision others consider unwise is not itself evidence of incapacity.
4. Best interests — if capacity is absent, act in the patient's best interests.
5. Least restrictive option — choose the least restrictive option that achieves the goal.

Assessing Capacity — The Four-Part Test

To have capacity for a specific decision, the patient must be able to:

• Understand the information given about the decision.
• Retain that information long enough to make the decision.
• Weigh the information — consider the pros, cons, and alternatives.
• Communicate their decision — verbally, by gesture, in writing, or by eye movement.

Best Interests When Capacity Is Absent

• Involve those close to the patient — relatives and carers inform the best-interests decision but cannot legally consent for an adult.
• Consider previously expressed wishes, values, beliefs, and preferences.
• Consult an Independent Mental Capacity Advocate (IMCA) if no one else is available.
• A Lasting Power of Attorney (LPA) for health and welfare may legally make the decision if validly registered with the Office of the Public Guardian.
• For serious treatment decisions, a Court of Protection ruling may be required.

Gillick Competence and Fraser Guidelines — Children Under 16

A child under 16 can give valid consent to a specific treatment if they have sufficient maturity and understanding to fully comprehend what is involved. This is assessed for each specific decision, not generally.

Fraser guidelines apply specifically to contraception. A doctor can prescribe to an under-16 without parental consent if all five criteria are met:

• The young person understands the advice and cannot be persuaded to involve parents.
• They are likely to have sexual intercourse with or without contraception.
• Their physical or mental health would suffer without contraception.
• Failure to provide contraception would be more harmful than providing it.
• Providing contraception is in their best interests.

Advance Decisions to Refuse Treatment (ADRT)

A legally valid ADRT must be followed even if the patient now lacks capacity. To be valid, it must:

• Be made by an adult with capacity at the time.
• Specify the treatment being refused and the circumstances in which refusal applies.
• Be in writing, signed, and witnessed — this is required if the ADRT refuses life-sustaining treatment.
• Not have been withdrawn or superseded by a subsequently made LPA.

The Competent Adult's Right to Refuse

Consent Station — PLAB 2 Structure

When a station asks you to 'obtain consent for' a procedure, cover all of the following:

1. Check what the patient already understands about their condition and the proposed procedure.
2. Explain the procedure: what it is, why it is needed, how it will be carried out.
3. Explain the benefits — what it aims to achieve.
4. Explain the risks: common side effects AND material risks per Montgomery (not every possible risk, those the patient would reasonably want to know).
5. Explain the alternatives, including the option of doing nothing and its consequences.
6. Confirm the right to withdraw consent at any time without it affecting their care.
7. Invite questions and check understanding: 'Could you tell me in your own words what will happen?'
8. Confirm their agreement and document the conversation.