By MRCSA in MRCS Part A — 04 Jul 2026

75 CONSENT

# 76 CONSENT

Consent is the legal and ethical backbone of every surgical interaction. The MRCS examiners love this topic because the rules are clear, the case law is famous, and there is always a clean answer. Most candidates lose marks not because they do not know the principles — but because they confuse the consent forms, mis-apply Gillick, or forget that Bolam no longer governs disclosure of risk.

This lesson distils consent into the framework the examiners actually test: the three pillars of valid consent, capacity under the Mental Capacity Act, the Montgomery standard for disclosure, the five NHS consent forms, the rules around children and Jehovah's Witnesses, and the doctrine of necessity in emergencies.

For consent to be legally valid, three conditions must be met:

1. Capacity — the patient must have the mental ability to make the decision.

2. Voluntariness — the decision must be free from coercion, undue influence or pressure (from family, employers or even clinicians).

3. Informed — the patient must have been given sufficient information about the procedure, its risks, benefits and alternatives, in a form they can understand.

Miss any one of these and the consent is invalid — and any subsequent procedure is technically a battery.

👩‍⚕️ Consent is a process, not a signature. The form is evidence that the conversation happened; it is not the conversation itself.

Capacity — the Mental Capacity Act 2005

The Mental Capacity Act (MCA) governs capacity assessment in England and Wales. Five statutory principles underpin the Act, but the two most heavily examined are:

- Assume capacity unless proven otherwise.

- An unwise decision is not, in itself, evidence of incapacity. A patient is allowed to make choices clinicians disagree with.

Capacity is decision-specific (a patient may have capacity to consent to a blood test but not to a Whipple's) and time-specific (capacity can fluctuate — e.g. delirium, intoxication, post-ictal).

The four-stage test

To have capacity, a patient must be able to:

1. Understand the information relevant to the decision.

2. Retain that information long enough to make the decision.

3. Weigh up the information as part of the decision-making process.

4. Communicate the decision (by any means — speech, writing, blinking, sign language).

Fail any one stage and the patient lacks capacity for that decision.

👩‍⚕️ Memory aid: U R W C — "U R With Capacity" — Understand, Retain, Weigh, Communicate.

If a patient lacks capacity, decisions are made in their best interests (MCA s.4), considering past wishes, beliefs, and the views of family or carers — but the final decision rests with the responsible clinician (unless an LPA or court order exists).

This is the single most testable piece of case law in MRCS ethics.

Before 2015, disclosure of risk was governed by the Bolam test (1957): a doctor was not negligent if their disclosure was supported by a responsible body of medical opinion. This was a doctor-centred standard.

Montgomery v Lanarkshire Health Board (2015) overturned this for consent. The Supreme Court ruled that a doctor must disclose any material risk — defined as a risk that:

- A reasonable person in the patient's position would attach significance to, OR

- The doctor knows (or should know) that this particular patient would attach significance to.

The standard is now patient-centred, not doctor-centred. The doctor must also discuss reasonable alternatives, including the option of doing nothing.

Bolam (pre-2015)	Montgomery (post-2015)
Reasonable doctor standard	Reasonable patient standard
What peers would disclose	What this patient would want to know
Applies to diagnosis and treatment	Applies to consent / disclosure of risk
Doctor-centred	Patient-centred

👩‍⚕️ Exam trap: Bolam still applies to standards of diagnosis and treatment (i.e. clinical negligence). It is only the consent/disclosure component where Montgomery has replaced it.

> Pearl: Mrs Montgomery was a diabetic mother of short stature whose obstetrician did not warn her about shoulder dystocia (~10% risk in diabetic women). The baby suffered cerebral palsy. The court ruled the risk was material and should have been disclosed.

Form	Who	When
Form 1	Adult with capacity	Standard elective surgery under GA/regional
Form 2	Parent/guardian	Child without capacity (Gillick incompetent or <16 lacking understanding)
Form 3	Adult or child with capacity	Procedure without GA or impaired consciousness — increasingly obsolete; many trusts now use Form 1 only
Form 4	No-one signs as patient	Adult who lacks capacity — clinician documents best-interests decision
Form 5	Child with capacity	Gillick-competent child consenting for themselves

👩‍⚕️ Easy marks: a competent 14-year-old with appendicitis signs Form 1 (or Form 5 in some trusts). An 11-year-old going for laparoscopy needs Form 2 signed by a parent. An unconscious trauma patient needing immediate laparotomy is Form 4.

This is a high-yield area because the rules differ by age band.

Under 16 — Gillick competence

A child under 16 can give valid consent if they have sufficient understanding and intelligence to comprehend fully what is proposed (Gillick v West Norfolk AHA, 1985). Capacity is assessed for the specific decision in front of them.

Fraser guidelines

Specifically concern contraception and sexual health advice for under-16s without parental knowledge. A doctor may proceed if the young person:

- Understands the advice.

- Cannot be persuaded to inform their parents.

- Is likely to begin or continue sexual activity regardless.

- Will suffer (physical or mental health) without advice/treatment.

- It is in their best interests.

👩‍⚕️ Common exam trap: Gillick = competence in general; Fraser = contraception specifically. Do not use them interchangeably.

16–17 year olds

Presumed competent to consent under the Family Law Reform Act 1969. However — and this is critical — a 16–17 year old cannot refuse life-saving treatment if a person with parental responsibility or a court overrides that refusal. Refusal in this age group is therefore not absolute, in contrast to a competent adult.

Parental responsibility

- The mother always has parental responsibility.

- The father has it if married to the mother at the time of birth, named on the birth certificate (post-2003), or by court order/parental responsibility agreement.

- Step-parents and grandparents do not automatically have it.

If a patient lacks capacity (unconscious, severely confused, intoxicated) and treatment is immediately necessary to save life or prevent serious deterioration, the clinician may proceed without consent under the doctrine of necessity. The decision is documented on a Form 4 and must be in the patient's best interests. Treatment should be limited to what is necessary in that episode — non-urgent decisions are deferred until capacity returns or proper substitute decision-making is in place.

Advance decisions and LPAs

Tool	What it does	Binding?
ADRT (Advance Decision to Refuse Treatment)	Patient, when competent, refuses specified future treatment	Legally binding if valid and applicable; must be written, signed, witnessed if refusing life-sustaining treatment
LPA — Health & Welfare	Donee makes health decisions when donor loses capacity	Legally binding; can refuse life-sustaining treatment only if explicitly stated
LPA — Property & Finance	Donee makes financial decisions	Does not confer health-decision authority
Advance statement	Records preferences (not refusals)	Not binding, but informs best-interests decisions

👩‍⚕️ A Property-and-Finance LPA does not allow the donee to consent or refuse medical treatment. Examiners love this distinction.

Jehovah's Witnesses

Adult Jehovah's Witnesses with capacity may refuse blood and most blood products (red cells, platelets, FFP, whole blood, cryoprecipitate). This refusal must be respected even if it results in death — this is a settled application of patient autonomy.

Some accept fractions (albumin, immunoglobulins, clotting factor concentrates) and cell salvage if blood remains in a continuous circuit. Always ask each patient specifically — practice is individual.

In children of Jehovah's Witness parents, parental refusal of life-saving transfusion can be overridden by the court in the child's best interests. In a genuine emergency where no time exists to seek a court order, transfusion under the doctrine of necessity is defensible — but seek legal authority if time permits.

Confidentiality and disclosure

Confidentiality is a corollary of consent: information given for one purpose cannot be shared without the patient's permission. Exceptions where disclosure is permitted or required:

- Notifiable diseases (Public Health (Control of Disease) Act 1984) — e.g. TB, meningitis, measles, food poisoning, COVID-19.

- Court order — a judge can compel disclosure.

- Statutory duty — e.g. Road Traffic Act (identify driver), terrorism legislation, FGM reporting in under-18s.

- Public interest — risk of serious harm to others (e.g. a patient with untreated epilepsy who continues to drive HGVs after DVLA refuses to inform — GMC guidance permits disclosure).

- GMC investigations.

👩‍⚕️ Disclosure should be proportionate — share the minimum information necessary, and where possible inform the patient first.

DNACPR

A Do Not Attempt CPR decision is a clinical decision about a specific intervention (CPR), made by the responsible clinician after discussion with the patient (or family if the patient lacks capacity). Key points:

- It is not a patient veto on CPR — patients cannot demand CPR that would not work, but they have the right to be informed of the decision (R (Tracey) v Cambridge, 2014).

- It does not affect any other treatment — the patient still receives full care otherwise.

- It should be reviewed regularly and travels with the patient (e.g. discharge to community).

Specific surgical scenarios examiners test

- Amputation — must specifically discuss phantom limb pain, mobility, prosthesis options, and confirm side (WHO surgical checklist).

- Fertility-affecting procedures (orchidectomy, hysterectomy, pelvic radiotherapy) — must discuss fertility implications and sperm/oocyte preservation options.

- Infection risk — disclose institutional infection rates if material (e.g. previous MRSA, HCV transmission risk for blood-exposed procedures).

- Transfusion — explicit consent for blood products is now standard practice in most UK trusts (post-SaBTO guidance, 2020).

- Operating surgeon identity — patients have the right to know who will perform their operation; significant changes (e.g. trainee instead of consultant) should be disclosed.

- Photography, tissue retention, students present — separate consent.

[Image: MCQs banner]

Test yourself

((The patient herself (Form 1/5)::☑️ Gillick competent — sufficient understanding of the decision, regardless of age or diagnosis.))
((Her parents (Form 2)::Not needed when the child is Gillick competent.))
((Both patient and parents::Dual signatures aren't required; competence is decision-specific to the patient.))
((The consultant surgeon::Doctors obtain consent, they don't provide it.))

👩‍⚕️ Down syndrome does not preclude capacity — assess the four-stage MCA test for this specific decision.

((The child (Form 1)::Unlikely Gillick competent at 11 for a GA procedure of this complexity.))
((Parent/guardian (Form 2)::☑️ Form 2 is parental consent for a child without capacity.))
((The anaesthetist (Form 3)::Form 3 is for procedures without GA; consent still comes from parent.))
((No consent needed (Form 4)::Form 4 is for adults lacking capacity in an emergency.))

A man is brought to A&E unconscious after a road traffic accident with massive intra-abdominal bleeding. He needs urgent laparotomy. The most appropriate next step is:

((Wait for next of kin::Next of kin cannot consent for an adult; delay risks death.))
((Proceed under the doctrine of necessity (Form 4)::☑️ Life-saving treatment in best interests when capacity is absent.))
((Contact the GP for consent::GP has no legal authority to consent for an adult.))
((Apply to the court::Far too slow for a life-threatening haemorrhage.))

👩‍⚕️ Relatives' views inform best-interests decisions but do not constitute legal consent for an adult.

A 4-year-old with severe anaemia needs urgent transfusion. The parents, Jehovah's Witnesses, refuse on religious grounds. The appropriate next step is:

((Respect parental refusal::Parents cannot refuse life-saving treatment on a child's behalf.))
((Transfuse immediately without authority::Only defensible if the child will die before a court can be reached.))
((Seek emergency court authorisation::☑️ Court can override parental refusal in the child's best interests.))
((Transfer to another hospital::Delay risks the child's life and doesn't change the legal position.))
((Use non-blood alternatives only::Inadequate when red cells are specifically required.))

Which case established that doctors must disclose risks a reasonable patient would consider material?

((Bolam v Friern (1957)::Reasonable-doctor standard for negligence — superseded for consent.))
((Bolitho v City and Hackney (1997)::Refined Bolam; peer opinion must withstand logical scrutiny.))
((Montgomery v Lanarkshire (2015)::☑️ Established the reasonable-patient standard for disclosure of risk.))
((Gillick v West Norfolk (1985)::Concerns competence in under-16s, not adult disclosure.))

👩‍⚕️ Bolam still governs diagnosis and treatment; Montgomery governs consent.

Which is NOT one of the four stages of capacity assessment under the MCA 2005?

((Understand the information::Stage 1 — comprehension of the decision.))
((Retain the information::Stage 2 — long enough to decide.))
((Agree with the clinician's recommendation::☑️ An unwise decision is not incapacity.))
((Weigh the information::Stage 3 — use it in reasoning.))
((Communicate the decision::Stage 4 — by any means.))

An 82-year-old with mild dementia refuses an elective hernia repair, stating she'd rather live with the lump than have surgery. She understands the risks and benefits. What is the correct action?

((Proceed under best interests::She has capacity for this decision — best-interests does not apply.))
((Respect her refusal::☑️ Capacity is decision-specific; an unwise decision is not incapacity.))
((Apply to the Court of Protection::Not required when capacity is intact.))
((Seek consent from her next of kin::Relatives cannot consent for a competent adult.))

((His refusal is binding as he is over 16::16–17-year-olds cannot refuse life-saving treatment if parents/court consent.))
((Treatment may proceed with parental consent::☑️ Refusal in 16–17-year-olds can be overridden for life-saving care.))
((Court order is mandatory before transfusing::Court is advisable but not strictly required when parents consent.))
((Treatment requires unanimous family agreement::No such legal requirement exists.))

👩‍⚕️ Adult-style autonomy to refuse life-saving treatment only crystallises at 18.

A patient with capacity has an ADRT refusing all blood products. He is now unconscious and bleeding heavily post-op. The correct action is:

((Transfuse — the ADRT is overridden by emergency::ADRTs are binding if valid and applicable to the situation.))
((Withhold transfusion and use alternatives::☑️ A valid, applicable ADRT is legally binding even in emergencies.))
((Ask family to consent on his behalf::Family cannot override a valid ADRT.))
((Apply for emergency court order::Court cannot override a valid ADRT for a competent adult's prior refusal.))

A man holds a Lasting Power of Attorney for property and finance for his elderly mother, who now lacks capacity. He insists on refusing her cataract surgery. What is the correct action?

((Accept his refusal as her legal representative::Property-and-finance LPA does not extend to medical decisions.))
((Make a best-interests decision; the LPA does not cover health::☑️ Only a Health & Welfare LPA confers medical decision-making.))
((Defer to the eldest child::No legal hierarchy of relatives for consent.))
((Apply to the Court of Protection immediately::Not required for routine decisions; best-interests process applies.))

A 14-year-old requests the combined oral contraceptive pill without informing her parents. Which framework applies?

((Gillick competence alone::Gillick is the general competence test; Fraser is the specific framework here.))
((Fraser guidelines::☑️ Specifically govern contraceptive advice/treatment for under-16s.))
((Mental Capacity Act 2005::Applies to those aged 16+.))
((Parental consent is mandatory::Not if Fraser criteria are met.))

A patient newly diagnosed with active pulmonary TB refuses to allow you to inform Public Health. What should you do?

((Respect his refusal — confidentiality is absolute::Confidentiality is not absolute; statutory exceptions exist.))
((Notify Public Health — TB is a notifiable disease::☑️ Disclosure is required by law under the 1984 Act.))
((Apply for a court order::Statutory duty makes a court order unnecessary.))
((Discharge the patient and document refusal::Fails the statutory and public-interest duty.))

Which is true of a DNACPR decision?

((It requires patient consent to be valid::It is a clinical decision; consent isn't required but discussion is.))
((It prevents administration of antibiotics::DNACPR applies only to CPR, not other treatments.))
((The patient must be informed of the decision where possible::☑️ Established by R (Tracey) v Cambridge (2014).))
((It is permanent once made::DNACPR decisions are reviewed regularly.))

A surgical trainee plans to perform a laparoscopic cholecystectomy under consultant supervision. The patient assumed the consultant would operate. What is required?

((No disclosure needed — the consultant supervises::Material to many patients; disclosure required under Montgomery.))
((Disclose that the trainee is the primary operator::☑️ Operator identity is material to consent; patient must be informed.))
((Disclose only if the patient asks::Montgomery imposes a proactive duty of disclosure.))
((Obtain a separate written consent from the trainee::Trainees don't sign as patient; the patient consents.))

Revision summary

- Valid consent = capacity + voluntary + informed. Miss any pillar and consent is invalid.

- MCA 2005 — four-stage test: Understand, Retain, Weigh, Communicate. Assume capacity; unwise ≠ incapable. Decision- and time-specific.

- Montgomery (2015): disclose any material risk a reasonable patient would value, plus alternatives. Bolam no longer governs consent (still governs diagnosis/treatment).

- Consent forms: 1 = adult with capacity; 2 = parent for child without capacity; 3 = no GA (largely obsolete); 4 = adult lacking capacity; 5 = competent child.

- Gillick = general competence under 16. Fraser = contraception specifically.

- 16–17y: can consent; cannot refuse life-saving treatment if parents/court override.

- Emergency: doctrine of necessity → Form 4, best interests.

- ADRT binds if valid and applicable; must be written/signed/witnessed if refusing life-sustaining treatment. Health & Welfare LPA overrides; Property & Finance LPA does NOT.

- Jehovah's Witnesses: adults can refuse; courts override parental refusal for children.

- Notifiable diseases, court order, statutory duty, public interest = lawful breaches of confidentiality.

- DNACPR: clinical decision; patient must be informed (Tracey).

- Specific scenarios: discuss fertility, phantom limb, transfusion, infection risk, and operator identity explicitly.

The three pillars of valid consent