Alex | Founder of Medfully
29 May 5 min read

Capacity in Medicine | Medicine Interview Questions & Tips

🧠 What is Capacity in Medicine?

Capacity is the ability of a person to make an informed and balanced decision. In other words, this is a combination of a patient’s ability to understand the information presented to them, the ability to weigh pros and cons and come up with a reasonable decision based on that.

All healthy adults are presumed to have capacity. However, if there are signs that a patient may be lacking capacity, then their capacity should be formally assessed by doctors and nurses.

☑️ How to check if a patient has Capacity?

Checking if a patient has capacity may involve checking if they:

  1. Can understand the proposed course of action.
  2. Retain all information until a decision has to be made.
  3. Weigh the risks and benefits presented to them.
  4. Communicate the decision to the team.

In practice, this may involve asking the patient to explain their reasoning.

👶 Capacity in Children (under 16): Gillick’s competence

Since children are still in the process of brain development, we cannot assume by default that patients below the age of 16 have the same capacity as adults. In principle, parents are involved in the care of patients under the age of 16, and usually, the parents have the autonomy to consent to or object to treatment in the name of their child.

Nonetheless, some patients under 16 may be deemed to have the capacity to consent if they are judged to be mature enough to understand the procedure and the implications of their actions. In such a situation, they are claimed to be Gillick competent (an important buzzword for your medicine interviews!).

Since there are no fixed rules for Gillick competence assessment, it has to be based on the professional judgement of the healthcare professional. Importantly, the assessment has to be done in relation to a specific procedure or treatment (for instance, a 10-year old may be competent and mature enough to understand the implications of taking a blood sample, but not necessarily those of an appendicectomy).

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❓What If a patient lacks Capacity: Possible solutions

All patients above the age of 16 are deemed to have capacity unless they have a condition affecting their brain or mind at the time of making a medically relevant decision. This can include everything from mental disorders (e.g. bipolar disorder), through neurological conditions (e.g. Alzheimer's disease) to coma or intoxication.

But what if the patient is unable to decide (for instance, if they are unconscious but require an urgent medical intervention)? There are a few possible outcomes:

Advance Directive: The patient may have previously signed a legal document, called the advance directive, in which they have specified what treatments they may not wish to receive in certain situations (remember patients have the right to decline, but not to demand specific treatments). A most common example of an advance directive is a DNAR form (short for Do Not Attempt Resuscitation), in which patients object to resuscitation in advance if they were to suffer sudden cardiac arrest.

LPA (Lasting Power of Attorney): In the UK, if a patient is above 18 and is deemed to have mental capacity, they may nominate a person to take responsibility for their care if they were to lose capacity in the future. In case the patient is unable to decide for themselves at some point, the person with the LPA is granted the authority to make a decision in the patient’s name Nonetheless, even in the above situation, doctors have to ensure the wishes of the LPA and in line with the patient's best interests and previously expressed wishes or opinions.


🧑‍⚕️ Lacking capacity: Doctors’ involvement

If not stated by the patient, then the decision will belong to the doctor in charge, who is duty-bound to act in line with the patient's best interests. Additionally, the doctor has the responsibility to inquire about the patient's potential wishes (for instance, from their relatives or by considering the religious and cultural background of the patient), but in case of uncertainty, they mustn't take them into consideration.