As every adult has the right to decide what should and should not be done to their body, consent has an essential role to play in medical treatment.

In 2015 the case of Mongomery v Lanarkshire Health Board changed the framework for doctors obtaining consent from patients for medical treatment. A doctor must no longer ask what a reasonable doctor must tell a patient but ask instead what a reasonable patient wants to know. The new test is whether “in the circumstances of the particular case, a reasonable person in the patient’s position would be likely to attach significance to the risk, or the doctor is or should be aware that the particular patient would be likely to attach significance to it”.

Following the decision in Montgomery, a number of medical defence organisations issued guidance to their doctors advising that the discussions with patients should be clearly noted within the patient’s medical records. In the immediate aftermath of Montgomery, some doctors feared that not only would the floodgates would be opened to claims regarding consent but also that consent would become a long onerous task in deciding what a patient would want to know.

So what does the reasonable patient really want to know?

In 2017 some judicial guidance was given in the case of Thefaut v Johnston. While the case relates to elective surgery it may have significance for other consent cases. The judgment focused on material risks which were subdivided into objective and subjective risks.

In relation to the objective risks of a procedure, the judgment warned against using jargon or overly technical language. The judge in Thefaut stressed that objective risks cannot be reduced to mere percentages. The risks of bleeding, infection, scarring, deep vein thrombosis (DVT), pulmonary embolism and even death are commonplace on a surgical consent form.

But do patients really know what these mean and, if not, how should this information be communicated to patients? Patients often receive leaflets containing information about their procedure but these can be inaccessible to the reasonable patient. The use of technologies such as podcasts, videos and websites are increasingly being used to help patients make an informed decision.

Subjective risks may be harder to judge. Examples given in Thefaut included the patient’s tolerance to pain or a desire to return to work. A doctor must consider whether there are factors which may contraindicate surgery.

Informed consent goes beyond the simple risks and benefits of the procedure. The alternatives to surgery should be discussed with the patient including what would happen if the patient had no treatment at all. Informed consent can include the option to do nothing even where that decision could harm the patient.

Setting patient expectations from an early stage is also important in informed consent. What a doctor might consider to be a good outcome from the procedure might not be a good outcome for the patient. For example, many patients undergo surgery to alleviate pain and expect a successful outcome to result in being pain-free. However, in reality, this might not be the case. Expectations post-surgery should be set pre-surgery.

When it comes to elective surgery, a patient may have strong views about the surgeon performing that procedure. Any change to the surgeon performing the surgery should be communicated to the patient and the patient given the opportunity to re-consent to the procedure with the new surgeon.

The timing of consent is also an important consideration. A patient needs to have time to absorb the information they are given about the procedure they are to undergo. There are cases where the patient has been gowned up ready to undergo the procedure before being asked to sign a consent form and consider the risks and benefits of the procedure. The judge in Thefaut noted that, in this scenario, free choice could not be exercised as there was not sufficient time and space to have a meaningful discussion.

The patient’s informed consent means little if it is then not properly documented by the doctor. While a signed consent form may assist in showing that the consent process has been initiated, it may only pay lip service to informed consent. Courts have warned against the over-reliance on signed consent forms. A full record needs to be made in the patient’s medical records. Without this a doctor can no longer expect to rely on his usual or standard practice to explain what information the patient might have been given.

Patient-centred, fully-informed consent may be a challenge to the previous paternalistic methods but it need not be an onerous task for the medical profession. It is not a move away from clinical respect as some have commented. It simply gives the patient the autonomy to make decisions about what happens to them.