This article sets out what claimants have to prove to successfully establish a clinical negligence claim and receive a compensation award.

Duty of care

Doctors owe a duty of care to their patient. The law defines this as a duty to provide care that conforms to the standard reasonably expected of a competent doctor.

The standard of care

What is the standard of care and what is considered reasonable in a particular case? Further, how can a claimant prove that the defendant doctor’s care has failed to meet the requisite standard?

The claimant first needs to show that on the balance of probabilities, the defendant’s alleged specific acts or omissions were a cause of or materially contributed to the injury or loss or may have caused deterioration in condition. They then have to prove that these acts or omissions were the cause of the injury or loss or may have caused deterioration in their condition that would not otherwise have occurred. Negligence is not actionable without proof of loss or injury arising from the negligent act or omission. The damage may be physical, mental or financial but it must meet all of the following criteria:

  • It must be caused by a breach of duty (causation),
  • It must be a type of damage recognised by law, and
  • It must come within the foreseeable area of risk created by the breach of duty.

The damage will not be the subject of a compensation claim, even if directly caused by the breach of duty, if it is of a completely different type or caused in a completely unforeseeable way. Nor will a doctor be held negligent for their inability to treat a patient successfully.

The Bolam Test

The famous case of Bolam v Friern Hospital Management Committee [1957] 1 WLR 582 concerned a patient who had depression and was voluntarily admitted to the defendant hospital to undergo electroconvulsive therapy (ECT). ECT was delivered without any muscle relaxant drugs and the patient was unrestrained apart from the presence of nursing staff to prevent him from falling off the bed. During the treatment, he sustained violent muscle spasms causing him to fracture both hips.

He pursued a claim, firstly on the ground that had he been warned of this risk he would not have undergone the treatment, and secondly on the ground that had he received the muscle relaxant drug his injuries would not have occurred. The defence maintained there was no requirement to explain the risk of treatment unless specifically asked to do so by the patient. It was held that a doctor was not guilty of negligence if he has acted in accordance with a practice accepted as proper by a responsible body of medical men skilled in that particular art.

The jury found for the defendant on both issues of consent and treatment. In doing so, the ‘Bolam test’ emerged as a legal benchmark, placing the burden of proof on claimants to demonstrate that no responsible body of professional opinion would have endorsed a particular course of action, be it the disclosure of risk or the method of treatment.

The case led to the following propositions about the standard of care: a doctor’s duty is to exercise skill and care according to the ordinary and reasonable standards of those who practice in the relevant field of medicine.

It is recognised that medical opinion may differ. A practitioner who acts in conformity with an accepted current practice is not negligent “merely because there is a body of opinion which would take a contrary view”. In ordinary circumstances, a doctor following a generally approved practice will not be held to be negligent (Marshall v Lindsey County Council). A court cannot choose between two approved practices, i.e. between two schools of thought (Maynard v West Midlands Regional Health Authority).

It was further stated in the Scottish case of Hunter v Hanley:

“In the realm of diagnosis and treatment there is ample scope for a genuine difference of opinion and one man clearly is not negligent merely because his conclusion differs from that of other professional men … the true test for establishing negligence in diagnosis or treatment on the part of a doctor is whether he has been proved to be guilty of such failure as no doctor of ordinary skill would be guilty of acting with ordinary care …”

In determining whether a body of doctors constitutes a reasonable body for the purposes of the Bolam test it is not simply a matter of counting heads; in appropriate circumstances the judge could find that a small number constituted the necessary defence (Defreitas v O’Brien).

For many years, doctors enjoyed the protection in law that the Bolam case brought.  However, this test was qualified in the equally well known case of Bolitho v City and Hackney Health Authority 1993. 

The Bolitho Test

The case of Bolitho v City and Hackney Health Authority dates back to 1997 and concerned the treatment of a sick child in hospital. Negligence was alleged, as on the night in question no doctor had responded to a call made by the night sister. It was agreed that if a doctor had come and had intubated the child, the cardiac arrest and brain damage would have been avoided. The experts in this case disagreed about whether it would have been mandatory to have intubated in the circumstances of this case. The doctor on call gave evidence that she would not have intubated even if she had responded to the call. The defendants in this case argued successfully that the claimant could not prove that if the doctor on call had attended they would have intubated the patient and so could not prove the outcome would have been different.  This decision was upheld in the Court of Appeal. It was appealed up to the House of Lords, who upheld the Court of Appeal’s decision.

Bolitho therefore established that a doctor could be liable for negligence in respect of diagnosis and treatment, despite a body of professional opinion sanctioning his conduct, where it had not been demonstrated to the judge’s satisfaction that the body of opinion relied on was reasonable or responsible.  In the vast majority of cases, the fact that distinguished experts in the field are of a particular opinion would demonstrate reasonableness of that opinion and merely being a minority view of accepted medical practice does not, of itself, render that view unreasonable or irresponsible.

However, in rare cases, if it could be demonstrated that the professional opinion was not capable of withstanding logical analysis, the judge would be entitled to hold that the body of opinion was not reasonable or responsible. Accordingly, following Bolitho, the final arbiter as to whether or not there has been clinical negligence is the court and not the medical profession. It is for the court to decide whether the requisite logical basis for a defendant’s expert medical opinion is absent.

To understand more about what would make the court conclude an expert medical opinion is unreasonable or irresponsible, we can look to case law which has shown us:

  1. A court might be more ready to find that the body of opinion was not capable of withstanding logical analysis if there was a dubious expert whose professional views existed at the fringe of medical consciousness, (see Khoo v Gunapathy d/o Muniandy).
  2. Or if the medical expert had  “a residual adherence to out of date ideas which on examination do not really stand up to analysis”, (see Hucks v Cole).
  3. Further if the expert’s practice was illogical or if there was a “clear precaution” which ought to have been taken, but was not. However if there are risks attached to the precaution and one body of medical opinion considers that the risks ought to have been taken and the other does not then there is no “clear precaution” but rather a balancing of risks. It is a matter of clinical judgement with logical basis.

In the recent case of Muller v King’s College Hospital NHS Foundation Trust 2017 further guidance was given on the application of Bolam and Bolitho. The case involved the misdiagnosis of a lump on the claimant’s foot which was initially diagnosed as a non malignant ulcer, when in fact it was a malignant melanoma. The defendant relied upon expert evidence to the effect that the misdiagnosis was not negligent because it was the sort of mistake that could be made by a histopathologist acting with reasonable skill and care.  The judge held that the law distinguishes between two different types of case.

“The first type is a case such as the present, where the patient’s condition is unknown, and what is alleged to be negligent is a doctor’s diagnosis of the condition, in the form of a report, with no decision made or advice given about treatment or further diagnostic procedures. The diagnosis is either right or wrong and, if wrong, either negligently so or not. Such a case could be called a pure diagnosis cases. At the other end of the spectrum is the second type of case a pure treatment case, where the nature of the patient’s condition is known and the alleged negligence consists in a decision to treat (or advise treatment of) a condition in particular manner”.

In the circumstances of the Muller case, as it was a pure diagnosis case, the judge was permitted to choose between competing expert opinion on the issue to be determined i.e. whether the histopathologist was negligent or not. The standard was an objective one of reasonable care and skill fixed by law. Given both sides experts agreed there were signs of a melanoma on the slides, which were objectively there to be seen, the judicial scrutiny established in Bolitho was applied and a breach of duty was established.

However, in pure treatment cases like Dyson v Heart of England NHS Trust 2017 the Bolam test is still applied. This case involved a claimant who had died as a result of untreatable bleeding following the prescription of a drug called Clexane. However it was not held in this case in applying the Bolam test, to have been negligent or unreasonable or illogical for the doctor in question to have given the claimant this prescription given the risk of pulmonary embolism. 

So in summary there appears to be a two-step process to determine the question of alleged clinical negligence:

  1. Whether the medical practitioner acted in accordance with a practice accepted as proper for an ordinarily competent medical practitioner by a responsible body of medical opinion; and
  2. Whether the practice survives Bolitho judicial scrutiny as being “responsible” or “reasonable”.

Advice and informed consent

Around 2000 years ago the Hippocratic Corpus advised doctors to reveal nothing to their patient of their present or future condition. This paternalistic attitude as in modern times been replaced by a more rights based approach and NICE guidance advises doctor so to give their patients evidence based information and support to enable patients to make informed decision about their care and treatment.

The Montgomery v Lanarkshire Health Board 2015 case drew fresh attention to the issue of informed consent.

Mrs Montgomery had diabetes and as a consequence there was a 9-10% risk of her baby sustaining shoulder dystocia during a natural delivery.  This risk was not disclosed to Mrs Montgomery and when she delivered her son vaginally; he experienced complications owing to shoulder dystocia, resulting in hypoxic insult with consequent cerebral palsy. Her obstetrician had not disclosed the increased risk of this complication in vaginal delivery, despite Mrs Montgomery asking if the baby’s size was a potential problem. Mrs Montgomery sued for negligence, arguing that, if she had known of the increased risk, she would have requested a caesarean section. The Supreme Court found in her favour. The ruling overturned previous case law which applied the Bolam test to decide what information should be disclosed namely whether a doctor’s conduct would be supported by a reasonable body of clinicians. In lay man terms it came down to  the view that a doctor only need tell a patient of the risks if they asked unless there was a substantial risk of adverse consequence. This approach failed to define what constituted a substantial risk or the patient’s perception of the significance of the risk.

The Montgomery case firmly rejected the application of Bolam to the issue of consent, establishing a duty of care to warn of material risks. The test of materiality defined in the Montgomery ruling was whether “a reasonable person in the patient’s position would be likely to attach significance to the risk, or the doctor is or should reasonably be aware that the particular patient would be likely to attach significance to it.”

The full implications of the case are undoubtedly still unknown, but Montgomery has clear relevance for medical law and ethics. Whilst the Montgomery ruling has not radically changed the process of consent; it has given appropriate recognition to patients as decision makers. This is clearly seen in the recent cases of ABC v St George’s & Ors 2017 and Shaw v Kovac & Ors 2017.

 In ABC v St George’s, the claimant successfully appealed the striking out of her claim concerning a failure of her father’s doctors to warn her that she might have Huntington’s disease. The Court of Appeal held it was arguably fair, just and reasonable to impose a duty on the father’s treating doctors to inform her about the risk she may have Huntington’s disease. This was critical because she fell pregnant and would have terminated the pregnancy had she known. The court rejected the defendant’s arguments for disputing they had a duty of care to tell the claimant and were heavily influenced in doing so by the GMC guidance on confidentiality.

In Shaw v Kovac & Ors 2017 a claimant who had undergone an operation for a trans-aortic valve implant and subsequently died would not have consented to the operation had he or his family been given proper information as to the true nature of, and risks inherent in the actual surgical procedure. As a consequence, no proper informed consent was given by the deceased claimant to the operation. The claimant’s family were successful in arguing and obtaining an additional award to compensate the clamant for his “loss of personal autonomy” and “unlawful invasion of the personal rights”. This award was novel and had never before been acknowledged in a case.


The Bolam test may be a reminder of the old days of medical paternalism but it remains an enduring comparator in clinical negligence cases when it comes to pure treatment cases like Dyson. However, in today’s society, we no longer put doctors on the pedestal we once did. The internet has created a new generation of well-informed patients, who are fully familiar with the intricacies of medical treatments as well as the objective care standards established in NICE and other guidelines.

The Bolitho case was the start of the erosion of medical protectionism enshrined in Bolam as it gave the judiciary far greater discretion when determining liability in negligence as demonstrated by the recent judgements in the pure diagnosis cases like Muller.

The Montgomery case on informed consent was framed as a clash of values—patient autonomy versus medical paternalism. In reality, medical decision making involves a nuanced negotiation of information. Today’s patients can expect a more active and informed role in treatment decisions, as demonstrated in the recent cases of ABC and  Shaw with a corresponding shift in emphasis on various values, including autonomy, in medical ethics.



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