Everything You Need to Know About Causation in Medical Negligence Cases

The complexity of medical negligence law makes it a confusing topic for the inexperienced. This is why it is so important to seek the services of a qualified legal professional if you feel you have a claim.

If you are thinking of making a medical negligence compensation claim, you will need to prove two things: that the care you received was not at an acceptable standard, and that this poor care caused the injury you are claiming for. Solicitors call this proving breach of duty, and causation.

In this latest post, our experienced solicitors look at what medical negligence causation is, how it can be proved, and other key points to consider.

What is Causation in Medical Negligence?

‘Causation’ in medical negligence cases means proving that negligence as a result of a breached duty of care has caused injury. Proving this is known as ‘establishing causation’.

How Do You Prove Causation in Medical Negligence Cases?

Proving causation in medical negligence cases is very difficult, and this can still be the case even when the ‘material contribution’ principle (proof that negligence made more than a minimal contribution to the damage incurred) can be applied.

A Balance of Probabilities

With many procedures and treatments, it is generally accepted that there that are potential complications which might affect the outcome. This is why, in order to establish causation, you must show through a ‘balance of probabilities’ that the breach was the reason for the injury.

This can be best explained using an example (the case of Barnett), where a patient was admitted to A&E with severe stomach pain and vomiting, only to be sent home after being examined by a doctor. The patient died five hours later from arsenic poisoning. In this case, although the doctor was negligent, no treatment could have saved the patient and so causation could not be proved. Therefore the claim failed.

What if There Are Multiple Factors Involved?

If there is more than one potential cause of an injury, we must be able to prove that the damage was caused by the incident we are claiming for. In the case of Wilsher v Essex Area Health Authority, a junior doctor neglected to give oxygen to a baby during its birth, and as a result the baby sadly became blind. However, when the baby’s parents tried to bring a claim, it was found that this negligence was just one of five possible reasons for the blindness. As it was not possible to identify which of the reasons was the fault, the claim was unsuccessful.

If multiple causes are seen as ‘cumulative’, however, a claim can still succeed. This would be because alone they would not have had the effect, but by acting together they have caused the injury. For example, a patient develops an infection after an operation, and negligent hospital care leads to this spreading and a further, more serious medical procedure being required as a result.

Breaking the Chain of Causation: What is Novus Actus Interveniens in Medical Negligence?

Novus actus interveniens in medical negligence cases is when an unforeseeable event occurs after a neglectful act which intervenes and worsens the effects.
This is known as “breaking the chain of causation” and often means the defendant will not be found liable – even if it can be proved that they acted negligently.

For example, in the case of McKew v Holland and Ors, a man’s leg had a tendency to give way regularly without warning – something the defendant admitted liability for. However, during the negotiation period, the man fell down the stairs and broke his ankle, worsening his injuries.

As a result, the court had to assess whether he had acted reasonably and carefully knowing his injury could cause him weakness. His actions were found to be unreasonable, and as they had broken the chain of causation, the defendant was not liable for the fall down the stairs.

Are the Effects of Medical Negligence Categorised Differently?

In short, yes. Injuries as a result of medical negligence are categorised as:
Divisible: Where the severity is linked to the dose of the agent which caused the injury. For example, giving too much of a drug, or anaesthetic.
Indivisible: Where the severity is not linked to the dose of the agent which caused the injury. For example, injecting a toxic drug into the wrong part of the body.

Are You Considering Making a Medical Negligence Claim?

The complexity of medical negligence law makes it a confusing topic for the inexperienced. This is why it is so important to seek the services of a qualified legal professional if you feel you have a claim.
If you would like to discuss your case with us, please get in touch with our friendly and experienced medical negligence solicitors today.