What is factual vs Medical causation in medical negligence?

To make a successful medical negligence claim, the treatment you received from your healthcare provider must have either caused your injury or materially contributed to it The two key legal principles underpinning medical negligence claims are factual and medical  causation.

Below, we’ll explain what these principles are and how they apply to medical negligence claims.

What is causation?

In law, causation is the connection between an action (or lack of action) and the resulting harm or damage.

It determines whether the conduct of a defendant, in this case, a healthcare professional, directly causes an injury to a patient ormaterially contributes to that injury..

Factual vs medical causation

There are two types of causation: factual and medical. Here’s what they mean:

Factual causation

Factual causation asks the question: “But for the healthcare provider’s actions, would the harm have happened in any event ?”

When deciding on an answer, the law asks the following questions:

• Were the defendant’s actions or inactions a or a material contributor to  the claimant’s harm?
• Was the harm a foreseeable outcome of the defendant’s actions or inactions?
• Did something else break the chain of causation? For example, was emergency treatment administered by another healthcare professional to cause  or materially contribute to the injury and was that action or inaction sufficiently gross to cause a break in the causation chain? .
• Are there any other matters like contributory negligence (where the claimant’s own actions partly caused the harm) or other elements of the injury that are ‘dose’ related and make up a percentage of the harm caused and which may be not negligently caused and  that apply here?

So, factual causation establishes what the direct cause of harm was in a medical negligence case based upon the facts of the case

• Sometimes the facts speak for themselves and this is known as the doctrine  res ipsa loquitur ; the facts of the case means  that they can  be  the only cause of the injury . This is rare.

Medical causation  in medical cases

In most cases, any follow-up medical treatment won’t break the chain of causation, as the patient wouldn’t have needed that treatment if the original negligence had not happened.

For example, in Webb v Barclays Bank and Portsmouth Hospitals NHS Trust, a patient who suffered an injury at work and had her leg amputated without being told of alternatives. However, she could still sue the original negligent party – her employer – rather than her hospital doctor. The second event was not deemed to be a gross event sufficient to break the chain of causation.

(Source: Carlil & Carbolic)

How is causation proved?

Expert medical evidence is key to proving medical  causation in a medical negligence claim.

Source: (Speedmedical)

What if there are several causes?

In medical negligence cases, there are often multiple factors that contribute to the injury and this is where the medicine is crucial . When there are several possible causes of injury, a solicitor has to prove that it was the negligent act being claimed for that was the cause or materially contributed to the  harm.

In the Wilsher v Essex AHA case, a premature baby suffered damage to her sight. Five possible causes were identified, including a doctor negligently administering too much oxygen. On this occasion, the hospital was not held liable because the claimant couldn’t prove the negligent act was more than 50% likely to have caused the damage.

However, in other cases, the courts use a different method called the ‘material contribution’ test. Under this test, if the negligence materially contributed to the damage (not just the risk of damage) and the contribution was more than negligible, the defendant may be liable.

(Source: Carlil & Carbolic)

What does a break in the chain of causation mean?

A break in the chain of causation occurs when something significant happens between the negligent act and the injury, making it the real cause of the injury. This is known as a ‘novus actus interveniens’ (a new intervening act), and it can mean that the healthcare professional or organisation is no longer held responsible.

In most causation medical negligence cases, follow-up treatment does not break the chain of causation because the patient wouldn’t have needed the extra treatment without the original negligence.

However, medical treatment can break the chain of causation if it is ‘palpably wrong’. This was demonstrated in the case of R v Jordan.

In this case, a patient who had been stabbed was given excessive intravenous fluids and a drug that his healthcare professionals knew he was allergic to. This negligence led to his unfortunate death from pneumonia. This course of treatment was deemed so wrong that it broke the chain of causation from the original injury, the stabbing .

(Source: Carlil & Carbolic & Oxford Reference)

How can Fletchers help?

If you believe you’ve suffered harm due to medical negligence and want help proving causation in your case, the team at The Compensation Experts can help manage your claim.

Speak to our experts to see if you’re entitled to a claim or speak to one of our team about what happened to you. If they believe you have a case, they’ll connect you with an experienced solicitor who can arrange specialist medical reports, access expert medical witnesses in your injury field, and build a comprehensive chain of evidence to support your claim.