The two elements of Clinical Negligence
To succeed in a clinical negligence claim, a claimant must prove:
Breach of Duty. That the healthcare professional failed to meet the expected standard of care.
Causation. That the breach directly caused or significantly contributed to the injury or worsening condition.
What are the types of Causation?
Causation is typically divided into two categories:
Factual Causation (the ‘But-For Test’) – The claimant must show that, ‘but for’ the healthcare provider’s negligence, the harm would not have occurred. If the injury would have happened regardless of the negligence, the claim may fail.
Legal Causation (Material Contribution Test) – In cases where multiple factors contributed to the harm, it must be shown that the negligence made a significant (material) contribution to the injury. This is particularly relevant in cases involving delayed diagnosis or inadequate treatment.
What are the challenges in proving Causation?
Pre-existing Conditions – If a patient already had an underlying illness, proving that the negligence, rather than the condition itself, caused the harm can be difficult.
Multiple Causes – If other factors (e.g., natural disease progression) played a role, the court must determine whether the negligence materially worsened the outcome.
Speculative Claims – Courts require strong medical evidence to link the negligence to the harm, rather than mere speculation.
Examples of Causation in Clinical Negligence
Because Causation in clinical negligence is proving that the healthcare provider’s negligence directly caused or materially contributed to the patient's harm, it can be a very blurred area of the law, and difficult to prove. Below are common examples of causation issues in medical negligence claims:
Delayed diagnosis leading to worsened condition
A patient visits their GP multiple times with persistent symptoms of bowel cancer, but the GP fails to refer them for further tests. By the time the cancer is diagnosed, it has progressed to an advanced stage, significantly reducing the patient’s life expectancy.
Causation Issue: The claimant must prove that an earlier diagnosis would have led to better treatment outcomes or a higher chance of survival.
Surgical error causing additional harm
A surgeon accidentally damages a nerve during a routine operation, leading to permanent paralysis in the patient’s arm.
Causation Issue: The patient must prove that the nerve damage was a direct result of the surgeon’s error and not an inherent risk of the procedure.
Medication errors resulting in harm
A doctor prescribes an incorrect dosage of blood-thinning medication, leading to excessive internal bleeding and a stroke.
Causation Issue: The claimant must show that the stroke would not have occurred if the correct dosage had been given.
Birth injury due to negligence
A midwife fails to monitor foetal distress during labour, leading to a prolonged lack of oxygen (hypoxia), which results in cerebral palsy.
Causation Issue: The claimant must prove that timely intervention (such as an emergency C-section) would have prevented the injury.
Failure to treat an infection promptly
A patient with a post-operative wound infection is not given antibiotics in time, leading to sepsis and organ failure.
Causation Issue: The patient must establish that timely antibiotic treatment would have prevented the infection from progressing to sepsis.
Misdiagnosis leading to unnecessary treatment
A patient is wrongly diagnosed with cancer and undergoes aggressive chemotherapy, which later turns out to be unnecessary.
Causation Issue: The claimant must prove that the unnecessary treatment caused physical and psychological harm.
Inadequate mental health care, resulting in suicide
A psychiatric patient with suicidal tendencies is discharged from a hospital without proper assessment, and they later take their own life.
Causation Issue: The claimant (e.g., family members) must prove that had the patient been kept under supervision, their suicide could have been prevented.
Anaesthesia errors leading to brain damage
A patient receives an excessive dose of anaesthesia, resulting in prolonged oxygen deprivation and permanent brain damage.
Causation Issue: The patient must demonstrate that the brain damage was directly caused by the anaesthetic overdose and not an unrelated medical condition.
Causation is often the most contested aspect of clinical negligence claims. Even if a breach of duty is established, the claim will fail unless causation is proven on the balance of probabilities (i.e., more likely than not). Medical expert testimony is usually essential in demonstrating this link and determining whether compensation is justified.
What are the key points for causation in Clinical Negligence?
"But-For" Test: The claimant must prove that the harm would not have occurred "but for" the negligence.
Material Contribution Test: If multiple factors contributed to the harm, it must be shown that negligence made a significant contribution.
Medical Evidence: Expert testimony is often crucial in proving causation.
Causation is often the most challenging aspect of a clinical negligence claim, as it requires clear evidence linking the medical error to the injury suffered and may make a very significant difference to the value of the claim.
Get Expert Legal Advice
If you have a medical negligence claim, please contact David Simpson, Partner and Head of the Medical Negligence at Coles Miller Solicitors.
His practice covers a wide range of medical negligence matters. David regularly deals with cases of high complexity and value; he has particular interest in cases involving Cauda Equina, vascular problems leading to amputation and mismanaged labour.
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