Difference Between a Breach of Duty and Causation

When you are receiving advice from your solicitor or barrister during a medical negligence case, you will come across legal terms like “a breach of duty of care” and “causation”.* What do they mean?

What is a Breach of Duty of Care?

A breach of duty of care is the first legal principle that you must prove to a court in order to succeed with a medical negligence case, the second is “causation”. If the treatment you receive by a doctor, consultant, hospital or staff is below the ordinary standard of care that a medical practitioner should provide to you, then a breach of duty of care may arise and the medical treatment may be regarded as negligent.

If it can be established that the medical treatment was negligent then we need to consider if causation follows from the negligent treatment.

Difference Between Breach of Duty and Causation in Medical Negligence Cases

  • Breach of Duty /Negligence

The treatment of the patient by the hospital, doctor or care provider is below the ordinary standard of care that a patient should ordinarily expect to receive

  • Causation

As a result of the breach of duty, the patient’s recovery has been delayed or the patient has suffered further injury or unfortunately passed away. In simple terms: due to the breach of duty, the patient has suffered further pain, injury or death that could have been avoided if the correct treatment was provided in the first place.

How Does Causation Contribute Towards Medical Negligence?

Causation in medical negligence cases means that due to the breach of duty of care, negligence arises and the patient has suffered pain, further  injury or death that could have been avoided if the correct treatment was provided in the first place.

Medical treatment can be complicated and there are multiple factors involved in treatment. It can be difficult to determine with 100% accuracy that a breach of duty of care arises and that the outcome for the patient has been altered due to the treatment.

That is why the court will assess the merits of a case on the “balance of probabilities”. In essence, this means that in assessing both a Plaintiff (patient) and the Defendants (care provider) sides of the case, a Judge may consider that the strength of the evidence is stronger on one side on the balance of probabilities.

How Can You Prove Causation in Medical Negligence Cases?

In order to succeed in court with a medical negligence action, the client must comply with the principles in the 1989 case of Dunne -v- National Maternity Hospital wherein, the court set out 6 key criteria to prove negligence;

  • The medical practitioner has been proven to be guilty of such failure,  where no medical practitioner of equal or general status and skill would be guilty if they were acting with ordinary care.
  • If the allegation of negligence against a medical practitioner is based on proof that they deviated from a general and approved practise, that will not establish negligence unless it is also proved that the course they took was no different than what another medical practitioner of like specialisation and skill would have followed, had they been taking the ordinary care required from a person of their qualifications.
  • If a medical practitioner charged with negligence defends their conduct by establishing that they followed a practice which was general and which was proved by his colleagues of “similar specialisation and skill“, they cannot escape liability if, in response, the Plaintiff establishes that such practice had inherent defects which ought to have been obvious to anyone giving the matter due consideration.
  • An honest difference of opinion between doctors as to which is the better of two ways of treating patients does not provide any grounds for leaving a question to the judge as to whether the person has followed one course rather than another.
  • It is not for the judge to decide which of the two alternative courses of treatment is preferable but the course of treatment followed on the evidence, complied with the careful conduct of a medical practitioner “of like specialisation and skill as that professed by the defendant”.
  • If there is an issue of fact, the determination of which is necessary for the decision as to whether or not a particular medical practice is or is not general and approved.

It is with these 6 principles in mind that we advise a client on the strength of a case. We appreciate that the principles can be confusing at first glance, but we guide our clients through every step of the legal process.

How do I prove Breach of Duty and Causation?: “The but-for test”

But for the negligent action of the medical practitioner, the injury would not have occurred

In approximately 30% of medical negligence cases we are involved in, we receive a report from an expert that identifies that a breach of a duty of care arises, but the breach has not affected the recovery or injury for the client. Therefore, there is no causal link between the action and the injury. In such cases, a breach of duty has not materially impacted the recovery of the client.

Case Study: Assessing Breach of Duty / Negligence and Causation

To demonstrate this, it is easier to look at a recent case that we declined to pursue.


We received instructions from a young man aged eighteen who had been treated at a hospital in Dublin. He sustained a fracture to his right index finger after receiving a kick during a football match. 

On arrival at the hospital, the finger was x-rayed, and no fracture was identified. Our client’s fingers were strapped, and he was informed that the finger would recover within two weeks. There was no follow-up appointment given for review by orthopaedics.  

Within a period of eighteen months, he continued to experience pain and swelling in the finger. His finger ached while writing in college and interfered with his performance at school and in examinations. He consulted his local G.P. who referred him for a further x-ray which demonstrated previous signs of a fracture. This fracture resulted from the kick at the football ground.

Establishing Lack of Causation:

We instructed an expert in the UK to review our client’s medical records. The expert confirmed that when our client initially attended the hospital following the football incident, the treating clinician failed to record that he had sustained a fracture. 

Our expert was of the view that the emergency department and the reporting radiologist, failed to identify the fracture on the x-ray taken immediately after the incident and that this fell below a reasonable standard of care.  

Furthermore, the lack of advice to follow up if persistent symptoms arose also fell below a reasonable standard of care. However, although the injury was not correctly diagnosed, the treatment would be the same if it had been correctly diagnosed so therefore causation did not arise. 

The treatment of strapping the finger in the hospital would have been the same if a fracture had been identified initially.  

In respect of the lack of follow-up, the expert was of the view that although the follow-up was not conducted, persisting symptoms like pain, swelling and weakness would not have been avoided even if follow-up had been conducted and therefore, causation did not follow.  

If you suspect that there has been a deficiency in your medical treatment or that of a loved one, it is important to get legal advice from specialist solicitors who understand medical negligence claims.

We have over 50 years of expert legal experience advising such patients. We are here to provide expert advice when you need it most.

Call us today on 1800 207 207 or contact us online.

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