The role of contributory negligence in defending a claim

27 Sep 2023

In order to succeed, a claim for medical negligence must prove that the practitioner involved had a duty of care to their patient, this duty was breached and that the breach resulted in harm to the patient. However, if it can be demonstrated that the claimant contributed in some way to their own injuries, this may offer a partial defence. This is important, because if such ‘contributory negligence’ can be proved, the defendant’s liability for compensation will be reduced accordingly. 

For many years, there was a rather paternalistic view of the doctor-patient relationship: patients were considered to have put themselves fully into the hands of their doctors and were entirely dependent on information supplied to them by healthcare professionals. Following recent legal cases, opinion has shifted, and patients are now viewed as competent adults who are capable of understanding that a successful outcome is not guaranteed, medical treatment always involves some degree of risk, and that they must take responsibility for accepting those risks and living with the consequences of their decisions. The principle of patient autonomy allows patients to make decisions about their own health care, even if this means refusing interventions recommended to them by a doctor. However, should a claim for medical negligence arise, the patient’s own actions may then be examined if it is thought that they contributed to the outcome in some way.

The issue of shared responsibility in healthcare is extremely important and potentially has far-reaching ramifications. It has been suggested that access to healthcare, and the quality of the care received, contribute only around 15% to our overall health and wellbeing. The roles played by health behaviours/lifestyle factors and social circumstances/environmental factors are thought to be far larger, at around 40% and 45% respectively. Successful medical treatment often requires compliance by patients. Factors which may reduce the success of treatments, and which may therefore constitute contributory negligence, include failing to give a full medical history, refusing recommended treatments or tests, or failing to re-attend if symptoms persist. Undesirable behavioural or lifestyle factors such as smoking, illicit drug use, excessive alcohol intake, poor diet or inactivity are also important.  

Proving contributory negligence can be particularly problematic and the burden of proof always lies with the defendant. It is necessary to show that there was fault on the part of the patient and that this contributed to the outcome in some way. Thus, causation is a key issue, but it can be difficult to determine the exact role played by each party if there is a complex series of events. For example, person A may cause an accident in which person B suffers an injury and requires treatment, but B delays going to hospital. Eventually, B receives treatment from person C, which either worsens the original injury or causes a new one. However, B also fails to follow medical advice, which prolongs recovery and worsens the outcome further. Determining who is at fault here for the eventual outcome is not easy. 

The claimant’s actions can only be deemed contributory negligence if they directly contribute to the harm suffered. Therefore, there must be a direct link in terms of place, time and/or circumstance, and any intervening events will weaken the evidence. Often, the ‘but for’ principle is applied: what would be the risk of the patient’s injuries, but for his own actions. Another issue is that of ‘reasonable foreseeability’. In the above example, in order to rely on a defence of contributory negligence, not only must it be proven on the balance of probabilities that B’s actions, or lack thereof, caused harm or exacerbated existing injuries, but a defendant must also show that B must have been aware that if he did not act as a reasonable person would in the same circumstances, a worsening of his condition would be likely.  Such proof is more difficult to obtain in cases where the claimant is a child, as the nature of the danger and the child’s ability to appreciate it may mitigate their actions. 

The extent to which the claimant’s actions contributed to the outcome will determine the reduction, if any, in compensation awarded. In order to determine the relative contributions made by the defendant and claimant, it is necessary to consider the blameworthiness of both parties, and the effect that each party’s actions had on the injuries suffered. Epidemiological evidence that the claimant’s actions carry an attributable risk of the observed outcome greater than 50% (the standard usually required in a balance of probabilities ruling) would be compelling in showing contributory negligence, but is often not available. Once apportionment has been made, the claimant’s contribution to their own injuries can be quantified in terms of absolute risk, and compensation reduced by this amount. Often, however, costs may still be claimed in full.  

Although cases where contributory negligence has been used as a successful defence strategy are rare, the recent shift in society’s view of the doctor-patient relationship means that this defence strategy is likely to become more common in the future. However, proving allegations of contributory negligence can be both costly and time-consuming, so should only be relied upon where the evidence is clear. 

Further reading:

Buckner F. (2002). Contributory negligence. The Journal of Medical Practice Management: MPM18(1), 28–32.

Freeman M. D. (2021). Principles and Methods for Evidence-Based Quantification of the Effect of Seat Belt Non-Use in Crash-Related Litigation. International Journal of Environmental Research and Public Health18(18), 9455.