Causation in medico-legal reporting: injury, symptoms, effects and consequences


When addressing causation of damage, one area of confusion for medical experts (and unfortunately for many instructing lawyers) is the distinction in the medico-legal use of the terms: Injury, Symptoms, Effects and Consequences.

Setting out the difference between injury, symptoms, effects and consequences

As most expert witnesses at medico-legal practises are unclear precisely how these terms should be used, many substitute one for another, and this has the effect of confusing the reader of the medical report. In addition, the writer is likely to have failed to address all of those issues in the medical report – something which is important in assessing the value of an injury claim. However, once the distinction between these terms is understood, experts can use these terms as an agenda to seek out relevant factual information during the interview and examination of the claimant and during the analysis of medical records.

‘Injury’ refers to the physical/psychological trauma suffered. ‘Symptoms’ refers to the physical/psychological manifestations of the injury. ‘Effects’ refers to the physical/psychological limitations experienced by the claimant as a result of the injury/symptoms, and ‘consequences’ refers to the restrictions on the activities of daily living since the accident, now and for the future, that result from the injury/symptoms/effects, and which will help formulate the financial claim.

To demonstrate the application of these terms in a typical personal injury report dealing with a claimant injured in a car accident: a soft-tissue injury to the claimant’s neck caused symptoms of severe headaches for two weeks, with the effect that the claimant had to rest most afternoons during that period, with the consequence that he was unable to work for two weeks after the accident.

It should be noted that, although doctors make a clear distinction between the terms ‘signs’ (manifestations of an injury that are objectively ascertainable) and ‘symptoms’ (manifestations of an injury as reported by the client), most lawyers do not appreciate this difference, and tend to conflate the distinct meanings of these terms. From a legal perspective, signs will either be supportive of, or not supportive of, the injury, symptoms and effects that the claimant claims and therefore it is important that the expert makes clear what the sign is and what it shows and how it supports or does not support particular aspects of the claimant’s claim.

‘Egg-Shell Skull’ principle and causation

The ‘Egg-Shell Skull’ principle means that someone who causes injury to another person must take that other person as they are. The claimants’ pre-existing condition may have made them more vulnerable to the effects of an injury. If the injured person has a particular vulnerability, which means that the impact of the accident or injury on him is more severe than would normally be expected, the person who causes the injury is responsible for all of the consequences, and damages will be assessed without any reduction for that pre-existing vulnerability.

For example, while a moderate traumatic brain injury is likely to cause permanent cognitive problems, arguably this is even more likely, and the consequences may be more severe and long-lasting, in an individual whose cognitive reserve has been diminished by an underlying neurological condition, for example multiple sclerosis. Damages will not be reduced because of this increased vulnerability – the defendant is liable for all of the consequences of the injury as they arise in this individual.

However the normal rules in relation to causation still apply. Damages are awarded for the difference that the injury has made. Therefore, if, due to the nature of the claimant’s pre-existing condition, their functioning is likely to have declined over time in any event in the absence of the index event, the important question in a claim for damages remains, ‘What would the claimant’s functioning have been over time, had the accident not taken place?’ Or ‘but for’ the accident what would the claimant’s functioning have been? While the claimant lived an independent life prior to the accident, due to their pre-existing condition it is likely that their physical and cognitive functioning would have declined over time, but it is difficult to say at what point this might have occurred. Therefore, damages will be assessed taking into account where applicable that the claimant’s post-accident condition would have arisen in any event because of their pre-existing condition. However, the added or increased consequences in that individual of the injury as a result of the pre-existing condition must be compensated for by the defendant.

Pre-existing vulnerability may increase damages

In terms of compensation, the pre-existing vulnerability may increase the amount of damages for the injury and its consequences over that which would normally flow from such an injury. The expert must however go on to clarify the difference between the situation consequent on and after the accident (and the likely future prognosis) and the situation as it would have been but for the accident, and therefore how the claimant’s life has been affected by the index event. The impact of the vulnerability on the claimant’s life in the absence of the index event may well reduce the damages awarded for the future consequences of the index event, compared with the damages which would otherwise be awarded for the consequences of the injury.

To report effectively on causation of damage, it is essential that the expert report writer addresses separately each of the injury, the symptoms, the effects of the injury and the consequences of the injury, and understands the difference between each. Where there is a pre-existing relevant condition, the expert must understand and distinguish between the competing rules. While the wrongdoer must take the victim as he is found, and in such condition as he was prior to the index event, and therefore vulnerability resulting from any pre-existing condition is not relevant in assessing the immediate impact of the index event, it is also essential to consider the position as it would have been in the absence of the index event and as a result of that pre-existing condition, which may well reduce the consequences of the index event.

Giles Eyre is a retired barrister and an Associate Member of Chambers at 9 Gough Square, London, having practised for many years in the field of injury claims and at the interface of law and medicine. He continues to provide training and workshops for experts on providing effective expert reports and evidence, and on medico-legal issues. He is co-author of Writing Medico-Legal Reports in Civil Claims – an essential guide, and author of Clinical Practice and the Law – a legal primer, both published and sold by Professional Solutions Publishing. Giles blogs on issues relevant to court experts in civil claims at Medico-legal Minder.