PI Brief Update

What is a Fair Test in Medical Law? - Dr Mark Burgin

08/12/23. Dr Mark Burgin explains how lawyer can use the concept of a fair test to ensure that the questions they ask are not biased or leading and become more successful.

‘A fair test is an investigation where only one variable is changed (the independent variable) and all other conditions (controlled variables) are kept the same. This allows the experimenter to isolate the effect of the independent variable on the dependent variable, which is the variable that is being measured or observed.’ Bard Google’s LLM

A simpler explanation is that you must change one thing at a time if you want to understand a system. If you change many things, you cannot know which of the things you changed had the effect you wanted. If you have a cough and the doctor gives you three treatments it is not easy to know which treatment got rid of the cough.

Applying the concept of a fair test to medical law case means that questions that the lawyers ask should explore one aspect of the case at a time. Each question should build the understanding of the subject step by step. The court can only be certain which was the answer if they can see the answer change with that aspect.

Unfair tests

It is not uncommon for lawyers to assume that two aspects are linked to each other when in fact the relationship is more complex. Using the aspects interchangeably can blur the differences between them and lead to perverse outcomes. Often the expert themselves has used the aspects correctly but not addressed the difference directly.

Asking the expert to consider speculative aspects can be as problematic as they are not real. Imagine that the cough in the example above had settled with a different treatment – would that change the likely diagnosis? As this did not happen the expert may end up discussing a possibility that is inconsistent with the facts. This can mislead the court and lead to an unjust outcome.

Using the wrong legal test will make the test unfair e.g. asking an expert whether ‘potentially’ it is ‘possible’ that the claimant is faking their symptoms. The correct test is whether it is more likely than not, on balance. If the expert answers the question in the way that it was asked then their answer will be the opposite of their opinion.

Fixing unfair tests

The first and most important step is to write better medical reports. As an expert becomes experienced they will recognise aspects of the case that will be confusing for the lawyers. Avoid the use of ambiguous language and use short sentences, LLMs can be useful in highlighting potentially confusing phrasing. Dealing fully and clearly with all the issues reduces the risk of a question with contains an unfair test.

Where the instructions contain an unfair test then pulling the question apart and analysing it before answering can help. Often the problem question is actually a series of questions which can be divided and answered separately. Sometimes there is a fallacy or a mistake in the medicine that will need addressing first before an answer can be given.

Other problems are that the question does not make sense, the grammar is wrong and it is confused and rambling. Or that instead of a question there is a statement with a question mark. Or that the question is ambiguous with many possible interpretations. In these cases it may be possible to fix the question by rephrasing it or clarification may be requested.

Preventing unfair tests

Lawyers can feel overwhelmed by the complexity of medicine and feel that they must ask a blunderbuss of questions. Many of these questions will be unfair and as a consequence will mislead the court, waste court time and irritate the expert. Many experts will see this approach as a personal attack and avoid being helpful by ‘working to rule’.

The first step is write down all the aspects of the case as a list and write what is known next to them. For a PI case that would be mechanism of injury, injuries, treatment, pre-existing conditions, losses associated, examination, opinions and prognoses. The lawyer can then spot any gaps in the evidence and inconsistencies.

The questions can then address whether changing an aspect would make a difference to the outcome. In PI cases whether providing engineering evidence would change the prognoses for instance. This also reduces the risk that the lawyer will challenge a part of the report that is not material or request inconsistent amendments.

Conclusions

The unfair test is a scientific concept that can usefully be applied to medical law. Using a systematic approach to understanding the medical expert report can ensure that questions do not embarrass the author. For new case handlers it both helps improve logical thinking and is a useful learning experience.

LLMs can both help the reader break down the medical expert report into aspects and create good questions. Learning to use LLMs can ensure that questions are written eloquently whilst still being clear and unambiguous. Many lawyers are already recognising the potential of LLMs to improve performance. 

Lawyers who understand the concept of an unfair test are impressive because they ask exactly the right questions. They are able to handle complex cases with precision and confidence. This means that the cases are rarely bogged down with misconceptions and they move with lightening speed to an irresistible conclusion.

Doctor Mark Burgin, BM BCh (oxon) MRCGP is on the General Practitioner Specialist Register.

Dr. Burgin can be contacted on This email address is being protected from spambots. You need JavaScript enabled to view it. and 0845 331 3304 website drmarkburgin.co.uk

This is part of a series of articles by Dr. Mark Burgin. The opinions expressed in this article are the author's own, not those of Law Brief Publishing Ltd, and are not necessarily commensurate with general legal or medico-legal expert consensus of opinion and/or literature. Any medical content is not exhaustive but at a level for the non-medical reader to understand.

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