Successfully tackling the RACGP written exams – it’s all in the Semantics.

Semantics – relating to meaning in language or logic.

In the didactic teaching days of old, written exams required recall and regurgitation of factual information, BUT oh how things have changed, and for the better.  In keeping with socratic methods, the RACGP exams now require contextual interpretation of knowledge.  That’s where semantics come in.   The stem of an exam question contains the  information necessary to define both the problem and its context, and if we misinterpret those critical key features, then our clinical knowledge will not be applied appropriately.  The key features are required to apply effective clinical reasoning. Our interpretation of the features can be influenced by our clinical, personal and affective biases.

Clinical Reasoning

Previous posts have explored clinical reasoning in detail, but to reiterate simplistically, it involves the ‘push and pull’ between the dual processes of non-analytical (pattern recognition) and analytical (hypothetico-deductive) approaches.   We apply clinical reasoning to both the diagnostic and therapeutic processes.   We tend to use non-analytical strategies when we perceive the problem to be easier (perhaps in clinical areas where we feel more confident), and save the analytical processes for the harder stuff.   This can be a trap, as if our perception of difficulty is based on misinterpreted information, it is likely that we will use the incorrect technique (1).  Then there’s also causal reasoning, which is going back to first principles (or pathophysiology) and this can be a useful backup strategy to approach a topic that you’re less familiar with.

Essentially when we are seeing a patient, or answering an exam question, we take the following steps:

1. Gather pertinent information including context
2. Develop a problem representation
3. Consider a list of differentials
4. Compare each differential to the pertinent information, our knowledge bank, and ‘illness scripts’ including those developed from experiences.
5. We use frameworks such as surgical sieves and Murtagh’s PROMPT to make sure we don’t miss anything.

Step 1 is the rate limiting step – even if we are experienced at steps 2-5, if we misinterpret information at Step 1, we will be reasoning with the wrong information.

The literature (2) identifies additional points at which clinical reasoning can go astray:

1. Difficulties in generating hypotheses, identifying cues and directing data gathering – i.e. failure to identify the key features required to inform the diagnosis.
2. Premature closure, i.e. focusing on some key features more than others.
3. Difficulties in prioritizing, e.g. failure to identify the impact of context.
4. Difficulties in painting an overall picture of the clinical situation, e.g. poor problem representation.
5. Difficulties elaborating a management plan, e.g. not considering the influence of the Domains of General Practice.

All of above hinge on the semantic interpretation of the information given.

Semantics

How do we interpret, link and organise information as clinicians?

We do this using syntax and semantics.

Syntax – The arrangement of words and phrases to create well-formed sentences in a language.

As you can appreciate, if English is your second language, the syntax part can be even more challenging.   We use syntax to define which symptoms and signs belong to what diagnosis.  This is called Syntactic theory, which also includes interpretation of timelines given, e.g. acute vs subacute vs chronic (3).

For example:  A patient presents telling you that they have had “non-stop diarrhoea for the past eight days”.

We can interpret this in several ways:

Most simplistically, the patient has had ‘non-stop diarrhoea” and ‘for the past eight days”.

OR to interpret more comprehensively,  the patient has had constant diarrhoea of recent onset.

The patient then tells you they have had ‘high fevers’ – which favours a bacterial versus viral diagnosis.   If the patient had noted “loose and more frequent bowel movements for the past six months” you may interpret the problem as a “chronic but variable bowel habit” and you might consider an alternative diagnosis of Inflammatory Bowel Disease.

Doctors with high diagnostic accuracy tend to have a large number of Semantic Axes, i.e.  multiple ways to consider and compare the information, as opposed to ‘weak diagnosticians’ who use the presenting facts with minimal consideration as to how those facts relate to each other.

The difference between good and poor diagnostic reasoning is not  lack of knowledge, but difficulty developing the semantic connections between the facts.  Doctors are intelligent people and have well formed study techniques by the time they reach GP Fellowship exams.  It is uncommon to have difficulty with the exams due to lack of knowledge, rather it’s lack of exposure to, and practice of semantic analysis and clinical reasoning, that is the contributor to unsatisfactory exam attempts.