Reverse Engineering the PSA®
The Examiner's Thought Process
Examiners rarely ask:
"Which diabetes guideline is correct?"
Instead they ask:
Which treatment is safest?
Which medicine should be started?
Which medicine should be withheld?
Which medicine is causing harm?
What monitoring is required?
Understanding this distinction is often the difference between an average score and an excellent one. When reviewing a diabetes scenario, ask yourself: "Why has the examiner included this piece of information?" The answer is usually the key to the question.
High-Yield Drug 1: Metformin MR
What Students Learn
Metformin is first-line treatment.
What Examiners Actually Test
The examiner is usually interested in:
A typical question may describe:
The best answer may be switching to modified-release metformin rather than unnecessarily escalating treatment.
PSA Question Insight
Whenever metformin appears, immediately look for:
eGFR
Nausea
Diarrhoea
Medicine adherence
Recent illness
These details are often the true focus of the question.
High-Yield Drug 2: SGLT2 Inhibitors
Examples
Dapagliflozin
Empagliflozin
Students often recognise SGLT2 inhibitors as glucose-lowering drugs.
Examiners increasingly view them as medicines that:
Reduce cardiovascular risk
Reduce heart failure hospitalisation
Slow progression of CKD
Provide significant cardio-renal protection
These benefits have driven their expanded role within the updated pathway.
PSA Trap 1: Sick Day Rules
A patient develops:
Vomiting
Diarrhoea
Sepsis
Dehydration
The candidate is then asked to review medication. The examiner expects recognition that SGLT2 inhibitors may need to be temporarily withheld during acute illness.
Reverse Engineering Tip
Whenever you see:
✅ Acute illness
✅ Dehydration
✅ AKI risk
Immediately review diabetes medications.
PSA Trap 2: Euglycaemic DKA
This is a classic modern prescribing question. The patient may have:
Ketones
Acidosis
Abdominal pain
Vomiting
Yet glucose is not markedly elevated.
Reverse Engineering Tip
Many students incorrectly exclude diabetic ketoacidosis. The examiner wants you to remember that SGLT2 inhibitors may be associated with ketoacidosis despite relatively normal blood glucose concentrations.
High-Yield Drug 3: Sulfonylureas
Examples
Students often focus on glucose control. Examiners focus on hypoglycaemia.
Typical PSA scenario:
Elderly patient
Reduced oral intake
Missed meals
Confusion
Falls
Sweating
Question: Which medicine is most likely contributing? The answer is frequently: Gliclazide.
Reverse Engineering Tip
Whenever sulfonylureas appear in a scenario involving confusion or reduced food intake, hypoglycaemia should immediately enter your differential diagnosis.
High-Yield Drug 4: GLP-1 Receptor Agonists
Examples
The updated pathway places increased importance on GLP-1 receptor agonists in selected patient groups.
What the Examiner Really Wants
The question is rarely: What is semaglutide? It is more commonly: Why would semaglutide be an appropriate choice?
Look for:
These are often the clues driving medicine selection.
The Five Most Predictable Diabetes Themes in the PSA
1. Renal Function
Always check:
eGFR
Urea and electrolytes
AKI history
If renal function is provided, it is almost always relevant.
2. Hypoglycaemia
Look for:
Confusion
Dizziness
Falls
Reduced consciousness
Sweating
Particularly when:
Insulin
Gliclazide
Sulfonylureas
appear in the medication history.
3. Sick Day Rules
Expect scenarios involving:
Acute illness
Gastroenteritis
Sepsis
Dehydration
These frequently test safe medicine withholding decisions.
4. Insulin Safety
Never underestimate insulin questions. Common themes include:
Omitted insulin
Incorrect doses
Prescribing errors
Incomplete prescriptions
These are classic patient-safety domains.
5. Cardiovascular Protection
Modern diabetes prescribing is no longer glucose-centric. Candidates should immediately consider:
before choosing therapy.
