Quick answer: most marks lost in the MRCEM SBA come from how questions are read and answered, not from gaps in knowledge. The common mistakes are choosing a correct answer instead of the best one, missing key words such as “first” or “most appropriate”, ignoring clues in the stem, answering from local practice instead of national guidance, and running out of time. Each one can be fixed with deliberate practice.
The MRCEM SBA gives you 180 questions in two 2-hour papers, so you have about 80 seconds per question (see our MRCEM SBA exam format guide). Under that pressure, small habits make a big difference. Here are the ten mistakes we see most often, and how to avoid each one.
1. Picking a correct answer instead of the best answer
In a single best answer question, several options may be reasonable. Only one is the most appropriate for this patient, at this moment. Candidates often choose the first option that looks right and move on.
How to avoid it: before you commit, ask “why is this better than the others?” If you cannot say why, read the options again.
2. Missing the key word in the question
“What is the first step?”, “What is the most likely diagnosis?” and “What is the definitive management?” are three different questions about the same patient. Giving the definitive treatment when the question asks for the immediate step is one of the easiest ways to lose a mark.
How to avoid it: read the final line of the question first, then read the scenario with that task in mind.
3. Ignoring the observations and results
Every number in the stem is there for a reason. A patient with the same symptoms needs very different management with a systolic blood pressure of 75 than with one of 125. Glucose, lactate, potassium and the ECG description often decide the answer.
How to avoid it: scan the observations before the history. Ask yourself whether the patient is stable or unstable, because that often changes the answer.
4. Forgetting ABCDE and resuscitation priorities
Resuscitation and stabilisation is one of the largest areas of the exam. When a patient is unwell, the best answer is often the one that deals with the immediate threat to life, not the one that confirms the diagnosis.
How to avoid it: if the patient is peri-arrest, hypoxic or shocked, think airway, breathing and circulation before imaging or specialist referral.
5. Answering from local practice
Your hospital’s protocol may differ from the national guideline. The exam follows national guidance, such as NICE, the Resuscitation Council UK and RCEM best practice.
How to avoid it: revise from the guidelines themselves. Our curated links to NICE guidelines and RCEM guidelines save you the search.
6. Reading too much into the question
The opposite mistake is inventing complications that are not in the stem. If the question does not mention an allergy, renal impairment or pregnancy, don’t assume one.
How to avoid it: answer the question in front of you, using only the information given.
7. Getting the numbers wrong
Drug doses, treatment thresholds and scoring systems come up often. Paediatric doses and fluid volumes, the paracetamol treatment line, potassium thresholds and decision rules such as CURB-65 or the Canadian CT head rule are all common ground.
How to avoid it: keep a one-page sheet of high-yield numbers and review it every few days. Short, repeated review works better than one long session.
8. Leaving paediatrics and procedures until last
Paediatric emergency medicine and procedural skills together account for about a quarter of the marks. Candidates who leave them until the final week often find there is not enough time to cover them properly.
How to avoid it: spread these topics through your revision plan from the start, as in our 12-week MRCEM SBA revision plan.
9. Poor time management
Spending three minutes on one hard question costs you time you need for easier ones later. Running out of time in paper 1 or 2 is one of the most common reasons well-prepared candidates fall short.
How to avoid it: answer every question on your first pass, flag the uncertain ones, and come back to them at the end. There is no negative marking, so never leave a question blank. Practise full papers under timed conditions before the exam.
10. Doing questions without learning from them
Doing thousands of questions will not help much if you only check whether you were right. The explanation is where the learning happens.
How to avoid it: read the explanation for every question, including the ones you got right. Note why each wrong option is wrong, and keep a list of topics you get wrong more than once.
Summary
- Choose the best answer, not just a correct one.
- Read the last line first and look for key words.
- Use the observations and results: they often decide the answer.
- Follow national guidance, not local habits.
- Practise timed papers and never leave a question blank.
- Learn from the explanation of every question.
Frequently asked questions
Is there negative marking in the MRCEM SBA?
No. Questions are machine-marked with no negative marking, so you should answer every question.
How much time do I have per question in the MRCEM SBA?
About 80 seconds: each 2-hour paper has 90 questions.
Which guidelines does the MRCEM SBA follow?
National UK guidance, such as NICE, the Resuscitation Council UK and RCEM best practice guidelines, rather than local hospital protocols.
How many practice questions should I do before the exam?
There is no magic number. Quality matters more than quantity: aim to cover every curriculum area, read every explanation and complete several full timed mock papers.
Next steps
The best way to spot these mistakes in your own answers is to practise. Try our 20 free MRCEM SBA sample questions, each with a detailed explanation. When you are ready for more, the MRCEM Pass question bank has over 2,200 questions, plus six timed mock tests to build your exam pace. View membership plans.
Written by Dr Syed Rahil. Exam facts checked against RCEM’s published exam pages on 30 September 2026.