MDC PQE common mistakes
MDC PQE · Understand the traps and how to avoid them.
Selecting the single most likely diagnosis and moving on, without ranking the two or three competing diagnoses that fit the same presenting complaint.
Candidates trained in clinical pattern recognition jump to the 'textbook' answer for a vignette (for example chest pain plus risk factors) and stop reasoning once one option looks plausible, so they miss the discriminator buried in the stem.
What to do instead
For every vignette, force a two-step habit: write the leading diagnosis and the single best alternative, then identify which finding in the stem rules the alternative out or in. If no finding discriminates, re-read for a negative or a time course you skimmed.
Treating a management question as a diagnosis question and choosing the treatment for the likely disease rather than the next step in the actual care pathway.
Stems that ask 'what is the most appropriate next step' are misread as 'what is the diagnosis', and candidates pick a definitive therapy that would only come after confirmation, or skip a safety step such as stabilisation or urgent referral.
What to do instead
Before answering, underline the exact question word (next step, best initial test, definitive management, most appropriate referral). Map the option to that stage of the pathway and eliminate any option that belongs to a later stage.
Applying adult physiology and drug dosing to paediatric or pregnancy scenarios without adjusting for age, weight, or altered pharmacokinetics.
Most revision material is adult-focused, so candidates carry over adult thresholds, fluid volumes, and contraindications into obstetric and paediatric items where the correct answer depends on the different physiology.
What to do instead
Flag any stem mentioning age under 16, pregnancy, or breastfeeding and consciously re-derive thresholds and contraindications for that group. Build a short personal list of drugs and investigations that are contraindicated or require dose adjustment in pregnancy and childhood.
Ignoring the emergency or red-flag feature in a stem and choosing a routine outpatient option.
Vignettes are long, and the one abnormal observation (low blood pressure, rising early warning score, sudden onset, neurological sign) is buried among normal findings, so it is skimmed over in the rush to reach the options.
What to do instead
Scan every stem first for vital signs, time course, and any 'sudden', 'severe', or 'unwell' descriptor before reading the options. If a red flag is present, eliminate all routine or delayed options first.
Confusing test characteristics, choosing a highly sensitive test when the question asks for confirmation, or a specific test when it asks for screening.
Sensitivity, specificity, and predictive value are learned as definitions rather than as decision rules, so candidates do not connect 'rule out' with high sensitivity and 'rule in' with high specificity under time pressure.
What to do instead
Memorise the decision rule explicitly: high sensitivity for exclusion and screening, high specificity for confirmation. Practise a handful of items where both a sensitive and a specific test are offered and state aloud which role the question demands.
Failing to distinguish a periapical from a periodontal cause when a tooth is painful or has a sinus tract, and selecting the wrong treatment.
Both presentations can show a discharging sinus, tenderness, and radiographic change, and candidates rely on the presence of a lesion rather than on vitality testing and probing depth to localise the source.
What to do instead
Work through a fixed diagnostic sequence for every dental pain item: vitality testing, percussion, probing depths, and sinus tract tracing. State which finding separates pulpal from periodontal origin before choosing endodontic or periodontal treatment.
Choosing a definitive restoration or extraction before addressing acute infection, haemostasis, or medical risk factors.
Candidates focus on the restorative solution and overlook that an uncontrolled medical condition, bleeding risk, or spreading infection changes the immediate priority and may contraindicate same-day definitive treatment.
What to do instead
For each dental management item, run a pre-treatment checklist: is the condition controlled, is there spreading infection or airway risk, is there bleeding or drug interaction risk. Prioritise the stabilising step over the definitive procedure.
Misreading a radiograph description in text and inferring findings that are not stated, such as assuming bone loss or a fracture from the clinical story alone.
Because images are described rather than shown, candidates fill gaps from expectation, so they treat a described radiolucency as confirmation of a diagnosis the text does not support.
What to do instead
List only the radiographic findings explicitly given in the stem, then match them to the options. If the option requires a finding that is not stated, treat it as unsupported rather than assuming it.
Overlooking drug interactions, allergy history, or systemic disease that alters dental prescribing and treatment planning.
The medical history is presented as background and candidates skim it as context, missing that a stated medication (for example an anticoagulant or bisphosphonate) is the key to the correct option.
What to do instead
Treat the medical history line as a question in itself: for each condition or drug listed, ask what it changes about prescribing, bleeding, healing, or positioning. Eliminate any option that ignores a stated interaction.
Spending disproportionate time on a few hard items and rushing the remainder, leaving easy marks lost to misread question stems.
High-stakes timing pressure and the emotional pull of an unfamiliar item cause candidates to over-invest in one question, and fatigue then produces avoidable errors on straightforward items later in the paper.
What to do instead
Set a per-question time budget from the total item count, flag and move on after the budget is exceeded, and reserve the final minutes for flagged items and a check of the question word on every answer.