DOH Doctor Exam common mistakes
DOH Doctor Exam · Understand the traps and how to avoid them.
Committing to the first plausible diagnosis at the top of a long stem and then reading every subsequent lab and imaging result as confirmation of it, even when a value (a normal lipase, a low TSH, a non-anion-gap) contradicts the chosen answer.
Stems are written to reward pattern recognition quickly; once a familiar script fires, the candidate stops generating alternatives and the remaining data get interpreted as supporting evidence rather than as discriminators.
What to do instead
Before looking at the options, write down three diagnoses in order of lethality. After reading the final sentence of the stem, explicitly ask 'which of my three does this last piece of data rule out?' and eliminate rather than confirm.
Selecting the definitive operative step (laparotomy, resection, fixation) for a hypotensive or under-resuscitated patient when the question asks for the next best step, instead of ordering volume/blood product resuscitation, focused assessment, or damage-control measures first.
The dramatic presentation pulls attention toward the intervention, and candidates conflate 'the treatment this patient ultimately needs' with 'the next thing to do in this room right now'.
What to do instead
For every surgical scenario, place the patient on a stability spectrum first, then apply the sequence airway and hemorrhage control, resuscitation and correction of physiology, definitive operation. If the patient is unstable, choose the option that buys time, not the one that fixes the lesion.
Using adult reference ranges and adult doses for pediatric vignettes: calling a heart rate of 130 'normal' in a febrile 3-year-old, applying adult fluid bolus volumes, or selecting a drug dose without recalculating from the child's weight in kilograms.
Most study exposure is adult-heavy, so adult norms feel correct; pediatric values are also presented as a dense table that candidates avoid learning in favour of clinical gestalt.
What to do instead
Before answering any pediatric item, state the child's weight and age band, then check heart rate, respiratory rate, and blood pressure against age-specific thresholds. For any pharmacologic option, do the arithmetic on the weight given in the stem instead of judging the drug name alone.
Escalating to advanced imaging, subspecialty referral, or admission when the correct ambulatory answer is reassurance, symptomatic care, a validated decision rule, or a defined period of watchful waiting.
Candidates equate thoroughness with safety and fear missing disease, so the most aggressive option feels defensible; the setting cue (office, primary care, follow-up visit) gets ignored.
What to do instead
Anchor on the setting first: ask what the guideline recommends for this exact presentation in an ambulatory patient with no red flags. Choose the least invasive step that is guideline-concordant, and reserve escalation for a named red flag that is actually present in the stem.
Working up abdominal pain or vaginal bleeding in a reproductive-age woman without a urine or serum beta-hCG as the first test, or failing to distinguish ectopic pregnancy from spontaneous abortion when both are listed.
The presentation resembles appendicitis, gastroenteritis, or dysmenorrhea, and the pregnancy test feels like a formality rather than the single most decisive data point.
What to do instead
Apply an automatic rule: any woman of reproductive age with abdominal pain, syncope, or bleeding gets a pregnancy test before any other test. If positive, decide location (intrauterine versus extrauterine) by ultrasound and quantitative beta-hCG before choosing management.
Ordering a confirmatory test (CT, ultrasound, laboratory panel) before performing the time-critical intervention in a patient who is peri-arrest or has an immediately life-threatening condition, such as delaying needle decompression or pericardiocentesis for imaging.
Habitual diagnostic sequencing is reinforced across all other domains, and the emergency stem's calm wording hides how little time the patient has.
What to do instead
Ask 'what will kill this patient in the next hour?' before reading the options. If the answer is a mechanical or airway problem, treat it clinically first and let imaging follow stabilization; only choose a test-first option when the patient is stable enough to tolerate it.
Diagnosing a primary psychiatric disorder without excluding substance intoxication or withdrawal, medication side effects, delirium, or a medical mimic such as hypothyroidism, hypercalcemia, or hypoglycemia, and omitting an explicit suicide-risk assessment.
The behavioural narrative in the stem is vivid and leads candidates to accept the psychiatric label, while medical screening and risk assessment feel like documentation rather than diagnostic reasoning.
What to do instead
Use a fixed two-step check for every psychiatric vignette: list the medical and drug-induced mimics that must be excluded, then state the safety assessment (ideation, plan, means, protective factors). Only select the primary psychiatric diagnosis once the stem has excluded both.
Answering from a memorized mechanism or biostatistics formula instead of from what the question actually asks, or the reverse, ignoring the mechanistic question and drifting into clinical management when the stem asks which receptor or pathway is involved.
Basic science items are studied as isolated facts, so recall gets triggered by a keyword while the actual interrogative ('which of the following is decreased', 'what is the mechanism') is skipped.
What to do instead
Read the final sentence of the stem first and underline the interrogative. If it asks for a mechanism, answer the mechanism even when a management option looks clinically correct; if it asks for the next step, do not choose a pathway answer.
Choosing the option that produces the best clinical outcome rather than the one that respects autonomy, capacity, consent, confidentiality, or mandatory reporting, such as overriding a competent adult's refusal or disclosing information to family without consent.
Years of clinical training reward 'fixing the problem', so ethical items feel like management items; candidates also skip the capacity assessment that determines whether a refusal is binding.
What to do instead
Before answering, classify the item as ethics and run a fixed sequence: does the patient have decision-making capacity, what does the patient want, what does the law require, what is the least restrictive option. If a competent patient refuses, the answer is to respect the refusal and document it, not to treat.
Confusing the levels of prevention or the screening rules, for example answering with a treatment when asked what reduces mortality in an asymptomatic population, or selecting a screening test with no proven mortality benefit, or missing the specified age and interval.
Screening recommendations are a long list of similar-looking entries, and the stem's phrasing ('what is the best next step in this asymptomatic 55-year-old') does not trigger a distinct reasoning frame.
What to do instead
Label the question as primary, secondary, or tertiary prevention before reading the options, then recall the specific grade A or B recommendation with its age range and interval. Eliminate any test that detects disease without demonstrated mortality benefit, and be suspicious of any screening option offered for a patient outside the recommended age band.