USMLE Step 1 · 4–6% of the exam
USMLE Step 1 biostatistics questions
Biostatistics & Epidemiology/Population Health makes up 4–6% of Step 1 on the official content outline. These are some of the most learnable points on the exam. Argonaut has 70 Step 1 biostatistics and epidemiology questions.
Free to try
Free Step 1 biostatistics questions
Full explanations, no account. Each opens on its own page.
- Statistical vs clinical significanceA randomized trial assigns 800 adults with type 2 diabetes mellitus to a structured dietary intervention or usual dietary advice.AQ-1125
- Measures of riskInvestigators follow 600 hospitalized adults who have no active Clostridioides difficile infection at enrollment.AQ-1127
What to expect
What Step 1 asks in biostatistics questions
General guidance from the content outline and how questions on this subject are usually built.
- Test characteristics: sensitivity, specificity, predictive values and likelihood ratios, often from a 2×2 table you build yourself.
- Study designs, and what each one can and can't show.
- Bias and confounding: naming the type from a short description.
- Measures of risk: relative risk, odds ratio, attributable risk, number needed to treat and to harm.
- Hypothesis testing: p-values, confidence intervals, power and error types.
- Reading a study abstract or figure and drawing the right conclusion.
Share from the official USMLE Step 1 content outline, checked 11 October 2026.
Coverage
Topics in the bank
21 topics, with the number of Step 1 questions on each. Topics with a chapter link to the Library.
- Study design14
- Outbreak investigation5
- Research ethics5
- Selection bias5
- Sensitivity, specificity and predictive values5
- Clinical trials4
- Measures of riskFree4
- Public health surveillanceFree4
- Bias in screening studies3
- Disease prevention3
- Incidence and prevalence3
- Clinical decision analysis2
- Meta-analysis2
- Standardization of rates2
- Survival analysisFree2
- Types of data2
- Bias in clinical studies1
- Causality1
- Confounding and effect modification1
- Statistical vs clinical significanceFree1
- Validity and generalizability1
Keep going
Read, then practice
- Measures of riskCalculate relative risk in a cohort study by dividing cumulative incidence in the exposed group by cumulative incidence in the unexposed group. Interpret it as a ratio of risks and distinguish it from an odds ratio, a risk difference, and evidence of causation.Free chapter
- Public health surveillanceUse a compatible illness and documented exposure to distinguish the threshold for prompt public health notification from the threshold for diagnostic confirmation. Explain that reporting a suspected measles case enables timely contact tracing and outbreak control without confirming the diagnosis.Free chapter
- Statistical vs clinical significanceDistinguish statistical significance from clinical importance when interpreting a modest treatment effect. A significant change in a surrogate endpoint such as HbA1c does not by itself establish improvement in patient-important outcomes.Free chapter
- Survival analysisInterpret right censoring in a Kaplan-Meier analysis. A censored participant contributes to the risk set through the last observed follow-up, but their event status afterward is unknown.Free chapter
- Step 1 cardiology questions7–11% of Step 1
- Step 1 neurology questions10–14% of Step 1
- Step 1 gastrointestinal questions6–10% of Step 1
- Step 1 renal questions11–15% of Step 1
Biostatistics questions, answered.
01How many Step 1 biostatistics questions does Argonaut have?
70 in the bank today, each a full clinical vignette with every answer choice explained. 2 of them are free to try on this page.
02How much of Step 1 is biostatistics content?
The official Step 1 content outline puts Biostatistics & Epidemiology/Population Health at 4–6% of the exam. Shares are ranges because items can count toward more than one area. Read the outline.
03Are these biostatistics questions free?
The questions listed here are free, with full explanations and no account. The rest of the Step 1 bank comes with Full access: $48 once, which also covers Step 2 CK. See pricing.
04What's the best way to practice biostatistics questions?
Do a mixed block first to find your weak topics, then drill them, and read every explanation, not only the ones you missed. Our guide on reviewing USMLE questions shows how. In Full access, ARGO picks those topics for you.
All 70 biostatistics questions, for $48.
Full access unlocks the whole Step 1 bank and the Step 2 CK bank, with ARGO drilling your weakest topics.
$48 · once · Step 1 + Step 2 CK