USMLE Step 1 Biostatistics and Epidemiology Practice Questions
4–6% of Step 1 · 17 practice questions with a note on every option
280 questions in 14 timed 30-minute blocks, with your score in biostatistics and epidemiology and every other content area.
Free biostatistics and epidemiology drillInvestigators conduct a prospective cohort study of hospital employees without diabetes. They enroll 1,000 employees who work rotating night shifts and 2,000 employees who work only day shifts and follow them for 10 years. Type 2 diabetes mellitus develops in 60 night-shift workers and 60 day-shift workers. Which of the following is the relative risk of type 2 diabetes mellitus associated with night-shift work?
Biostatistics & Epidemiology/Population Health on Step 1
Biostatistics & Epidemiology/Population Health is 4–6% of Step 1. These questions are quick points if you can build a two-by-two table and know the study designs, and lost time if you cannot.
- Share of Step 1
- 4–6% of the exam, per the USMLE content outline
- On our mock exam
- 14 of 280 questions, with your score for this system in the result
- Our drill
- 10 questions from 17 biostatistics and epidemiology questions, untimed, a note on every option; one free attempt, unlimited with a pass
What Step 1 biostatistics and epidemiology questions test
- Sensitivity, specificity, predictive values and likelihood ratios
- Relative risk, odds ratio, attributable risk, absolute risk reduction and number needed to treat
- Study designs: cohort, case-control, cross-sectional, randomized trials and their strengths
- Bias and confounding, and how each design limits them
- Hypothesis testing, type I and II errors, power, P values and confidence intervals
- Screening, prevention levels and incidence versus prevalence
Sit all 280 questions in timed blocks
280 questions in 14 timed 30-minute blocks, with your score in biostatistics and epidemiology and every other content area.
Free biostatistics and epidemiology drillHow to study it
- Build the two-by-two table every time; most calculations fall out of it.
- Learn which measure goes with which design: odds ratio for case-control, relative risk for cohort.
- Practice by doing ten calculation questions in a row until each takes under a minute.
Common questions
Is there a calculator on Step 1?
No. The numbers in biostatistics questions are chosen so you can work them by hand.
How many biostatistics questions are on Step 1?
The content outline puts Biostatistics & Epidemiology/Population Health at 4–6% of Step 1. Our 280-question mock includes 14.
280 questions in 14 timed 30-minute blocks, with your score in biostatistics and epidemiology and every other content area.
Free biostatistics and epidemiology drillThe other Step 1 systems
Sources
- USMLE: Step 1 (blocks, items, testing day, break time)
- USMLE: Step 2 CK (blocks, items, testing day, break time)
- USMLE: Test delivery software updates for Step 2 CK and Step 1 (May 2026)
- USMLE: Step 1 content outline and specifications
- USMLE: Step 2 CK content outline and specifications
- USMLE: Examination results and scoring (minimum passing scores)
- USMLE Bulletin: Scoring and score reporting (about 60% correct to pass; result timing)
- USMLE Bulletin: Eligibility (attempt limits)
- USMLE: Apply for exams (2026 and 2027 fees, FSMB registration, region fees)
- USMLE: Performance data (pass rates)
- Intealth ECFMG: Fees overview (ECFMG Certification)
Original practice questions written to the USMLE content outlines and current standard references. USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and NBME. Independent practice, not affiliated with or endorsed by the FSMB, NBME or Intealth (ECFMG). Follow current guidelines in clinical practice.