Biostatistics & Study Design USMLE Step 1 Practice Questions
64 board-style USMLE Step 1 questions in Biostatistics & Behavioral Science. Each question shows the correct answer; create a free account for the full explanation and adaptive practice.
- USMLE Step 1 · medium25. A chemoprophylaxis regimen is administered to household contacts during a meningococcal outbreak. Baseline vital signs are stable; temperature 37.2°C, HR 88/min, BP 118/76 mmHg.…
- USMLE Step 1 · easy26. A randomized controlled trial enrolls 500 healthy adults (mean age 35) during winter. Symptomatic, PCR-confirmed influenza develops in 10% of placebo recipients and 5% of vaccin…
- USMLE Step 1 · medium27. A propensity-matched observational study compares beta-blocker therapy versus no beta-blocker after myocardial infarction in 500 post-MI patients. After matching, investigators…
- USMLE Step 1 · medium28. A 42-year-old woman with obesity (BMI 34 kg/m²) presents for metabolic evaluation. Vital signs: BP 138/82 mmHg, HR 88 bpm, RR 14/min, temp 37°C. Fasting insulin is 18 mIU/L. Res…
- USMLE Step 1 · hard29. A regression model evaluates the effect of obesity on obstructive sleep apnea severity in 250 adults (mean BMI 34 kg/m², apnea-hypopnea index 28 events/hour). Investigators incl…
- USMLE Step 1 · hard30. A 52-year-old man with hypertension (BP 168/98 mmHg, HR 88, RR 16, Temp 37.2°C) undergoes evaluation for cardiovascular risk. A regression model predicts systolic blood pressure…
- USMLE Step 1 · hard31. A 58-year-old man with type 2 diabetes (HbA1c 9.2%, fasting glucose 187 mg/dL) presents for cost analysis study enrollment. Linear regression models his HbA1c versus annual heal…
- USMLE Step 1 · medium32. A 78-year-old woman with advanced dementia (MRI shows cerebral atrophy) presents with baseline Mini-Cog score of 0/30. Her daughter reports progressive memory loss over 3 years…
- USMLE Step 1 · medium33. A rehabilitation study evaluates mobility outcomes in 47 elderly patients (mean age 72) using a 0–20 mobility scale. At baseline, 60% of highly functional participants score 20…
- USMLE Step 1 · medium34. A psychiatry research group develops a novel 12-item anhedonia scale in 200 patients with major depressive disorder (mean age 42, BP 128/82, HR 88) and 100 healthy controls (BP…
- USMLE Step 1 · medium35. A 58-year-old man with type 2 diabetes mellitus presents for device validation testing. Blood pressure is 138/82 mmHg, heart rate 76/min, temperature 37.2°C. A fasting glucose o…
- USMLE Step 1 · medium36. A team develops a questionnaire to measure asthma control in adolescents. Pediatric pulmonologists review the draft noting it includes wheeze frequency and rescue inhaler use bu…
- USMLE Step 1 · medium37. A dermatopathologist reviews 60 skin biopsy slides, classifying each as benign or malignant based on histologic features including cellular atypia and mitotic rate. Four weeks l…
- USMLE Step 1 · medium38. A 32 year old woman with stable generalized anxiety disorder completes the same validated anxiety inventory on Monday and again 1 week later before any treatment change. Investi…
- USMLE Step 1 · medium39. A 50-year-old man with heart failure (ejection fraction 35% on echocardiography) on metoprolol and lisinopril completes a new 12-item questionnaire designed to measure medicatio…
- USMLE Step 1 · medium40. A 38-year-old woman with systemic lupus erythematosus (ANA positive, complement levels low) presenting with fatigue and arthralgia enrolls in a treatment trial. Vital signs: BP…
- USMLE Step 1 · easy41. A trial of 12,000 adults with chronic low back pain compares a new exercise app with standard counseling. Mean pain score improves by 0.2 points on a 10 point scale in the app g…
- USMLE Step 1 · hard42. A 68-year-old man presents with fatigue, dyspnea, and petechiae. Vital signs show HR 102 bpm, BP 128/76 mmHg, RR 18/min, and SpO2 94% on room air. CBC reveals WBC 45,000/μL with…
- USMLE Step 1 · medium43. A randomized trial of a new asthma medication in 400 patients shows no difference in FEV1 decline (primary endpoint: -120 mL/year in both groups; p=0.18). Investigators perform…
- USMLE Step 1 · medium44. A data safety monitoring board reviews efficacy outcomes every 3 months during a large stroke prevention trial enrolling 2,400 patients. The biostatistician notes that repeated…
- USMLE Step 1 · medium45. A Phase III trial randomizes 300 participants with stage III non-small cell lung cancer in a 2:1 ratio (200 to new tyrosine kinase inhibitor versus 100 to standard chemotherapy)…
- USMLE Step 1 · medium46. A residency program introduces a sepsis checklist intervention across 10 hospitals, with each site randomly assigned a staggered implementation month over 12 months. Baseline se…
- USMLE Step 1 · hard47. A 59 year old man with refractory lymphoma enrolls in a phase 2 trial with 3 treatment arms. After a planned interim analysis, the arm with the lowest response rate is dropped a…
- USMLE Step 1 · medium48. A 52-year-old woman with rheumatoid arthritis (ESR 48 mm/h, CRP 12 mg/L) presenting with joint pain and morning stiffness is screened for a biologic therapy trial. She has no hi…