Epidemiology: Incidence and Prevalence Practice Questions
20 free Epidemiology: Incidence and Prevalence practice questions for the USMLE Step 1, each with the correct answer and a detailed explanation. Open any question below, or take the full set as an interactive quiz.
Questions
20 questions
All Epidemiology: Incidence and Prevalence questions
- Q1. A study reports that 50 new cases of hepatitis A occurred in a population of 100,000 over one year. What does this measure represent?
- Q2. A cross-sectional survey finds that 5% of a community currently has asthma. What epidemiologic measure is being reported?
- Q3. Which of the following will increase prevalence without changing incidence?
- Q4. A disease has an annual incidence of 10 per 1,000 people and an average disease duration of 5 years. What is the approximate prevalence?
- Q5. A rare disease suddenly becomes more easily detectable due to improved diagnostic tests. What will happen to prevalence and incidence in the short term?
- Q6. A study tracks a group of disease-free individuals over time to identify new cases. What measure does this design best determine?
- Q7. Which of the following will decrease prevalence but not incidence?
- Q8. Point prevalence differs from period prevalence in which way?
- Q9. A population has 1,000 total cases of hypertension in a population of 20,000. What is the prevalence?
- Q10. If the incidence of a fatal disease remains constant but survival improves, what happens to prevalence?
- Q11. In a stable population, which relationship is generally true?
- Q12. A hospital wants to measure the burden of chronic kidney disease among its current patients. Which measure should be used?
- Q13. A researcher finds that the period prevalence of flu during winter is higher than the point prevalence measured on a single day in winter. Why?
- Q14. During an outbreak, the incidence of a disease rises sharply. What immediate effect does this have on prevalence?
- Q15. Which scenario best illustrates incidence?
- Q16. Which scenario best illustrates prevalence?
- Q17. If incidence remains the same but mortality increases, what happens to prevalence?
- Q18. A chronic condition has low incidence but high prevalence. What is the most likely reason?
- Q19. Which of the following combinations would result in a very low prevalence?
- Q20. A researcher wants to know how many people lived with influenza at any point during a 3-month season. What measure should be calculated?