Epi Night School: Final Exam

Test your knowledge!

Welcome to the final exam of Epidemiology Night School! Over the course of this series, we’ve explored the principles and methods that form the foundation of epidemiology. From understanding risk and bias to investigating outbreaks and interpreting health data, you’ve learned how to think like an epidemiologist. Now it’s time to put that knowledge to the test!

Below is a series of questions based on the lessons we’ve covered. Try answering them before scrolling to the answers. Don’t worry—this isn’t graded, but it’s a great way to see how far you’ve come.

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Part 1: Basic Epidemiology Concepts

Question 1: The 5 W’s of Epidemiology

What are the 5 W’s of epidemiology, and how do they guide the investigation of a disease outbreak?

Question 2: Incidence vs. Prevalence

Explain the difference between incidence and prevalence. Which measure would you use to track new cases of flu during an outbreak, and why?

Question 3: Absolute Risk vs. Relative Risk

You read a headline that says, “Eating blueberries reduces your risk of heart disease by 25%!” Why is it important to understand the absolute risk in this scenario?

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Part 2: Investigating Outbreaks

Question 4: Epidemic Curves

What can an epidemic curve tell you about the source of an outbreak?

Question 5: Steps of Outbreak Investigation

List the key steps in investigating an outbreak. Why is it important to define a case early in the process?

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Part 3: Study Design and Bias

Question 6: Study Design

What’s the main difference between a cohort study and a case-control study? Which would you use to study a rare disease, and why?

Question 7: Confounding Factors

What is a confounding factor? Provide an example.

Question 8: Types of Bias

Match the bias to its definition:

1. Recall Bias

2. Selection Bias

3. Observer Bias

• A - Participants remember past exposures differently based on their disease status.

• B - Study results are skewed because of how participants were chosen.

• C - A researcher’s knowledge of a participant’s exposure influences their observations.

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Part 4: Risk Interpretation and Statistics

Question 9: Odds Ratios

In a study, the odds of illness in unvaccinated individuals are 0.5, while the odds of illness in vaccinated individuals are 0.05. What is the odds ratio? What does this tell you about the vaccine?

Question 10: P-Values

What does a p-value of 0.03 mean in the context of a study? How does it differ from a confidence interval?

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Part 5: Advanced Topics

Question 11: Health Data Visualization

Why are graphs, maps, and charts critical in epidemiology? What are some common pitfalls to avoid when creating them?

Question 12: Public Health Surveillance

What is syndromic surveillance, and how does it differ from passive surveillance? Provide an example of each.