What is the typical design in a cross-sectional study?

• A. Disease outcome in exposed versus non-exposed groups.
• B. Cohort study design with follow-up.
• C. Randomized controlled trial design.
• D. Ecological study design.

Answer: (A)

Cross-sectional studies provide a snapshot in time, measuring both exposure and disease status for individuals at the same moment. This design yields prevalence data and allows comparison of how common a disease is between those exposed and those not exposed. That makes comparing disease outcome in exposed versus non-exposed groups the typical cross-sectional approach. It’s not about following people over time to see who develops disease (that’s a cohort design), it’s not about assigning an intervention (that’s a randomized trial), and it isn’t based on group-level data alone (that would be an ecological study). Remember, while you can observe an association between exposure and disease in a cross-sectional study, you can’t determine which came first, so causality isn’t established.