A survey was used to classify health status in a community at a single point in time to examine carriers of a disease. What is the proper study design?

• A. Concurrent cohort study
• B. Case-control study
• C. Experimental study
• D. Cross-sectional study

Answer: (D)

The key idea here is a snapshot view of a population. A cross-sectional study collects data on people’s health status and other characteristics at a single point in time to describe how common a condition or carrier status is within the group. It’s like taking a census of health right now, which makes it ideal for estimating prevalence of disease carriers in the community.

Other designs describe disease after some time or look backward or involve assigning interventions. A concurrent cohort study follows people over time from exposure to outcome, so it’s about incidence and temporality rather than a one-time snapshot. A case-control study starts with disease status and looks back to prior exposures, which isn’t the same as surveying everyone to classify health status at one moment. An experimental study involves the investigator assigning an exposure and often testing effects, which isn’t just observing health status in a population at a single time.

So, describing health status and carrier prevalence in a community at one point in time aligns with a cross-sectional study.