What study design was used in this feline GI study?

• A. Prospective cohort study
• B. Retrospective case-control study
• C. Cross-sectional survey
• D. Randomized controlled trial

Answer: (B)

Retrospective case-control design is used to uncover associations between exposures and a disease by looking back in time at what happened before the illness developed. In this setup, you identify a group of cats with the GI disease (cases) and a similar group without the disease (controls) from existing records, then compare how often each group was exposed to potential risk factors such as diet, medications, infections, or environmental factors. Since the data are drawn from past records, this approach is efficient and cost-effective, especially for diseases that aren’t very common.

This design helps determine whether certain exposures appear more frequently in diseased cats than in healthy cats, often yielding an odds ratio that estimates the strength of association. It’s particularly well suited to a feline GI study because it leverages available medical records to explore possible etiologic clues without waiting to see who develops disease in the future.

By contrast, a prospective cohort would follow healthy cats over time to see who develops GI disease, a cross-sectional study would capture exposure and disease at a single moment without clarifying temporality, and a randomized trial would assign exposures or treatments to test effects—none of which are the primary aim when the goal is to identify associations from past data.