Certified in Public Health (CPH) Practice Exam

What is the primary focus of a case-control study?

1. To establish a causal relationship between an exposure and a disease.

2. To compare the incidence of disease in exposed versus non-exposed groups.

3. To determine demographic factors associated with disease incidence.

4. To assess the effect of interventions in a population.

The correct answer is: To establish a causal relationship between an exposure and a disease.

A case-control study primarily aims to establish associations between exposures and outcomes, particularly in situations where the outcome (often a disease) is already known. By selecting individuals with the disease (cases) and comparing them with individuals without the disease (controls), researchers can observe past exposures or risk factors that may be linked to the disease. This retrospective approach allows for the identification of potential causal relationships, making it easier to generate hypotheses for further investigation. Through this design, researchers can uncover patterns or trends about how specific exposures are related to the presence of the disease, although it’s important to note that while associations can be made, causality requires further analysis typically done through different types of studies, such as cohort studies or randomized controlled trials. Case-control studies are particularly useful in studying rare diseases, where establishing such a causal relationship would be challenging through other methods.