University of Central Florida (UCF) HSC4501 Epidemiology of chronic diseases Exam 1 Practice

In a cross-sectional study you measure exposure and disease at one point in time, so you don’t know which came first. That lack of temporality means the observed association could be due to the exposure leading to disease, or reverse causation where having the disease changes exposure status, or a third variable (confounder) that is linked to both. Because you can’t establish the sequence of events, you can’t infer causality from the association alone. Longitudinal designs, where exposure is assessed before outcomes develop, are needed to support causal inferences. Cross-sectional studies can reveal associations and generate hypotheses, but they don’t prove cause and effect.