What is a cross-sectional study?

A cross-sectional study is characterized by its focus on analyzing data from a population at a specific point in time. This design allows researchers to assess the prevalence of certain characteristics or outcomes within that population without concerning themselves with changes over time. By examining a snapshot of data at one moment, cross-sectional studies can provide valuable insights into the relationships between different variables, making them particularly useful in fields like epidemiology or public health. They enable researchers to identify correlations and patterns that may inform further longitudinal studies or interventions.

The other options describe different research methodologies or focuses that do not align with the definition of a cross-sectional study. For example, following participants over a long period pertains to longitudinal studies, while collecting data exclusively through interviews suggests a specific data collection method rather than a study design. Additionally, comparing outcomes across different populations implies a comparative study approach, which is also distinct from the cross-sectional design.