What is a characteristic feature of a cohort study?

A cohort study is characterized by its longitudinal design, which involves following a group of individuals (the cohort) over a period of time to observe outcomes and changes. This forward-looking approach allows researchers to track exposure to certain risk factors and the subsequent emergence of health outcomes. By following subjects over time, researchers can better establish causal relationships and assess the temporal sequence between exposures and outcomes.

This feature distinguishes cohort studies from other study designs that may focus on cross-sectional observations or rely heavily on retrospective data. Cohort studies can include both exposed and unexposed populations and can also encompass various age groups, depending on the research question. However, the principal defining element is their timeframe and the ability to observe changes in participants throughout the study.