What is a cohort study?

A cohort study is indeed a type of observational study in which two or more groups of people, known as cohorts, are followed over time to observe and compare outcomes. This design allows researchers to investigate the incidence, prevalence, and natural history of conditions or diseases in specified populations. By tracking cohorts, researchers can identify relationships between exposures (such as lifestyle factors or medical interventions) and health outcomes.

Cohort studies are valuable because they provide insight into temporal relationships, allowing researchers to see how exposure status influences outcomes over time. Unlike experimental studies, cohort studies do not involve random assignment to treatment groups, making them particularly useful in situations where randomization is not feasible or ethical. This type of study design can help uncover patterns and associations, contributing to our understanding of health at the population level.

The other options describe different types of study designs that do not fit the definition of a cohort study: experimental studies focus on treatment outcomes with random assignment, cross-sectional studies analyze data from a specific point in time, and qualitative studies emphasize in-depth individual cases rather than population comparisons over time.