Which study design is used to determine both incidence and prevalence?

The study design that can determine both incidence and prevalence is the cohort study. Cohort studies involve following a group of individuals over time to observe outcomes, and during this process, researchers can determine the number of new cases of a disease that develop within the study population (incidence). Additionally, because cohort studies can assess the health status of participants at a specific point in time, they also allow for the measurement of existing cases of disease (prevalence).

This dual capability is key to understanding the burden of disease in a population. For instance, in a cohort study, researchers can collect baseline data on participants' health and then track whose health changes over time, making it possible to calculate how common a condition is at the beginning of the study (prevalence) and how many new cases emerge as time progresses (incidence).

While cross-sectional surveys can determine the prevalence of a condition at a single point in time, they do not track participants over time to determine incidence. Similarly, case-control studies are retrospective and compare subjects with and without an outcome, making them unsuitable for directly measuring incidence and prevalence. Prospective cohort studies indeed measure incidence as participants are followed over time, but they do not capture prevalence since they typically focus on new cases rather