Observational retrospective cohort study is a type of study in which researchers identify a group of individuals who have been exposed to a particular factor (such as a medication, lifestyle behavior, or environmental exposure) in the past and compare their outcomes to a similar group of individuals who were not exposed to the factor.
In a retrospective cohort study, data is collected from the records of participants rather than being gathered prospectively. This means that researchers look back at existing data, such as medical records or databases, to identify participants who were exposed to the factor of interest and those who were not.
Observational studies, including retrospective cohort studies, can be useful for investigating associations between exposures and outcomes in real-world settings. However, they are subject to certain limitations, such as potential biases and confounding variables, which can affect the interpretation of results. Therefore, researchers must carefully design their studies and analyze the data appropriately to minimize these limitations and draw valid conclusions.