Historical Cohort Studies

A historical cohort study is a research method that looks at groups of people from the past to understand how certain exposures or behaviors may have influenced their health outcomes. Researchers identify a group based on past exposure—like smoking or a specific medication—and then examine their medical records over time to see what health issues they developed. This approach helps scientists determine links between factors and diseases without needing to follow people into the future, making it useful for studying long-term effects of exposures using existing data.