About
Cohort studies are a type of observational research method where a group of individuals, sharing a particular characteristic or exposure, are followed over time to assess the outcomes they experience. These studies are particularly useful in understanding the etiology of diseases, assessing risk factors, and establishing links between exposures and outcomes. For example, researchers might start with a group of people who smoke and a group who don't, and then track them over several years to compare the incidence of lung cancer between the two cohorts. Cohort studies can be either prospective, where participants are followed forward in time, or retrospective, where past data is used to track outcomes. While cohort studies can provide robust evidence and allow for calculation of incidence and relative risk, they are time-consuming, often expensive, and can be subject to various biases such as loss to follow-up, confounding, and selection bias. Nevertheless, they are a crucial tool in epidemiological research for studying diseases and health outcomes in populations.