A prospective study is a type of longitudinal study that follows a group of similar individuals (cohorts) over time to determine how certain factors affect rates of a particular outcome. In a prospective study, the investigators design the study, recruit subjects, and collect baseline data on all subjects before any of them have developed the outcomes of interest. The subjects are then followed and observed over a period of time to gather information and record the development of outcomes. The distinguishing feature of a prospective cohort study is that at the time the investigators begin enrolling subjects and collecting baseline exposure information, none of the subjects have developed any of the outcomes of interest.
Prospective studies are important for research on the etiology of diseases and disorders. They usually have fewer potential sources of bias and confounding than retrospective studies. Prospective cohort studies are often used in fields related to health and medicine and can be used to conduct both exploratory and explanatory research.
In contrast to prospective studies, retrospective studies involve sampling individuals and collecting information about their past. Retrospective investigations are often criticized because they are more prone to bias and confounding. However, retrospective studies are useful when the outcome of interest is uncommon, and the size of a prospective investigation required to estimate relative risk is often too large to be feasible.
In summary, a prospective study is a type of longitudinal study that follows a group of individuals over time to determine how certain factors affect rates of a particular outcome. It is an important research method in the field of health and medicine and has fewer potential sources of bias and confounding than retrospective studies.
