What characterizes a retrospective design in research?

A retrospective design in research is characterized by looking back in time at existing data or historical records. This type of study typically involves analyzing data that has already been collected, which can include medical records, personal accounts, or previously collected survey results. Retrospective designs are often used to identify relationships between past exposures, events, or conditions and current outcomes. This method is particularly valuable in fields such as epidemiology, where researchers might investigate the effects of a certain risk factor or intervention by examining data from participants who have already experienced the outcomes of interest.

Using historical data allows researchers to explore patterns, trends, and associations that may not be easily observable with prospective studies, where data is collected moving forward in time from the point of the study's initiation. This characteristic enables researchers to draw conclusions about causality or correlation in situations where conducting a new study or collecting new data may not be feasible or ethical.