How can recall bias affect the results of a case-control study?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Know the investigations of researchers using genomic information to reconstruct the cause and transmission routes of the bubonic plague and the Black Death — epidemiology Researchers using genomic information to trace the transmission routes in past epidemics of plague.

In a case-control study, recall bias occurs when there is a systematic difference in how cases and controls remember or report past exposures. Because these studies are often retrospective, they rely on participants accurately recalling information about their history.1

Individuals who have a disease (cases) are often more motivated to search their memories for potential causes of their condition than healthy individuals (controls), leading to differential reporting of exposures. This discrepancy can distort the odds ratio, potentially creating a false association or masking a true one between an exposure and the disease.1

To minimize this bias, researchers often select controls from a population with a different disease that has a similar impact or clinical history as the cases. This approach helps ensure that both groups are equally likely to have had their information recorded or to recall past events with similar levels of detail.1