Inepidemiological research,recall bias is asystematic error caused by differences in the accuracy or completeness of therecollections retrieved ("recalled") by study participants regarding events or experiences from the past.[1] It is sometimes also referred to asresponse bias,responder bias orreporting bias.
Recall bias is a type ofmeasurement bias, and can be amethodological issue in research involvinginterviews orquestionnaires. In this case, it could lead to misclassification of various types ofexposure.[2] Recall bias is of particular concern inretrospective studies that use acase-control design to investigate theetiology of a disease or psychiatric condition.[3][4][5] For example, in studies of risk factors forbreast cancer, women who have had the disease may search their memories more thoroughly than members of the unaffected control group for possible causes of their cancer. Those in the case group (those with breast cancer) may be able to recall a greater number of potential risk factors they had been exposed to than those in the control group (women unaffected by breast cancer). This can potentially exaggerate the relation between a potential risk factor and the disease.[6]
To minimize recall bias, some clinical trials have adopted a "wash out period", i.e., a substantial time period that must elapse between the subject's first observation and their subsequent observation of the same event.[7] Use of hospital records rather than patient experience can also help to avoid recall bias.[8] Standardising sampling methods can help to avoid needing recall information in the first place.[9]
Often, recall bias is difficult to avoid, and many studies change experiment design to avoid recalling information.[9]
^Moren, Alain; Valenciano, Marta (Kitching, Aileen, ed.)."Information (measurement) bias".Field Epidemiology Manual. FEM Wiki. Archived fromthe original on 2019-08-18. Retrieved28 March 2013.{{cite web}}: CS1 maint: multiple names: authors list (link)
