Definition

A type of bias that occurs when participants in a research study or clinical trial do not accurately remember a past event or experience or leave out details when reporting about them. Recall bias is more likely to occur when the event happened a long time ago or when the study participant has a poor memory. Other factors that could affect recall bias are the participant’s age, disease status, education, socioeconomic status, pre-existing beliefs, and how important the event being recalled is to the participant. Recall bias can lead to wrong conclusions about what the study showed. It can occur in studies that ask participants to provide information from memory, such as in case-control studies or retrospective cohort studies.