Recall Bias

Recall bias is an error that arises when people with a disease remember or report their past exposures differently from people without it. In case-control studies of mesothelioma or lung cancer, it can make an exposure seem more, or less, common among patients than it really was.

Origin

Recall bias is one of the classic information biases described in epidemiology texts, and it became a standard concern with the growth of case-control studies in the mid-20th century, which depend on asking people about past habits and exposures.

Significance in Asbestos Context

Asbestos case-control studies often rely on interviews or questionnaires, sometimes answered by family members after the patient has died. A person who knows they have mesothelioma may search their memory harder for asbestos contact than a healthy comparison subject, which can inflate the apparent link; on the other hand, exposures from decades earlier, or from a parent's work clothes, are easily forgotten, which can hide real exposures. Researchers reduce the problem by using job histories, records and expert assessment of jobs rather than self-reported "asbestos exposure." Defense lawyers sometimes raise recall bias against a plaintiff's own exposure history, suggesting that memories formed after diagnosis are unreliable. That is one reason documents such as employment records, union cards, Social Security earnings statements, military records and coworker testimony carry weight: they confirm where and when someone worked independently of memory.

Example Sentence

The defense expert argued that recall bias explained why more cases than controls reported working near brake repair.

Related Terms

Case-Control Study, Selection Bias, Confounding, Exposure History, Coworker Testimony, Exposure Reconstruction, Epidemiology

Notes

• Write down your work and home history now, with dates, places and products, before memories fade.
• Gather documents that confirm your history: pay stubs, union records, Social Security earnings statements, military records.
• Names of coworkers who can confirm your work conditions can be very helpful.