American Board of Surgery Qualifying Exam (ABS QE) Practice Test

What is recall bias in the context of research studies?

1. Knowledge of presence of disorder alters recall by subjects

2. A tendency to give socially approved answers to questions

3. A distortion of the effects of exposure on outcomes

4. Loss of subjects from a follow-up study

The correct answer is: Knowledge of presence of disorder alters recall by subjects

Recall bias refers specifically to the situation where the knowledge of whether an individual has a particular disorder influences their ability to remember or report past exposures or behaviors accurately. In research studies, especially those that rely on retrospective data collection, individuals who have experienced a certain health outcome may consciously or unconsciously alter their memories regarding previous exposures or risks. For instance, a patient diagnosed with a condition may be more likely to remember and report risk factors or behaviors associated with that condition than someone who does not have the disorder. This differential recall can distort data and lead to inaccurate associations between exposure and outcome. This particular type of bias is critical to recognize because it can compromise the internal validity of the study, making it harder to draw unbiased conclusions about cause-and-effect relationships. It highlights the importance of designing studies that either mitigate such biases or include methods to assess and adjust for them in the analysis.