A study was conducted to assess the relationship between the use of an over-the-counter pain reliever during pregnancy and the development of a neural tube defect in the offspring. Mothers whose children have neural tube defects, as well as age-matched controls (mothers whose children do not have such abnormalities), were interviewed using a standard questionnaire. The study showed that the use of the pain reliever during pregnancy increases the odds of a neural tube defect, even after adjusting for race, other medication use, comorbidities, family history of congenital abnormalities, and serum folate levels. The odds ratio is 1.5 (p = 0.03). Which of the following should be the major concern when interpreting the results of this study?
A)Selection bias
B)Interviewer bias
C)Recall bias
D)Observer bias
E)Confounding

Question

A study was conducted to assess the relationship between the use of an over-the-counter pain reliever during pregnancy and the development of a neural tube defect in the offspring.  Mothers whose children have neural tube defects, as well as age-matched controls (mothers whose children do not have such abnormalities), were interviewed using a standard questionnaire.  The study showed that the use of the pain reliever during pregnancy increases the odds of a neural tube defect, even after adjusting for race, other medication use, comorbidities, family history of congenital abnormalities, and serum folate levels.  The odds ratio is 1.5 (p = 0.03).  Which of the following should be the major concern when interpreting the results of this study?
A)Selection bias
B)Interviewer bias
C)Recall bias
D)Observer bias
E)Confounding

Quizplus · Accepted Answer

Explanation: Recall bias should always be considered as a potential problem in case-control studies because it can cause an overestimation of the effect of an exposure. In this scenario, the women whose children have neural tube defects (cases) are more likely to report use of the drug than the women whose children are healthy (controls). Over-estimation may be due to distress due to the birth of a baby with a congenital abnormality or the desire to find potential explanations for that outcome. Other typical scenarios that may illustrate recall bias are: Spouses whose husbands are diagnosed with lung cancer tend to over-report the number of the cigarettes smoked daily by the patient; patients with melanoma may provide unreliable reports of their tanning ability. (Choice A) No information is given on how the patients were selected for the study. (Choice B) Using a standard questionnaire minimizes the potential for interviewer bias. (Choice D) Observer bias results in misclassification of the outcome (eg, labeling a healthy baby as having an abnormality and vice versa). It is explained by knowledge of the exposure status of the patients by the physician who makes the diagnosis. In this scenario, the diagnosis of the congenital abnormality was made at birth; therefore, there is little potential for observer bias. (Choice E) Two techniques were used to control the potential confounders in this study: matching and adjustment during the data analysis. This included adjustment for comorbidities and other medication use, which should help account for differences in the reasons for pain medication use. Although, given the potential for unmeasured confounders, confounding should always be considered, use of these analysis techniques in this scenario makes confounding less likely than recall bias. Educational objective: Recall bias is a potential problem in case-control studies. It results in over-reporting of the exposure by the cases.

A Study Was Conducted to Assess the Relationship Between the Use