In a case-control study, which of the following is a potential problem?

In a case-control study, which of the following is a potential problem?

• A. Recall bias
• B. Prospective data collection
• C. Randomization bias
• D. Blinding bias

Answer: (A)

In case-control studies, exposure information is usually gathered after disease status is known, relying on participants’ memories. This sets up recall bias, where cases may remember exposures differently from controls—perhaps overreporting or underreporting certain exposures in an effort to find a reason for their illness. Such differential misclassification can distort the observed association between exposure and disease, often making the link appear stronger (or weaker) than it truly is. Prospective data collection describes a feature of cohort designs and tends to reduce recall bias, not represent a problem in this context. Randomization bias isn’t a typical issue here because case-control studies don’t involve random assignment of exposure. Blinding can help limit some measurement biases, but the classic, most problematic bias in this design is recall bias.

In case-control studies, exposure information is usually gathered after disease status is known, relying on participants’ memories. This sets up recall bias, where cases may remember exposures differently from controls—perhaps overreporting or underreporting certain exposures in an effort to find a reason for their illness. Such differential misclassification can distort the observed association between exposure and disease, often making the link appear stronger (or weaker) than it truly is.

Prospective data collection describes a feature of cohort designs and tends to reduce recall bias, not represent a problem in this context. Randomization bias isn’t a typical issue here because case-control studies don’t involve random assignment of exposure. Blinding can help limit some measurement biases, but the classic, most problematic bias in this design is recall bias.