In a case-control study investigating the association between occupational asbestos exposure and mesothelioma, investigators compare exposure history in 80 mesothelioma cases and 160 matched controls. The Odds Ratio (OR) is 12.4. Which type of bias is MOST likely to affect this study?
- A Selection bias due to Berkson's fallacy
- B Lead-time bias inflating the apparent association
- C Recall bias because cases are more likely to remember asbestos exposure than controls ✓
- D Neyman bias because only survivors are enrolled
Correct answer: C. Recall bias because cases are more likely to remember asbestos exposure than controls
Explanation
In case-control studies, subjects report past exposures retrospectively. Cases (mesothelioma patients) are more motivated and likely to recall exposure to asbestos than controls who have no diagnosed disease — this is recall bias, the most important threat to internal validity in case-control studies. Berkson's fallacy is a selection bias specific to hospital-based studies. Lead-time bias applies to screening and survival. Neyman (prevalence-incidence) bias occurs when cases who die or recover quickly are underrepresented.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.