With the introduction of low-dose CT screening for lung cancer, some individuals are diagnosed with nodules that meet pathological criteria for cancer but would never have caused symptoms or death during their lifetime. This phenomenon is called:
- A Length-time bias
- B Lead-time bias
- C Overdiagnosis ✓
- D Recall bias
Correct answer: C. Overdiagnosis
Explanation
Overdiagnosis is the detection of pseudo-disease, that is, lesions fulfilling histological criteria of cancer that would never progress to clinical illness or death. It inflates apparent incidence and exposes people to unnecessary treatment. It is distinguished from length-time bias, where screening preferentially picks up slow-growing but still genuinely progressive tumours because they spend longer in the detectable preclinical phase. Lead-time bias concerns earlier detection without change in death time.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.