Biostatistics & Study Design USMLE Step 1 Practice Question
A prospective cohort study follows 200 adults with advanced pulmonary fibrosis (FVC 40-50% predicted) for decline in forced vital capacity. Participants with the most rapid symptom progression are disproportionately lost to follow-up because they become too ill to return for testing. Mean baseline FEV1 is 1.2 L with SpO2 92% on room air. No participants report smoking after enrollment. Which bias is most likely introduced if this differential loss to follow-up is ignored?
Answer choices
- ASpectrum bias
- BRandom measurement error
- CInformative censoringCorrect answer
- DEcological fallacy
- ECronbach alpha inflation
- FBerkson bias
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