A positive result: 80% of what?

A positive result: 80% of what? Original fictional 2×2 example: 80 true positives, 20 false negatives, 30 false positives and 270 true negatives. Sensitivity is 80/100 = 80%. Positive predictive value is 80/110 ≈ 73%. These denominators answer different questions; no real test performance or personal diagnosis is claimed. Silent caption-led lesson with original diagrams; no narration or music. Sources: NIH/NCI sensitivity: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/sensitivity NIH/NCI positive predictive value: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/positive-predictive-value Original AI-assisted educational content; AI source review: 16 October 2026. No clinician certification is claimed. Write the denominator before calculating a diagnostic-test percentage. https://meyshan.com/app/recall?utm_source=meyshantube&utm_medium=video&utm_campaign=student_daily_202610&utm_content=d26_c #MedicalStudents #MedicalEducation #ActiveRecall Transcript: on-screen text from this silent video; no spoken narration.