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NBME CBSE PUBLIC HEALTH SCIENCES EXAM
NEWEST 2024 ACTUAL EXAM 160 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED A+
What is sensitivity? - ANSWER- Proportion of all people with disease who test + or the ability of a test to correctly identify those with disease.
What does a value approaching 100% in sensitivity indicate? - ANSWER- Desirable for ruling out disease, indicates a low false-negative rate.
What is a high sensitivity test used for? - ANSWER- Screening.
What is sensitivity? - ANSWER- Proportion of people with disease correctly identified by a test
What is the value of sensitivity approaching 100% desirable for?
- ANSWER- Ruling in disease
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What does sensitivity indicate? - ANSWER- Low false positive rate
How is sensitivity calculated? - ANSWER- TP/(TN+FP)
What is the 1-FP rate? - ANSWER- Complement of false positive rate
When is a high specificity test used? - ANSWER- Confirmation after a positive screening
What is positive predictive value? - ANSWER- Probability that a person with a positive test result actually has the disease
How is positive predictive value calculated? - ANSWER-
TP/(TP+FP)
How does positive predictive value vary? - ANSWER- Directly with pretest probability
What is negative predictive value? - ANSWER- Probability that a person with a negative test result actually does not have the disease 2 / 3
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How is negative predictive value calculated? - ANSWER-
TN/(TN+FN)
How does negative predictive value vary? - ANSWER- Inversely with prevalence or pretest probability
What does the receiver operating characteristic (ROC) curve demonstrate? - ANSWER- How well a diagnostic test can distinguish between two groups
What does the ROC curve plot? - ANSWER- True positive rate (sensitivity) against false positive rate (1-specificity)
What does a better performing test have in terms of the ROC curve? - ANSWER- Higher area under the curve (AUC) and closer to the upper left corner
What is precision? - ANSWER- Consistency and reproducibility of a test
What decreases precision? - ANSWER- Random variation or random error
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