Core biostatistics and epidemiology formulas including sensitivity, specificity, relative risk, and study design, as cloze cards with each term defined.
35 cards · cloze cards · AI-written, checked twice. Edit anything.
- Sensitivity is calculated as ____.
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true positives / (true positives + false negatives)- Specificity is calculated as ____.
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true negatives / (true negatives + false positives)- Positive predictive value (PPV) is calculated as ____.
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true positives / (true positives + false positives)- Negative predictive value (NPV) is calculated as ____.
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true negatives / (true negatives + false negatives)- A highly sensitive test, when its result is negative, is used to ____ disease (mnemonic SnNout).
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rule out- A highly specific test, when its result is positive, is used to ____ disease (mnemonic SpPin).
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rule in- Prevalence is defined as the ____.
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proportion of a population that has a disease at a given point in time- Incidence is defined as the ____.
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rate at which new cases of a disease occur in a population over a specified time period- How does positive predictive value change as disease prevalence increases, if a test's sensitivity and specificity stay constant?
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PPV increases- How does negative predictive value change as disease prevalence increases, if a test's sensitivity and specificity stay constant?
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NPV decreases- Relative risk is calculated as ____.
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incidence in the exposed group divided by incidence in the unexposed group- Relative risk is the primary risk measure calculated in which type of study design?
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Cohort study- In a 2x2 exposure/disease table with cells a, b, c, d, the odds ratio is calculated as ____.
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(a x d) / (b x c)- An odds ratio closely approximates relative risk under what condition?
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When the disease being studied is rare.- Odds ratio is the primary risk measure calculated in which type of study design?
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Case-control study
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