Exam 3: Screening In Medicine Flashcards
Should every patient be screened for a particular disease if it has a screening test for it?
No
What two questions should every patient ask their physician when a screening test is recommended?
- How accurate ?
2. How confident?
What test correctly reports a positive result in a patient that actually does have a disease?
True positive
What test correctly reports a negative result in a patient that actually does not have the disease
True Negative
What test incorrectly reports a positive result in a patient that does not have the disease
False positive
Which test incorrectly reports a negative result in a patient that actually does have the disease
False Negative
This test is best at detecting the presence of disease when disease is present
Sensitivity test
TP / (TP + FN) x 100% = ?
Sensitivity
This test is great a detecting the absence of disease when the disease is absent
Specificity
TN / (TN + FP) x 100% = ?
Specificity
This test tells us how accurately a positive test predicts the presence of disease
Positive Predictive Value
TP / (TP + FP) x 100% = ?
Positive Predictive Value
This test tells us how accurately a negative test predicts the absence of disease
Negative Predictive Value
TN/ (TN + FN) x100% = ?
Negative Predictive Value
This calculation is the proportion of time that a patient is correctly identified as either having a disease or not having a disease with a positive or negative test, respectively
Diagnostic Accuracy (DA) [or diagnostic precision (DP)]
(TP + TN) / (TP + FP + FN + TN) x 100 % = ?
Diagnostic accuracy or diagnostic Precision
This is a ratio of the probability of a “given test result” for a person with disease divided by the probability of the same test result for a person without disease
Likelihood ratio
Probability of a positive test in the presence of disease divided by the probability of a positive test in the absence of disease is what ratio?
Likelihood of positive ratio
Sensitivity / (1-specificity) = ?
Likelihood ratio positive
Probability of a negative test in the presence of disease divided by the probability of a negative test in the absence of disease is what ratio?
Likelihood ratio negative
(1-sensitivity) / specificity = ?
Likelihood ratio negative
What should LR + be to demonstrate the test is most beneficial?
Greater 10
What should LR - be to demonstrate the test is most beneficial ?
Less than 0.1
The ability to accurately discern between those that do an those that do not have the disease is known as __________?
Validity