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
The extent which results accurately reflect what was being assessed (true situation of study population)
Internal validity
The extent to which results are applicable to other populations (not included in the original study; also known as generalizability)
External validity
The ability of a test to give the same result on repeated uses is known as ______________?
Reliability
True or false
A valid test is always reliable, yet a reliable test is not always valid
True
The normal and abnormal range of blood sugar tests are a good example of this type of testing
Multiple cutoff values
