Block 10 Flashcards
Sensitivity
True positives
Equation for sensitivity
TP/TP+FN
Specificity
True negatives
Eq for specificity
TN/TN+FP
Diagnostic test
Any medical test performed to aid the diagnosis or detection of disease
4 uses of diagnostic tests
Diagnosis
Monitoring
Screening
prognosis
Importance of sensitivity and specificity in informing diagnosis
importance of diagnostic accuracy in testing is directly proportional to the tests potential to cause patient consequences and harm
true positive
test indicates disease when there is disease
true negative
test indicates no disease when there is no disease
false negative
test indicates no disease when there is disease
false positive
test indicates disease when there is none
positive predictive value
probability that subjects with a positive screening test truly have the disease
negative predictive value
probability that subjects with a negative screening test truly dont have the disease
likelyhood ratio
likelyhood that a given test result would be expected in a patient with the target disorder compared to the likelyhood that the same result would be expected in a patient without the target disorder
screening
systematic application of a test to identify individuals at sufficient risk of a specific disorder to warrant further investigation or direct preventative action, amongst people who have not sought medical attention on account of any symptoms of that disorder
purpose of screening
opportunities for primary prevention and treatment are limited, gives potential for early and more effective treatment
which cancers commonly screened for
colorectal, breast, cervical
what does the PPD test screen for
Tuberculosis
prenatal blood tests for
foetal abnormalities
newborn bloodspot test for
sickle cell, CF, congenital hypothyroidism, metabolic disease (PKU, MCADD, etc.)
Opthalmascopy screens for
diabetic retinopathy