Sensitivity and Specificity Flashcards
a diagnostic test that is positive in the presence of disease
true positive
a diagnostic test that is negative in the absence of disease
true negative
a diagnostic test that is positive but no pathogen or disease is present
false positive
a diagnostic test that is negative but the pathogen or disease is present
false negative
what is the proportion of people who truly have the disease and are identified by a specific positive test
sensitivity
what is the proportion of people who do not have the disease and are identified by having a specific negative test
specificity
how is sensitivity calculated
number of true positives / total number of patients WITH disease or pathogen
how is specificity calculated
number of true negatives / total number of patients WITHOUT disease or pathogen
if a highly sensitive test is negative, what does this mean
we can exclude the organism tested from DX
rule out of the disease
(SNout) sensitivity rules out
sensitive tests are useful for what
screening out disease
(SNout) sensitivity rules out dz
if a highly specific test is positive, what does this mean
we can confirm or rule in disease form DX
(SPin) specificity rules in dz
specific test are useful for what
confirming disease
(SPin) specificity rules in dz
