Dichotomous
test: T+, " positive" test result suggesting presence
of disease; T- , "negative" test result suggesting absence
of the disease*.
True
disease status of the subjects investigated must be verified by
a method independent from the diagnostic test under scrutiny.
The
probabilities of finding a positive or negative test result in
case of presence or absence of disease are constant and independent
from the population investigated.
*
In clinical chemistry often by transforming results into a dichotomous
variable comparing it with a treshold (cut-off value) and indicating
whether is lies below or above this limit.
