Clin Path Math Flashcards
(15 cards)
Sensitivity (calculation)
TP/(TP+FN) * 100
Specificity (calculation)
TN/(TN+FP) * 100
PPV or PVPT (calculation)
TP/(TP+FP) * 100
NPV or PVNT (calculation)
TN/(TN+FN) * 100
Prevalence (calculation)
(TP+FN)/(TP+TN+FP+FN) * 100
Sensitivity (meaning)
A positive or abnormal test result occurring in animals with the disease
Specificity (meaning)
A negative or normal test result in nondiseased animals
PPV or PVPT (meaning)
The likelihood that an animal with a positive or abnormal test will actually have the disease
NPV or PVNT
The likelihood that an animal with a negative or normal test will be free of the disease
Prevalence (meaning)
% of animals in a given population that have a certain disease
CV (calculation)
SD/mean * 100
CV (meaning)
Indicates the amount of random error (imprecision) that is present in an assay
E.g., a high CV indicates an assay lacks precision
Precision (meaning)
How reproducible the test results are when the assay is replicated ;
Determined by calculating CV
Negative bias vs. positive bias
Negative bias if results are below the true value ;
Positive bias if results are above the true value
Accuracy (meaning)
Average of several assay results are close to the true value ;
Positive or negative bias
