(RECOMMENDED TO BE PERFORMED BY END-USER LABORATORIES PRIOR TO USE IN ROUTINE DIAGNOSTICS)
version 12 October 2022
Accuracy, precision, sensitivity, and specificity are some examples of assay performance characteristics described by the Clinical and Laboratory Standards Institute (CLSI) as properties of a test that is used to describe its quality. Accuracy is defined as the closeness of agreement between a measured quantity value and a true quantity value of a measurand. Precision is defined as the closeness of agreement between measured quantity values obtained by replicating measurements on the same or similar objects under specified conditions. Clinical sensitivity is defined as the ability of the test to correctly identify a disease at a particular decision threshold, also called the true positive fraction. Clinical specificity is defined as the proportion of test results that are true negatives. Determination of the assay accuracy, precision, sensitivity, and specificity, through validation experiments, is the responsibility of the manufacturer or test developer. In contrast, verification studies aim to confirm the performance specifications established by the manufacturer through validation activities, performed by the end-user laboratory prior to use of an FDA-cleared assay for patient testing.