- Binary qualitative tests with an analytical cutoff: For some qualitative tests (e.g. when non-diseased subject samples have a true zero concentration of the analyte of interest), clinical performance and analytical accuracy of the qualitative tests are the same concepts, and, therefore, in most situations, a study for evaluation of analytical accuracy can be considered as a study for clinical performance evaluation with measures such as clinical sensitivity, clinical specificity, positive and negative likelihood ratios, and positive and negative predictive values for a binary qualitative test. When certain types of CMs are used in the study, measures such as positive percent agreement (PPA) and negative percent agreement (NPA) should be estimated instead.
- Binary qualitative tests with a clinical cutoff: For some qualitative tests, clinical performance related to the target condition (for example, cancer present or absent) and analytical accuracy related to the amount of the analyte detected are different concepts and the cutoff for the qualitative test is chosen to optimize clinical sensitivity and clinical specificity of the test based on a clinical data set. Note that the scientific evidence recommended to support a CLIA waiver for a qualitative test is related to the analytical accuracy of the qualitative test. Issues related to the clinical performance of a qualitative test are out of the scope of the guidance (please contact FDA through a Pre-Submission for further discussion).
- Each untrained operator should run the candidate test with a minimum of 5 samples that are positive by the CM and 5 samples that are negative by the CM.
See More FAQs