Definitions
Accuracy:
The closeness of agreement between the average value obtained from a large series of test results and an accepted reference value.
False Negative:
A specimen known to be positive for the target marker and misclassified by the device.
False Positive:
A specimen known to be negative for the target marker and misclassified by the device.
Negative Predictive Value (NPV):
The probability of a patient with a negative test not having the disease.
Positive Predictive Value (PPV):
The probability of a patient with a positive test having the disease.
Repeatability:
Precision under repeatability conditions. Repeatability conditions: Conditions where independent test results are obtained with the same method on identical test items in the same laboratory by the same operator using the same equipment within short intervals of time.
Reproducibility:
Reproducibility conditions: Conditions where test results are obtained with the same method on identical test items in different laboratories with different operators using using different equipment.
Robustness:
The robustness of an analytical procedure is a measure of its capacity to remain unaffected by small but deliberate variations in method parameters and provides an indication of its reliability during normal usage.
Sensitivity (analytical):
The limit of detection: ie the smallest amount of target marker that can be precisely detected
Sensitivity (diagnostic):
A measure of the ability of the assay under investigation to identify correctly specimens that contain the target marker (reference assays positive). Sensitivity is the number of true positives recognised by the assay.
Specificity (diagnostic):
A measure of the ability of the assay under investigation to identify correctly specimens that do not contain the target marker (reference assays negative). Specificity is the number of true negatives recognised by the assay
Seroconversion Panel
A series of specimens sequentially collected over a period of time from an individual developing antigens or antibodies in response to a primary infection.
True Negative:
A specimen known to be negative for the target marker and correctly classified by the device.
True Positive:
A specimen known to be positive for the target marker and correctly classified by the device.
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