Drug Test Dictionary

Accuracy: The skill of a testing device to produce a result that matches the known statistical value for the sample.

Cross Reactivity: The degree in which the test substances other than the target compound are shown to generate positive test results.

Cutoff Concentration: The specific concentration of drug in the sample that is chosen as a limit to distinguish a positive from a negative test result. Samples with concentrations above the cutoff level are considered positive and results below are considered negative.

False Negative Test Result: A test result which states that no drug is present when, in fact a tested drug is present in an amount greater the cutoff concentration.

False Positive Test Result: A test result which states that a drug is present when, in fact, the drug is not present or is present in an amount less than the cutoff concentration.

Interference: The effect that compounds has on the accuracy of any test measurement.

Negative Test Result: A test result which states that no drug is present in an amount greater than the cutoff concentration.

Positive Test Result: A test result which states that a drug is present.

Precision: The ability of a test device to produce the same value during repeated
measurements.

Quantitative Test Result: A test result expressed in numerical terms in order to determine the specific quantity of drug present in the sample.

Qualitative Test Result: A test result expressed in non-numerical terms in order to
determine the presence or absence of a drug in the sample.

Target Drug: The drug that the test device is designed to detect.

Test Reproducibility: The ability of a test device to produce the same value during repeated measurements in various laboratories which are participating in a collaborative study.

Test Sensitivity: For quantitative test devices: The smallest concentration of a drug that produces a response distinguishable from the background or blank value.

Test Specificity: The ability of a test device to determine exclusively the drug that are claimed to be detected without cross-reacting with other related substances that are not intended to be detected.