This glossary explains common laboratory, workplace, medical, legal, and anti-doping terms. A program’s formal definition controls when it differs from this general explanation.
- Adulterated specimen
- A specimen that meets defined criteria indicating an added substance or abnormal characteristic inconsistent with normal human urine under the governing program.
- Analyte
- The drug, metabolite, marker, or other substance a test is designed to detect or measure.
- B sample / split specimen
- A separately sealed portion of a collected specimen that may be tested after an adverse or positive A-sample result under applicable rules.
- Chain of custody
- The documented history of specimen collection, possession, transfer, analysis, storage, and disposition.
- Confirmation test
- A more specific analytical test used to identify selected analytes following a screen, commonly using mass spectrometry.
- Cutoff
- A program-defined decision concentration used to classify a result; it is not necessarily a boundary between use and no use.
- Detection window
- The period during which a particular method may detect an analyte in a specimen above its cutoff.
- Dilute specimen
- A urine specimen with creatinine and specific-gravity measurements meeting a program’s dilute criteria.
- Drug panel
- The group of drug classes or analytes included in a test.
- False negative
- A negative result when the target condition is actually present according to an accepted reference.
- False positive
- A positive result when the target condition is absent according to an accepted reference. A true medication finding with a legitimate explanation is not necessarily a laboratory false positive.
- Immunoassay
- A testing method that uses antibodies to screen for a drug or class of related compounds.
- Invalid result
- A result that cannot be reported as valid under defined specimen or analytical criteria.
- LC-MS/MS
- Liquid chromatography with tandem mass spectrometry, a highly specific analytical method used for confirmation and identification.
- Medical review officer (MRO)
- A qualified physician who reviews laboratory and medical information and verifies results under applicable workplace programs.
- Metabolite
- A substance produced when the body processes a drug or other compound.
- Negative
- No reportable target was detected at or above the applicable cutoff; it does not prove no prior use.
- Nonnegative
- A screening or intermediate classification requiring further review; it should not automatically be treated as a final positive.
- Presumptive positive
- An initial screen result meeting the screening threshold before required confirmation or medical review.
- Positive
- A program-defined report that an analyte was identified at or above the applicable cutoff after required steps.
- Screening test
- An initial test designed for efficient detection; it may be less specific than confirmation.
- Sensitivity
- The ability of a test to identify the target when it is present.
- Specificity
- The ability of a test to report negative when the target is absent.
- Specimen validity testing
- Measurements used to evaluate whether a specimen is consistent with expected characteristics and suitable for testing.
- Substituted specimen
- A specimen meeting defined criteria indicating it is not consistent with normal human urine.
- Therapeutic use exemption (TUE)
- Authorization under an anti-doping program to use a prohibited substance or method for a documented medical need when criteria are met.
Use the Drug Testing FAQ for practical answers and the complete guide for detailed articles.