Confirmatory Drug Test

Definition - What does Confirmatory Drug Test mean?

A confirmatory drug test is a second test conducted after drugs have been detected during an initial drug screening test. This confirmation test is performed on a different sample, or aliquot, taken from the same specimen. The confirmatory drug test is used to determine the type and quantity of drug or drug metabolite present in the sample. A confirmation test may also be referred to as a confirmed drug test or directed analysis.

WorkplaceTesting explains Confirmatory Drug Test

A confirmatory drug test is usually ordered in response to a positive result from a screening drug test. This second test uses the same sample, but different technology to confirm the initial results and provide further analysis. This two-test authentication of positive results is intended to reduce false positives and provide greater confidence in results.

Drug testing may be used for employee screening and safety purposes, or pursuant to court order. Department of Transportation guidelines require that employees engaged in safety-sensitive functions must submit to drug and alcohol testing under a number of circumstances. As an industry standard, a confirmatory test is done with a different scientific method than the first to nearly eliminate the chance of a false positive test. Typically, a screening test is done by an immunoassay test, be it an instant onsite test or in a lab, whereas the confirmatory test is either gas chromatography- mass spectrometry (GC-MS) or liquid chromatography- mass spectrometry depending on the specimen type being tested. GC-MS testing is considered the most rigorous confirmation method for drugs of abuse testing.

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