Accuracy: The ability of the test result to measure the "true" quantity of a drug; if any, in a urine specimen.

Aliquot:  A portion of a urine specimen used for drug testing.

Blind Sample:  A negative sample or a sample spiked with a drug that is submitted to look like a donor specimen, to perform a "blind" quality control check on processes and procedures.

Certified Laboratory:  A laboratory which has met certain minimum performance standards set by an accrediting agency, and has received a certificate to verify this fact (e.g., from the U.S. Department of Health and Human Services--HHS, or the College of American Pathologists--CAP).

Chain of Custody:  The procedure used to document the handling and storage of the urine specimen from the time the donor gives it to the collector until it is destroyed.

Custody and Control Form:  The form used to document the chain of custody--the handling and storage of a urine specimen from the time of collection until the time of disposal.  This form links the individual to the urine sample.  It is written proof of everything that happens to the specimen while at the collection site and the laboratory.

Collection Site:  A facility, such as a clinic, designated by the company where employees present themselves for the purpose of providing a specimen of their urine, blood, breath, or saliva to be analyzed for the presence of drugs.

Confirmation Tests:  The first test of a urine sample is called an initial test.  This test is fairly accurate and reliable but can also detect over-the-counter medications.  Therefore, if the initial test is positive, a second test (by gas chromatography/mass spectrometry, or GC/MS) should be done on the sample immediately.  This confirmatory test is highly accurate and will rule out any false positives (mistakes made) on the first test.

Detection Limit:  The lowest concentration of a drug which can reliably be detected in a specimen.

DHHS Cut-Off Levels:  A cut-off level is a value that is used to determine whether a drug test is positive or negative.  Many employers use the cut-off levels established by the Department of Health and Human Services.  These cutoff levels have been proven accurate and reliable, as well as defensible in a court of law.

Dilute Specimen:  A urine specimen where the creatinine and specific gravity are less than the normal reference range.  These two markers establish that the urine is of suffecient concentration for the DHHS cut-off levels to be accurate.

EAP (Employee Assistance Program):  EAP'S are usually multifaceted programs designed to assist employees with personal problems that affect their job perfomance.  Although some EAPs focus primarily on alcohol and other drug problems, most EAPs address a wide range of employee problems: stress, marital difficulties, financial trouble, and legal problems.

"False Negative":  An erroneous result of a drug test that indicates the absence of a drug that is actually present.

"False Positive":  An erroneous result of a drug test that indicates the presence of a drug that is actually absent.

HHS:  Department of Health and Human Services.

HHS Certified Laboratory:  The term used to describe a laboratory that is certified by the Department of Health and Human Services and participates in the National Laboratory Certification Program.

Initial Test:  Test used to eliminate "negative" urine specimens from further consideration (also known as a screening test).  The vast majority of drug tests are "negative" on the initial test (or screen).  Only those specimens which test "positive" on the initial test are subject to further testing (a confirmatory assay).

Medical Review Officer (MRO):  Although not always required, an MRO is an important part of an effective drug testing program.  An MRO is generally a licensed medical doctor who has special training in substance abuse.  Using an MRO helps to protect both the employer and the employees.  For example, if a drug test is positive, the MRO reviews the results, makes sure the chain of custody procedures were followed, and contacts the employee to make sure there are no medical or other legitimate reasons for the positive results.  For example, some prescription medicines can cause a positive test result.  If this is the case, and if a doctor prescribed the medicine, the test is reported as negative.  Otherwise, the MRO reports the positive test results to the employer.  Only after the MRO his reached his or her final conclusion does the MRO report the result to the employer.

Metabolite:  A compound produced from the chemical changes of a drug in the body.

Performance Testing:  A quality control program designed to monitor the analytical accuracy and precision of a drug-testing laboratory.  This is accomplished by periodically submitting human urine samples intentionally "spiked" with a drug or drug metabolite to laboratories being monitored.  Test results must conform to predetermined limits of accuracy and precision.

Presumptive "Positive": A sample which has tested "positive" on a screening test, but which has not been confirmed by an equally sensitive alternative chemical method, such as GC/MS.

Quality Assurance:  Practices that ensure accurate laboratory results.

Split Sample:  A laboratory specimen that is subdivided at the time of collection and maintained as two separate samples.  In the event of a retest, the second sample would be analyzed.

Split Specimen:  When a single specimen is split into two separate specimen bottles.  Split specimens are never collected from two different voids by the donor.

Tamper-Evident Label/Seal:  The term refers to the label that is used to seal the specimen bottle.  In addition to sealing the specimen bottle, it also provides an appropriate specimen number.

Verified "Positive" Test Result: A test result that is "positive" for both the initial and confirmatory tests, and reviewed and verified by the medical review officer as "positive."

Sources:

de Bernardo, Mark A., Workplace Drug Testing:  An Employer's Development and Implementation , Institute for a Drug Free Workplace, 1994, pp. 93-95. CSAP Technical Report 12:  Urine Specimen Collection Handbook for Federal Workplace Drug Testing Programs, Substance Abuse and Mental Health Services Administration, Center for Substance Abuse Prevention, 1996, pp. 53-54.