Urine Drug Screen
This procedure requires that one provide a sample of urine. Either a test card is used on site for immediate results, or the sample is sent away to a lab to undergo gas chromatography/mass spectrometry (also known as GCMS), high performance liquid chromatography or immunoassay analysis. The majority of tests administered in pre-hire and even most probate scenarios are of the immediate, and less accurate "at home" variety. Most "dip stick" type tests have higher thresholds for a positive than do the GCMS tests. If a positive result (drug presence indicated) is found, the sample is usually sent to a lab for GCMS confirmation. This is largely due to the costliness of GCMS labaratory testing and time it takes to process and receive results. The results of any urine test reflect factors including, but not limited to age, weight, race, and often these factors are what determines whether the test is valid or not.
The efficacy of urine testing is debatable due to systematic cheating. It is widely reported that sample substitution and adulteration occur frequently, and both are effective methods of avoiding would-be positive tests. There are a number of adulterant "masking" agents that are sold, though they are often nothing more than a simple diuretic and are rarely more effective than caffeine. Some people drink copious amounts of water to successfully dilute the concentration of drug metabolites in their urine below detectable thresholds. Often this results in clear samples that may be rejected on the grounds of being too dilute, although a complex B vitamin will make urine yellow despite this practice of waterloading. Specific Gravity testing can be done to identify whether or not the sample is of dilute nature, though this is used infrequently on otherwise inconspicuous samples. The substance Niacin is also frequently used for its reported "flushing" effect, though this is also of disputable adeptness. Some types of urinalysis can detect the use of these "detox" products, though they are rarely used unless some facet of the sample is suspicious. Also, the wide availability of at home drug screens allows an individual to take their own test before they receive one, thus knowing the results ahead of time- giving the user further opportunity to dilute the sample or to find a substitute.
Pros: Urine drug test kits are available as on-site tests, or laboratory analysis. Referred to as "the gold standard", urinalysis is the most common test type and used by federally mandated drug testing programs.
Cons: The main disadvantages of urine-based drug test kits is/are (1.) the ease at which they can be "cheated" via simple adulteration or substitution, unless specimen collection is directly observed, (2.) inability to detect current / on-the-job drug abuse, (3.) the need for bathroom facilities, and (4.) with respect to SAMHSA-5, or NIDA-5, the inability to test for drugs used in current society.