Drug tests and drug screens perform similar functions, but their differences in technique and application can produce different results. No matter which one you wish to use, American Screening Corp offers a wide variety of both products. As you decide which option to choose (or whether to use both), you should know the difference between drug testing and drug screening. This way, you can make an informed decision as you review potential job candidates.
How Do They Work?
A drug screen has multiple panels that test the candidate’s urine for elevated levels of drug metabolites (traces of drugs that your body has metabolized). It will produce non-negative results only if the amount of drug metabolites is over a certain threshold. Drug screens test for the presence of those drugs and only produce non-negative results—not necessarily “positive” ones. One of the most common types of drug screens is the enzyme multiplied immunoassay technique, also known as EMIT. The EMIT test uses visible spectroscopy to determine the level of metabolites present in the candidate’s urine by observing how they interact with certain antibodies. You do not need to send these tests to a lab, and they often produce results within minutes.
A drug test utilizes GC-MS technology (gas chromatography-mass spectrometry) to confirm or refute the presence of drug metabolites in the person’s urine. GC-MS tests are performed in a lab and take longer to produce results, but they are so accurate that they can tell whether the urine is even human. Gas chromatography separates the different substances in the urine, then mass spectrometry analyzes and measures the exact amounts of each substance. GC-MS testing has multiple uses. For example, forensic scientists use it to determine whether a deceased person had any drugs in their system at the time of death. Pediatricians use it to test for congenital diseases in babies. GC-MS testing can even test for pollutants or impurities in plastic and other materials.
How Involved Are They?
Both drug screens and drug tests detect traces of alcohol, cannabis, and other drugs, usually in a person’s urine (though sometimes hair or saliva is used). Most drug test manufacturers carry both products, including American Screening.
A drug screen shows you the big picture, so to speak. Drug screens have multiple panels, and they test for a wide variety of substances, and the results are available within minutes. Drug screens generally test for all the “popular” illicit substances, including but not limited to cannabis, opioids, cocaine, and methamphetamines. Therefore, many employers opt to perform drug screens first and then follow up with drug tests only if the screen produces non-negative results for any substance.
A drug test, meanwhile, is more focused and accurate. For example, if a drug screen detects traces of opiates or THC (tetrahydrocannabinol, the psychoactive component in cannabis), a follow-up drug test is sometimes required to confirm or refute those results. Drug tests are available with fewer panels and allow you to test for a few specific substances. This option means that, if you wish, you can decide to test only for illicit substances and not for prescription drugs.
The culture and nature of your company can influence what kind of test (and how many panels) you would like to use. For example, a four-panel test tends to eliminate cannabis as a tested substance. While recreational cannabis is not federally legal, it is either decriminalized or fully legalized in several states. Some companies opt not to test for cannabis, but the decision is yours. Testing for cannabis is recommended for jobs that involve regularly operating a vehicle or other heavy machinery.
Drug tests come in a few different varieties: an employer can test a candidate’s urine, saliva, hair, or a combination of the three. Urine tests are the most popular option, followed up by saliva. Their convenience makes them common options. Employers use hair tests less often, but they can detect traces of any drugs used within the last three months.
How Accurate Are They?
A drug screen is highly reactive and produces results within a few minutes. Employers often choose them for this reason. However, the alacrity of those results also means that they have a higher chance of producing false non-negative results (also known as a “false positive”). For example, drug screens cannot tell the difference between poppy seeds and opiates or between over-the-counter pain medication and THC on some occasions.
In cases like these, when a drug screen tests positive for an illicit substance, employers then have the option to perform a drug test. Drug tests take longer to produce results (sometimes up to a week), but they are extremely accurate. If you are testing for prescription drugs as well as illicit ones, the best practice is to have a medical review officer on hand. If your candidate or current employee tests positive for a prescription drug, the medical review officer can ask that person to provide proof of that prescription.
Much like drug screens, lab-based drug tests have a threshold: if the amount of a substance is too minuscule, it does not come up positive. That threshold is much lower for a lab-based drug test than for a drug screen. However, it still prevents people who have inhaled secondhand marijuana smoke or have eaten a poppy seed bagel from testing positive. Although, it is still inadvisable to do either of those things right before taking a drug test for the risk of testing positive.
Many drug test manufacturers offer convenient kits for both drug testing and drug screening. Many employers opt to perform a drug screen with multiple panels at first, then perform a follow-up drug test if any panels produce non-negative results. Drug screens are simple, wide-ranging, and quick to produce results. On the other hand, drug tests that are sent to a lab take longer, but they are more accurate. When you know the difference between drug testing and drug screening, you can more confidently make the hiring decision that best fits the culture and the needs of your company.
