The Life Cycle of a U.S. Drug Test Part 2
Dr. Todd Simo, HireRight’s Chief Medical Officer, continues his exploration of the various steps that are involved in the drug testing process.
To appreciate all that a drug test process entails, we’re presenting an overview of the life cycle of a drug test in the United States, from collection, to delivery, to testing, to the end results. In our previous article, we examined the first five steps involved in a drug test in the United States, starting with the collection of a sample of urine, oral fluid, or hair from the donor (the candidate, employee, or contractor). Once the specimen is collected and a chain of custody established, the package is handed off to a courier service for transportation to a laboratory.
Step Six: Laboratory Testing
Upon receipt, the laboratory will accession (accurately record the arrival and condition of) the specimen. The initial inspection will look for fatal flaws such as a break in the chain of custody, improper documentation, non-matching specimens and records, or evidence, of tampering. The lab will create an internal lab chain of custody and gather a sample of the specimen for testing. Some specimens will need to be prepared; oral fluid is extracted from the buffer while hair is washed and processed from a solid to a liquid state. Tests are performed to assure the specimen is not adulterated or substituted.
Then it’s time for the immunoassay test, which uses antibodies to detect the presence of drugs and other substances in the specimen. This initial screening doesn’t measure the specific amount of a drug present in the sample; instead, it provides either a quick negative or a presumptive positive result (which indicates the possible presence of a detectable drug). This test uses an antibody technology to measure the presence of a marker for drugs or their metabolites. Also, specimen validity tests are a critical part of the testing process. These tests are conducted to assure the specimen received is consistent with the physical parameters of that type of specimen.
Step Seven: False Positives
While these immunoassay tests are extremely sensitive, they are used to detect negative specimens, as they’re not as highly specific. This means that cross reactivity may cause tests to offer a presumptively positive result even when a drug is not present. Some reasons this may occur include:
Many stimulants will cause the amphetamines immunoassay test to be positive.
Various cannabinoids are cross-reactive with Tetrahydrocannabinol (THC).
There is a class of antidepressants that are cross-reactive with Phencyclidine (PCP).
In order to avoid false positives, confirmation testing is needed on any presumptive positive result.
Step Eight: Confirmation Testing
In cases where there is a presumptive positive, confirmation testing is initiated to determine the actual contents of the specimen. These tests eliminate false positives and are only performed to confirm the presence of drugs and/or analytes (a chemical substance) that are part of the requested panel. These tests will then provide a definitive level of the analyte that’s detected and typically include these procedures:
Chromatology, which separates the components of a specimen to find out what it’s comprised of.
Mass spectrometry, which measures the mass-to-charge ratio of molecules in a sample, which helps identify known compounds.
The quantitative level (the drug levels in the urine) is an important part of the confirmation testing process. If the quantitative level is under the established confirmation cutoff, the specimen is reported by the laboratory as a negative result (just as if no drug was found). The reasoning here is that the confirmation cutoff levels were established to rule out trace or insignificant exposure as a reason for a positive drug test.
Step Nine: Medical Review Officers
When test results are confirmed positive, a medical review officer (MRO) is typically brought in. This person serves as an independent and impartial “gatekeeper” and an advocate for the accuracy and integrity of the drug testing process. This person reviews the chain of custody and the test results and is essential in determining whether there is a legitimate medical explanation for confirmed positive, adulterated, substituted, and invalid drug tests results from the laboratory.
In so doing, the MRO may request additional paperwork from the lab before attempting to contact the donor. The MRO will make multiple attempts over a designated period of time to interview the donor, offering them an opportunity to present a reasonable, verifiable medical explanation for the test results. The MRO will then produce a report to the employer or requesting company that indicates a result of positive (if the donor did not have a reasonable, verifiable medical explanation), refusal, canceled, or negative the substance was legally obtained and verifiable.
This review of a donor’s test results does not establish a doctor-patient relationship with the donor. In fact, part of the MRO’s duties is to look out for potential hazards that become apparent during the testing process. In the U.S., the DOT, the Federal Motor Carrier Safety Administration (FMSCA), and the Federal Aviation Administration (FAA) each have safety standards codified within their regulation. If the MRO has reason to believe that a medication used or the underlying medical condition of the donor could potentially impact that person’s ability to adhere to those regulations and work safely, the MRO must disclose that information to the employer. It is not the MRO’s role to make an employment decision. They do not advocate for the donor or attempt to resolve any allegations the donor makes; nor do they advocate for the employer or create employer policy. They also do not provide employers or donors with legal advice on how to handle a given scenario. The MRO’s primary function is to ensure the external chain of custody has remained intact and to determine whether the testing process was fair and accurate.
Step Ten: Checks and Balances
Throughout it all, there’s a series of checks and balances in place that are designed to protect primarily the donor During the collection process, along with ensuring that the proper specimen is collected and chain of custody established, in some collection scenarios (such as a cold urine specimen) that might suggest donor misconduct, the rules allow the donor to have an immediate recollection; however, if the donor fails to provide another specimen during that collection event, the collector will report it to the employer as a refusal to test.
During the lab process, immunoassay tests help provide quick negative results, so donors are not waiting longer than necessary for proper clearance. And during the MRO process, the donor is given the opportunity to present a reasonable explanation for a positive test result prior to it being reported to the company. This process is embedded in the normal flow of the result delivery.
The End Result? Fair, Accurate Tests
This is how it should be. Throughout the transportation industry — as in other industries — candidates, drivers, employees, or contractors taking a drug test and employers requiring a drug test are protected by this series of checks and balances, which are meant to protect the integrity of every donor’s test result and not penalize those with extenuating circumstances. From initial collection through the final review, testing for drugs or other substances is a highly involved process that functions under strict collection, transportation, and scientific guidelines, utilizes the latest science, and affords every donor the opportunity for a fair and accurate test.
For more information about drug employment testing, visit HireRight’s Drug & Health Screening Services and our Drug & Alcohol Testing page.
Release Date: February 28, 2023
Dr. Todd Simo
Dr. Todd Simo currently serves as the Chief Medical Officer and Managing Director of Transportation at HireRight. He came to HireRight with a decade of experience in the medical consulting arena. Prior to HireRight, he was the Medical Director of an occupational health clinic in Virginia and owned a consulting firm providing medical director service to multiple companies located throughout the country. In that capacity, he established multiple customer specific health and drug screening services. In his current position, he oversees HireRight's medical department.