Limits of Interpreting A Drug Test
Showing: Forensic Drug Testing
By: Kelly Hack, Content Writer
There are many variables regarding the analyses of substance abuse testing. Clients will often ask about specifics pertaining to the determination of time, dose and frequency when detecting substance(s) of abuse.
When testing a reservoir matrix- a material or substance, which can accumulate and retain drug and alcohol biomarkers (eg., urine, blood, hair, nail, umbilical cord, or meconium, etc.), the reported quantitation of a drug or its metabolite cannot be used to determine when/if a specific substance was used, how much of a substance was used or how often a substance was used. Test results show only if a substance was detected or not detected.
A specimen’s window of detection provides an estimated timeframe for detecting substance(s) of abuse. Based on extensive research studies, the generally accepted windows of detection for specimens used in our testing are as follows:
- Scalp Hair- Up to approximately 3 months prior to collection.
- Fingernail- Up to approximately 3-6 months prior to collection.
- Umbilical Cord- Up to approximately 20 weeks prior to birth.
- Meconium- Up to approximately 20 weeks prior to birth.
- Urine- Up to approximately 2-3 days prior to collection.
- Blood (PEth)-May be up to approximately 2-4 weeks prior to collection.
It is important to know that the interpretation of drug testing results may be determined by a Medical Review Officer (MRO). A Medical Review Officer is a licensed physician (MD or DO) who has knowledge of substance abuse disorders and has appropriate medical training to interpret and evaluate an individual’s positive test result together with his or her medical history and any other relevant biomedical information.1This is an incredibly important aspect of drug testing. A laboratory can detect substances, but a MRO may be used to interpret what that detection means.
1.Journal of Occupational and Environmental Medicine: (January 2003-Volume 45-Issue 1-p 102-103) Quaifications of medical Review Officers (MRO’s) in Regulated and Nonregulated Drug Testing. Departments: ACOEM Consensus Opinion Statementhttps://www.usdtl.com/blog/limits-of-interpreting-a-drug-test
To view larger image, please click here.https://www.usdtl.com/blog/drug-guide-for-parents-learn-the-facts-to-keep-your-teen-safe
Numerous studies have shown that meconium specimens are too often unavailable for substance exposure testing. Universal collection of umbilical cord specimens offers a solution.
By Joseph Salerno
Unable, despite her best efforts to shake her addiction, a woman exposes her unborn child to drugs in the womb. The baby is born, healthy and beautiful with all the promise the future holds. Three days later, the withdrawal symptoms kick in. The baby wails, flush with the pains of withdrawal and inconsolable, unable to sleep, experiencing seizures. The NICU physician wants to know what the baby has been exposed to, but now it’s too late. The meconium has already been passed and discarded, and the umbilical cord is gone, lost opportunities for concrete answers. Now it’s a guessing game.
This isn’t just a “what-if” scenario, unfortunately, but a potential reality in a surprisingly large number of newborn substance exposure cases. Withdrawal symptoms in substance exposed newborns can be delayed up to three, five, even seven days after the baby is born. Cases of in utero barbiturate exposure may not manifest withdrawal signs until 14 days post-delivery. By that time it’s too late to test any of the baby’s specimens for biomarkers of substance exposure, because the specimens are gone.
Universal collection of umbilical cord specimens offers a solution to avoid this dilemma. Umbilical cord is the only universally available specimen for substance exposure testing. Numerous studies have shown meconium is not available for testing in up to 27% of births. Meconium may be passed in utero. In some cases, there is not enough meconium volume to test even when it is able to be collected.
And again, meconium may have been passed by the newborn and discarded well before they begin to exhibit withdrawal symptoms. Unfortunately, this can also be a problem when the signs of in utero substance exposure emerge after the umbilical cord has been discarded. Newborn urine testing is not a viable option in these cases, because urine provides only a 1-3 day window of detection for substance exposure biomarkers, compared to the 20 week look-back of umbilical cord.
Universal collection of umbilical cord specimens for every birth ensures there are no lost opportunities should the need for substance exposure testing arise. Umbilical cord collection is extremely easy, requiring very little additional effort during post delivery procedures. Only six inches of the cord is required for substance testing, taking up very little storage space.
Umbilical cord tissue is a very stable and reliable specimen. Cord tissue is stable up to 1 week at room temperature, and up to 3 weeks when refrigerated, without jeopardizing the testing results. This is ample time for the emergence of newborn withdrawal symptoms, even in the most extreme cases. Enough time to avoid a missed opportunity for real answers. Only one donor and one collector are present during the umbilical cord collection – in contrast to the multiple collections and multiple collectors involved with meconium – greatly improving chain-of-custody integrity. Umbilical cord specimens are ready for transport just minutes after the birth, greatly improving turnaround time for results reporting. Meconium passages can be delayed for days before being sent to the lab.
1. Arendt, R., Singer, L., Minnes, S. and Salvator, A. (1999). Accuracy in detecting prenatal drug exposure. Journal of Drug Issues. 29(2), 203-214.
2. Ostrea, E., Knapp, D., Tannenbaum, L., Ostrea, A., Romero, A., Salari, V. and Ager, J. (2001). Estimates of illicit drug use during pregnancy by maternal interview, hair analysis, and meconium analysis. Pediatrics. 138, 344-348.
3. Lester, B., ElSohly, M., Wright, L., Smeriglio, V., Verter, J., Bauer, C., Shankaran, S., Bada, H., Walls, C., Huestis, M., Finnegan, L. and Maza, P. (2001). The maternal lifestyle study: Drug use by meconium toxicology and maternal self-report. Pediatrics. 107(2), 309-317.
4. Derauf, C., Katz, A. and Easa, D.. (2003). Agreement between Maternal Self-reported Ethanol Intake and Tobacco Use During Pregnancy and Meconium Assays for Fatty Acid Ethyl Esters and Cotinine. American Journal of Epidemiology. 158, 705–709.
5. Eylera, F., Behnkea, M., Wobiea, K., Garvanb, C. and Tebb, I. (2005). Relative ability of biologic specimens and interviews to detect prenatal cocaine use. Neurotoxicology and Teratology. 27, 677 – 687.https://www.usdtl.com/blog/lost-opportunities
When a child is exposed to illegal substance abuse they often also face other coexisting obstacles to a normal life – neglect, abuse, violence, and other vulnerabilities. Substance abuse is a disease, one that often prevents adults from doing what is in a child’s best interests. Our environmental exposure test for children can help.
Our hair environmental exposure test is the only drug test designed to detect passive exposure to drugs and detect both native drugs and drug metabolites in the hair specimen. Drug metabolites are produced in the body only if drugs have been ingested. Children in drug exposed environments are most often not drug users themselves, so drug metabolites are typically absent in child specimens. However, the hair, like a sponge, can absorb non-metabolized drug (native drug) if it is exposed through things such as touching or being in contact with drugs or drug users.
Standard hair tests with other labs will only report a positive exposure result if drug metabolites are detected, even when the native drug is in the child’s hair specimen. Our hair environmental exposure test reports a positive result if either native drugs or drug metabolites are detected.
A hair exposure test can provide evidence of drugs in a child’s environment for the past 3 months. A positive test result suggests that the child has experienced one or more of the following: passive inhalation of drug smoke, contact with drug smoke, contact with sweat or sebum (skin oil) of a drug user, contact with the actual drug, or accidental or intentional ingestion of illegal drugs.
ChildGuard®is the only child hair test designed to detect exposure to native drugs and drug metabolites.https://www.usdtl.com/blog/we-can-help-you-help-them-with-childguard
By Joseph Salerno
The movement and location of physical evidence from the time it is obtained until the time it is presented in court is the legal definition of chain of custody. The results of any newborn alcohol or substance of abuse test performed at USDTL may eventually be presented as evidence in a court of law, and this is why USDTL maintains universal chain of custody regardless of the client source of testing specimens. A court can exclude the results of a test if a chain of custody for the newborn sample was not maintained by the hospital and USDTL.
Chain of custody for specimens sent to USDTL is maintained as a chronological paper trail of collection and transfers of specimens throughout the testing process. The paper trail is signed and dated by each person who handles the specimen, both when they receive the specimen into their own hands, and when they hand it off to the next person in the process. Less transfers of a specimen that need to be documented is better for the chain of custody overall. A well maintained and legal chain of custody begins at the time of specimen collection and continues uninterrupted until test results have been presented in court, if necessary.
There are several key elements of the chain of custody for alcohol and drug test samples that must be present when samples arrive at USDTL. First, the specimen container must be sealed with an intact security seal. Next, the sample must be accompanied by a Chain of Custody and Control Form with an identification number matching the number on the specimen container. The Chain of Custody and Control Form is the first piece of the chain of custody paper trail. Thirdly, the Chain of Custody and Control Form must be signed and dated by an authorized agent from the client. If one or more of these elements are missing, USDTL must return the sample to the client.
An unbroken chain of custody ensures sample integrity in several ways that preserve the legal usefulness of alcohol and drug testing results.
Chain of custody ensures that the original sample is the same as the one that is tested and ensures that the integrity of the sample is preserved during transport. Tampering, substitution, or alteration of the sample prior to being tested is prevented by the chain of custody process, which ensures thatit has been handled only by the donor, a qualified collector, and lab testing personnel.
Maintaining chain of custody for newborn samples destined for alcohol and drug testing is a simple process, but all those who handle a drug testing specimen need to be vigilant about the process nonetheless. Diligent maintenance of chain of custody is always in the child’s best interest. Unfortunately, it is only when the legal impact of an improperly maintained chain of custody is realized, that the full value of a well maintained chain of custody is understood. Ultimately, chain of custody protects the institution that is collecting the specimen, as well as the newborn whose health and well-being may rely on the results of a USDTL alcohol or drug test.
Reference: Giannelli, P. (1996). Forensic Science: Chain of Custody. Criminal Law Bulletin, 32(5), 447-465.https://www.usdtl.com/blog/maintaining-chain-of-custody-protects-health-institutions-and-newborns
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