A question that comes up often is which is better: urine drug testing or oral fluid drug testing. The answer: it depends on what you are trying to accomplish and how you want to accomplish it.
Urine drug testing is traditional and has been around since the early eighties. It has held up in courts as an accurate drug test with proper collection procedures, initial screening at a certified laboratory, GC/MS confirmation testing when necessary, and finally review and verification by a medical review officer.
Many drug panels are available with urine drug testing including: cocaine, marijuana (THC, cannabinoids), phencyclidine (PCP—angel dust), amphetamines (including methamphetamines, also known as crystal meth), opiates (including heroin, codeine, morphine, hydrocodone, hydromorphone, oxycodone), benzodiazepines (such as Xanax), barbiturates, methadone, propoxyphene, methaqualone (Quaaludes), meperidine, fentanyl, buprenorphine, tramadol and more. The window of detection after usage of these drugs varies from drug to drug and is never an exact science.
Typically with urine drug testing the metabolite of drugs shows up in the urine within 24 hours and stays for 48 – 96 additional hours. Some approximate detection time are shown in the chart below for urine and oral fluid testing.
Facilities with trained collectors for urine specimen collections are readily available throughout the United States; additionally there are options for mobile on site collections in most areas. Currently, urine is the only specimen allowed for drug testing for the DOT drug testing program.
A couple disadvantages with urine drug testing:
- Very recent use of a drug is not detected
- Bathroom requirements, YUCK factor of collecting urine
- Cheating on the test can be an issue since the urination is done in private
- Observed collections required same gender
- Potential shy bladder, donor unable to provide specimen
Oral fluid or saliva drug testing is currently available and at some time in the near future will be allowed for DOT required drug testing. This will certainly require oral specimen collectors to be trained and qualified and also to perform proficiency demonstrations (mock collections). This discussion addresses lab based oral fluid drug testing and not instant oral fluid drug testing kits.
At most laboratories, oral-fluid tests will detect the following classes of drugs: marijuana, amphetamines (including ecstasy), cocaine and metabolites, opiates and phencyclidine (PCP). Some labs will do an alcohol test also on the drug test panel; and some labs can add additional drugs: oxycodone, barbiturates, methadone and benzodiazepines.
The main advantages of oral fluid drug testing today for non-DOT drug testing programs are:
- Shorter window of detection; recent drug use within minutes or hours can be detected
- The collection is gender neutral with no bathroom requirement
- The collection is observed, non-invasive and cheating on the test is very difficult
- Shy bladder concerns eliminated
Food, beverages, over-the-counter medication, and mouthwash affect the oral fluid drug test results; for this reason, the donor is to refrain from consumption of food or beverages for 10 minutes prior to specimen collection.
The disadvantages or limitations of oral fluid testing are:
- The shorter window of detection will not detect drug used 3 or more days out
- The specimen volume collected may not be sufficient unless the collection device has an indicator to show adequate volume
- Limited drug panels for testing
- More expensive then urine drug testing unless the employer takes on the role of specimen collector
- Very limited availability of collection facilities trained, with appropriate supplies on hand with the ability to conduct oral fluid collections.
Oral fluid drug tests and urine drug tests side by side show similar positive rates but not among the same donor tests. This may indicate that some donors are getting away with drug use on the oral fluid test and then others are getting away with drug use on the urine drug test.
Recent Studies from Quest Diagnostics show the oral fluid marijuana positivity rate was 70% higher than that of urine (3.4% vs. 2.0%) in the first half of 2012 as compared with 2011. “The higher oral fluid detection rate for marijuana strongly suggests that observed oral fluid collection curbs evasive donor behavior,” stated Dr. Barry Sample. “Simply put, it is extremely difficult to cheat an oral fluid collection when someone is observing.”
While both urine and oral fluid testing are highly effective in detecting recent drug use, urine specimen collection is unobserved, affording donors seeking to potentially evade detection with the means to adulterate the specimen. In contrast, oral fluid specimens are collected when the donor places a swab in his or her mouth under direct observation of the drug test administrator.
Approximate Detection Times—Oral Fluid and Urine
|Alcohol||6–24 hours||12 to 24 hours|
|Amphetamines||1 to 3 days||12 hours|
|Methamphetamine||3 to 5 days||1 to 3 days|
|MDMA (Ecstasy)||3 to 4 days||3 to 4 days|
|Barbiturates||1 to 2 days||1 to 2 days|
|Benzodiazepines||Up to 7 days||6 to 48 hours|
|Cannabis||7-10 Days||2 - 24 hours|
|Cocaine||2 to 5 days||2 to 10 days|
|Opiates||2 to 4 days||1 to 3 days|
|Methadone||7 to 10 days||24 hours|
|PCP||3 to 7 days||1 to 3 days|