An increasing number of companies require employees -- or those applying for jobs -- to submit to drug screening. And they want to get the results back as soon as possible.
Rapid-result drug tests are suddenly very popular, according to Dr. Howard Leaman, medical director of Intermountain Health Care's Health Services to Business program. The program's Salt Lake area WorkMed Clinics now offer rapid testing as one option.But rapid testing is only truly rapid if the results are negative for drug use. Any specimen that might be positive for use must by law be confirmed in a traditional laboratory test. Possible positives are reported out as "needs further testing," since that doesn't necessarily mean illicit drug use is a fact.
The rapid test is a chemical test done in a disposable urine testing container or with a card that is dipped in such a container or by similar methods. The test contains a reagent strip that will show a reaction if it detects drugs. There's a built-in threshold, so there can be no question that someone is testing positive for, say, secondhand marijuana smoke. It documents only personal use.
The rapid test can detect marijuana, cocaine, opiates, methamphetamines and PCP.
But Leaman is quick to point out that, along with advantages, rapid screening also has pitfalls.
"The biggest drawback is that the donor of the specimen can introduce an adulterant into the urine so that test results come back as negative" when illicit drugs are, in fact, being used, he said.
Labs test first for adulterants. And "many companies have policies that deal with that; sometimes worse than for testing positive" for drug use, he said.
Adulterants can often get past the rapid test. "Clinics go out of their way to control collection of specimens. But you can get into almost any specimen" if you're determined, Leaman said.
Sheran Smith, president of Northwest Toxicology, notes that "these devices can be useful in obtaining rapid negative test results, however, the importance of confirmation testing cannot be over-emphasized." In the specimens that underwent the follow-up testing at Northwest Toxicology during the first three months of 1999, only half of those that screened possibly positive for amphetamines and 25 percent of those that that screened possibly positive for opiates were actually confirmed to result from illicit drug use. The rest of them, she said, were found to contain prescription medications or other substances that "cross-react with the screening immunoassays or contained drugs below the cutoff levels."
Follow-up lab testing was unable to confirm use of marijuana, cocaine or PCP between 7 and 8 percent of the time.
If the drug test can be beaten and the results aren't always accurate, why use that method? Leaman said it's very simple. Employers can kill a lot of time having drug tests done and getting results back. In some cases, positions may not be filled until the process is completed. By rapidly finding employees or applicants who test negative for drug use, work can begin immediately.
The cost for the two testing methods is about the same, he said, but having the results back quickly can translate into a fatter bottom line for businesses.
While there's potential to use the rapid test to see if your teenager is smoking marijuana or taking other drugs, Leaman doesn't recommend it. "If you are the parent of a teenager and worried that your child is using drugs, you should arrange screening through a program or a group that does counseling." For one thing, teenagers have made popular several substances that wouldn't be found with the test, like Ecstasy. And counseling and support are important.
Sports teams, however, may find rapid testing a good idea as a screening tool, he said.
And people who must have Department of Transportation testing, such as pilots and truckers, are never offered the rapid screening option. A test in a regular lab is required.
You can reach Lois M. Collins by e-mail at lois@desnews.com