The Des Moines Register
Thursday, April 16, 1998, Page 10S

Drug tests bring worries of accuracy

"I go to extraordinary lengths before I call a positive."
-- Dr. David Berg
Medical review officer

By LYNN HICKS
REGISTER BUISNESS WRITER

    The water-cooler talk is true: Poppy seeds can produce a positive test for heroin, and cold medicine can suggest methamphetamine.
    But medical experts say workers have little to worry about as changes in Iowa's drug-testing law go into effect today.
    That's because the new law requires medical review officers to evaluate drug tests.  They act as judges, determining whether the positive test is a result of illegal drug use or a legitimate medical cause.
    "I'm there to protect people from false positives as much as I'm there to find drug (evidence) for their employers," said Dr. David Berg, an MRO and director of occupational medicine for the Des Moines office of HealthSouth.  "I go to extraordinary lengths before I call a positive."
    Accuracy is a concern as private-sector employers gain more power to test employees for drugs and alcohol.  Occupational health clinics and laboratories say the law could lead to more business, but they don't expect a rush starting today.
    Business groups have been pushing for a change for years, and some construction companies and other safety-sensitive employers are moving quickly to start testing, said James Aipperspach, president of the Iowa Association of Business and Industry.  But most are still learning about the changes and deciding what options to take.
    Employers are not required to test.  They could randomly test workers for alcohol and other drugs.  They could test if they have reasonable suspicion that a worker is under the influence.  They could require workers to get treatment after a confirmed positive drug test, or they could fire them.  Critics say the law gives employers more power than police.  They also question the reliability of testing, and say the workers would have little recourse if they falsely test positive.
    The new law protects employers from liability unless they clearly should have known a false positive test result was in error and ignored the correct test result.
    The Iowa Civil Liberties Union isn't saying whether it will fight the law.  But lawyers and legislators have talked to the group about a challenge, said executive director Ben Stone.
    Random testing could result in more false positives, said Craig Zwerling, a University of Iowa professor and expert on drug-testing.
    Statistics vary widely on the likelihood of false positives, depending on the test and the lab.  Civil libertarians say 5 percent is a conservative estimate.
    Medical experts acknowledge that false positives aren't impossible.   But they say urinalysis, the most common means of drug testing, has improved.
    The Iowa Methodist Medical Center laboratory's testing is more than 99 percent reliable, said Rich Snyder, who supervises drug testing.
    The lab uses a combination of gas chromatography and mass spectrometry, which is considered by most experts to be the most precise procedure for the detection of banned substances.  The new Iowa law requires such a technique to be used to confirm positive tests.
    Employees can request a second confirmatory test at another lab, at their expense.  If that test comes back negative, the employer must reimburse the employee.
    But tests still read some innocuous substances as illegal drugs.   Because of the poppy seed problem, the federal government is raising the threshold for the detection of opiates in urine.  Additional tests can be done to determine whether a Vicks inhaler is causing a methamphetamine positive, experts say.
    Medical review officers also look at more than the test, searching for evidence of needle tracks or asking whether the person is on a prescription drug.
    Testers also watch for adulterated samples.  An industry is booming on the Internet, providing drug users with tips and products to taint their tests.   Snyder said most of the methods, such as mixing the urine with bleach or soap, are easy to catch.
    Medical review officers also are on guard for every excuse imaginable.   They've heard them all, including the one gold-medal snowboarder Ross Rebagliati gave when he tested positive during the Olympics.  Second-hand marijuana smoke will produce a positive test only in extreme cases, research has shown.
    "There's no way," Berg scoffed.

Reporter Lynn Hicks can be reached
at hicksl@news.dmreg.com or (515)
284-8211.

The Des Moines Register
Thursday, April 16, 1998, Page 10S
letters@news.dmreg.com