US EXPERT EXPLAINS DRUG TEST COMPLEXITIES

RICHARD E. Struempler is president and chief executive officer of
Total Quality Management Services, Inc., a Texas-based consultancy
firm on drug tests that maintains an office in Manila.

Struempler has over 25 years of experience in Forensic Urine Drug
Testing, and over 14 years under his belt managing SAMHSA-certified
drug-testing laboratories assaying over 30,000 specimens per month. He
has also established programs for education and training in Forensic
Urine Drug Testing for all levels.

Here he fields questions, via e-mail, from the Bulletin on the
complexities of the urine drug-testing procedure - questions that
may be playing on a lot of people's minds ever since the drug
controversy erupted in the Philippine Basketball Association.

MB: What does a 'positive' result really mean?

Struempler: A "positive" result simple means that a drug or drug breakdown
product was detected in the urine at or above a pre-determined "cutoff"
level. One unit below the cutoff level and it would have been reported as
"negative". A positive result CANNOT tell you when or how much drug was
used, nor can it tell you if the use was a one-time experiment or a chronic
drug abuse problem. If appropriate cutoff levels are used in the case of
marijuana use, you can say that the positive result DID NOT come from
breathing second-hand smoke. This is the most common reason given for a
positive marijuana result by the donor.

MB: When does 'positive' result not indicate drug abuse/ drug
use?

S: A "positive" drug test indicates only that the drug(s) being tested
were present in the urine. It cannot tell you how the drugs came to be
present. Before determining a finding of "drug abuse" from the donor,
someone with knowledge of drug testing issues must be able to rule out
the presence of drugs not related to abuse. For example, morphine may
be present in the urine due to prescription medication with codeine in
it, eating certain types of poppy seed cakes or muffins, or from the
use of heroin. Only the latter would typically be consistent with drug
abuse. The other two causes would be considered a medical exception,
and the result should be reported to the person receiving the final
result as a "NEGATIVE" even though morphine was detected.

MB: What do 're-test' results achieve?

S: "Re-tests" can come in a number of forms -- from a re-testing of
the original "positive" sample, to a recollection and then testing of
that second sample. If the original sample is retested, then the
method used for the re-test must be either the same or technically
superior to the original test. Due to breakdown of the drug over time
in the urine, a re-tested sample could easily reveal lower amounts
than originally detected, and this may be interpreted in error and
considered now "negative". A second sample collected and then tested
as "negative" should never be allowed to impeach a previous "positive"
sample. The second sample could easily have been collected outside of
the "window of detection", or that time period in which drug can be
detected, from the last use.

MB: Most of the cases the PBA is handling involves metampethamine
hydrocloride, otherwise known as 'shabu.' Is it possible that this
substance can manifest itself in a urine drug test through the use of
over-the-counter medication, diet pills or food supplements?

S: Depending upon the testing procedures used, some cough and cold
medicine as well as diet pills can result in a "false positive" test
for "shabu". This is the problem with many of the "screening" or
immunoassay tests. The active ingredient in many cold and diet
preparations is very similar to methamphetamine or "shabu" or as we
call it, "crystal meth". Any positive result must be confirmed by a
second more specific test to rule out the false positive that may
occur. This is a critical aspect of testing for "shabu".

MB: In your almost 30 years in this field, have you ever encountered a
case where a drug test made a mistake?

S: In 1982, the US Navy drug-testing program reported out literally
several thousand positive drug testing results that did not meet
appropriate scientific evidence. These had to be reversed, or
officially reported as "negative". Most of these, we believe, were in
fact true positives, but not all of the steps necessary for a valid
result were present. Rather that risk falsely accusing someone of drug
use, all of these results were thrown out. It was this event that lead
to the development of the rigid drug-testing program now used in the
United States. These events were very similar to what I see occurring
with the PBA at this time. It appears to be the same issues on a
smaller scale. Since the revision of the program in 1983, and
literally millions of tests performed, I have personally seen only two
specimens where a laboratory that was following US guidelines for
testing was not able to reconfirm a previously reported positive result.

MB: If there are mistakes, where do they usually occur?

S: In these cases, we were not able to determine an analytical error
or mishandling of the specimen. These 1-in-10,000,000 or more
"false-positives" remain a mystery today. In general, most errors
occur at the collection site -- not in the laboratory.

MB: In the US, what are the chances of a 'human error' marring the
tests?

S: This is a very interesting question that is almost always raised by
attorneys representing a person with a positive test. In the US, the
entire program's quality control and risk management is designed to
err in favor of a negative result. If in the processing of the sample,
there is ever a question regarding the proper handling or testing of
the specimen, a "negative" result will be reported. Only results in
which there is clear indisputable evidence by scientific methods is a
"positive" result reported. As a result, there are those who use drugs
who will not be detected. The idea is that if you randomly continue to
test employees, those who use drugs will continue to use drugs and
will eventually be detected. The program must be designed to have NO
FALSE POSITIVES. Those being tested must also be given the opportunity
to provide evidence of a legitimate medical explanation for positive
results, such as prescription medication, and those results would also
be reported to the "employer" as a NEGATIVE meaning "negative for
abusing drugs". As I have indicated, this field of science is very
complex, with new issues coming up each day. That is why it is
critical that those administering the program understand and deal
appropriately with these issues.

S: As you can tell from these responses, issues involving urine drug
testing, can be somewhat complex. To those not familiar with the
science of urine drug testing or attempting to manipulate information,
it is easy to create a smokescreen of excuses for a positive test
result that could cause others to doubt the validity of the result.

Urine drug testing can be a valuable tool in fighting the war against
drug abuse, but if specimens are not properly collected, handled,
tested and results interpreted correctly, then urine drug testing can
be a disaster for both those being tested as well as those trying to
administer their program.