Are rates of positive tests truly declining?

Using the Quest Diagnostics Drug Testing Index, which annually measures the proportion of positive test results among workers in safety-sensitive positions and in the general workforce, positive test rates for these groups combined in the U.S. have demonstrated a consistent downward trend. In 1988 the combined rate was 13.6%, but that had dropped to 3.8% in the latest results in 2006. Based on this data set, one might conclude that drug testing programs are satisfactorily meeting public and workplace safety concerns around substance use.

Yet this view would be misleading, for additional information suggests otherwise. In fact, a definite disparity exists between the annual decline in positive test rates and what drug users, employers, and regulators intuitively know and relate concerning actual outcomes—reporting higher instances of usage with lower frequency of detection.

To cite one example, the Oregon State Police in May 2007 conducted an anonymous, voluntary testing of truckers and found the drug use rate among that group to be around 10%—significantly greater than any annual percentage cited in the Drug Testing Index since 1991. The State Police have responded to public safety concerns by conducting these road checks of commercial truckers in Oregon since 1998. The 2007 check showed that the presence of marijuana and opiates—two of the five categories in the Department of Transportation's (DOT's) five-panel drug test—accounted for the largest percentage of positives.

Effect of cheating

How can this be explained given what we “know” about the practice of drug testing? We know that individuals (collectors, laboratories, medical review officers, etc.) conducting the drug testing protocols account for a good portion of the variability. But less understood is the effect of individuals who intentionally “cheat” the system—here we're talking primarily about the user of adulterants/dilutants/substitutes as well as those who manufacture and distribute such products. Cheaters seem to be prospering, and as a result the present rates of positive tests could serve to be more of an indicator of how cheaters are becoming more successful.

There is a growing body of literature around the reporting of flaws or vulnerabilities in the implementation of drug testing programs from point of collection through laboratory procedures, affecting both DOT and nonregulated drug testing. In regard to DOT, we know that:

• The Government Accountability Office's (GAO's) undercover report on the DOT drug testing program found major deficiencies and lack of controls concerning the collection process in urine testing (see January/February 2008 issue);

• The GAO found that adulterants/dilutants/substitutes were widely available through the Internet, easily purchased, easily transported into the collection site for use, and virtually undetected by laboratory results using the DOT testing procedures; and

• The U.S. House Subcommittee on Highways and Transit conducted an October 2007 hearing that revealed inconsistent implementation procedures among 24 collection sites with regard to much of the DOT collection protocol.

Without discounting the great efforts made in the drug testing field to maintain and improve upon a crucial public safety process, a fiction resides in the belief that testing irregularities or deficiencies can be controlled by what we already do within our purview. What we find difficult is how to address the effect stemming from the motivation to sabotage the process—the daily barrage of new technologies by which individuals cheat the system. Even if the protocols could adequately handle yesterday's technologies, how do we stay current in subduing tomorrow's new wonders that could nullify testing results in the future?

Meaningful legislation

In seeking to mitigate the hazards of adulterants/dilutants/substitutes, the focus must broaden to include at least more legal responsibility to the worker being tested and to the entrepreneurs who create these products. The National Drug Testing Integrity Act (HR 4910) was brought forward for a second time in Congress in 2006. If it had been enacted, it would have prohibited the manufacture, sale, marketing, or distribution of products or substances designed or intended to defraud a drug test.

The truth is that more people are using than the data suggest, and they are not being caught consistently by drug testing protocols and procedures. Just think how public and workplace safety would be secured if we could stop just half of the cheaters from being able to cheat. Such a goal can be achieved only through a collective, concerted effort to make the use of adulterants/dilutants/substitutes an extremely unattractive alternative.