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Reversing a 10-year downward trend, workplace drug use increased during the year 2000 according to a semiannual Drug Testing Index released by Quest Diagnostics Inc., a Teterboro, NJ-based provider of diagnostic testing and information services. Quest’s services include gene-based testing, routine medical testing, drug abuse testing, and nonhospital-based anatomic pathology testing.
From 1988, when the survey was first conducted, through the end of 1999, the annual "positivity rate" (the proportion of positive test results to all drug tests performed by Quest Diagnostics) declined from 13.6% to 4.6% (See chart, below.) However, during 2000, the overall positivity rate increased slightly to 4.7%.
The Drug Testing Index summarized the results of workplace drug tests performed between January and December 2000. The Drug Testing Index looks at positivity rates among three major testing populations: federally mandated, safety-sensitive workers; the general work force; and the combined U.S. work force.
All of the increase in positivity occurred in the general U.S. workforce, which excludes federally mandated, safety-sensitive workers, such as pilots, bus and truck drivers, and workers in nuclear power plants, for whom routine drug testing is mandated by the U.S. Department of Transportation and the Nuclear Regulatory Commission. The positivity rate among federally mandated, safety-sensitive workers continued to decline in 2000 to 3.1% from 3.2% in 1999. The positivity rate for the general work force increased from 4.8% to 4.9%.
R.H. Barry Sample, PhD, director of science and technology for Quest’s corporate health and wellness division, indicates that this turnaround is the direct result of an increase in drug use among workers. "In the 13 years that we have been measuring drug use in the workplace, this is the first time we have seen an increase in the rate of positivity," he notes. "This appears to be due to an increase in drug use among current general work force employees, mainly among employees who are subject to random on-the-job testing."
The positivity rate for the general work force increased even more sharply in three key segments of on-the-job testing: "For cause," which indicates reasonable suspicion; "post-accident" and "random drug testing." For these three categories, the rate of positivity in the general work force went up 9.1%. By contrast, the rate of positivity for these three categories declined 4.3% for federally mandated, safety-sensitive drug tests.
The incidence of cheating on drug tests declined during 2000, decreasing 52% from 1999, according to the Drug Testing Index. Cheating on drug tests can involve the use of masking agents, or chemicals that are added to drug testing specimens in an attempt to defeat the process of detecting drug use. These agents include oxidizing adulterants, which include nitrites, as well as bleach and pyridinium chlorochromate. Cheating also can involve the use of "substituted" or "invalid" samples.
[Editor’s note: For more localized workplace drug test data, visit the Quest Diagnostics web site: www.questdiagnostics.com.]