But use of certain drugs has increased significantly

Drug use among American workers declined dramatically over the past 25 years, although the rate of positive test results for certain drugs, including amphetamine and opiates, continues to climb, according to a landmark analysis of workplace drug test results released by Quest Diagnostics

The special 25th anniversary Drug Testing Index (DTI) coincides with the passage of the Drug-Free Workplace Act in 1988, which was a catalyst for greater awareness of the problem of workplace drug use and the implementation of workplace drug education and monitoring programs, including drug testing by federal agencies and private employers in the United States.

"Today's Quest Diagnostics Drug Testing Index provides the best evidence to date that the Drug-Free Workplace Act and the public and private initiatives it helped to spur have led to steep declines in drug use among much of the American workforce," said Laura Shelton, executive director, Drug and Alcohol Testing Industry Association (DATIA). "While more needs to be done to reduce illicit drug use by workers, we should take heart from the tremendous progress employers have made to create safer workplaces for millions of Americans."

The DTI analysis examined more than 125 million urine drug tests performed by Quest Diagnostics forensic toxicology laboratories across the United States as a service for government and private employers between 1988 and 2012. The analysis examined the annual positivity rate for employees in positions subject to certain federal safety regulations, such as truck drivers, train operators, airline and nuclear power plant workers (federally mandated safety-sensitive workers); workers primarily from private companies (U.S. general workforce); and the results of both groups together (combined U.S. workforce).

The index reports the percentage of results that tested positive for the presence of a drug or its metabolite, an adulterant, or that involved a specimen that was deemed to be unacceptable for testing ("positivity"). The company's testing services identify approximately 20 commonly abused drugs, including marijuana, opiates, and cocaine.

Key findings from the analysis:

  • The positivity rate for the combined U.S. workforce declined 74%, from 13.6% in 1988 to 3.5% in 2012.
  • The positivity rate for the federally-mandated safety sensitive workforce declined by 38%, from 2.6% in 1992 to 1.6% in 2012.
  • The positivity rate for the U.S. general workforce declined by 60%, from 10.3% in 1992 to 4.1% in 2012.

Despite the declines in overall drug use, the DTI analysis also found that the positivity rate for certain segments of drugs has increased.

  • Positivity rates for amphetamines, including amphetamine and methamphetamine, has nearly tripled (196% higher) in the combined U.S. workforce and, in 2012, were at the highest level since 1997. The positivity rate for amphetamine itself, including prescription medications such as Adderall, has more than doubled in the last 10 years.
  • Positivity rates for prescription opiates, which include the drugs hydrocodone, hydromorphone, oxycodone and oxymorphone, have also increased steadily over the last decade: more than doubling for hydrocodone and hydromorphone and up 71% for oxycodone: reflective of national prescribing trends.

These data are consistent with other studies, including a 2012 Quest Diagnostics Health Trends analysis of more than 75,000 test results from patients tested for compliance through the company's prescription drug monitoring services. This report found that the majority of Americans misused their prescription medications, including opioids and amphetamine medications.

The DTI report also found that changing positivity rates often mirrored larger developments in drug use in the U.S. For instance, a decline in drug positives for methamphetamine observed in 2005 roughly coincided with federal and state efforts to crackdown on so-called "meth labs" and put over-the-counter medicines: such as ephedrine and pseudoephedrine: behind the pharmacy counter.

The Drug-Free Workplace Act of 1988 requires federal contractors and all federal grantees to agree to provide drug-free workplaces as a precondition of receiving a contract or grant from a federal agency. Although the law did not mandate mandatory drug testing, federal agencies subsequently promulgated drug testing regulations affecting "safety-sensitive" employees and other federal employees. Many private employers also created policies consistent with the federal requirements in order to minimize the hazards of drug use in the workplace.

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