Quest Diagnostics reports that the percentage of positive drug tests among the American workforce has increased for the first time in more than a decade. The rise in marijuana and amphetamine use is the blame after evaluating 8.5 million urine, oral fluid and hair drug test results.
The positivity rate increased to 3.7% in 2013, up from 3.5% in 2012.
"After years of declines, the prevalence of positive workforce drug tests is increasing," said Dr. Barry Sample, director of science and technology at Quest Diagnostics. "This increase indicates that employers should be aware of the potential for drug use by their workers and the risk that represents for the health and safety of their employees and the public."
Marijuana positivity rates increased 6.2% nationally and by double digits in Colorado and Washington. Marijuana is the most commonly detected drug. These increased rates are consistent with the 2012 National Survey on Drug Use and Health, which showed an increased in self-reported marijuana use between 2007 and 2012.
"Washington and Colorado are believed by many to foreshadow future trends in 'recreational' marijuana use. While Quest's Drug Testing Index shows dramatic spikes in marijuana positivity rates over the past year, a longer view of the data suggests a more complex picture," said Dr. Sample. "It is possible that relaxed societal views of marijuana use in those two states, relative to others, may in part be responsible for the recent increase in positivity rates. Yet, this doesn't explain why both states also experienced steep rises - and declines - in positivity in recent years. We will be very interested to see how our data evolves over the next year or two in these states relative to those that have not legalized so-called 'recreational' marijuana.
"What we do know is that workforce positivity for marijuana is definitely on the rise across the United States. It is important for people to remember that while some states have legalized marijuana, the federal government has not. Employers generally have the authority to restrict the 'recreational' use of marijuana by employees and impose sanctions, including termination, on employees with positive drug tests in all 50 states," added Dr. Sample.