A new study published by Quest Diagnostics reported an increase in the workforce drug test positivity rate for the first time in ten years, fueled primarily by marijuana and amphetamines.  The Quest Drug Testing Index (DTI) released on September 11, 2014 also showed a large increase in positive marijuana test results in Colorado and Washington, where “recreational” marijuana now is permitted.

The DTI involved the analysis of de-identified results from urine, oral fluid and hair drug tests performed by Quest Diagnostics workplace drug testing laboratories across the country.  The results were analyzed by three categories of workers: (1) employees with private companies (U.S. general workforce), (2) employees subject to federal drug testing rules (safety-sensitive workforce) and (3) a combination of both groups (combined U.S. workforce).

The DTI found a positivity rate of 3.7 percent for the 7.6 million urine drug tests in the combined U.S. workforce, an increase from 3.5 percent in 2012.  According to Quest, the relative increase of 5.7 percent is the first time the positivity rate for combined national workplace urine drug tests has increased since 2003.

In addition, marijuana continued to be the most commonly detected illicit drug, with its positivity rate increasing 6.2 percent in the combined U.S. workforce, 5.6 percent in the safety-sensitive workforce and 5 percent in the general U.S. workforce.  When the urine test data for the general workforce was examined at the state level, it indicated marijuana positivity rate increases in Colorado and Washington — the two states with “recreational use” laws — of 20 and 23 percent respectively.  These figures are significant when compared with the 5 percent average increase among the U.S. general workforce in all states.  DTI data also showed a significant increase in oral fluid tests for marijuana, with positivity rates increasing 27 percent over the prior year.

Quest’s study also showed that amphetamine use (and methamphetamine use in particular) is on the rise with amphetamine positivity results reaching their highest levels on record and methamphetamine positive rates at their highest levels since 2007 (across all specimen types).

The study did register a decrease in one area, with a decline in positive test rates for prescription opiates (e.g., hydrocodone and oxycodone) of 8.3% between 2013 and 2012.

As the country’s attitude toward marijuana use relaxes, and more laws permitting marijuana use are enacted, employers should brace themselves for the increased likelihood of positive employee drug test results.  Employers should review their policies and ensure that they are familiar with the laws governing drug testing and marijuana use in all states where they operate.