A report by Quest Diagnostics reveals that analysis of more than ten million workplace drug test results shows increases in marijuana positivity across nearly all employee testing categories.
Increases in post-accident positivity in the general U.S. workforce outpace those for all other testing reasons, including pre-employment screening.
Positivity rates in the combined U.S. workforce increased nearly five percent in urine drug tests (4.2% in 2017 versus 4.4% in 2018), climbing to the highest level since 2004 (4.5%) and are now more than 25 percent higher than the thirty-year low of 3.5 percent recorded between 2010 and 2012.
Marijuana continues to top the list of the most commonly detected illicit substances across all workforce categories (general U.S. workforce; federally mandated, safety-sensitive workforce; and combined U.S. workforce, which includes the prior two populations) and specimen types (urine, oral fluid, and hair).
In the general U.S. workforce, the positivity rate for opiates in urine drug testing declined across all opiate categories.
Among the general workforce screening for opiates (mostly codeine and morphine), positivity declined nearly 21 percent between 2017 and 2018 (0.39% versus 0.31%), the largest drop in three years and nearly 37 percent decrease since the peak in 2015 (0.49%).
The report adds that between 2017 and 2018, the percentage of invalid results in the federally mandated, safety-sensitive workforce jumped 80 percent (0.15% versus 0.27%), and 40 percent in the general U.S. workforce (0.15% versus 0.21%).