An analysis of employee drug tests conducted by Quest Diagnostics indicates that U.S. workforce drug use has increased each year – and by double-digits over two years – between 2015 and 2017 in five of 16 major U.S. industry sectors, with the largest increase in “positivity rates” occurring in transportation and warehousing.

[Above drug testing photo from the Dept. of Defense.]

Data from the Quest Diagnostics Drug Testing Index indicated that five U.S. economic sectors experienced double-digit year-over-year increases in drug test “positivity” rates between 2015 and 2017: Transportation and warehousing (21.4%); other services, except public administration (15.4%); finance and insurance (13%); retail trade (12.8%); and wholesale trade (11.8%).

The firm added that “significant increases” in both cocaine and marijuana “positivity” were the main factors driving the spike in drug test positivity rates among U.S. transportation and warehouse workers.

The company also said year-over-year cocaine positivity increased more than 22 percent between 2015 and 2017 (0.22 percent in 2015, 0.25 percent in 2016, and 0.27 percent in 2017) while marijuana positivity increased by more than 33 percent over the same timeframe.

Consistent with its annual Drug Testing Index report, Quest said marijuana was the most commonly detected substance, with the highest drug positivity rate of all drug classes across the majority of industry sectors.

That dovetails with concerns expressed in two reports back in October that the legalization of marijuana might lead to an increase in motor vehicle crashes.

“The new IIHS-HLDI research on marijuana and crashes indicates that legalizing marijuana for all uses is having a negative impact on the safety of our roads,” noted David Harkey, president of IIHS-HLDI, in a statement. “Despite the difficulty of isolating the specific effects of marijuana impairment on crash risk, the evidence is growing that legalizing its use increases crashes. States exploring legalizing marijuana should consider this effect on highway safety.”

“Our analysis suggests that employers can’t assume that workforce drug use isn’t an issue in their industry. In fact, drug test positivity in the majority of industry sectors analyzed is growing,” noted Barry Sample, senior director of science and technology for Quest Diagnostics Employer Solutions, in a statement on Dec. 19.

Other findings from Quest’s analysis include:

• The amphetamine positivity rate grew year-over-year and nearly 14 percent between 2015 and 2017 in the educational services sector, and rose by nearly 16 percent in the health care and social assistance sectors. Amphetamine is a central nervous system stimulant and includes drugs such as Adderall, often prescribed for attention deficit disorder but that may also be used illicitly.
• Methamphetamine positivity was highest in the construction sector in each of the three years analyzed, and experienced a 15 percent increase during that period. Methamphetamine, which is a prescription drug but is most often associated with illicit use and production in clandestine laboratories, is a potent version of amphetamine that has more harmful effects on the central nervous system and has a high potential for misuse.
• The construction sector ranked highest among industries for cocaine positivity – 0.41 percent in 2017 – which is more than 33 percent higher the general U.S. workforce. The construction sector also exhibited a more than 26 percent increase in marijuana positivity between 2015 and 2017.
• In the manufacturing sector, both marijuana and methamphetamine positivity increased year-over-year, by more than 23 and 27 percent, respectively, between 2015 and 2017.
• The information sector showed the largest growth (more than 20 percent) in amphetamine positivity between 2015 and 2017, but was the only sector to experience a year-over-year decline (more than 8 percent) in marijuana positivity during that same period.