Positive Marijuana Drug Tests Up by 11 Percent in Colorado

By: Mark Wiletsky

Positive results from workforce drug tests are at the highest rate in 12 years, according to the recently released Quest Diagnostics Drug Testing Index. Of particular significance to Colorado employers is the increase in positive marijuana results in urine drug tests in 2016 — the first year of results after Colorado legalized recreational marijuana use.


In creating its annual report, Quest Diagnostics analyzes more than 10 million drug test results from tests it conducted on behalf of U.S. employers. Positive results for marijuana for the general U.S. workforce increased significantly over the past few years, with the percentages of positive marijuana results varying by the method of test-ing, as follows:
• Oral fluid testing: up nearly 75 percent from 2013 (5.1 percent) to 2016 (8.9 percent);
• Hair testing: up over 4 percent from 2015 (7.0 percent) to 2016 (7.3 percent);
• Urine testing: up 4 percent from 2015 (2.4 percent) to 2016 (2.5 percent)

In Colorado, the increase in positive marijuana urine tests was a striking 11 percent from 2015 (2.61 percent) to 2016 (2.9 percent).

To read this story and other complete articles featured in the June 26, 2017 print edition of Law Week Colorado, copies are available for purchase online.