The Quest Diagnostics Drug Testing Index™ (DTI) is a series of reports that provide insights into trends in workforce drug use based on positivity rates of deidentified laboratory tests performed by Quest Diagnostics for a range of illicit, legal and prescription drugs. It examines test results according to three categories of workers: the federally mandated, safety-sensitive workforce; the general U.S. workforce; and the combined U.S. workforce. Federally mandated, safety-sensitive workers in