[Workplace urine testing programs are a poor method for identifying employees who are under the influence, and do not significantly reduce job accident rates, according to a study published in the scientific journal Addiction.
Investigators at the University of Victoria in British Columbia reviewed 20 years of published literature pertaining to the efficacy of workplace drug testing, with a special emphasis on marijuana – the most commonly detected drug.
Researchers found: “[I]t is not clear that heavy cannabis users represent a meaningful job safety risk unless using before work or on the job; urine tests have poor validity and low sensitivity to detect employees who represent a safety risk; drug testing is related to reductions in the prevalence of cannabis positive tests among employees, but this might not translate into fewer cannabis users; and urinalysis has not been shown to have a meaningful impact on job injury/accident rates.”
Authors concluded, “Urinalysis testing is not recommended as a diagnostic tool to identify employees who represent a job safety risk from cannabis use.”
Urinalysis detects the presence of inert, fat soluble byproducts of marijuana, the most common of which remains present in urine for days, weeks, or even months after past use – long after any psychoactive effects of the drug have worn off.