IRVINE, Calif., Sept. 20 (UPI) -- A University of California at Irvine study provides strong evidence that workplace drug testing may reduce employee drug use.
Other workplace drug policies such as a written "zero tolerance" standard or employee assistance programs don't explain the association between testing and less worker drug use, according to study leader Christopher Carpenter, a health economist at University of California at Irvine's Paul Merage School of Business.
Carpenter also considered the health profile of employees at work sites with lower drug-use rates to determine if healthier workers self-select workplaces that are more likely to screen their employees.
Because other policies and workforce characteristics likely dampen drug use to some degree, and because previous research did not account for those effects, Carpenter says, past studies may have overstated the testing-drug use link.
"My results don't definitively prove that drug testing directly reduces drug use, but they are the strongest evidence to date," said Carpenter.
Failing to account for other workplace characteristics and drug policies may bloat the drug testing use association by as much as 25 percent, according to the online edition of Health Services Research.