CoAdvantage- Do drug tests work? The answer is complicated and nuanced. In short, drug screening probably does help to curb drug use and potentially reduce performance problems and accidents, but not necessarily to a degree that justifies the costs involved.
One study looked at pre-employment drug testing at a large hospital over a six-month period. The employees who tested positive for drugs were found to have a 28% higher turnover rate and a 64% higher rate of disciplinary warnings. In fact, a full quarter of the employees who tested positive received poor performance valuations compared to only 5% of those who tested negative.
However, there were so few cases in the drug-positive group that the results did not attain statistical significance.
Another longer-term study looked at over 5,000 U.S. Postal Service job applicants. It found that employees who tested positive for drugs had a 45% higher absentee rate and a 40% higher dismissal rate when compared to the drug-negative group. A follow-up study found those rates increased to 59% and 47% respectively over time.
Interestingly, despite these results being statistically significant, the study found no significant relationship between drug test results and accidents or injuries. Then again, another study found those who test positive for marijuana have 55% more industrial accidents and 85% more injuries.
The National Bureau of Economic Research points out that drug testing in the U.S. military is likely responsible for curbing drug use within the armed forces. Before 1981, when the military implemented its drug testing program, drug use occurred within the military at approximately the same rate as the general population. However, NBER reports, “Drug prevalence rates in the military fell from 27.6 percent in 1980 to only 3.4 percent in 1992.”
Altogether, these studies and others like them suggest that identifying employees who consume mind-altering substances may be beneficial, but it’s not clear that it’s beneficial enough to outweigh the downsides of drug testing – alienating current and prospective employees, not to mention the sheer cost and labor associated with a drug testing program. Regarding the military, for example, some have questioned the utility of the zero-tolerance policy given the increase in lost servicemembers and the difficulty in replacing them.
A word of warning, too: be cautious about which sources you follow when researching this question. Make sure they’re not just reputable and credible but also impartial. There are a lot of drug testing organizations and laboratories that produce research of varying quality around this question. Those organizations may be vested in advocating for drug testing; review their research with that in mind.
That can even be true of private organizations eager to prove the efficacy of their own drug-testing programs. For example, legal advisory site UpCounsel cites a seemingly misleading old report from Georgia Power, which had reported a reduction in accidents following an increase in drug testing. However, attributing that decline to drug testing is questionable, given that they didn’t begin the more aggressive drug testing policies until the middle of the period of decline, and after the sharpest decline in accidents came before the drug screening program.
Altogether, determining whether drug testing really “works” is a complicated – and subjective–question worth digging into but offers few firm answers.
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