There are approximately 14.8 million drug users in the United States, and more than 3/4 of them hold jobs. Data from government studies has shown that drug users are “almost four times as likely to be involved in a workplace accident as sober workers, and five times as likely to file a workers’ compensation claim. Employees who use drugs also miss more days of work, are late more often and leave jobs without an explanation at a greater rate. These factors can wreak havoc on a business owner’s bottom line, costing them huge portions of profit in lost productivity, workman’s compensation claims, and property damage. A standard drug test, whether it be a urinalysis or hair follicle test costs as little as $2 per person and can significantly reduce the occurrence of drug use by employees.

http://www.nytimes.com/2007/05/10/business/worldbusiness/10iht-users.4.5654684.html