There has never been a single, controlled scientific study showing drug urinalysis improves workplace safety. Claims that drug testing works are based on dubious anecdotal reports or the mere observation of a declining rate of drug positives in the working population, which has nothing to do with job performance. Such scientific studies as have been conducted have found little difference between the performance of drug urine positive workers and others. The largest survey to date, covering 4,396 postal workers nationwide, found no difference in accident records between workers who tested positive on pre-employment drug screens and those who did not. The study did find that drug positive workers had a 50% higher rate of absenteeism and dismissals. Put another way, however, drug users had a 93.4% attendance record (versus 95.8% for non-users) and fully 85% kept their jobs for a year (versus 89.5% for non-users)! An economic analysis of postal workers in Boston concluded that the net savings of drug testing were marginal, and that there could be many situations where it is not cost effective. Another survey of health workers in Georgia found no difference in job performance between drug-positive and drug-negative workers.
