While RSDT deters drug use and identifies students using drugs so that they can receive evaluation and treatment if needed, RSDT does not eliminate drug use among all students. If a school has few positive random drug test results, it does not mean that the students have stopped using illicit drugs; rather, it probably means that the drug tests being used are failing to identify the drug users.
Schools with positive drug test result rates below 3% should contact their testing providers and try another type or brand of test. Each substance tested (urine, oral fluids, hair, and sweat) has its own advantages and disadvantages. Some tests are better at identifying positives than others. On-site oral fluid tests are particularly likely to miss many drug users, especially marijuana users. Therefore, it is important for every school using RSDT to continuously evaluate its program and its testing provider by tracking its positive test rate.
For more information, read the Institute for Behavior & Health, Inc. paper on Low Positive Test Rates.