Number of drug tests has doubled since the introduction of the saliva test

When the police suspect that a driver is under the influence of drugs, a quick saliva test has since 2010 been enough to give a first indication of the situation. If it comes up positive, a doctor is summoned to the scene to take a blood sample that is then sent to the lab for a definitive analysis. The National Institute of Criminalistics and Criminology (NICC) is the most important lab in this regard. Since the introduction of the saliva test, the NICC has analysed 15,000 blood samples.

Before the introduction of the saliva test the police had to conduct a urine test to get a first indication, and this was a much more involved and time-consuming procedure. The fact that the saliva test is quicker and easier has certainly had its effect: the number of drug tests the police carry out during roadside checks has more than doubled since the saliva test was introduced.

What’s more, not only is the saliva test quicker than the urine test, it is also more reliable. In this context, the NICC compared two large data sets of blood samples, i.e. one from before the introduction of the saliva test and one from afterwards. Of the urine tests that apparently came back positive, 17% ended up giving a negative result in the blood test, whereas with the saliva test just 6% turned out to be false positives. Specifically for cannabis, the most frequently used substance among drivers under the influence of drugs, the number of false-positive tests went down from 24% to 6%.