The Accuracy of Drug Test Kits

Every drug test kit (urine, saliva, blood, hair follicle) works great to provide fairly accurate results. The accuracy of the results for each drug test kit depends on the quality of the sample usually but there is room for error. The tests are fairly reliable though.

Accuracy
Saliva drug test kits are 98% accurate. Urine drug test kits are 96-97% accurate. Hair follicle drug test kits are 98-99% accurate. Blood tests are a rarity when testing for drugs but because of the procedure to extract the sample and screen it, the accuracy should be around 99.9% for the blood test.
There is another problem with the accuracy of these tests though. In some cases, the results may show that there is a positive for drugs in the sample provided. This could be caused by a false positive. There are a few things that could occur to mess up the results. Over the counter drugs could also be read to provide a positive on the drug test so that could be a problem.

Either way, all of the drug test kits are fairly accurate so it is not really something that has to be worried about. In case there is a chance that a false positive occurs, it may be necessary for a doctor to review the results to figure out which drug has triggered the positive results.