Surprisingly the drug that the smallest percentage of false positives or negatives occurs on is Cocaine. Marijuana is actually the number one drug to come up as a false positive or negative. But it’s also important to keep in mind that there are some drugs that are often missed completely on drug screens. Despite the test having that screen it’s more often than not invalid and unable to detect the presence of Oxycodone, and the family of opiods that this drug belongs to. Studies showed that over 80% of doctors didn’t realize that to test for Oxycododone and that specific strain of opiates they needed to order a special test to accurately determine if the sample was dirty.

One of the more common kinds of drug testing is when an officer or law enforcement individual (trooper / cop / sheriff) administers a “field test” which is an on the spot urine drug test. There is a specific kind of “field test” testing device that’s used for these, and because of the startling amount of research done into false positives, and how inaccurate some of those testing devices being used in the field were the researchers almost demanded a moratorium (or a complete suspension) on their being used. There was even a moment when one of those “field test” kits turned orange indicating the presence of Cocaine……the test had only been exposed to the atmosphere. The test had simply been waved back and forth in the air a few times, and suddenly turned orange.