Drug testing is very common. Most people have submitted a sample for drug testing at least once. Tests for home use are available from numerous retailers in-store or online. Test kits for home use almost always emphasize accuracy. The various methods of analyzing samples in a lab have estimated accuracy rates as well.
The reported accuracy rates are usually around 99%. Sometimes a decimal is included to get numbers like 99.6% or 99.8%. These percentages lead to a belief that errors are very, very rare because the tests are almost 100% accurate. These accuracy rates are based on ideal conditions, but circumstances, in reality, are often far from ideal.
Drug screening is done with hair, urine, saliva, or blood. Instant tests usually screen urine or saliva. They provide results within minutes, but instant tests are not as reliable as laboratory analysis. An instant test can detect anywhere from 1 to 27 substances.
Some detect broad drug classes such as opiates or benzodiazepines, while more extensive tests screen for specific drugs within classes. The instant tests screen for metabolites instead of the drug itself. Metabolites are the byproducts produced by our bodies after the drug is metabolized, and metabolites are present after the drug itself is gone. Laboratory analysis screens for substances and their metabolites.
Drug tests can have serious consequences. Many employers require a clean drug test before hiring applicants, and people who are employed can be fired for positive drug tests. Doctors, nurses, and other medical professionals are at risk of losing more than their jobs. They can lose their professional licenses entirely.
Legal consequences of a failed drug test include arrest, loss of a driver’s license, and incarceration. Sometimes drug tests are supposed to be positive for a specific medication. Controlled medications for pain, anxiety, and substance abuse treatment are monitored. Doctors may refuse to renew a prescription when a patient has a negative result for a drug that should have been detected.
The repercussions of failing a drug test can be life-altering, but it’s very difficult to address inaccurate results. People that unexpectedly fail drug tests often find themselves in terrible positions. Business owners, law enforcement officers, and even medical care providers frequently view drug tests as infallible.
Claims that results were not accurate are dismissed as lies. Modern drug testing methods certainly appear to have near-perfect accuracy, but the numbers can be misleading. The predicted accuracy is based on ideal conditions. Numerous factors affect the accuracy of drug tests in reality.
Human error is always a possibility. Home drug testing kits can be tampered with or damaged. The person administering the test or reading the results may not understand the instructions. Mistakes happen when samples are collected and sent to a lab as well.
Contaminants are easily introduced when the person handling or transporting samples does not follow proper handwashing and collection techniques. Samples may be incorrectly labeled after collection or mixed up during transport.
Mistakes can also occur in the laboratory. Laboratory equipment should be routinely evaluated with control tests to ensure accuracy. The control tests alert technicians that equipment isn’t working correctly or needs to be recalibrated.
Busy technicians may skip control tests or make mistakes during calibration. The results of each analysis must be carefully documented to avoid attributing results to the wrong sample. Some drug testing facilities process thousands of samples every day. There are many opportunities for a mistake to occur.
The results of a drug screen may be misleading even if everything is done correctly. People metabolize substances at different rates. Some substances are known to trigger false positives for certain drug classes. These substances vary depending on the testing method.
Combinations of different medications and even certain foods can also cause inaccurate test results. Instant tests lose accuracy as the number of substances they detect increases. A 27-panel instant test is much more likely to produce a false positive than a 7-panel test.
Drug testing is a useful tool, but it is important to remember that it is just a tool. No drug testing method is guaranteed to be free of errors. Complete faith in a drug screen can cost valuable employees and negatively impact lives.
It can also destroy trust between friends and family. The consequences of a mistake are severe enough to justify another method of testing or more extensive analysis when the results of an initial drug test are questionable.
How Reliable Is a Drug Test with 99.9% Accuracy?