What do these tests do? These tests indicate if one or more prescription or illegal drugs are present in urine. These tests detect the presence of drugs such as marijuana, cocaine, opiates, methamphetamine, amphetamines, PCP, benzodiazepine, barbiturates, methadone, tricyclic antidepressants, ecstasy, and oxycodone.
The testing is done in two steps. First, you do a quick at-home test. Second, if the test suggests that drugs may be present, you send the sample to a laboratory for additional testing.
What type of test are these? They are qualitative tests -- you find out if a particular drug may be in the urine, but not how much is present.
Many things can affect the accuracy of these tests, including (but not limited to):
- the way you did the test
- the way you stored the test or urine
- what the person ate or drank before taking the test
- any other prescription or over-the-counter drugs the person may have taken before the test
If the test results are negative, can you be sure that the person you tested did not abuse drugs? No. No drug test of this type is 100% accurate. There are several factors that can make the test results negative even though the person is abusing drugs. First, you may have tested for the wrong drugs. Or, you may not have tested the urine when it contained drugs. It takes time for drugs to appear in the urine after a person takes them, and they do not stay in the urine indefinitely; you may have collected the urine too late or too soon. It is also possible that the chemicals in the test went bad because they were stored incorrectly or they passed their expiration date.