In recent years there is a drastic increase in drug and alcohol consumption which is a disturbing factor for the welfare of the society. It is due to the fact that, when employees report to work after consuming alcohol and drug there is a lot of possibility of accidents taking place. If so it will affect productivity, safety of the employees and customers and spoil the name of the concern. Therefore it is very necessary that drug testing should be done in work places, educational institutions, shelters, rehabilitation centres and medical facilities.
False Positive Drug Tests
It is very important to understand False Positive and False Negative Drug Tests, their causes and how to minimise them to maintain a drug free work place for the welfare of the people. A False Positive Drug Test occurs when the test result shows the presence of drug in a human sample, even when they have not taken alcohol or abused drugs. A False Negative Drug Test happens when the person has actually consumed alcohol or drug and still it is not detected in the drug test. Therefore it is very essential that the root causes for this problem is identified to ensure that the immunoassay technique is carried out without faults.
Causes for a False Positive Drug Test
A False Positive Drug Test may occur by many factors. It might be due to some food items, inter-cross reactivity with regular medication, inadequate amount of test sample, laboratory mistakes or specimen handling problems. Anyhow persons, who are getting false positive results in employee drug testing, face problems because their employees think that they are under the influence of the drugs. This false result may affect their candidature for the applied job or termination if they are already employed. The false positive drug results are due to the following reasons.
Due to food and drinks
- A false positive drug test might be due to the intake of poppy seeds, which gives positive for opioids.
- Ingesting Hemp and Cannabidiol products may show a false positive for THC which is a psychoactive component of Marijuana.
Due to Medicines
- Intake of some antibiotic medicines may show a false positive result for buprenorphine and morphine or opiates.
- Some pain killers which are anti-inflammatory like ibuprofen can show a false positive result for barbiturates and cannabinoids.
- Antidepressants like trazodone and bupropion, may indicate a false positive result for amphetamines.
- Intake of Antihistamines namely diphenhydramine (Benadryl), some times show a false positive result for opiates or PCP (phencyclidine).
- When some medicines are taken to cure cold and allergies such as phenylephrine, nonprescribed nasal antihistamine and inhalation can indicate a false positive result for amphetamines.
- Inter-cross reactions may take place with certain medicines and produce a false positive test result.
Due to environment and activities
- During specimen collection and handling, if it is not carefully handled contamination may take place in the nearby objects or surfaces. Due to this the result may be false positive.
- If a person comes into close proximity with people using cocaine or methamphetamine, then it may cause a false positive test result due to passive exposure.
- If a person is exposed to marijuana smoke in a closed area without ventilation, it may end up in false positive drug test result. This is due to second hand smoke.
Minimizing Errors in Drug Test Results
A False positive Drug Test result may wrongly denote that a certain person has a disease which causes a great anxiety, worry and fear to that person. This condition may result in spoiling his mental as well as physical health. Apart from this it will certainly affect his career. Hence preventing and minimizing false positive drug test results are very necessary.
The first step to reduce false positive is to inform the person who is administering the drug test about the medications or food supplements taken well before the drug test. This precaution will be very helpful if those medications have the tendency to trigger a false result. Also avoiding going to the places where there is drug smoke or contamination would certainly reduce the false positives.
To provide a genuine and true result in the drug test, confirmation is essential. Hence if false positive or false negative results occur, this error can be minimized by sending the human sample to the laboratory for second testing and evaluation. The specimen is made to undergo Gas Chromatography, Mass Spectroscopy, or Liquid Chromatography to get the correct result.
Further it is mandatory to conduct the above said positive immunologic test and this result should be considered a “Presumed Positive” or “Non-Negative Result”. To have an accurate result, the confirmatory and screening results should be reviewed by a specialist Medical Review Officer. The main objective of this review is to analyse the medications and medical conditions of the person who underwent the drug test. These precautions and steps will certainly minimize the false positive results.
Frequently Asked Questions
1. What is meant by False Negative Test?
If a person has consumed an illicit drug and if it is not detected by drug test then it is a false negative. This might have happened due to the fact that small traces of drug had not been screened.
2. Give an example for False Positive Test?
If a person does not have diabetes and the test result show that he has diabetes that is a false positive test.
3. What is the probability of getting a false positive and false negative?
Statistics show that False Positives occur about 5% to 10 % and False Negatives occur 10% to 15% among the total number of drug tests conducted.
4. What is the consequence of a False Positive Test?
A False positive Drug Test result may wrongly denote that a certain person has a disease which causes a great anxiety, worry and fear to that person. This condition may result in spoiling his mental as well as physical health.
5. How does American Screening Corporation help in drug testing?
American Screening Corp helps in conducting periodic drug and alcohol tests to the employees so that they carry out their regular duties with care and concern. It also assists in minimising false positive and false negative tests by manufacturing and supplying high quality, tamper proof and reliable drug test kits.
