There are a number of different drug tests available to detect substance abuse. The most common ones are urine drug testing, hair follicle drug testing, and saliva drug testing, but these aren’t the only choices. Despite what retailers and manufacturers may claim, it is difficult to measure how accurate an individual testing kit is. This isn’t to say that any drug test is more accurate than any other, but it is important to consider the context of the drug test when assessing results.
How Does Drug Testing Work?
There are a number of different drug tests available to detect substance abuse. The most common ones are urine drug testing, hair follicle drug testing, and saliva drug testing, but these aren’t the only choices. Despite what retailers and manufacturers may claim, it is difficult to measure how accurate an individual testing kit is. This isn’t to say that any drug test is more accurate than any other, but it is important to consider the context of the drug test when assessing results.
Saliva Drug Testing
Saliva drug testing involves placing a swab in the mouth for up to 10 minutes, or until a satisfactory amount of saliva has been collected. Some saliva drug tests use colour indicators to show when enough saliva is on the swab. The swab is taken and inserted into the kit, where the saliva on the swab responds to testing strips built into the kit.
Generally saliva drug tests will screen for a number of popular drugs of abuse at the same time. The simplest oral fluid drug test is our 3 in 1 saliva drug screen. At the other extreme, we now offer a comprehensive 13 drug saliva drug screen.
How Accurate are Mouth Swab Drug Tests?
Saliva drug tests are most accurate when determining how recently drugs were used. They have many advantages over urine drug tests. They have the shortest detection window of every drug testing method. This makes them useful in the event someone is suspected of having used drugs onsite.
Urine Drug Testing
Urine drug testing involves the use of either a cup or a dip card. A donor collects a sample of their urine privately using the sterile or integrated cup. An integrated cup has strips built in that respond to the sample immediately. For sterile cups, a dip card is placed into the cup and it will react similarly to the ones in an integrated cup.
Urine drug test kits that can screen for for single drugs only, such as cannabis or cocaine, or they can test for a number of drugs at the same time. 5 panel or 10 panel drug tests are often used by employers in pre-employment testing. If drug driving is a concern, some employers now use a roadside drugs test kit, which screens for many of the drugs that are picked up by a police drugalyser. Larger drug tests can also screen for alcohol.
Presently, the most comprehensive urine drug test is the 13 panel drug test with integrated cup.
How Accurate are Urine Drug Tests?
Urine drug tests are used across a number of industries. This traditional drug screening method comes with plenty of benefits, including having a longer detection window and being able to screen for up to 16 different substances.
Hair Drug Testing
A hair sample is taken from close to the donor’s scalp and sent to a SAMHSA-certified lab where it is analysed. Hair drug testing has some drawbacks, including not offering instant results. A hair drug test can take a few days to be completed.
Drug Test Accuracy Statistics
The majority of drug tests are 99% accurate. The accuracy of the results can depend on some individual factors though, including how often drugs are used, cross-reactivity to prescription medication, how much time passed between drug use and testing, and even the metabolism of the donor.
According to WebMD – and accounting for those statistics – a positive result obtained through an instant immunoassay are roughly 90% true, while a negative test result is around 85% true. The good news is that uncertainty over instant test results can be taken care of through laboratory confirmation testing.
When it comes to workplace drug testing, accuracy is paramount. False positives can ruin careers and reputations. That’s why confirmation testing with GC/MS is so critical. But this two-step process takes time and money. For many employers, it simply isn’t feasible to send every screening test off to the lab. So they rely on the high accuracy rates of instant tests – around 90% for positives and 85% for negatives according to experts.
To maximise precision, responsible employers combine multiple methods. For example, conducting both urine and saliva tests. Urine has a longer detection window ideal for identifying habitual users. But saliva excels at pinpointing recent use, critical for ensuring workplace safety. This multi-pronged approach costs more upfront but provides robust data to make truly informed decisions. At the end of the day, investing in accurate drug testing protects employees, clients, and the company’s reputation.
What is GC/MS Testing?
GC/MS testing (Gas chromatography-mass spectrometry) testing is used in laboratory settings to confirm the initial findings of an instant immunoassay. It is a two-step process that involves isolating the compounds in the specimen first by size (GC) and then by structure (MS). These tests are virtually foolproof, offering an accuracy of over 99.99%.
Photo Credit: Anthony Cunningham
Zoom Testing is a leading UK drug testing company and a supplier of Drug Test Kits.
This post was originally published in 2017. It was last updated in June 2023.
