The importance of using the right drug detection device

Many workplaces opt to test their employees for drugs and alcohol, but there can be issues with the quality of testing being used.

Once the need for a formal testing regime has been identified, there are a series of flow-on decisions that need to be made, such as what type of testing will be utilised, what substances will be part of the screening process and which testing product will best suit the needs of the business.

As with any business purchasing decision, price will always be a factor. However, selecting a product based on cost alone can have far-reaching, often expensive and often unforeseen implications. With a drug testing program, the product selection also has potentially very substantial OH&S consequences.

In the case of saliva detection devices, it is fair to say that not all products are created equal. There is a range of cheap devices on the market, but these solutions bring additional risk. Lower priced options are far more likely to deliver false results — both positive and negative.

Recording false positives adds further burden to the process, as all non-negative results require additional confirmatory testing. This takes time, adds cost and can lead to unjustified suspension from duties for affected employees, which then attracts undue negative stigma.

False negatives are even more concerning, as they are never verified. While additional testing is required in the event of a positive (or non-negative) reading, a false negative goes unchallenged. The upshot is that staff may be open to unidentified risk. This therefore directly compromises the overall intent of the testing process — to provide an adequately safe working environment — and opens the business up to the costs associated with safety breaches or incidents that are completely avoidable.

Companies utilising inferior solutions are also susceptible to reputational risk. If results reliability is not constant, and it is possible for an individual to fail one test and pass on another under the same conditions, it threatens to jeopardise the integrity of the entire program and the company’s public image.

The Centre for Forensic Science Research & Education, based in the United States, conducted a laboratory-based evaluation of 10 saliva testing devices, including the Securetec DrugWipe Saliva Detection Device from Pathtech. The purpose of the study was to determine sensitivity, specificity and accuracy of each device; determine individual performance at different concentration levels; and compare positive result concentrations versus advertised cut-off concentrations.

The study tested for a range of substances, including: amphetamine/methamphetamine, cocaine, opiates, THC (cannabis) and benzodiazepines. The testing protocols used were developed based on the manufacturers’ instructions for each of the tested devices and each device was tested in triplicate for each of the controls, under a blind analysis. Results were interpreted and recorded independently by two individuals and the data analysis parameters used were: a) true positives and negatives; and b) false positives and negatives.

For the purposes of the exercise, positive results were recorded as true positives if the substance was detected, irrespective of concentration. For negative results, the concentration was compared to the manufacturer’s cut-off concentration then scored as a true or false negative.

Of the tested devices, only the DrugWipe recorded a zero result for both false positives and for false negatives. Additionally, it scored 100% for sensitivity, specificity and accuracy — no other device achieved this result.

It was recognised as having a ‘best overall performance’, outperforming rival products in the three key measurement criteria. The THC test strip on alternatives was also deemed to be problematic, which was not found to be the case with the DrugWipe device.

DrugWipe devices require only 10 microlitres of saliva for analysis, which is considerably less than some of the other available options. This means that sampling can easily be carried out in even the hottest environments, where it is often difficult for participants to produce enough saliva.

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