Workplace Drug Testing | Employee Drug Testing

workplace drug testing explained

Workplace drug and alcohol testing can be confusing and it is extremely challenging to get past the first stage without expert help. If you find yourself in this predicament, you're in good company! Organisations both large and small approach us on a regular basis seeking to find a solution to this issue; often finding the range of different perspectives, sometimes incorrect advice previously received, testing methods and conflicting information can stifle efforts to address this important issue. The following are a short list of questions that we are frequently asked to address.

Is on-site workplace drug & alcohol testing accurate?
Workplace drug & alcohol screening limitations?
What about consequences from a drug or alcohol test?
Do we need a drug and alcohol policy?
How do we introduce a drug and alcohol policy?

is on-site workplace drug & alcohol testing accurate?

On-site drug testing in the workplace can be performed with a high degree of accuracy and has become an accepted method of screening samples quickly, prior to sending any samples returning abnormal results to an approved laboratory for "confirmation testing".

However it is important to note that the testing devices used should be considered screening kits only. This means that samples that present a non-negative drug screening result should be referred to an approved laboratory for confirmation testing. A valid type of secondary testing should also be conducted for abnormal alcohol readings, however in workplace environments, abnormal alcohol testing normally involves repeating the test on a properly calibrated high quality fuel cell based alcohol testing unit.

On-site drug testing kits are immunoassays using the same principles as found in screening tests in laboratories. Occasionally it is possible for any immunoassay whether on-site or in a laboratory to cross-react with another substance (including other pharmaceutical drugs) that are very closely related to the structure of the "target substance" (producing a false positive), or to detect a drug that is very close to the cut-off level as a "positive" result when in fact it is actually slightly under the cut-off level. The latter circumstance is a “false positive” in name only as there was drug present however it didn’t reach the confirmatory cut-off.

It is also possible that on-site kits can produce a non-negative result on-site, however the initial screening immunoassay test in the laboratory can return a negative result. However this rarely occurs and normally only when the level of drug in the sample is very close to the cut-off level used to evaluate the sample (which is not common at all).

For the vast majority of samples - in over 98% of samples that are tested this does not occur simply due to the fact that the levels are dramatically higher or lower than the benchmark cut-off levels. Perhaps what is more relevant is the fact that should the on-site test produce a non-negative result the probability of drug being present irrespective of reaching the cut-off level during the confirmatory process is extremely high.

workplace drug & alcohol screening limitations

Cross-Reactivity (false positive results) - It is widely acknowledged that the antibodies used in immunoassays (common initial screening tests) cannot recognise subtle differences in chemical structure between the targeted drugs and their metabolites and other analogous compounds. Accordingly, it is possible for various pharmaceuticals to produce false-positive results (where the result is later found to produce a "negative" result in the laboratory). This phenomenon is not encountered frequently, however it should be understood that certain pharmaceuticals and other non-pharmaceuticals (like poppy seeds) could potentially produce errant results in an initial screening test. The latter is perhaps more likely in Australia, where the morphine (opiate) cut-off level in urine testing (currently 300 ng/mL) is quite low in comparison to the United States (currently 2000 ng/mL) at the time of this publication. Often initial screening test kits are slightly more sensitive than the target cut-off levels (leading to a greater chance of a false positive result than a false negative result - sell below).

Another source of potential false positive results could be the environment. A good example of this was found in a study of children living in families where crack cocaine was tested, where 85% of the children returned positive hair drug testing results for cocaine (Smith & Kidwell, 1996).

Pharmaceuticals - It is also possible that pharmaceuticals can produce concentrations in a screening test (and indeed in the laboratory) where the levels can be high enough to be interpreted as confirmed positive results, even from prescribed use. This category of results, we refer to as "Consistent with Declared Medications" (or "CWDM"). Any company policy must be prepared for the possibility of these results, which they might treat as surrogate negative results (no ramifications), after laboratory confirmation testing. Normal risk analysis investigations could comprise an evaluation of the person's relative risk with respect to the work undertaken. We have also experienced situations where individuals might be prescribed alternative medications with less potential risk of harm or injury than a medication that was previously prescribed. Naturally, this may be a favourable outcome, which otherwise might not have been identified.

False Negatives - Various testing devices are subject to inherent limitations in terms of sensitivity (failing to detect that the drug class exceeds a specific level). This is more likely to be caused by the limitations of a specific technology, noting that some drug types are present in extremely low levels in certain matrices and the detection can accordingly be extremely difficult. False positives and false negatives that arise due to sensitivity issues tend to be more problematic when the drug that is present is at a concentration that is very close to the cut-off level. At levels outside of this equivocal area, the sensitivity (in terms of the likelihood of false positive and false negative results) improve considerably.

Confirmation Testing and Proficiency Testing - due to the complications arising from the above issues, it is extremely important that non-negative results found in initial screening are referred to a properly accredited laboratory for confirmation testing. The analysis of samples in those laboratories incorporates highly sensitive Gas/ Liquid Chromatography which is considerably more sensitive and specific than screening devices (and of course produces quantitative results), which can then be compared to confirmatory cut-off tables as the final determinant in positive vs negative results. Proficiency testing programs are designed to increase the likelihood that Collection Agencies produce true negative and true positive results.

References:
Smith, F.P & Kidwell, D.A (1996). "Cocaine in hair, saliva, skin swabs and urine of cocaine users' children. Forensic Science International, 83, 179-189.

what about consequences from a drug or alcohol test?

We believe that the only way to modify behaviour is to have some sort of penalty (or consequence) for those people who choose not to comply with a testing program following an education program.

The Australian drink driving situation is probably a model example of this idea.

Why?

We all know that if we drive on the roads after drinking - there is a very real chance that we could;

lose our licence
lose our job
kill someone else and/ or
kill ourselves.

This is a combination of consequences if we are caught and education by government (through various TV, radio and billboard advertising media) teaching us the dangers that we face if we drink and drive. These two aspects combined; consequences and education have altered our behaviour and have subsequently made our roads a safer place for our families.

This same philosophy needs to be introduced in a drug & alcohol program in our workplaces. There needs to be a consequence for breaching the policy (to encourage a change in behaviour) and education (to inform us and our work mates about the dangers of drugs and alcohol in the workplace and to teach us ways in which we can change our behaviour). Using just one of these approaches on their own would most likely have negligible impact; in the same way that if there were no consequences for drink driving - just simply education about the dangers - we would probably still be hearing about drink driving fatalities on a regular basis just like we did many years ago.

So how does this translate in our experience?

Our normal starting point in most drug and alcohol testing programs is that we expect to find between 10% and 15% of positive results at the commencement of a program. In some instances this can be higher and in very rare cases it can be lower. Organisations who think that they have "no problem" are often mortified when they realise the extent of recent drug & alcohol use by their workforce.

After commencing a testing and educational program we expect to reduce this positive rate to 2-3%. Many of our clients now even achieve 0% positive rate or very close to 0% (sometimes in cases when they commenced with an initial benchmark as high as 20%). This indicates the effectiveness of a program and direct feedback to our staff normally includes comments that they "feel safer", "wish it had been introduced years ago", "feel healthier", "have saved their marriage", "now have more money for their family". Additionally, some people have modified their consumption; they might still consume the drugs and/or alcohol, however they do so in a way that has little chance of presenting positive test results - and of course this improves the safety conditions for their work-mates and themselves. Modified consumption like this still achieves the ultimate objective of improving the safety of the workplace.

do we need a drug & alcohol policy?

A policy is an extremely important aspect of any workplace Drug and Alcohol Program. This is because the policy

explains the testing process to all staff
demonstrates the companies commitment to workplace safety, in particular dealing with drugs and alcohol
explains how various situations should be dealt with such as refusal to test, dealing with medications and first, second and third instances of discovering a positive result.
may be relied upon by Courts or Industrial Commissions

how do we introduce a drug & alcohol policy?

Policy introduction is almost as important as the policy itself. Often companies benefit from having close interaction with staff throughout the policy development process.

This normally greatly assists program acceptance and improves the "ownership" of the policy.

Some of the tools that can be utilised to facilitate a smooth implementation program includes: