CANSFORD LABS

Hair drug testing: When is a positive test result actually a positive?

May 25, 2016

IHair drug testing resultst can be extremely disheartening for a donor to lose access to their child because their hair drug test shows the presence of drugs. It can be even worse when this happens and yet the donor hasn’t actually taken any drugs. In fact, not all positive test results indicate drug use. 

When a donor is asked to take a hair drug and alcohol test, apprehension often sets it. Sometimes, it’s not because they have actively taken drugs, but it’s because they haven’t taken drugs. The fear that sets in is often because the donor may have been around individuals who have been using drugs but the donor’s exposure to this environment may show the presence of drugs in their own system. 

However, laboratory hair drug testing is able to take this account. Drug testing labs are able to differentiate between situations where donors have actively been using drugs and situations where they have been exposed to drugs from the environment. 

Here’s how lab’s use cut-offs to assess active drug use and why disclosing the use of prescription medication can make all the difference in Family Court.

Analytical cut-offs and user cut-offs 

Once the lab has completed their analysis of the hair sample, they’ll produce a report detailing everything they have found and in what quantities. Yet, two samples from the same individual analysed by two different laboratories may have different results, with outcomes that can be very different, one may be negative and the other positive. This is often because of the use of cut-offs

A cut-off is a value which the results in the hair drug test are compared against. If levels of a drug or multiple drugs rise above the cut-off, the result is considered as ‘positive’. If however the results fall below the cut-off, then the results are considered as ‘negative’. 

Cut-offs usually come in two forms, an analytical cut-off and a user cut-off. The analytical cut-off indicates that the level of a drug detected is of a significant quantity for that particular drug, and therefore can be detected reliably by the analytical methods.

The second type of cut-off is the user cut-off, which indicates whether an individual has drugs in their system within the period of time covered by the samples or due to some form of contamination. For example, external contamination may occur where a person may be in a room with a group of other individuals who have been smoking marijuana, but haven’t necessarily smoked any marijuana themselves. Following analysis of a hair strand sample, the user cut-off would indicate that this is probably the case. 

Cut-offs are important as they protect individuals from ‘false positives’, cases where they are assumed to have been using drugs, but haven’t actively used any substances. Hence, the user cut-off is able to tell you when a positive test result is actually indicative of drug use or contamination from your environment. 

Ultimately, user cut-offs can help Family Courts come to the an accurate and correct decision.

The effect of medication

A positive result may also occur where a donor is taking medication. Not all donors may be using drugs for recreational reasons. It may be the case that the user is currently taking prescription medication such as codeine, which will show up in a hair strand drug test.

The important thing to note here is that donors should disclose the use of any type of medication they are taking at the time of testing. If a donor fails to disclose any of this information, this can skew the interpretation of the results as there is no legitimate reason presented as to why these drugs are in the donor’s system. 

The lab responsible for testing should present all the results as they find them, and it’s then up to the Family Court to make a decision based on the findings. 

Ultimately, not all positive test results indicate actual drug use. It could be that the donor has been in an environment where other individuals have been using drugs, or the donor themselves may be taking prescription medication. In either case, it’s important to disclose all the facts, both those in the lab report and the supporting context surrounding those results, to the court to ensure they can come to the right decision.

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