Methodology of Urine Drug Testing at CLS

Point of Care Testing Cups (Insta-Cups)

CLS offers medical offices with point of care testing cups if desired. These cups are very simple to use and easy to read for medical staff. A patient simply provides a urine sample, and within a short amount of time a simple positive or negative result is provided on the cup.

While providing a yes or no, these devices are known to be less than accurate. All cups of these type must be approved by the FDA for use, but the FDA only requires an average accuracy of 80% on these tests to be certified. This means that practices could receive inaccurate results up to 20% of the time. While the real number of inaccurate results via insta-cups that we have observed is closer to 10%, that is still a fairly large number. Further instant cups are unable to determine whether or not a sample has been diluted or adulterated in any way.

For these reasons CLS recommends to submit the sample to our lab for a more rigorous and accurate screening and confirmation process. Learn more below!

Screening Infrared Spectroscopy Analyzer

At CLS we also offer an option to have a qualitative drug screen performed via our Infrared Spectroscopy Analyzer. This device utilizes an immunoassay method to determine whether certain drug classes, and some individual drugs are present in the patients urine. This results gives out a positive and negative indication, with a rough approximation of the level present in the urine. It further tests urine creatinine which is useful for determining whether the collected sample has been diluted or altered in any way.

While this testing method is very useful, the limitations that it has also should be considered. The cutoff levels for this machine are higher than more precise methods, possibly resulting in false negatives. There are also known cross-reactivities that exist between drugs when tested in this manner that could result in inaccurate test results.

CLS suggests having patient samples confirmed via LC-MS/MS testing for the most accurate test results.

Confirmation Testing with LC-MS/MS Technology

Confirmation testing, which utilizes a state of the art technology called liquid chromatography tandem mass spectrometry (LC-MS/MS), is considered the golden standard of drug testing for its increased accuracy and sensitivity. This test provides quantitative test results to provide you with a more accurate concentration level, and increased detection ability. LC-MS/MS allows for the detection of individual drugs and their corresponding metabolites. Contrary to screening devices, the cutoff levels with this type of method are significantly lower yielding more accurate results. All test results are individually reviewed and released by our trained toxicology team.

Using confirmation testing (quantitative) in combination with immunoassay screening (qualitative), or on its own provides the information health care professionals need to develop and maintain patient treatment plans and medication monitoring services.