Application of Urine Drug Testing
The application of UDT can be challenging without a basic understanding of the pros and cons of the two different methods of UDT (IA and chromatography-mass spectrometry). Even with that understanding, there are numerous competing principles here: we want to reliably detect those that are high-risk (addicted, misusing, etc), without spending a lot of money or human resources, or unnecessarily inconveniencing patients or staff. Using "double-testing" (sending same urine sample for both IA and chromatography) is a helpful way to get more reliable results, but even then it is not always clear what the patient is using. What if a drug shows up on IA but not chromatography? Was it a false positive? Or was it out of the detection window for chromatography?
In order to make UDT practical, we need a way of dealing with all forms of results. You could think of it like a spectrum of concern - some results are very alarming, some are not alarming at all, and there's everything in between. If results are very concerning, and very reliable, then risks are great and we act accordingly (high risk stream, taper and d/c, offer addiction treatment, etc). If results are mildly concerning, then we may tighten our control and continue to observe with increased scrutiny. With addiction in particular, patients tend to declare themselves. If it's a very minor "infraction", like cancelling a UDT last minute with absolutely no other concerns, then we may do nothing or issue a warning.
The application of UDT often doesn't have black and white answers. UDT must be applied in the context of the individual patient. Remember that UDT is simply meant to give us a more objective assessment of this patient's risk! We use UDT to adjust how we prescribe/monitor the patient, and if risk>>benefit then we stop prescribing and/or offer alternatives treatments. To get a sense of how we can apply results of UDT, take a look at the Learning Module section. There are numerous real cases on there illustrating how we apply the results of UDT to individual patients.