Urine Drug Testing (UDT)
Evidence for best practice in the monitoring of patients being prescribed opioids for CNCP is lacking. Current Canadian guidelines (2017) advise that the prescriber may use urine drug testing (UDT) as a risk mitigation strategy. In patients with active substance use disorder, these guidelines suggest UDT. CDC Guidelines (2016) however, suggest that the prescriber "should use [UDT]" in all patients being prescribed opioids for CNCP. Other tools to assess risk, such as patient self-assessment, is useful for history taking but it suffers from patient subjectivity as patients often withhold drug use information. UDT, however, is an objective test that is easy to perform in a clinical setting and gives powerful information about patient drug use. Helpful preliminary information can be quickly obtained in a point-of-care setting through inexpensive UDT immunoassays. Confirmatory testing with highly accurate mass spectrometry is available in most laboratories as well. UDT is especially useful for detecting unexpected drug use (drugs not prescribed), and if concerns are found then results can be acted on to improve safety. Patients prescribed opioids with a substance use disorder are at higher risk of opioid addiction, overdose and death. Information about substance use is therefore critical to assessing a patient's risk with opioid medications.
Although there is a lack of evidence surrounding the use of UDT in opioid risk mitigation, there are studies that suggest it can be an effective tool. The Marathon Family Health Team (MFHT) designed and implemented HARMS as a practical and easy-to-use approach for the prescribing and monitoring of opioids that is centered around the use of UDT. HARMS aims to assess the risk of a patient through systematic monitoring with UDT to adjust their risk. Based on the results of the UDT the patient's risk category is adjusted so that ongoing monitoring and prescribing can be tailored to that evolving level of risk. Preliminary research suggests that the HARMS Program works. Over a 12-month period, nearly 20% of patients initially stratified as low risk had direct changes to management based on results of UDT (escalation to higher risk stream or addiction program, or taper and discontinuation). Results have been presented at conferences across Canada and are currently being submitted for peer-reviewed publication. These results are promising and warrant further investigation (See Research and Awards section).