Evaluation of a Point of Care Urine Drug Test System for Application in Outpatient Pain Management Clinics

Abstract Introduction/Objective Most states require testing for illicit and controlled substances in ambulatory, non-terminal pain management populations to ensure prescription compliance. Point of care (POC) urine drug testing (UDT) is a widely adopted testing method that assists with clinical decision making within minutes. However, these immunoassays may lack the sensitivity and specificity needed for potent medications such as fentanyl. This study compares the performance characteristics of a POC UDT to an in-house, high throughput, automated chemistry analyzer and the reference method, gas chromatography-mass spectrometry (GC-MS). Providers should be aware of the limitations of each methodology given the rise of synthetic opioid misuse, and the need to quantify multiple substances and metabolites within the same drug class. Methods/Case Report 100 residual deidentified patient urine samples from an ambulatory pain management population were analyzed using GC-MS, Profile®-V MEDTOX Scan® POCT device (Burlington, NC), and a Beckman Coulter AU480® Chemistry Analyzer using EMIT® II Plus reagents (Beckman Coulter; Brea, CA). Drug classes on the Profile®-V included: amphetamines, barbiturates, benzodiazepines, buprenorphine, cocaine metabolite, methamphetamine, methadone, opiates, oxycodone, cannabinoids and phencyclidine. Drug classes on the AU480® included the same except without a methamphetamine-specific immunoassay. Results (if a Case Study enter NA) The results from GC-MS showed that 99% (99/100) of the samples were positive for one or more of the drug classes. Overall, the AU480® was 90% sensitive and 98% specific while the MEDTOX Scan® was 87% sensitive and 98% specific. Both devices exhibited variable performance across drug classes. Neither the AU480® nor the MEDTOX Scan® detected fentanyl in five specimens. Conclusion POCT-UDS systems like the Profile®-V MEDTOX Scan® can provide good accuracy and may offer a time and cost benefit when compared to higher throughput analyzers like the AU-480®. Due to the low reference values of immunoassays, definitive testing such as GC-MS is recommended for use in the pain management population.