Describing prescription opioid adherence among individuals with chronic pain using urine drug testing.

Adherence monitoring for prescription opioid use is a clinical imperative for individuals prescribed opioids for chronic pain. Urine drug testing (UDT) provides objective evidence for prescription opioid adherence, as recommended by national guidelines to be part of adherence monitoring. The aim of this study was to describe prescription opioid adherence using UDT results in chronic pain patients and to examine the association between demographic characteristics and adherence to their prescribed opiate regimens. We used a retrospective chart review of 120 consecutive patients at an urban pain management clinic. Data collected included UDT results, pain level, and demographic characteristics. Descriptive and correlational statistics were used for data analysis. About 54% of the individuals appeared nonadherent to their prescribed opiate regimen as defined by absence or inappropriate level of prescribed controlled medication, presence of additional nonprescribed controlled substance(s), presence of illicit substance(s), or presence of adulterant in the urine sample. Of the participants, 23% had absence of one or more of their prescribed controlled medications and 12.5% had presence of one or more other opioids. Marijuana was the main illicit substance used (24.2%), followed by cocaine (11.7%). Patients' age, pain level, sex, ethnicity, and injury compensation were not associated with UDT results. UDT results could be useful to educate and guide patients on the proper use of controlled medications. Results from UDT are highly contextual and easily misinterpreted, requiring comparison with a variety of clinical indicators over time before deciding if there is adherence to a prescribed opiate regimen for individuals with chronic pain.