Provider Misinterpretation, Documentation, and Follow-Up of Definitive Urine Drug Testing Results

Urine drug testing (UDT) is an essential tool to monitor opioid misuse among patients on chronic opioid therapy. Inaccurate interpretation of UDT can have deleterious consequences. Providers' ability to accurately interpret and document UDT, particularly definitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) results, has not been widely studied.

To examine whether providers correctly interpret, document, and communicate LC-MS/MS UDT results.

This is a retrospective chart review of 160 UDT results (80 aberrant; 80 non-aberrant) between August 2017 and February 2018 from 5 ambulatory clinics (3 primary care, 1 oncology, 1 pain management). Aberrant results were classified into one or more of the following categories: illicit drug use, simulated compliance, not taking prescribed medication, and taking a medication not prescribed. Accurate result interpretation was defined as concordance between the provider's documented interpretation and an expert laboratory toxicologist's interpretation. Outcome measures were concordance between provider and laboratory interpretation of UDT results, documentation of UDT results, results acknowledgement in the electronic health record, communication of results to the patient, and rate of prescription refills.

Aberrant results were most frequently due to illicit drug use. Overall, only 88 of the 160 (55%) had any documented provider interpretations of which 25/88 (28%) were discordant with the laboratory toxicologist's interpretation. Thirty-six of the 160 (23%) documented communication of the results to the patient. Communicating results was more likely to be documented if the results were aberrant compared with non-aberrant (33/80 [41%] vs. 3/80 [4%], p < 0.001). In all cases where provider interpretations were discordant with the laboratory interpretation, prescriptions were refilled.

Erroneous provider interpretation of UDT results, infrequent documentation of interpretation, lack of communication of results to patients, and prescription refills despite inaccurate interpretations are common. Expert assistance with urine toxicology interpretations may be needed to improve provider accuracy when interpreting toxicology results.