Profiles of Urine Drug Test in Clinical Pain Patients vs Pain Research Study Subjects.

Objective: To examine similarities and differences in urine drug test (UDT) results in clinical pain patients and pain subjects participating in pain research studies.

Design: An observational study with retrospective chart review and data analysis.

Methods: We analyzed 1,874 UDT results obtained from 1) clinical pain patients (Clinical Group; n = 1,529) and 2) pain subjects consented to participate in pain research studies (Research Group; n = 345). Since several medications such as opioids used in pain management are drugs of abuse (DOA) and can result in a positive UDT, we specifically identified those cases of positive UDT due to nonprescribed DOA and designated these cases as positive UDT with DOA (PUD).

Results: We found that 1) there was a higher rate of PUD in clinical pain patients (41.3%) than in pain research study subjects (14.8%); 2) although subjects in the Research Group were informed ahead of time that UDT will be conducted as a screening test, a substantial number (14.8%) of pain research study subjects still showed PUD; 3) there were different types of DOA between clinical pain patients (cannabinoids as the top DOA) and research study subjects (cocaine as the top DOA); and 4) a common factor associated with PUD was opioid therapy in both Clinical Group and Research Group.

Conclusion: These results support previous findings that PUD is a common finding in clinical pain patients, particularly in those prescribed opioid therapy, and we suggest that UDT be used as routine screening testing in pain research studies.