A new study finds racial differences in opioid prescribing, monitoring and follow-up treatment practices. Black patients are less likely than white patients to have their pain levels documented, and to be referred to a pain specialist. They are more likely to be referred for substance abuse assessment after being prescribed opioids, MedicalXpress reports.

Among patients given at least one urine drug test, black patients were given more tests, especially if they were on higher opioid doses, the study found.

The study included data from 1,646 white and 253 black patients who filled opioid prescriptions for noncancer pain for more than 90 days. Black and white patients were equally likely to have a history of substance abuse, the article notes.

The findings appear in the journal Pain.

“The emerging picture is that black patients who are able to overcome the barriers to securing a prescription for opioid medications may still be subjected to differential monitoring and follow-up treatment practices that could impact the effectiveness of their pain management,” researcher Leslie R.M. Dr. Hausmann, PhD, of the VA Pittsbrugh Healthcare System, said in a news release.