A new study has found that while emergency room prescribing of opioid pain medications for ER patients complaining of pain has increased in recent years, doctors are less likely to prescribe them for minority patients than white ones. Even in cases where patients complain of severe pain, such as kidney stones, the difference holds.

The study, "Trends in Opioid Prescribing by Race/Ethnicity for Patients Seeking Care in US Emergency Departments," was published this week in the Journal of the American Medical Association. It analyzed more than 150,000 ER visits between 1993 and 2005 and found racial differences in prescribing in all US regions, in both urban and rural hospitals, and for all types of pain.

The study found that the prescribing of drugs for pain in the ER rose during the period in question, from 23% of those complaining of pain in 1993 to 37% in 2005. That increase reflects increased understanding of the necessity of pain management by physicians. Now, doctors in accredited hospitals must ask patients about pain, just as they monitor vital signs. But while prescribing is on the increase, the racial divide remains.

According to the study, 31% of white patients in pain were prescribed opioids, compared to 28% of Asians, 24% of Hispanics, and 23% of blacks. When it comes to the severe pain related to kidney stones, whites got opioids 72% of the time, compared to 68% for Hispanics, 67% for Asians, and only 56% for blacks.

"The gaps between whites and nonwhites have not appeared to close at all," said study coauthor Dr. Mark Pletcher of the University of California, San Francisco.

Researchers are looking for reasons for the discrepancy. Pletcher suggested to the Associated Press that minority patients "may be less likely to keep complaining about their pain or feel they deserve good pain control."

Linda Simoni-Wastila of the University of Maryland, Baltimore, School of Pharmacy told the AP the findings could reveal some doctors' suspicions that minority patients could be drug abusers lying about pain to get narcotics. She said that according to her own research, blacks are the least likely group to abuse prescription drugs.

The study's authors suggested that the finding could indicate either that doctors are less likely to see signs of pain reliever abuse in white patients or that they are underrating pain in minority patients. Whatever the reason, it seems that the racial injustice associated with drug prohibition reaches even into the emergency room.

"It's time to move past describing disparities and work on narrowing them," Dr. Thomas Fisher, an emergency room doctor at the University of Chicago Medical Center who was not involved in the study, told the AP. Fisher, who is black, said that even he needed to be careful not to let subconscious assumptions inappropriately influence his prescribing decisions. "If anybody argues they have no social biases that sway clinical practice, they have not been thoughtful about the issue or they're not being honest with themselves," he said.