The paper, written by a panel of top pain experts and based on a survey of more than 180 pain-related studies from a broad range of specialties, documents a phenomenon that pain specialists have long suspected but don't fully understand.
The authors pull together research on racial and ethnic disparities in the perception, diagnosis and treatment of pain in locations ranging from the emergency department to the cancer clinic, and in conditions ranging from chronic pain to acute pain induced in laboratory experiments.
Researchers and pain specialists who are also members of the American Pain Society publish their findings in the current issue of the journal Pain Medicine.
"Across the board, and consistently, there are racial and ethnic differences in pain," says lead author Carmen R. Green, M.D., an anesthesiologist and pain management specialist at the University of Michigan Health System. "There's much we still don't understand about why these health disparities based upon race and ethnicity exist, so more research is needed. We hope our work will increase awareness of this issue among patients and providers alike." Green chairs the APS Special Interest Group on racial and ethnic disparities in pain.
The new paper echoes the recently published findings from the Institute of Medicine's panel on health disparities, which collected evidence of racial and ethnic differences in many areas of medical and surgical care.
The IOM panel's report included some perspective on differences in emergency and cancer pain treatment. But the new paper goes further by including data from more fields, including chronic pain and disability, and considering pain medication access issues. It also offers recommendations for future research.
For instance, co-author Knox Todd, M.D., MPH, of the Rollins School of Public Health at Emory University, presents results from emergency medicine studies that showed Hispanics with broken bones in their arms or legs were twice as likely as non-Hispanic whites to go without pain medication in their emergency department visits, even after differences in language, gender and insurance status were taken into account.
Another co-author, Karen O. Anderson, Ph.D., of the M.D. Anderson Cancer Center, cited studies in cancer pain. One study showed that Hispanics and African Americans with cancer were less likely to be assessed for pain, and did not receive the level of pain medications recommended by the World Health Organization. Another study showed that African American cancer patients in nursing homes had a 64 percent greater chance of receiving no pain treatment than did non-Hispanic whites.
The report also draws on Green's own work in the area of chronic pain, including her recently published findings that, regardless of their age, African-Americans with chronic non-cancer pain from any source suffered more psychological and physical effects than non-Hispanic whites with chronic non-cancer pain.
In addition to these clinical pain studies, the authors describe the racial and ethnic differences in pain sensitivity and pain response that have been found in numerous experiments. For instance, scientists using pressure, heat or cold to induce pain have found that African-Americans and Hispanics tend to have lower thresholds of pain tolerance. Other studies have found that pain-study participants from Nepal and India had higher pain tolerances than Western counterparts.
Taken together, these findings suggest that something in the brain's pain-processing and pain-killing systems may vary by race and ethnicity. But more studies are needed to know for sure, writes co-author Roger Fillingim, Ph.D., of the University of Florida College of Dentistry.
Green and her colleagues also focus on research that has examined how communication between patients and health care providers, and the social context of their interaction, can influence pain diagnosis and treatment.
They also cite numerous studies showing that African-Americans and members of other racial and ethnic minorities are consistently under-treated for pain across a range of conditions, from cancer and chest pain to post-surgical and chronic lower-back pain.
Access to pain care and pain medications can also vary by race and ethnicity, the authors find. They note findings that pharmacies in neighborhoods with large minority populations tend not to carry narcotic pain medicines such as morphine.
"Physician prescribing patterns, as well as patients' own attitudes and beliefs regarding pain, and socioeconomic factors, may all contribute to racial and ethnic differences in pain management," writes co-author Raymond Tait, Ph.D., of the St. Louis University School of Medicine. "But all of these issues related to health care delivery are yet to be adequately explored."
In fact, says Green, the review of the literature on race, ethnicity and pain only showed the authors how much more there is to find out on this topic.
For instance, much more research is needed on how cultural beliefs, as well as patient-level decision making and preferences, influence the pain-related behavior of patients from racial and ethnic minorities. Further studies should be done, the authors say, to correlate experimental findings on pain perception and tolerance with clinical pain, especially where there are differences between racial and ethnic groups.
Even the tools that doctors and nurses use to ask patients how severe their pain is need to be examined for cultural and linguistic sensitivity. Better data on disparities in various health care settings, and in different insurance and legal contexts, should be gathered. And more studies are needed to understand how stereotypes and other sources of bias can color the interaction between health care providers and patients, and what strategies might counteract these effects.
"Clearly, local, state, federal and private sector initiatives, in combination with advocacy and scientific organizations, are necessary to understand racial and ethnic disparities in pain if we are to improve the quality of pain care for all," says Green. "In the meantime, it's important for patients from all backgrounds to speak up about their pain to their health providers, and insist on getting the effective treatments that now exist, and referrals to pain specialists. Don't assume that pain has to be a part of your life."
Besides Anderson, Green, Fillingim, Tait and Todd, the paper's authors are: Tamara Baker, Ph.D., of the U-M School of Public Health; Lisa C. Campbell, Ph.D., of the Duke University Medical Center; Sheila Decker, Ph.D., of the University of Iowa School of Nursing; Donna A. Kaloukalani, M.D., MPH, of Washington University; Kathryn Lasch, Ph.D., of the New England Medical Center; Cynthia Myers, Ph.D., of University of California, Los Angeles; and April Vallerand, Ph.D., RN, of the Wayne State University College of Nursing.
Reference: Pain Medicine, Vol. 4, No. 3, Sept. 2003, p. 277-294.
Available online at http://www.blackwell-synergy.com/links/doi/10.1046/j.1526-4637.2003.03034.x/full/.
Journal
Pain Medicine