Whites and African-American pain thresholds most likely the same

A new study that measures pain sensitivities among Whites and African-Americans suggests assessment procedures may be to blame for reported racial differences in the amount of pain experienced.

Previous research and anecdotal clinical evidence have suggested that African-Americans tend to be more sensitive to pain than Whites, but the latest research study shows the two groups simply interpret standard pain rating scales differently. The new study also confirms earlier findings that women are more sensitive to pain than men.

University of Calgary psychologist Dr. Tavis Campbell led the research project while at Duke University Medical Center in Durham, North Carolina. The results are being published in the April issue of the medical journal, The Journal of Pain.

“Many pain medications are addictive and have unpleasant side effects, so it’s important for physicians to be able to understand exactly how much pain their patients are experiencing,” Campbell says. “This research supports well-established findings of slightly higher sensitivity to pain among women compared to men, but revealed no differences between Whites and African-Americans.”

Campbell and his research colleagues tested 135 men and women aged 25-45, a group that included 72 African-Americans and 59 women. Researchers inflated a blood pressure cuff on each subject’s arm and left it inflated for several minutes, creating an aching sensation not unlike many clinical pains. The participants were then asked to rate their pain according to standard pain rating scales, which measure both the unpleasantness and intensity of the sensation.

Pain rating scales use terms ranging from ‘neutral’ to ‘very intolerable’ for the unpleasantness of the sensation, and words ranging from ‘nothing’ to ‘extremely intense’ for its intensity. There are 11 gradations in between. (See Backgrounder at www.ucalgary.ca/news/march04/pain-background.html)

“If we used the standard pain scales, women reported more pain than men, and African-Americans reported more pain than Whites,” Campbell says. “But if we first gave them some cards with the descriptors on them and said, ‘You arrange these in any way that you want, from the least painful to the most painful,’ then women became more similar in their pain reports to men, but there was no difference between African-Americans and Whites.”

Socio-cultural variables, such as differences in vernacular, may be worth investigating further, Campbell suggests. “One possible explanation is that African-Americans and Whites just describe painful sensations differently.”