Ethnic and sex differences in response to clinical and induced pain in chronic spinal pain patients.

There is widely held clinical opinion and some tentative research justification for stereotypic or ethnic and sex differences in response to pain. To more adequately test this notion, 60 chronic spinal pain patients (black, Mexican American, and Caucasian, with ten men and ten women per group), all having persistent spinal pain for over 1 year, were studied. They were administered the ischemic pain test, a numerical estimate of spinal pain, and two independent raters scaled the amount of pain emphasis, based upon the patient's physical condition and pain behaviors. Results showed ethnic differences on the ischemic test (a psychophysiologic scaling technique used to approximate clinical pain and pain tolerance) with Mexican Americans describing the highest levels. Women of all ethnic groups tended to be judged as emphasizing their pain more than men, based upon judgment of their pain behaviors, and upon their own numerical estimates of pain. They also indicated that they more nearly approached their pain tolerance. It was concluded that while ethnic and sex differences were found, stereotypic responses were not uniform, and tended to be related to the manner in which that pain was assessed. These results are discussed in light of cultural differences.