Ethnic differences in pain tolerance: Clinical implications in a chronic pain population

Objective: Although numerous studies have independently examined ethnic dif ferences in clinical and experimental pain, few have investigated differenc es in both sensitivity to controlled noxious stimuli and clinical pain repo rts in the same sample. The present experiment examined the effects of ethn icity (African American vs. white) on experimental pain tolerance and adjus tment to chronic pain. Methods: Three hundred thirty-seven (68 African Amer ican and 269 white) patients with chronic pain referred to a multidisciplin ary treatment center participated in the study. In addition to completing a number of standardized questionnaires assessing adjustment to chronic pain , participants underwent a submaximal effort tourniquet procedure. This exp erimental pain procedure yields a measure of tolerance for a controlled nox ious stimulus tie, arm ischemia). Results: African American subjects report ed higher levels of clinical pain as well as greater pain-related disabilit y than white participants. In addition, substantial group differences were observed for ischemic pain tolerance, with African Americans demonstrating less tolerance than whites. Correlational analyses revealed a small but sig nificant inverse relationship between ischemic pain tolerance and the repor ted severity of chronic pain. Conclusions: Collectively these findings supp ort previous research revealing ethnic differences in responses to both cli nical and experimental pain. Moreover, the present results suggest that enh anced sensitivity to noxious stimuli on the part of African Americans may b e associated with ethnic differences in reported clinical pain, although th e magnitude of ethnic differences was much greater for ischemic pain tolera nce than for clinical pain measures.