Racial differences in osteoarthritis pain and function: potential explanatory factors

Objective This study examined factors underlying racial differences in pain and function among patients with hip and/or knee osteoarthritis (OA) Methods Participants were n = 491 African Americans and Caucasians enrolled in a clinical trial of telephone-based OA self-management Arthritis Impact Measurement Scales-2 (AIMS2) pain and function subscales were obtained at baseline Potential explanatory variables included arthritis self-efficacy, AIMS2 affect subscale, problem- and emotion-focused pain coping, demographic characteristics, body mass index, self-reported health, joint(s) with OA, symptom duration, pain medication use, current exercise, and AIMS2 pain subscale (in models of function) Variables associated with both race and pain or function, and which reduced the association of race with pain or function by >= 10%, were included in final multivariable models. Results In simple linear regression models, African Americans had worse scores than Caucasians on AIMS2 pain (B = 0 65, P = 0 001) and function (B = 0.59, P < 0.001) subscales In multivariable models race was no longer associated with pain (B = 0 03, P = 0 874) or function (B = 0 07, P = 0 509), indicating these associations were accounted for by other covanates Variables associated with worse AIMS2 pain and function were worse AIMS2 affect scores, greater emotion-focused coping, lower arthritis self-efficacy, and fair or poor self-reported health AIMS2 pain scores were also significantly associated with AIMS2 function Conclusion Factors explaining racial differences in pain and function were largely psychological, including arthritis self-efficacy, affect, and use of emotion-focused coping Self-management and psychological interventions can influence these factors, and greater dissemination among African Americans may be a key step toward reducing racial disparities in pain and function Published by Elsevier Ltd on behalf of Osteoarthritis Research Society International