Clinical pain, pain catastrophizing, and sleep quality in Ethnic/Race Groups with or at risk for Knee Osteoarthritis: A moderated mediation model

Abstract

Cognitive and behavioral factors are known to contribute to painful knee osteoarthritis (OA), including poor sleep quality and pain catastrophizing. The overall aim of this study was to further elucidate the relationships among knee pain, pain catastrophizing, and sleep quality in non-Hispanic Black (NHB) and non-Hispanic White (NHW) adults with/at risk for knee OA. Our overall hypothesis is that pain catastrophizing disrupts sleep, which subsequently exacerbates knee pain severity. We also hypothesized that these associations would differ by ethnic/race group. We conducted a cross-sectional study of adults with/at risk for knee OA using community and clinic-based recruitment from two study sites both in the Southeastern United States. All participants (N = 171) provided sociodemographic data before completing the following validated measures: Western Ontario and McMaster Universities Osteoarthritis Index, Insomnia Severity Index, Coping Strategies Questionnaire (for pain catastrophizing), and PROMIS Depression items. Mean age was 58 years; 52% were NHB and 48% NWH. Controlling for age, BMI, education, gender, and depression, results revealed that ethnic/race group significantly moderated the association between pain catastrophizing and sleep quality (p = .025). Greater pain catastrophizing was associated with poorer sleep quality for NHW (p = .003), but not NHB (p = .684) participants. Accordingly, sleep quality was found to significantly mediate the association between pain catastrophizing and knee pain severity for NHW (confidence interval .0705 to .5988), but not NHB (confidence interval -.1526 to .2113). Findings suggest that pain catastrophizing promotes poor sleep, and poor sleep, in turn, promotes knee pain severity in NHW with/at risk for knee OA. Interestingly, pain catastrophizing may have a greater impact on the sleep quality of NHW compared to NHB peers. Future studies should evaluate protective factors in NHB populations that may explain the reduced impact of pain catastrophizing on sleep quality. R37AG033906-11.