At the Intersection of Ethnicity/Race and Poverty: Knee Pain and Physical Function
Knee osteoarthritis (OA) disproportionately affects racial and ethnic minorities. Non-Hispanic Blacks (NHB) report a higher prevalence and severity of knee OA symptoms than their non-Hispanic White (NHW) counterparts. The role of poverty in explaining this disparity remains unclear.
The overall aim of this cross-sectional study was to determine whether ethnic/racial differences in knee pain and physical function varied according to poverty status.
NHB and NHW adults with or at risk of knee OA self-reported sociodemographic information, and completed the Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) and the Short Physical Performance Battery (SPPB). Annual income was adjusted for number of household occupants to determine poverty status (i.e., living above versus below poverty line).
Findings revealed 120 individuals living above the poverty line (49% NHB, 77% NHW) and 71 individuals living below the poverty line (51% NHB, 23% NHW). Adjusted multivariable models revealed significant ethnic/race by poverty status interactions for knee pain (p = 0.036) and physical function (p = 0.032) on the WOMAC, as well as physical function on the SPPB (p = 0.042). Post hoc contrasts generally revealed that NHW adults living above the poverty line experienced the least severe knee pain and best physical function, while NHB adults living below the poverty line experienced the most severe knee pain and poorest physical function.
Results of the present study add to the literature by emphasizing the importance of considering poverty and/or other indicators of socioeconomic status in studies examining ethnic/racial disparities in pain and physical function.
KeywordsEthnicity/race Poverty Knee pain Physical function Osteoarthritis
Financial support was provided by NIH/NIA Grants R37AG033906-14 (R.B.F) and R01AG054370 (K.T.S); UF CTSA Grant UL1TR001427 and UAB CTSA Grant UL1TR001417 from the NIH Center for Advancing Translational Sciences; NIH Training Grants TL1TR001418 provided to the University of Alabama at Birmingham (K.A.T.); University of Florida McKnight Brain Institute Career Enhancement Award and NIH/NINDS Grant K22NS102334 (E.L.T.), and NIH/NIA Grant R00AG052642 (E.J.B).
Compliance with Ethical Standards
All procedures were reviewed and approved by the Institutional Review Boards at the University of Florida and University of Alabama at Birmingham.
Conflict of Interest
The authors declare that they have no conflict of interest.
All procedures performed in this study with human participants were in accordance with the ethical standards of the University of Florida and the University of Alabama at Birmingham, and with the 1964 Helsinki declaration and its later amendments.
Informed consent was obtained from all individual participants included in the study.
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