Disparities in Total Hip Arthroplasty Outcomes: Census Tract Data Show Interactions Between Race and Community Deprivation.

Abstract

Socioeconomic factors such as poverty may mediate racial disparities in health outcomes after total hip arthroplasty (THA) and confound analyses of differences between blacks and whites. Using a large institutional THA registry, we built models incorporating individual and census tract data and analyzed interactions between race and percent of population with Medicaid coverage and its association with 2-year patient-reported outcomes. Black patients undergoing THA had worse baseline and 2-year pain and function scores compared with whites. We observed strong positive correlations between census tract Medicaid coverage and percent living below poverty (rho = 0.69; P < 0.001). Disparities in 2-year Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function were magnified in communities with high census tract Medicaid coverage. For blacks in these communities, 2-year WOMAC function scores were predicted to be -5.54 points lower (80.42 versus 85.96) compared with blacks in less deprived communities, a difference not observed among whites. WOMAC pain and function 2 years after THA are similar among blacks and whites in communities with little deprivation (low percent census tract Medicaid coverage). WOMAC function at 2 years is worse among blacks in areas of higher deprivation but is not seen among whites. Level II - Cohort Study.