Although previous research has suggested that unequal access to care contributes to the documented racial and ethnic disparities in total joint arthroplasty (TJA) delivery in the United States, a study to be presented today found that, even with universal insurance coverage, minority patients remain 30 to 50 percent less likely to undergo primary TJA than their white counterparts.

“While total hip and total knee arthroplasty represent highly successful procedures with the potential to greatly improve patients’ pain and quality of life, the benefits of these procedures are not being equally shared among all members of the population,” lead author Kanu Okike, MD, MPH, from Hawaii Permanente Medical Group, Kaiser Permanente, told AAOS Now Daily Edition. “As a result, minority patients may be disproportionately suffering under the burden of end-stage arthritic disease as compared to white patients.”

Previous studies have suggested that some healthcare disparities can be ameliorated in managed care systems with universal coverage, Dr. Okike added. “In a prior study conducted in our system, for example, we found that minority patients who underwent total hip arthroplasty within the managed care system experienced outcomes that were similar to, or in some cases better than, their white counterparts.”

For the present study, Dr. Okike and researchers sought to determine whether there were differences in the execution of primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) on the basis of race and ethnicity in an integrated healthcare system. The cohort included patients aged ≥50 years with a diagnosis of hip or knee osteoarthritis (OA) between 2015 and 2019. In total, there were 99,548 patients in the THA cohort and 290,324 in the TKA cohort. The outcome of interest was reception of primary THA and/or TKA, and the dependent variable was race/ethnicity. The researchers calculated incidence rate ratios (IRRs) using multivariable Poisson regression while controlling for potential confounders.

Overall, 10.2 percent of patients were Black, 20.5 percent were Hispanic, 9.6 percent were Asian, and 59.7 percent were white.

In the multivariable analysis, the IRRs for primary THA and TKA were significantly lower for all minority groups compared to white patients (Table 1).

“Studies in other healthcare settings have suggested that disparities in coverage and access often contribute to utilization differences. Our findings suggest that differences in utilization can persist even in settings of universal coverage,” Dr. Okike said. Although the study was not designed to investigate the specific reasons for these disparities, prior studies in other settings have identified a number of possible contributing factors, “including differential recommendations on the part of surgeons and decreased perceived benefit on the part of patients,” he said.

The findings of this study are limited by the potential for residual confounding. “While we assessed for the utilization of THA and TKA among patients who carried a diagnosis of hip and/or knee OA, we were not able to determine the suitability of arthroplasty for each particular patient,” Dr. Okike noted. Future research is needed to determine the specific reasons for the observed racial/ethnic disparities in this group of patients, as well as to identify interventions which could ameliorate these disparities, he added.

The study will be presented as Paper 678 at 11:30 a.m. in Ballroom 6B.

Dr. Okike’s coauthors on “Association between Race/Ethnicity and Total Joint Arthroplasty Utilization in a Universally Insured Population” are Richard Nick Chang; Kathryn Elizabeth Royse, PhD; Elizabeth W. Paxton, PhD; and Adrian D. Hinman, MD.

Ariel DeMaio is the managing editor of AAOS Now. She can be reached at ademaio@aaos.org.