Addressing Disparities in Total Hip Replacement Outcomes

Commentary

The reduction of health disparities in the U.S. has been a national goal since the 1990 rollout of Healthy People 2000¹. A decade later, in January 2000, the U.S. Department of Health and Human Services launched Healthy People 2010, a framework for improving the health of all people in the U.S. with 2 overarching goals: to increase quality and years of healthy life and to eliminate health disparities². Almost 2 decades later, health disparities remain a major national concern. Within the field of orthopaedic surgery, the elimination of longstanding racial and ethnic disparities in joint replacement surgery is far from being realized. In fact, racial disparities in joint replacement may be growing. In a longitudinal analysis of Medicare administrative data from 1991 to 2008, growing racial disparities in joint arthroplasty access and outcomes were found, with black patients having both lower utilization and higher complication rates than white patients³. There is a complex web of potential reasons that might explain why these racial and ethnic disparities in joint replacement have been so intransigent, including socioeconomic factors, patient risk factors, patient preference, mistrust, comorbidities, physician expertise, hospital characteristics, quality, geography, and bias.

It is in the context of this national landscape that the results of this large registry trial on total hip arthroplasty (THA) by Okike et al. is important. The results demonstrate generally similar or better THA outcomes in minority populations in the Kaiser Permanente network, a multi-hospital, multi-region integrated health system. These findings are of particular interest. The authors suggest 3 overarching explanations for the relative consistency of the outcomes across racial and ethnic groups. First, the population is well insured—all patients were health maintenance organization (HMO) members with universal access to care within the Kaiser integrated health system. Second, there is well-established systemwide standardization of quality processes for THA. Finally, the surgeons across the system generally perform >30 cases annually, another indication of attention to quality. These findings mirror those from the Veterans Affairs system of almost no racial differences in hip and knee replacements performed in that system⁴.

The findings of these 2 studies suggest that the problem of racial disparity in total joint replacement is neither immutable nor intractable. Disparity in THA does not seem to be an issue of race and ethnicity, both of which are primarily social not biological constructs, but of access, insurance, and quality. Okike et al. showed quite elegantly that when access to care, insurance status, and quality are standardized across race and ethnicities, racial differences in THA outcomes may be eliminated. The study builds on a growing scientific literature that suggests improvements in access and standardization of health-care quality are central to the elimination of health-care disparities within and outside of managed care settings^5,6.

There are limitations to the generalizability of these results. The study population was largely a working population with reasonably high income and education levels across all racial groups. In addition, no information was provided about the functional outcomes across races, and it would be helpful to know there were no disparities in that regard. The controlled, closed-system environment of Kaiser Permanente is different from the community, insurance, and practice environment of the rest of the nation. Further, it is conceivable that the decrease in revision rates observed in the minority groups represents a disparity in access to or indications for revision, as discussed by the authors. Nonetheless, we should be encouraged that 2 decades after the national call for eliminating health disparities in the U.S., 1 large national health system has achieved substantial progress toward the elimination of racial disparity for THA outcomes. Kaiser Permanente has also achieved impressive gains in eliminating racial disparities in hypertension, diabetes, and cholesterol control, while much of the nation lags⁷. Perhaps, as the national debate about health-care reform continues, there are some simple lessons from Kaiser Permanente that might inform the future direction of our nation. Universal access to insurance, integrated health-care delivery, and standardization of quality might just be the critical path to eliminating health-care disparities and improving the health of all Americans.