Total Joint Replacement in Medicare Beneficiaries from 2009 to 2017: Disparities and Geographic Variation

There are insufficient data on the geographic variation and disparities in the use of elective primary total hip and knee arthroplasty for Medicare beneficiaries. The goals of this study by Thirukumaran et al were to identify these variations and disparities, determine whether Black Medicare beneficiaries have continued to undergo lower numbers of total hip and total knee replacements across regions and whether these disparities affected all Black beneficiaries or preferentially affected socioeconomically disadvantaged Black beneficiaries.

Medicare enrollment and claims data from 2009 to 2017 examining Hospital Referral Region (HRR)-level were used.  Variation and disparities by race (non-Hispanic White and Black) and socioeconomic status (Medicare only and dual eligibility for both Medicare and Medicaid) were determined. HRR-level age and sex outcomes for standardized total hip replacement and total knee replacement utilization rates for White

Medicare-only beneficiaries, White dual-eligible beneficiaries, Black Medicare only beneficiaries and black dual-eligible beneficiaries and differences in race between these groups as a representation of disparities were recorded. The main exposure variables were race, socioeconomic group and year. Multi-level mixed effects linear regression models were constructed to estimate trends in total hip replacement and total knee replacement rates and to determine whether rates were lower in HRR‘s with significant percentages of Black beneficiaries or dual-eligible beneficiaries.

The study investigated over 900,000 total hip and and 2000 total knee replacements. In 2017 the average HRR-level total hip replacement rate was 4.6 for operative procedures per 1000 beneficiaries and the average HRR-level total knee replacement rate was 9.66 operative procedures per 1000 beneficiaries with a threefold variation across HRRs. In 2017 the total hip replacement rate was 32% higher for White Medicare only beneficiaries and 48% higher for Black Medicare only beneficiaries than in 2009. Nevertheless, because the operative rates for Black and White dual eligible beneficiaries was unchanged over the period of the investigation the Medicare-only and dual eligibility disparity for 2017 from White beneficiaries increased by 0.75 operative procedures per 1000 from 2009 and the disparity for Black beneficiaries by 1.13 operative procedures per thousand beneficiaries. Disparities in total knee replacement disparities did not change. Importantly, the rates for White dual eligible beneficiaries were significantly lower than those for Black Medicare only beneficiaries for both total hip and total knee arthroplasties and there were fewer operative procedures performed with more of Black wodual-eligibility beneficiaries.

The conclusions of the study were that although the total hip replacement use for Medicare only beneficiaries of both races increased disparities for both White and Black dual eligible beneficiaries are increasing, programs to improve quality and equity must recognize and reverse both racial and socioeconomic barriers and re-focus on regions with high concentrations of disadvantaged beneficiaries.

Reference:
Thirukumaran et al.: J. Bone Joint Surg.,102:2120-2128, 2020.