Background: Black and Hispanic older adults with arthritis are less likely to receive total knee arthroplasty (TKA) than non-Hispanic Whites despite the effectiveness of the procedure. Disparities in functional outcomes after TKA have also been recognized. The mechanisms for disparities in utilization and functional outcomes remain unknown.
Methods: Data from 102,767 women enrolled in the Women’s Health Initiative who had linked Medicare claims data were used to evaluate racial/ethnic disparities in TKA utilization and outcomes. Chapter 1 evaluated utilization rates after adjusting for need for TKA and medical access factors. Chapter 2 assessed physical function in the decades pre- and post-TKA by race/ethnicity. Chapter 3 evaluated racial disparities in post-TKA rehabilitation.
Results: Chapter 1: Black and Hispanic women were significantly less likely to receive TKA than non-Hispanic White women after accounting for need [Black: HR (95%CI)=0.70 (0.63-0.79); Hispanic=0.58 (0.44-0.77)]. Medical access factors had a modest effect on mediating disparities in utilization [Black: HR (95%CI)=0.75 (0.67-0.88); Hispanic=0.65 (0.47-0.89)]. Chapter 2: Among women who underwent TKA, Black women had significantly worse physical function for the entire decade pre-operatively compared with White women (mean difference=5.8 points, p-value<0.01) and had delayed surgery from the time of onset of mobility limitations. Poorer function pre-operatively largely explained racial disparities in functional outcomes post-TKA. Chapter 3: Black women, who had poorer function pre-operatively than White women, received more intensive rehabilitation services postoperatively. After accounting for differences in need for PT services, Black and White women appear to be equally as likely to continue rehabilitation after discharge home, through receipt of either home health or outpatient services.
Discussion: Neither need nor medical access explained why Black and Hispanic women underutilized TKA procedures compared with White women. Delays in receiving TKAs among Black women contribute to poorer functional improvement postoperatively. A better understanding of the decision-making process among surgical candidates is needed to ensure that women of minority race/ethnicity with arthritis receive appropriate treatment and in a timely manner. Efforts to reduce postoperative functional outcomes should be focused pre-operatively at optimizing physical function for Black and Hispanic women with arthritis and improving timely receipt of TKA once need arises.