Association of Patient Race and Hospital with Utilization of Regional Anesthesia for Treatment of Post-Operative Pain in Total Knee Arthroplasty: A Retrospective Analysis Using Medicare Claims

Regional anesthesia for total knee arthroplasty has been deemed high priority by national and international societies and its use can serve as a measure of healthcare equity. We estimated the association between utilization of regional anesthesia for postoperative pain and 1) race and 2) hospital in patients undergoing total knee arthroplasty. We hypothesized that Black patients would be less likely than White patients to receive regional anesthesia, and that variability in regional anesthesia would more likely be attributable to the hospital where surgery occurred than race.

We used Medicare fee-for-service claims for patients aged 65 or older who underwent primary total knee arthroplasty between 1/1/2011 and 12/31/2016. Our primary outcome was administration of regional anesthesia for postoperative pain, defined as any peripheral (femoral, lumbar plexus, or other) or neuraxial (spinal or epidural) block. Our primary exposure was self-reported race (Black, White, or Other). We defined clinical significance as a relative difference of 10% in regional anesthesia administration.

Data from 733,406 cases across 2,507 hospitals were analyzed: 90.7% of patients were identified as White, 4.7% as Black, and 4.6% as Other. Median hospital-level prevalence of use of regional anesthesia was 51% (interquartile range 18-79%). Black patients did not have a statistically different probability of receiving a regional anesthetic compared to White patients (adjusted estimates: Black 53.3%, 95% CI 52.5-54.1%; White 52.7%, 95% CI 52.4-54.1%, p=0.132). Findings were robust to alternate specifications of the exposure and outcome. Analysis-of-variance revealed that 42.0% of the variation in block administration was attributable to hospital, compared to less than 0.01% to race, after adjusting for other patient-level confounders.

Race was not associated with administration of regional anesthesia in Medicare patients undergoing primary total knee arthroplasty. Variation in the use of regional anesthesia was primarily associated with the hospital where surgery occurred.