141 - Racial and Ethnic Disparities in Outpatient Microdiscectomy Utilization: A Comprehensive Trends Analysis using National and Regional State Data

Introduction: Although racial and ethnic disparities within spine surgery have been well documented, no data exists on disparities in outpatient procedures including lumbar microdiscectomy, one of the most performed procedures within spine surgery.
Aims/

Objectives: The purpose of this study was to 1) assess disparities in the utilization of outpatient microdiscectomy amongst white, Black, and Hispanic patients on a national and state level and 2) trend these disparities over time to see whether they have improved, persisted, or worsened.

Methods: We conducted a retrospective cohort study using data from the 2015-2018 Healthcare Cost and Utilization Project (HCUP) New York State Ambulatory Surgery Database and the 2018 HCUP National Ambulatory Surgery Sample (NASS). Patients who underwent same-day discharge microdiscectomy were identified using common procedural codes. In our primary analysis, differences in per-capita utilization rates of same-day outpatient microdiscectomy were assessed and trended over time by race and ethnicity using the New York statewide data. Poisson regression was used to evaluate the association between utilization rates for microdiscectomy and race/ethnicity after adjustment for age, insurance, socioeconomic status, and comordbidities.

Results: During the study period, Black and Hispanic patients were significantly less likely to undergo outpatient microdiscectomy when compared to white patients in New York state (adjusted rate ratio [aRR], 0.26; 95% Confidence Interval [CI], 0.25-0.27; P < 0.001). This disparity was also observed at the national level (white vs. Black vs. Hispanic OP-microdiscectomy rate per million person-years: 408.7 vs. 148.5 vs. 129.8), with disparities being most pronounced in the Midwest and South (p < 0.001 for both).
From 2015 to 2018, there was a persisting disparity in microdiscectomy utilization for Black patients over time (e.g. white vs. Black OP-microdiscectomy rate per million person-years: 443.4 vs. 115.3 in 2015 compared with 383.2 vs. 106.1 in 2018, Ptrend < 0.001) and an improving disparity for Hispanic patients over time (e.g. white vs. Hispanic OP-microdiscectomy rate per million person-years: 443.4 vs. 115.3 vs. 74.1 in 2015 compared with 383.2 vs. 106.1 vs. 115.1 in 2018, P for trend < 0.001). These results held in adjusted Poisson regression models.

Conclusions: In this study, we found evidence of racial and ethnic disparities in outpatient microdiscectomy utilization between white, Black, and Hispanic patients both on a national and state level. Racial and ethnic disparities in microdiscectomy utilization on the national level across the United States were most pronounced in the Midwest and South. Disparities on the state level, specifically New York state, were found to be improving between white and Hispanic patients over time. These encouraging trends in New York may reflect the effectiveness of several governmental legislative enactments within the state that have encouraged the emergence of hospital affiliated outpatient centers and free-standing ASCs in rural and underserved areas. Further research is needed to see if these trends have also held in other states and on a national level and why trends have not also simultaneously improved for Black patients.