Does Medicare Insurance Mitigate Racial/Ethnic Disparities in Access to Lumbar Spinal Surgery When Compared to Commercial Insurance?

Study Design: Retrospective cohort study. Objective: Compare disparities in lumbar surgical care utilization in Commercially insured versus Medicare patients. Summary of Background Data: While disparities in spinal surgery have been previously described, less evidence exists on effective strategies to mitigate them. Theoretically, universal health care coverage under Medicare should improve health care access. Materials and Methods: Utilizing National Inpatient Sample data (2003-2018), we included inpatient lumbar discectomy or laminectomy/fusion cases in black, white, or Hispanic patients aged 18-74 years, with Commercial or Medicare insurance. A multivariable Poisson distribution model determined race/ethnicity subgroup-specific rate ratios (RRs) of patients undergoing lumbar surgery compared to their respective population distribution (using US Census data) based on race/ethnicity, region, gender, primary payor, and age (Commercially insured age subgroups: 18-39, 40-54, and 55-64 y; Medicare age subgroup: 65-74 y). Results: Of the 2,310,956 lumbar spine procedures included, 88.9%, 6.1%, and 5.0% represented white, black, and Hispanic patients, respectively. Among Commercially insured patients, black and Hispanic (compared to white) patients had lower rates of surgical care utilization; however, these disparities decreased with increasing age: black (RR=0.37, 95% CI: 0.37-0.38) and Hispanic patients (RR=0.53, 95% CI: 0.52-0.54) aged 18-39 years versus black (RR=0.72, 95% CI: 0.71-0.73) and Hispanic patients (RR=0.64, 95% CI: 0.63-0.65) aged 55-64 years. Racial/ethnic disparities persisted in Medicare patients, especially when compared to the neighboring age subgroup that was Commercially insured: black (RR=0.61, 95% CI: 0.60-0.62) and Hispanic patients (RR=0.61, 95% CI: 0.60-0.61) under Medicare. Conclusions: Disparities in surgical care utilization among black and Hispanic patients persist regardless of health care coverage, and an expansion of Medicare eligibility alone may not comprehensively address health care disparities. Level of Evidence: Level III.