Patient- and Provider-level Factors Contribute to Socioeconomic Disparities in Lumbar and Cervical Fusion Outcomes

Introduction: Recent studies find patient-level factors such as socioeconomic status (SES) including race/ethnicity, income, and education influence post-surgical outcomes following lumbar and cervical spinal fusion. Fewer studies, however, examine the influence of provider-level factors (e.g., exposure to diversity) on surgical outcomes. We aim to examine how both patient- and provider-level factors, and their interaction effect post-surgical outcomes.

Methods: The Clinformatics® Data Mart Database was used to review patients undergoing lumbar and cervical fusion between 2003 and 2021. We used the provider patient racial diversity index (ppRDI)—defined as the proportion of non-white minority patients comprising a physician’s patient population—to divide patients into three categories. After propensity score matching, we created multivariate models to determine the effect of patient SES, provider category, and SES-provider interaction on outcomes. Primary outcomes included hospital length of stay (LOS), and rate of 30-day readmission, and complication; secondary outcomes included post-operative emergency room (ER) visits, discharge status, and hospital charges.

Results: 39,680 patients were identified. Upon multivariate analysis, Asian race was associated with increased ER visit (OR=1.85;95%CI=0.99-3.2) while Black race was associated with decreased discharge to home (OR=0.67;95%CI=0.54-0.83), and increased LOS (Coeff.=0.70;95%CI=0.16-1.25) compared to White race. ppRDI category II was associated with increased complication (OR=1.1;95%CI=1-1.21), LOS (Coeff.=0.56;95%CI=0.37-0.76), hospital charge (Coeff.=47700;95%CI=40200-55300), and decreased discharge home (OR=0.76;95%CI=0.70-0.82). Category III was associated with increased LOS (Coeff.=0.62;95%CI=0.43-0.81), hospital charge (Coeff.=36800;95%CI=29200-44400), and decreased discharge to home (OR=0.90;95%CI=0.83-0.97). Asian patients treated by category II providers had decreased odds of readmission (OR=0.38;95%CI=0.14-0.96) while Black patients treated by category III providers had increased odds of discharge to home (OR=1.41;95%CI=1.1-1.9).

Conclusion : We corroborate past findings that patient-level SES factors are associated with worse outcomes and find select instances of improved outcomes for minority patients treated by surgeons with high ppRDI. Our findings suggest the need for prospective studies to evaluate provider-level interventions (e.g., diversity training) to reduce outcome disparities.