Association Between Race/Ethnicity and Spinal Fusion Outcomes in a Managed Health-Care Model

Race and ethnicity and insurance status have been identified as major contributors to disparities in health care. Several studies have analyzed racial and ethnic disparities in patients with private and government insurances, but very little is known about disparities in managed care models. Kaiser Permanente (KP) is a health-care organization (health maintenance organization, HMO) within the managed health-care system. It provides integrated care through its network of facilities and doctors, with equal access to all of its beneficiaries. Hence, the objective of this study was to determine whether there are health-care disparities in spinal fusion outcomes among patients enrolled in a managed health-care system such as Kaiser Permanente.

Using data from the KP Spine Registry, we performed a retrospective cohort study of adults ≥18 years of age who underwent spinal fusion. The predictor was race/ethnicity (White [reference], Black, Hispanic, Asian). The primary outcome was reoperations, and the secondary outcomes were 90-day emergency department (ED) visits, 90-day readmissions, and 90-day and 1-year mortality. Multivariable Cox regression and logistic regression models were used to adjust for confounders.

We included 40,258 patients with spinal fusions. A lower reoperation risk was observed for Black (hazard ratio [HR] = 0.90; 95% confidence interval [CI] = 0.82 to 0.99; p = 0.038), Hispanic (HR = 0.78; 95% CI = 0.71 to 0.85; p < 0.001), and Asian (HR = 0.62; 95% CI = 0.55 to 0.71; p < 0.001) patients. Black (odds ratio [OR] = 1.25; 95% CI = 1.14 to 1.36; p < 0.001) and Hispanic (OR = 1.15; 95% CI = 1.07 to 1.25; p < 0.001) patients had a higher likelihood of an ED visit within 90 days. A higher likelihood of readmission within 90 days was also observed for Black patients (OR = 1.18; 95% CI = 1.05 to 1.32; p = 0.005). No significant differences in 90-day and 1-year mortality were observed.

Despite equal access to spine surgery in a managed health-care system such as Kaiser Permanente, our study showed that some disparities exist among Black and Hispanic patients. We believe that managed care networks can reduce disparities relative to other health-care delivery systems, although more work needs to be done to ensure equitable outcomes in all domains. These findings underscore the urgent need to address these disparities with further research.

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.