A Systematic Review of the State of Neurosurgical Disparities Research: Past, Present, and Future

Background: The social determinants of health, which influence healthcare access, patient outcomes, and population-level burden of disease, contribute to health disparities experienced by marginalized patient populations. In the present study, we sought to evaluate the landscape of health disparities research within neurosurgery. Methods: Embase, Ovid-MEDLINE, Scopus, Web of Science, Cochrane Library, and ProQuest Dissertations databases were queried for original research on health disparities regarding access to, outcomes of, and/or postoperative management after neurosurgical procedures in the United States. Results: Of 883 studies screened, 196 were included, of which 144 had a neurosurgery-affiliated author. We found a significant increase in the number of neurosurgical disparities reports beginning in 2010, with only 10 studies reported before 2010. Of the included studies, 3.1% used prospective methods and 63.8% used data from national registries. The disparities analyzed were racial/ethnic (79.6%), economic/socioeconomic (53.6%), gender (18.9%), and disabled populations (0.5%), with 40.1% analyzing multiple or intersecting disparities. Of the included reports, 96.9% were in phase 1 (detecting phase of disparities research), with a few studies in phase 2 (understanding phase), and none in phase 3 (reducing phase). The spine was the most prevalent subspecialty evaluated (34.2%), followed by neuro-oncology (19.9%), cerebrovascular (16.3%), pediatrics (10.7%), functional (9.2%), general neurosurgery (5.1%), and trauma (4.1%). Senior authors with a neurosurgical affiliation accounted for 79.2% of the reports, 93% of whom were academically affiliated. Conclusions: Although a recent increase has occurred in neurosurgical disparities research within the past decade, most studies were limited to the detection of disparities without understanding or evaluating any interventions for a reduction in disparities. Future research in neurosurgical disparities should incorporate the latter 2 factors to reduce disparities and improve outcomes for all patients.