Background The Institute of Medicine called attention to the pervasive differences in treatments and outcomes between ethnic groups. We sought to highlight the geographic and racial disparities in access to treatment for unruptured cerebral aneurysms.

Methods We performed a retrospective cohort study involving patients with unruptured cerebral aneurysms from 2000 to 2010, registered in the National Inpatient Sample (NIS) database. Primary outcomes were those patients receiving treatment and the ratio of untreated to treated aneurysms per state. The purpose of this study was to determine if there were geographic and racial disparities in access to treatment of unruptured cerebral aneurysms based on the NIS. Logistic regression and analysis of variance (ANOVA) techniques were used.

Results There were 57 418 patients diagnosed with unruptured aneurysms (mean age 61.4 years, 70.5% females), with 18 231 undergoing treatment. Males (OR 0.67, 95% CI 0.64 to 0.71, p<0.0001), Asian (OR 0.88, 95% CI 0.81 to 0.96, p=0.003), Hispanic (OR 0.76, 95% CI 0.65 to 0.90, p=0.001), African American (OR 0.57, 95% CI 0.53 to 0.62, p<0.0001), and patients without insurance (OR 0.76, 95% CI 0.67 to 0.87, p<0.0001) were associated with decreased chance of treatment. The opposite was true for lower Charlson Comorbidity Index (OR 3.03, 95% CI 2.71 to 3.39, p<0.0001), coverage by Medicaid (OR 1.12, 95% CI 1.03 to 1.23, p=0.012), or private insurance (OR 1.92, 95% CI 1.80 to 2.04, p<0.0001), and lower income (OR 1.22, 95% CI 1.15 to 1.31, p<0.0001). Significant regional variability was observed among the different states (p=0.006, ANOVA), with Maryland being an outlier.

Conclusions Based on the NIS database, the rate of treatment of unruptured cerebral aneurysms varies according to sex, race, and region.