The association of unfavorable outcomes with the intensity of neurosurgical care in the United States.

There is wide regional variability in the volume of procedures performed for similar surgical patients throughout the United States. We investigated the association of the intensity of neurosurgical care (defined as the average annual number of neurosurgical procedures per capita) with mortality, length of stay (LOS), and rate of unfavorable discharge for inpatients after neurosurgical procedures.We performed a retrospective cohort study involving the 202,518 patients who underwent cranial neurosurgical procedures from 2005-2010 and were registered in the National Inpatient Sample (NIS) database. Regression techniques were used to investigate the association of the average intensity of neurosurgical care with the average mortality, LOS, and rate of unfavorable discharge.The inpatient neurosurgical mortality, rate of unfavorable discharge, and average LOS varied significantly among several states. In a multivariate analysis male gender, coverage by Medicaid, and minority racial status were associated with increased mortality, rate of unfavorable discharge, and LOS. The opposite was true for coverage by private insurance, higher income, fewer comorbidities and small hospital size. There was no correlation of the intensity of neurosurgical care with the mortality (Pearson's ρ = -0.18, P = 0.29), rate of unfavorable discharge (Pearson's ρ = 0.08, P = 0.62), and LOS of cranial neurosurgical procedures (Pearson's ρ = -0.21, P = 0.22).We observed significant disparities in mortality, LOS, and rate of unfavorable discharge for cranial neurosurgical procedures in the United States. Increased intensity of neurosurgical care was not associated with improved outcomes.