Geographical Variation in TBI Mortality by Proximity to the Nearest Neurosurgeon

Abstract

Background: Trauma mortality disproportionately affects populations farther from potentially lifesaving trauma care, and traumatic brain injury (TBI) is no exception. Previous examinations have examined proximity to trauma centers as an explanation for trauma mortality, but little is known about the relationship between proximity to neurosurgeons specifically in TBI mortality.
Materials & Methods: In this cross-sectional study, county level TBI mortality rates from 2008 to 2014 were examined in relation to the distance to the nearest neurosurgeon. The geographic coordinates of each practicing neurosurgeon in the United States were determined by geocoding their name and practice’s address from the 2017 Medicare Physician and Other Supplier file. Using multivariate linear regression, the association between TBI mortality and the distance from the center of the county to closest neurosurgeon was examined, adjusting for the demographics and urbanization of the county.
Results: 761 of the 3108 counties (24.5%) in the continental US were excluded from the analysis because they had 20 or fewer TBI deaths during this time, producing unstable estimates. Excluded counties accounted for 1.67% of the US population. The mean (95% CI) mortality rate among all counties was 23.6 (23.3 - 23.9; p<0.001) per 100,000 population. After adjusting for demographics and urbanization, the mortality rate increased by 0.96 (95% CI: 0.82 - 1.10; p<0.001) for every additional 10 miles from the nearest neurosurgeon.
Conclusions: These findings suggest that proximity to neurosurgeons may influence TBI mortality independent of urbanization. Further research into this topic may help to allocate scarce public health resources.