The Source for Neurovascular News and Education

August 15, 2020


The likelihood of patients being transferred was influenced by race and socioeconomic status, but not by the treatment approach.



A relatively high proportion of patients with aneurysmal subarachnoid hemorrhage (SAH) are transferred between acute care hospitals, and these transfer rates differ by race and socioeconomic status, according to an analysis of a nationally representative sample of patients published online recently ahead of print in the Journal of Neurosurgery.


While data are rapidly being collected on the relative merits and best approaches for the transfer of patients with acute ischemic stroke (AIS), the same cannot be said for patients with aneurysmal SAH. The authors, led by Christopher Roark, MD (University of Colorado, Aurora), point out that most studies on this topic are limited to single-center, retrospective experiences.


Maxim Mokin, MD, PhD (University of South Florida, Tampa), who was not involved in the current study, noted to Neurovascular Exchange: “There are fundamental differences in what studies looking at AIS transfer versus aneurysmal SAH focus on. For AIS, we mainly evaluate the time metrics and reasons for delay. While important, time is not as critical for aneurysmal SAH. These and other studies instead try to address gender, race, and socioeconomic disparities among the patients with aneurysmal SAH.”


Roark and colleagues used 2013-2014 data from the National Inpatient Sample (NIS) to define an observational cohort of patients with ruptured brain aneurysms. The initial search identified patients with SAH (ICD-9-CM 430). Those with concomitant codes suggesting trauma or other intracranial vascular abnormalities as well as those who had not undergone a subsequent procedure to repair an intracranial aneurysm were excluded.


Based on these criteria, the researchers identified a cohort of 4,373 patients. Of these, 1,379 had undergone microsurgical clip ligation and 2,994 had undergone endovascular repair.


White Race, Low Income Tied to Transfer


Patients who were transferred were more likely to be sent to urban teaching hospitals than to nonteaching hospitals. Other factors highly associated with being transferred were white race and living in the lowest income zip code. Repair type (clipping vs coiling) and primary payer were not associated with transfer status.


Factors Associated With Being a Transfer Patient on Multivariate Analysis


Odds Ratio (95% CI)

Treatment in Urban Teaching vs Nonteaching Hospital

2.17 (1.72-2.74)

Any Other Race vs White

0.90 (0.72-1.11)

Highest vs Lowest Income Zip Code

0.77 (0.64-0.94)


“These results are the first to characterize interhospital transfer for aneurysmal SAH patients using a nationally representative sample,” write the authors. “Patients with [this condition] require highly specialized surgical and critical care, so evidence of a strong correlation between SAH volume and outcome supports transfer to high-volume quaternary care centers. Conversely, given the risk of early rebleeding, the transfer of patients with aneurysmal SAH carries unique risks.”


They conclude that “future studies should attempt to better understand the effect of transfer characteristics on SAH outcome and should further explore racial and socioeconomic differences in transfer patterns.”


Mokin agreed, noting, “As the authors correctly pointed out, one of the key remaining questions is the effect of transfer on patients’ outcomes, and the role of racial and socioeconomic disparities.”




Roark C, Case D, Gritz M et al. Nationwide analysis of hospital-to-hospital transfer in patients with aneurysmal subarachnoid hemorrhage requiring aneurysm repair. J Neurosurg. 2018;Epub ahead of print.



Roark and Mokin report no relevant conflicts of interest.