The effect of transfer and hospital volume in subarachnoid hemorrhage patients

Introduction: Prompt management of aneurysmal subarachnoid hemorrhage (SAH) is critical. Literature is inconclusive regarding outcomes for patients directly admitted to specialized centers versus transferred from lower-volume hospitals. Providers are often unclear about the safety of transferring critical patients. This study evaluated the "transfer effect" in a large sample of aneurysmal SAH patients undergoing treatment. Methods: Using Nationwide Inpatient Sample 2002-2007 data, we analyzed outcomes of SAH patients treated with coil or clip procedures. Analyses studied the effect of direct-admit versus transfer admission on mortality, discharge disposition, complications, length of stay (LOS), and total charges. Results: Of 47,114 patients, 31,711 (67.3 %) were direct-admits and 15,403 (32.7 %) were transfers. More transfer patients were coiled than direct-admits (45.3 vs. 33.7 %, p < 0.0001) and fewer underwent ventriculostomy (26.6 vs. 31.5 %, p = 0.003). Older age (OR 1.2, p < 0.0001), higher disease severity (OR 1.4, p < 0.0001), lower volume (OR 1.5, p < 0.0001), and ventriculostomy (OR 2.1, p < 0.0001) increased mortality and predicted non-routine discharge, complications, LOS, and charges. Transfer patients had similar mortality (OR 0.9, p = 0.13) and complications (OR 0.9, p = 0.22) as direct-admits, but incurred higher non-routine discharge (OR 1.3, p = 0.002). Analysis of grade V patients demonstrated similar outcomes between direct-admits and transfers; however, charges for treating transfer patients were notably higher (401,386 vs. 242,774, p = 0.03). Conclusion: Patients treated in the lowest volume hospitals were 1.6 times more likely to die than those treated at the highest quintile hospitals. Among the critically ill grade V patients, transfer to higher-volume specialized centers did not increase the likelihood of a poor prognosis.