The Effect of Transfer and Hospital Volume in Subarachnoid Hemorrhage Patients

Abstract

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. 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. 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). 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.