Abstract WP173: Aneurysmal Subarachnoid Hemorrhage Patient Outcomes: Direct Admission vs Interhospital Transfers in a Large Urban Health System

Introduction: Aneurysmal Subarachnoid hemorrhage (SAH) is a neuroemergency requiring early intervention, advanced neurocritical care, and multidisciplinary expertise. The American Heart Association (AHA) recommends transferring SAH patients to Comprehensive Stroke Centers (CSCs) for definitive management. The impact of interhospital transfer (IHT) on outcomes has not been well studied. We compared outcomes among SAH patients transferred through the Neuroemergencies Management and Transfers (NEMAT) program versus those admitted directly via the Emergency department (ED) to our CSC. Methods: Data were collected from Get With the Guidelines (GTWG) and NEMAT QA databases within the Mount Sinai Health System (1/1/2021-5/30/2025). Primary outcomes were discharge disposition, length of stay (LOS), and change in modified Rankin Scale (mRS) from admission to discharge, with transfer status as the primary predictor. Covariates included sex, age, Hunt-Hess score, pre-stroke mRS, and mortality. Associations between transfer status and outcomes were assessed with bivariate analyses (Fisher’s exact for discharge, Wilcoxon rank-sum test for LOS, and t-test for mRS change). Multivariable regression models were constructed for each outcome (multinomial for discharge, gamma for LOS, linear regression for mRS change), adjusting for covariates. Results: Of 385 SAH patients, 343 were transfers, 61.6% female, median age 58 (IQR: 20), median Hunt-Hess score 2 (IQR: 2), and12.2% deceased. At discharge, 196 patients went home, 120 to rehabilitation, 47 expired, 13 to acute care, 7 left against medical advice, and 2 to hospice. Median LOS was 16.4 days (IQR 17.1) and mean change in mRS was 2.35 (SD 1.94). Transfer status was not associated with discharge disposition (p>0.999) or adjusted models, except for hospice (RR: 901.63, p=0.001), though only 2 patients went to hospice. Transfer status was linked to longer LOS in unadjusted analysis (median difference: 6.66 days, p=0.004), but not significant after adjustment (10% decrease, median adjusted decrease of 1.66 days, p=0.562). Transfer status was not associated with change in mRS, unadjusted (mean difference: 0.73, p=0.171) or adjusted (β=0.12, p=0.789). Conclusion: In a large urban health system with centralized triage and transfer, aSAH patients undergoing IHT had outcomes comparable to direct ED admits. Larger multicenter studies are needed to confirm these findings and evaluate transfer-related effects across diverse settings.