Abstract TP533: Decreasing Treatments for Subarachnoid Hemorrhage at Highest Volume Centers: A 10-Year Cohort Study

Abstract

Introduction: With increasing availability of endovascular aneurysm treatments away from tertiary referral centers, greater numbers of patients with aneurysmal subarachnoid hemorrhage (SAH) may be treated at lower-volume centers. This trend over time as well as its influence on patient outcomes remains poorly characterized. Methods: Using administrative data on all discharges from hospitals in New York (2005-2014) and Florida (2005-2015), we identified patients with treated aneurysmal SAH. Primary outcome was in-hospital mortality. Patients with trauma were excluded. Logistic regression adjusted for comorbidities was used to assess the relationship of hospital volume on outcome. Results are provided as median [IQR], mean ± SD and OR [95% CI]. Results: Among 12,290 patients with aneurysmal SAH, 69% were female and median age was 55 [46 - 65]. 62% were treated with endovascular coiling (EC) and 37% with surgical clipping (SC). Over the time span of the study, the number of hospitals treating SAH did not increase (88 vs. 71, 2005 vs. 2014), nor did the number of patients with SAH (1159 vs. 1212, 2005 vs. 2014). Hospitals that treated fewer numbers of patients with SAH annually were more likely to perform SC than EC (51% vs. 40%, 1-10 vs. ≥ 40 annual SAH treatments, p<0.001). Over the course of the study, mean annual SAH treatments per hospital decreased (38 ± 23 vs 34 ± 18, 2005 vs. 2014, p<0.0001) with fewer SAHs treated at the highest volume centers and increasing numbers at intermediate volume centers (Figure). In adjusted logistic regression, the likelihood of in-hospital mortality decreased with increasing annual SAH treatment volume (-3.3% per 10 SAH admissions/year, p<0.05). Conclusion: In this 10-year observational cohort, lower volume hospitals were more likely to perform SC, and fewer SAH patients were treated at the highest volume centers over time. These findings corroborate a de-centralization of SAH care, which may be associated with worse outcomes.