Antti Lindgren1,2, Sarah Burt3, Ellie Bragan Turner3, Atte Meretoja4,5, Jin-Moo Lee6, Thomas M Hemmen7, Mark Alberts8, Robin Lemmens9,10,11, Mervyn DI Vergouwen1, Gabriel Je Rinkel1. 1. 1 Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, The Netherlands. 2. 2 Department of Neurosurgery, NeuroCenter, Kuopio University Hospital, Kuopio, Finland. 3. 3 Dr Foster Ltd, London, UK. 4. 4 Department of Neurology, Helsinki University Hospital, Helsinki, Finland. 5. 5 Department of Medicine at the Royal Melbourne Hospital, University of Melbourne, Parkville, Australia. 6. 6 Department of Neurology, and the Hope Center for Neurological disorders, Washington University School of Medicine, St. Louis, MO, USA. 7. 7 Department of Neurosciences, University of California, San Diego, CA, USA. 8. 8 Department of Neurology, Hartford Hospital, Hartford, CT, USA. 9. 9 KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology, Leuven Institute for Neuroscience and Disease (LIND), Leuven, Belgium. 10. 10 VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium. 11. 11 Department of Neurology, University Hospitals Leuven, Leuven, Belgium.
Abstract
BACKGROUND: Inverse association between hospital case-volume and case-fatality has been observed for various nonsurgical interventions and surgical procedures. AIMS: To study the impact of hospital case-volume on outcome after aneurysmal subarachnoid hemorrhage (aSAH). METHODS: We included aSAH patients who underwent aneurysm coiling or clipping from tertiary care medical centers across three continents using the Dr Foster Stroke GOAL database 2007-2014. Hospitals were categorized by annual case-volume (low volume: <41/year; intermediate: 41-70/year; high: >70/year). Primary outcome was 14-day in-hospital case-fatality. We calculated proportions, and used multiple logistic regression to adjust for age, sex, differences in comorbidity or disease severity, aneurysm treatment modality, and hospital. RESULTS: We included 8525 patients (2363 treated in low volume hospitals, 3563 treated in intermediate volume hospitals, and 2599 in high-volume hospitals). Crude 14-day case-fatality for hospitals with low case-volume was 10.4% (95% confidence interval (CI) 9.2-11.7%), for intermediate volume 7.0% (95% CI 6.2-7.9%; adjusted odds ratio (OR) 0.63 (95%CI 0.47-0.85)) and for high volume 5.4% (95% CI 4.6-6.3%; adjusted OR 0.50 (95% CI 0.33-0.74)). In patients with clipped aneurysms, adjusted OR for 14-day case-fatality was 0.46 (95% CI 0.30-0.71) for hospitals with intermediate case-volume and 0.42 (95% CI 0.25-0.72) with high case-volume. In patients with coiled aneurysms, adjusted OR was 0.77 (95% CI 0.55-1.07) for hospitals with intermediate case-volume and 0.56 (95% CI 0.36-0.87) with high case-volume. CONCLUSIONS: Even within a subset of large, tertiary care centers, intermediate and high hospital case-volume is associated with lower case-fatality after aSAH regardless of treatment modality, supporting centralization to higher volume centers.
BACKGROUND: Inverse association between hospital case-volume and case-fatality has been observed for various nonsurgical interventions and surgical procedures. AIMS: To study the impact of hospital case-volume on outcome after aneurysmal subarachnoid hemorrhage (aSAH). METHODS: We included aSAH patients who underwent aneurysm coiling or clipping from tertiary care medical centers across three continents using the Dr Foster Stroke GOAL database 2007-2014. Hospitals were categorized by annual case-volume (low volume: <41/year; intermediate: 41-70/year; high: >70/year). Primary outcome was 14-day in-hospital case-fatality. We calculated proportions, and used multiple logistic regression to adjust for age, sex, differences in comorbidity or disease severity, aneurysm treatment modality, and hospital. RESULTS: We included 8525 patients (2363 treated in low volume hospitals, 3563 treated in intermediate volume hospitals, and 2599 in high-volume hospitals). Crude 14-day case-fatality for hospitals with low case-volume was 10.4% (95% confidence interval (CI) 9.2-11.7%), for intermediate volume 7.0% (95% CI 6.2-7.9%; adjusted odds ratio (OR) 0.63 (95%CI 0.47-0.85)) and for high volume 5.4% (95% CI 4.6-6.3%; adjusted OR 0.50 (95% CI 0.33-0.74)). In patients with clipped aneurysms, adjusted OR for 14-day case-fatality was 0.46 (95% CI 0.30-0.71) for hospitals with intermediate case-volume and 0.42 (95% CI 0.25-0.72) with high case-volume. In patients with coiled aneurysms, adjusted OR was 0.77 (95% CI 0.55-1.07) for hospitals with intermediate case-volume and 0.56 (95% CI 0.36-0.87) with high case-volume. CONCLUSIONS: Even within a subset of large, tertiary care centers, intermediate and high hospital case-volume is associated with lower case-fatality after aSAH regardless of treatment modality, supporting centralization to higher volume centers.