Subarachnoid Hemorrhage Admissions Research Articles

Abstract TP34: Outcomes and Trends of Subarachnoid Hemorrhage During the COVID-19 Pandemic

Background: Hemorrhagic cerebrovascular manifestations are known to be associated with COVID-19. Our study aims to describe the trends and outcomes of patients with Subarachnoid Hemorrhage (SAH) using a Nationwide Inpatient Sample (NIS) database. Methods: We examined the 2016-2020 NIS database, focusing on patients aged 18 years and older with a primary SAH discharge diagnosis. Comparative outcome analyses between pre-COVID (2016-2019) and COVID year (2020) were performed. NIS-Subarachnoid Hemorrhage Severity Score (NIS-SSS) was used as a surrogate marker for the modified Rankin Scale. Results: Our analysis of 119,005 patients with subarachnoid hemorrhage (SAH) unveiled a median age of 59.6 years with 72,650 (61.0%) being female. Comparisons across age (p=0.867), gender (p=0.08), and length of stay (p=0.130) showed no significant differences between groups. Median NIS-SSS score was 3.6, revealing an increase from pre-COVID 3.3 to COVID 5.6 (p=0.0006). Adjusted analyses exhibited similar inpatient mortality (COVID vs. pre-COVID: OR 0.98, 95% CI 0.89-1.08, p=0.71). However, advancing age (OR 1.01, p<0.001), NIS severity score >10 points (OR 11.11, p<0.001), CHF (OR 1.47, p<0.001), coagulopathy (OR 1.47,p<0.001), cocaine use (OR 1.46, p=0.001), and weekend discharges (OR 1.09, p=0.04) were linked to increased mortality odds. In 2020, non-COVID SAH rates remained stable (9.2% - 9.4%, Ptrend=0.42), while COVID-associated SAH surged (1.2% - 21%, Ptrend=0.023). Conclusion: Our study finds no disparity in outcomes for patients hospitalized with aneurysmal subarachnoid hemorrhage (aSAH) during the COVID-19 pandemic when contrasted with the preceding years. However, a substantial rise in SAH admissions among COVID-19 patients is evident. Exploring the physiological reasons behind this observed trend could be a crucial avenue for further investigation.

Relationship between Social Distancing and Admissions for Cerebrovascular Accidents at a Tertiary Medical Center during the COVID-19 Pandemic: A Retrospective, Community-Based Study.

We evaluated the trend of admission of patients with acute cerebrovascular accidents (CVAs) during social distancing measures implemented during the coronavirus disease 2019 (COVID-19) era. The data of patients admitted with transient ischemic attack, ischemic stroke, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH) to the emergency department of the Hanyang University Seoul Hospital were retrospectively analyzed. The data were compared between the pre-COVID-19 and COVID-19 periods. Poisson regression analysis was performed to evaluate changes in admission rates as a function of the year, social distancing level, and the interaction between the year and social distancing level. The number of admissions for CVAs dropped from 674 in the pre-COVID-19 period to 582 in the COVID-19 period. The decline in the number of admissions for ICH during social distancing measures was statistically significant, while the declines in SAH and ischemic stroke admissions were not. When the social distancing level was raised, admissions for CVAs dropped by 19.8%. The correlation between social distancing and decreased admissions for CVAs is a paradoxical relationship that may be of interest to the field of public health.

Treat COVID-19, but Not Only COVID-19: Stroke Matters as Well

Introduction: During the COVID-19 pandemic, studies reported less number of hospitalizations for acute stroke and reduction in the use of recanalization treatments. This study analyzes nationwide data on stroke admissions and management in the Czech Republic during the first wave of the COVID-19 pandemic. Methods: We compared the early COVID-19 pandemic (March–May 2020) with the pre-pandemic period (January–February 2020 and March–May 2019): (a) the National Register of Reimbursed Health Services provided volume of all admissions for subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), and ischemic stroke (IS), and volume of recanalization treatments (intravenous thrombolysis [IVT] and mechanical thrombectomy [MT]); (b) Registry of Stroke Care Quality provided door-to-needle time (DNT), onset-to-door time (ODT), and stroke severity at admission (National Institutes of Health Stroke Scale, NIHSS) for IS. Results: During the pandemic (March–May 2020), the peak number of COVID-19 patients treated in Czech hospitals was 39 per million. In March–May 2020 versus March–May 2019, hospital admissions decreased as follows: stroke overall by 14% (p < 0.001), IS by 14% (p < 0.001), SAH by 15% (p = 0.07), and ICH by 7% (p = 0.17). The mean age was 74 years versus 74 years (p = 0.33), and 52% versus 51% were men (p = 0.34). The volumes of IVT and MT decreased by 14% (p = 0.001) and 19% (p = 0.01), respectively. The proportions of all IS patients receiving IVT or MT remained unchanged, with, respectively, 17% versus 17% receiving IVT (p = 0.86) and 5% versus 5% receiving MT (p = 0.48). DNT and ODT were 24 versus 25 min (p = 0.58) and 168 versus 156 min (p = 0.23), respectively. NIHSS at admission did not differ (6 vs. 6; p = 0.54). Conclusion: Even with a low burden of COVID-19 during the first wave and no change in organization and logistics of stroke services, stroke admissions and volume of recanalization treatments decreased. Public health communication campaigns should encourage people to seek emergency medical care for stroke symptoms during the COVID-19 pandemic.

Exploring the Collateral Damage of the COVID-19 Pandemic on Stroke Care: A Statewide Analysis.

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Abstract 14: Global Impact of the Covid-19 Pandemic on Subarachnoid Hemorrhage

Introduction: During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The objective was to examine whether subarachnoid hemorrhage(SAH) hospitalizations and ruptured aneurysm coiling interventions demonstrated similar declines. Methods: We conducted a global, retrospective, observational study across 6 continents, 37 countries, and 140 comprehensive stroke centers. Patients with diagnosis of SAH, ruptured aneurysm coiling interventions, COVID-19 were identified using ICD-10 codes or by prospectively maintained stroke databases. The 3-month cumulative volume, monthly volumes for SAH hospitalizations and ruptured aneurysm coiling procedures were compared for the period before (1-year and immediately before) and during the COVID-19 pandemic (March 1 to May 31, 2020). Results: There was a significant decline in SAH hospitalizations with 2,044 admissions in the 3 months immediately before and 1,585 admissions during the pandemic, representing a decline of 22.5% (95%CI, -24.3 to -20.7, p&lt;0.0001). Embolization of ruptured aneurysms declined with 1,170 to 1,035 procedures, respectively, representing an 11.5%(95%CI, -13.5 to -9.8, p=0.002) drop. Hospitals with higher COVID-19 hospitalization burden demonstrated greater declines in SAH and ruptured aneurysm coiling compared to lower COVID-19 burden. A relative increase in coiling of ruptured aneurysms was noted in low coiling volume hospitals of 41.1% (95%CI, 32.3-50.6, p=0.008) despite a decrease in SAH admissions in this tertile. Conclusions: There was a global decrease in subarachnoid hemorrhage admissions and ruptured aneurysm embolizations during the COVID-19 pandemic. Among low-volume coiling SAH hospitals, there was an increase in the ruptured aneurysm coiling intervention. These findings in SAH are consistent with a global decrease in other emergencies such as stroke and myocardial infarction.*On behalf of the SVIN COVID-19 Collaborators

Abstract P418: Stroke Admissions and Outcomes Among Cerebral Amyloid Angiopathy and Alzheimer’s Disease in the National Inpatient Sample

Background/Purpose: Although cerebral amyloid angiopathy (CAA) and Alzheimer’s Disease (AD) can manifest as separate diseases it can co-exist due to shared amyloid β pathogenic mechanisms. We assessed admission rates and outcomes of ischemic stroke (IS), intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH) among hospitalized patients with a secondary diagnosis of AD and CAA. Methods: Adult patients discharged with a secondary diagnosis of CAA or AD in National Inpatient Sample (NIS) in the years 2016 and 2017 were identified. Admission rates for IS, ICH, and SAH were primary outcomes. In-hospital mortality and discharge to home were secondary outcomes. Multivariate logistic regression analysis was performed to evaluate secondary outcomes with model adjusted for demographics, medical history, hospital characteristics, and Elixhauser comorbidity index. Results: Among 60,609,519 admissions in NIS, 893,834 (1.5%) patients had a secondary diagnosis of AD [mean age 82.1 years and 62% women] and 14,850 (0.02%) patients had CAA [mean age 76.2 years and 51% women]. Combined AD+CAA was present in 1,335 (0.002%) patients. Compared to AD and controls (non AD or CAA), patients with CAA had higher admission rates for IS (11.5% CAA vs 2.8% AD vs 1.7% control, p&lt;0.0001), for ICH (29.5% CAA vs 0.4% AD vs 0.2% control, p&lt;0.0001) and for SAH (3% CAA vs 0.1% AD vs 0.1% control, p&lt;0.0001). Among patients admitted for IS, discharge to home was less likely in AD compared to controls (10.4% AD vs 36.3% control, OR=0.40; 95%CI=0.36-0.44). Among patients admitted for ICH, discharge to home was less likely in AD compared to controls (6.3% AD vs 18.5% control, OR=0.57; 95%CI=0.41-0.78) but higher in CAA (17.8% CAA vs 18.5% control, OR=1.35; 95%CI=1.11-1.63). In-hospital mortality was less likely in patients with CAA than controls among patients admitted for ICH (9.6% CAA vs 23% control, OR=0.33; 95%CI=0.26-0.41) and SAH (6.7% CAA vs 19.1% control, OR=0.27; 95%CI=0.11-0.62). Conclusion: Admissions for IS, ICH, and SAH were higher among CAA compared to AD in NIS. CAA patients had lower in-hospital mortality for ICH and SAH admissions and higher rates of home discharge for ICH admissions. AD patients were less likely to be discharged home for IS and ICH admissions.

Cortical Blood Flow Insufficiency Scores with Computed Tomography Perfusion can Predict Outcomes in Aneurysmal Subarachnoid Hemorrhage Patients: A Cohort Study.

The World Federation of Neurosurgical Societies (WFNS) scale is widely accepted for predicting outcomes for subarachnoid hemorrhage (SAH) patients. However, it is difficult to definitely predict outcomes for the most poor grade, WFNS grade 5. The present study aimed to investigate the prognostic ability of a novel classification using computed tomography perfusion (CTP) findings, called the cortical blood flow insufficiency (CBFI) scores. CTP was performed on admission for aneurysmal SAH followed by radical treatments within 72 hours of onset. Twenty-four cerebral cortex regions of interest (ROIs) were defined. CBFI was defined as Tmax > 4s in each ROI, and CBFI scores were calculated based on the total number of ROIs with CBFI. Using the optimal cutoff value based on receiver operating characteristics (ROC) analysis to predict patient functional outcomes, CBFI scores were divided into "high" or "low" CBFI scores. Patient functional outcomes at 90days were categorized based on modified Rankin Scale scores (0-3, favorable group; 4-6 unfavorable group) (0-4, non-catastrophic group; 5-6, catastrophic group). Fifty-seven patients were included in this study, of whom 21 (36.8%) and 13 (22.8%) were in the unfavorable and the catastrophic groups, respectively. A factor predicting unfavorable and catastrophic outcomes was CBFI score cutoff value of 7 points (area under the curve, 0.73 and 0.81, respectively). In multivariable logistic regression analysis for unfavorable outcome, high CBFI scores (odds ratio (OR), 8.6; 95% confidence interval (CI), 1.1-65.4; P = 0.04) and WFNS grade 5 (OR, 30.0; 95% CI, 4.5-201.0; P < 0.001) remained as independent predictors, while for catastrophic outcome, high CBFI scores (OR, 25.3; 95% CI, 3.3-194.0; P = 0.002) and age (OR, 1.1; 95% CI, 1.0-1.2; P = 0.02) remained as independent predictors. Conversely, WFNS grade 5 was not an independent predictor of catastrophic outcomes (OR, 3.8; 95% CI, 0.6-24.0; P = 0.15). In high CBFI scores, the OR of the delayed cerebral ischemia (DCI) occurrence was 9.6 (95% CI, 1.5-61.4; P = 0.02) after adjusting for age. High CBFI scores could predict unfavorable and catastrophic outcomes for aneurysmal SAH patients and DCI occurrence.

Abstract WP209: Trends in Mortality, Length of Stay and Effect of Teaching Hospital Status in Subarachnoid Hemorrhage Patients in the United States From 2000-2014

Background and Purpose: Subarachnoid Hemorrhage (SAH) is a significant cause of morbidity and mortality in the United States. Mortality and length of stay (LOS) are significant in cases of SAH. The primary objective of our study was to analyze the mortality rate, LOS associated with SAH hospital admissions from 2000 to 2014. We also analyzed if teaching status of the hospital has any effect on LOS and mortality. Methods: Nationwide inpatient sample (NIS) database was used to identify SAH admissions in all patients from 2000 to 2014 using ICD-9-CM code 430 as the principal discharge diagnosis. NIS is the largest all-payer inpatient care database in the United States, containing data on more than 7 million hospital stays. It has a large sample size which is ideal for developing national and regional estimates. Results: A total of 376,263 discharges with a diagnosis of SAH were analyzed from 2000 to 2014 from the NIS database. The number of hospitalizations increased from 24,993 in 2000 to 25,775 in 2014. In-hospital mortality decreased from 25.85% in 2000 to 18.86% in 2014 a decrease of 27.04% (P &lt; 0.0001). Mean LOS has remained the same from 11.8 days to 12 days during the same period. Mortality rates and LOS in non-teaching hospitals was 30.26% and 9.2 days in 2000 and 28.71% and 6.9 days in 2014(P &lt; 0.0001). Mortality rates and LOS in teaching hospitals was 23.3% and 13.2 days in 2000 and 18.28% and 12.5 days in 2014(P &lt; 0.0001). Conclusion: Overall in-hospital mortality associated with SAH has decreased over the years. The decrease in mortality can be attributed to early diagnosis and early institution of aggressive treatments. LOS in teaching hospitals is considerably higher which can be attributed to the complex co-morbid cases admitted and transferred to teaching hospitals. Mortality from SAH in non-teaching hospitals is significantly higher. Further research needs to be done to find the disparities in mortality rates based on teaching status of the hospital.

The Timing of Tracheostomy and Outcomes After Aneurysmal Subarachnoid Hemorrhage: A Nationwide Inpatient Sample Analysis.

The goal of this study was to investigate the association of tracheostomy timing with outcomes after aneurysmal subarachnoid hemorrhage (SAH) in a national population. Poor-grade aneurysmal SAH patients were extracted from the Nationwide Inpatient Sample (2002-2011). Multivariable linear regression was used to analyze predictors of tracheostomy timing and multivariable logistic regression was used to evaluate the association of timing of intervention with mortality, complications, and discharge to institutional care. Covariates included patient demographics, comorbidities, severity of subarachnoid hemorrhage (measured using the NIS-SAH severity scale), hospital characteristics, and other complications and length of stay. The median time to tracheostomy among 1380 poor-grade SAH admissions was 11 (interquartile range: 7-15) days after intubation. The mean number of days from intubation to tracheostomy in SAH patients at the hospital (p < 0.001) was the strongest predictor of tracheostomy timing for a patient, while comorbidities and SAH severity were not significant predictors. Mortality, neurologic complications, and discharge disposition did not differ significantly by tracheostomy time. However, later tracheostomy (when evaluated continuously) was associated with greater odds of pulmonary complications (p = 0.004), venous thromboembolism (p = 0.04), and pneumonia (p = 0.02), as well as a longer hospitalization (p < 0.001). Subgroup analysis only found these associations between tracheostomy timing and medical complications in patients with moderately poor grade (NIS-SAH severity scale 7-9), while there were no significant differences by timing of intervention in very poor-grade patients (NIS-SAH severity scale > 9). In this analysis of a large, national data set, variation in hospital practices was the strongest predictor of tracheostomy timing for an individual. In patients with moderately poor grade, later tracheostomy was independently associated with pulmonary complications, venous thromboembolism, pneumonia, and a longer hospitalization, but not with mortality, neurological complications, or discharge disposition. However, tracheostomy timing was not significantly associated with outcomes in very poor-grade patients.

Re-evaluating the Weekend Effect on SAH: A Nationwide Analysis of the Association Between Mortality and Weekend Admission

Multiple studies have shown worse outcomes in patients admitted for medical and surgical conditions on the weekend. However, past literature analyzing this "weekend effect" on subarachnoid hemorrhage (SAH) found no significant increase in mortality. This study utilizes more recent data to re-evaluate the association between weekend admission and mortality of patients hospitalized for SAH. This retrospective cohort study queried the SAH patients in the Nationwide Inpatient Sample (NIS) database who were discharged from 2006 through 2014 during the weekend. Of the 54,703 admissions for SAH identified during the study period, 14,821 (27.1%) occurred over the weekend. Patients admitted over the weekend had a mean age of 59.2years and were most likely to be female (59.6%), to be white (62.9%), located in the south region of the USA (40.1%), and be admitted to a teaching hospital (74.4%). When compared directly to weekday admissions, patients admitted over the weekend had higher odds of in-hospital mortality (odds ratio 1.07; confidence interval 95%, 1.02-1.12). There was no significant difference shown in the rate patients get surgical clipping versus endovascular coiling (p = 0.28) or the amount of time between admission to procedure for clipping (p = 0.473) or coiling (p = 0.255) on the weekend versus a weekday. Based on our findings, the likelihood of the in-hospital mortality was higher for patients admitted over the weekend. However, the characteristics of the study, primarily observational, prevent us arriving at an accurate conclusion about why this occurs; hence, we believe it is an important starting point to consider for future research.

Preventable Readmissions and Predictors of Readmission After Subarachnoid Hemorrhage.

To estimate rates of all-cause and potentially preventable readmissions up to 90days after discharge for aneurysmal subarachnoid hemorrhage (SAH) and medical comorbidities associated with readmissions BACKGROUND: Readmission rate is a common metric linked to compensation and used as a proxy to quality of care. Prior studies in SAH have reported 30-day readmission rates of 7-17% with a higher readmission risk among those with the higher SAH severity, ≥ 3 comorbidities, and non-home discharge. Intermediate-term rates, up to 90-days, and the proportion of these readmissions that are potentially preventable are unknown. Furthermore, the specific medical comorbidities associated with readmissions are unknown. Index SAH admissions were identified from the 2013 Nationwide Readmissions Database. All-cause readmissions were defined as any readmission during the 30-, 60-, and 90-day post-discharge period. Potentially preventable readmissions were identified using Prevention Quality Indicators developed by the US Agency for Healthcare Research and Quality. Unadjusted and adjusted Poisson models were used to identify factors associated with increased readmission rates. Out of 9987 index admissions for SAH, 7949 (79%) survived to discharge. The percentage of 30-, 60-, and 90-day all-cause readmissions were 7.8, 16.6, and 26%, respectively. Up to 14% of readmissions in the first 30days were considered potentially preventable and acute conditions (dehydration, bacterial pneumonia, and urinary tract infections) accounted for over half, whereas acute cerebrovascular disease was the most common cause for neurological return. In multivariable analysis, significant predictors of a higher readmission rate included diabetes (rate ratio [RR] 1.09, 95% confidence interval [CI] 1.03-1.15), congestive heart failure (RR 1.09, 1.003-1.18), and renal impairment (RR 1.35, 1.13-1.61). Only discharge home was associated with a lower readmission rate (RR 0.89, 0.85-0.93). SAH has a 30-day readmission rate of 7.8% which continues to rise into the intermediate-term. A low but constant proportion of readmissions are potentially preventable. Several chronic medical comorbidities were associated with readmissions. Prospective studies are warranted to clarify causal relationships.

Predicting delayed cerebral ischemia after subarachnoid hemorrhage using physiological time series data

To develop and validate a prediction model for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) using a temporal unsupervised feature engineering approach, demonstrating improved precision over standard features. 488 consecutive SAH admissions from 2006 to 2014 to a tertiary care hospital were included. Models were trained on 80%, while 20% were set aside for validation testing. Baseline information and standard grading scales were evaluated: age, sex, Hunt Hess grade, modified Fisher Scale (mFS), and Glasgow Coma Scale (GCS). An unsupervised approach applying random kernels was used to extract features from physiological time series (systolic and diastolic blood pressure, heart rate, respiratory rate, and oxygen saturation). Classifiers (Partial Least Squares, linear and kernel Support Vector Machines) were trained on feature subsets of the derivation dataset. Models were applied to the validation dataset. The performances of the best classifiers on the validation dataset are reported by feature subset. Standard grading scale (mFS): AUC 0.58. Combined demographics and grading scales: AUC 0.60. Random kernel derived physiologic features: AUC 0.74. Combined baseline and physiologic features with redundant feature reduction: AUC 0.77. Current DCI prediction tools rely on admission imaging and are advantageously simple to employ. However, using an agnostic and computationally inexpensive learning approach for high-frequency physiologic time series data, we demonstrated that our models achieve higher classification accuracy.

Incorporating High-Frequency Physiologic Data Using Computational Dictionary Learning Improves Prediction of Delayed Cerebral Ischemia Compared to Existing Methods.

Accurate prediction of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) can be critical for planning interventions to prevent poor neurological outcome. This paper presents a model using convolution dictionary learning to extract features from physiological data available from bedside monitors. We develop and validate a prediction model for DCI after SAH, demonstrating improved precision over standard methods alone. 488 consecutive SAH admissions from 2006 to 2014 to a tertiary care hospital were included. Models were trained on 80%, while 20% were set aside for validation testing. Modified Fisher Scale was considered the standard grading scale in clinical use; baseline features also analyzed included age, sex, Hunt-Hess, and Glasgow Coma Scales. An unsupervised approach using convolution dictionary learning was used to extract features from physiological time series (systolic blood pressure and diastolic blood pressure, heart rate, respiratory rate, and oxygen saturation). Classifiers (partial least squares and linear and kernel support vector machines) were trained on feature subsets of the derivation dataset. Models were applied to the validation dataset. The performances of the best classifiers on the validation dataset are reported by feature subset. Standard grading scale (mFS): AUC 0.54. Combined demographics and grading scales (baseline features): AUC 0.63. Kernel derived physiologic features: AUC 0.66. Combined baseline and physiologic features with redundant feature reduction: AUC 0.71 on derivation dataset and 0.78 on validation dataset. Current DCI prediction tools rely on admission imaging and are advantageously simple to employ. However, using an agnostic and computationally inexpensive learning approach for high-frequency physiologic time series data, we demonstrated that we could incorporate individual physiologic data to achieve higher classification accuracy.

Abstract TMP59: Predictors of Readmissions After Aneurysmal Subarachnoid Hemorrhage

Objective: To identify factors associated with readmission after aneurysmal subarachnoid hemorrhage (SAH) using nationally representative data Background: Readmission rate is a common metric linked to hospital compensation and as a proxy to quality of care. Prior studies in SAH have reported higher risk of readmission among those with longer length of stay (LOS) and discharge to skilled nursing facility. These studies were limited by small sample sizes and single-center design. Methods: The Nationwide Readmissions Database is a de-identified national database of readmissions with data on 49% of U.S. admissions in 2013. We used International Classification of Disease, Ninth Revision, Clinical Modification codes to identify index SAH admissions, comorbidities, and outcomes. Unadjusted and adjusted Poisson models were used to identify factors associated with increase readmission rate up to 1 year after discharge. Results: Out of 14464 index admissions for SAH, 8587 (59.4%) were female, average age was 61.2±16.1 years, with an even distribution of socioeconomic status. Among 11035 who survived to discharge, there were 2765 readmissions (25.1%) up to 1 year. In univariate analysis, variables associated with increased readmission rate included age, atrial fibrillation, CHF, diabetes, renal impairment, COPD, tracheostomy, percutaneous endoscopic gastrostomy, discharge not to home, and greater LOS. In multivariable analysis, significant predictors of higher readmission rate included LOS (0.001 greater rate per day increase, 95% CI 0.0001-0.002), CHF (rate ratio [RR] 1.08, 1.02-1.14), diabetes (RR 1.09, 1.05-1.14), renal impairment (RR 1.15, 1.09-1.2), COPD (RR 1.08, 1.02-1.14). Factors associated with lower readmission rate were age (0.0013 lower rate per year increase, -0.003, 0.0001) and discharge home (RR 0.92, 0.88-0.95). Conclusions: In this nationwide database several medical comorbidities were associated with higher readmission rates after SAH, in addition to previously reported variables of discharge disposition and LOS. Given that 1 out of 4 SAH patients are readmitted within the year, prospective studies are warranted on the feasibility and efficacy of interventions tailored to high-risk subgroups.

Decreasing Risk of Fatal Subarachnoid Hemorrhage and Other Epidemiological Trends in the Era of Coiling Implementation in Australia.

Subarachnoid hemorrhage (SAH) is associated with a high risk of mortality and disability in survivors. We examined the epidemiology and burden of SAH in our population during a time services were re-organized to facilitate access to evidence-based endovascular coiling and neurosurgical care. SAH hospitalizations from 2001 to 2009, in New South Wales, Australia, were linked to death registrations to June 30, 2010. We assessed the variability of admission rates, fatal SAH rates and case fatality over time and according to patient demographic characteristics. There were 4,945 eligible patients admitted to hospital with SAH. The risk of fatal SAH significantly decreased by 2.7% on average per year (95% CI = 0.3-4.9%). Case fatality at 2, 30, 90, and 365 days significantly declined over time. The average annual percentage reduction in mortality ranged from 4.4% for 30-day mortality (95% CI -6.1 to -2.7) (P < 0.001) to 4.7% for mortality within 2 days (-7.1 to -2.2) (P < 0.001) (Table 3). Three percent of patients received coiling at the start of the study period, increasing to 28% at the end (P-value for trend <0.001). Females were significantly more likely to be hospitalized for a SAH compared to males [incident rate ratio (IRR) = 1.33, 95% CI = 1.23-1.44] (P < 0.001) and to die from SAH (IRR = 1.40, 95% CI = 1.24-1.59) (P < 0.001). People born in South-East Asia and the Oceania region had a significantly increased risk of SAH, while the risk of fatal SAH was greater in South-East and North-East Asian born residents. People residing in areas of least disadvantage had the lowest risk of hospitalization (IRR = 0.83, 95% CI = 0.74-0.92) and also the lowest risk of fatal SAH (0.81, 95% CI = 0.66-1.00) (P < 0.001 and P = 0.003, respectively). For every 100 SAH admissions, 20 and 15 might be avoided in males and females, respectively, if the risk of SAH in our population equated to that of the most socio-economically advantaged. Our study reports reductions in mortality risk in SAH corresponding to identifiable changes in health service delivery and evolving treatments such as coiling. Addressing inequities in SAH risk and mortality may require the targeting of prevalent and modifiable risk factors to improve population outcomes.

Impact of Weekend Presentation on Short-Term Outcomes and Choice of Clipping vs Coiling in Subarachnoid Hemorrhage.

Presentation on a weekend is commonly associated with higher mortality and a decreased likelihood of receiving invasive procedures. To determine whether weekend presentation influences mortality, discharge destination, or type of treatment received (clip vs coil) in subarachnoid hemorrhage (SAH). We performed a serial cross-sectional retrospective study using the Nationwide Inpatient Sample. All adult discharges with a primary diagnosis of SAH (ICD-9-CM 435) from 2005 to 2010 were included, and records with trauma or arteriovenous malformation were excluded. Unadjusted and adjusted associations between weekend presentation and 3 outcomes (in-hospital mortality, discharge destination, and treatment with clip vs coil) were estimated using chi-square tests and multilevel logistic regression. A total of 46 093 admissions for nontraumatic SAH were included in the sample; 24.6% presented on a weekend, 68.9% on a weekday, and 6.5% had unknown day of presentation. Weekend admission was not a significant predictor of inpatient mortality (25.4% weekend vs 24.9% weekday; P = .44), or a combined poor outcome measure of mortality or discharge to long-term acute care or hospice (30.3% weekend vs 29.4% weekday; P = .23). Among those treated for aneurysm obliteration, the proportion of clipped vs coiled did not change with weekend vs weekday presentation (21.5% clipped with weekend presentation vs 21.6% weekday, P = .95; 21.5% coiled with weekend presentation vs 22.4% weekday, P = .19). Presentation with nontraumatic SAH on a weekend did not influence mortality, discharge destination, or type of treatment received (clip vs coil) compared with weekday presentation.

Associations between Temperature and Hospital Admissions for Subarachnoid Hemorrhage in Korea.

The relationship between temperature and subarachnoid hemorrhage (SAH) is less studied than that between temperature and myocardial infarction or other cardiovascular diseases. This study investigated the association between daily temperature and risk of SAH by analyzing the hospital admission records of 111,316 SAH patients from 2004 to 2012 in Korea. A Poisson regression model was used to examine the association between temperature and daily SAH hospital admissions. To analyze data and identify vulnerable groups, we used the following subgroups: sex, age, insurance type, area (rural or urban), and different climate zones. We confirmed a markedly higher SAH risk only for people of low socioeconomic status in both hot and cold temperatures; the relative risk (RR) in the Medicaid group was significantly increased and ranged from 1.04 to 1.11 for cold temperatures and 1.10 to 1.11 for hot temperatures. For the National Health Insurance group, the RR was increased to 1.02 for the maximum temperature only. The increased risk for SAH was highest in the temperate zone. An increase above the heat threshold temperature and a decrease below the cold threshold temperature were correlated with an increased risk of SAH in susceptible populations and were associated with different lag effects and RRs.

Seasonality of stroke in Finland

Introduction: The burden of stroke is increasing globally. Reports on seasonal variations in stroke occurrence are conflicting and long-term data are absent.Methods: A retrospective cohort study using discharge registry data of all acute stroke admissions in Finland during 2004–2014 for patients ≥18 years age. A total of 97,018 admissions for ischemic stroke (IS) were included, 18,252 admissions for intracerebral hemorrhage (ICH) and 11,271 admissions for subarachnoid hemorrhage (SAH).Results: The rate of IS admissions increased (p = 0.025) while SAH admission rate decreased (p < 0.0001), and ICH admission rate remained stable during the study period. The lowest seasonal admission rates were detected in summer and the highest in autumn for all stroke subtypes. Seasonal variation of IS was more pronounced in men (p = 0.020), while no sex difference was detected in ICH or SAH. The seasonal patterns of in-hospital mortality and length of stay (LOS) differed markedly by stroke subtype. Diagnoses of hypertension, atrial fibrillation, or diabetes showed no seasonality.Conclusions: All major stroke subtypes occurred most commonly in autumn and most infrequently in summer. Seasonality of in-hospital mortality and length of hospital stay appears to vary by stroke subtype. The seasonal pattern of ischemic stroke occurrence appears to have changed during the past decades.Key messagesAll major stroke subtypes (ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage) occurred most frequently in autumn and least frequently in summer.Seasonal patterns of in-hospital mortality and length of stay differed markedly by stroke subtype.The seasonal pattern of ischemic stroke occurrence in Finland seems to have changed compared to 1982–1992.

Subarachnoid hemorrhage admissions retrospectively identified using a prediction model.

Objective:To create an accurate prediction model using variables collected in widely available health administrative data records to identify hospitalizations for primary subarachnoid hemorrhage (SAH).Methods:A previously established complete cohort of consecutive primary SAH patients was combined with a random sample of control hospitalizations. Chi-square recursive partitioning was used to derive and internally validate a model to predict the probability that a patient had primary SAH (due to aneurysm or arteriovenous malformation) using health administrative data.Results:A total of 10,322 hospitalizations with 631 having primary SAH (6.1%) were included in the study (5,122 derivation, 5,200 validation). In the validation patients, our recursive partitioning algorithm had a sensitivity of 96.5% (95% confidence interval [CI] 93.9–98.0), a specificity of 99.8% (95% CI 99.6–99.9), and a positive likelihood ratio of 483 (95% CI 254–879). In this population, patients meeting criteria for the algorithm had a probability of 45% of truly having primary SAH.Conclusions:Routinely collected health administrative data can be used to accurately identify hospitalized patients with a high probability of having a primary SAH. This algorithm may allow, upon validation, an easy and accurate method to create validated cohorts of primary SAH from either ruptured aneurysm or arteriovenous malformation.

Ambient Nitric Oxide Associated with Increased Risk of Emergency Hospital Admission for Subarachnoid Hemorrhage

Introduction: Subarachnoid hemorrhage accounts for nearly 10% of the amount of stroke cases and usually leads to death or complications. Within the human body, nitric oxide also could be generated either by classical nitric oxide synthase (NOS) in oxygen sufficient circumstances, or through the nitrate-nitrite-nitric oxide pathway in low oxygen tension. Endogenous nitric oxide is regarded as playing an important role in many physiological processes. However, a number of studies have reported the air pollutant nitric oxide is associated with human disease. No previous study has investigated the links between ambient nitric oxide and the hospital emergency admissions for subarachnoid hemorrhage. Methods: A log-linear time series regression with quasi-Poisson was applied to estimate the association between nitric oxide and the emergency hospital admissions of subarachnoid hemorrhage. In addition, time series regression with binary outcomes and negative binomial model as alternative analytical methods were also attempted to overcome the problems of overdispersion and excessive zero count outcomes. Results: In the current study, nitric oxide has positive and statistically significant associations with male subarachnoid hemorrhage admissions. An Interquartile range increase in background nitric oxide was associated with 5.6% [95% confidence interval (95%CI), 2.5 to 8.7] for male subarachnoid hemorrhage hospital admissions on lag 2 day and the corresponding effect for lag 3 day was 5.0% (95%CI, 1.9 to 8.2). In addition, people who were older than 65 years old were more vulnerable to ambient nitric oxide. Conclusions: The present study suggests that ambient nitric oxide was associated with the male emergency hospital admissions of subarachnoid hemorrhage. These findings need to be assessed together with other sources of evidence to better understand the health effects of nitric oxide at environmentally relevant levels.