Substantial Within-Country Variation in the Incidence of Subarachnoid Hemorrhage: A Nationwide Finnish Study

Demographic disparities in the incidence and case fatality of subarachnoid haemorrhage: an 18-year nationwide study from New Zealand

Background

Although the incidence and case-fatality of subarachnoid haemorrhage (SAH) vary within countries, few countries have reported nationwide rates, especially for multi-ethnic populations. We assessed the nationwide incidence and case-fatality of SAH in New Zealand (NZ) and explored variations by sex, district, ethnicity and time.

Methods

We used administrative health data from the national hospital discharge and cause-of-death collections to identify hospitalised and fatal non-hospitalised aneurysmal SAHs in NZ between 2001 and 2018. For validation, we compared these administrative data to those of two prospective Auckland Regional Community Stroke Studies. We subsequently estimated the incidence and case-fatality of SAH and calculated adjusted rate ratios (RR) with 95% confidence intervals to assess differences between sub-populations.

Findings

Over 78,187,500 cumulative person-years, we identified 5371 SAHs (95% sensitivity and 85% positive predictive values) resulting in an annual age-standardised nationwide incidence of 8.2/100,000. In total, 2452 (46%) patients died within 30 days after SAH. Compared to European/others, Māori had greater incidence (RR = 2.23 (2.08-2.39)) and case-fatality (RR = 1.14 (1.06-1.22)), whereas SAH incidence was also greater in Pacific peoples (RR = 1.40 (1.24-1.59)) but lesser in Asians (RR = 0.79 (0.71-0.89)). By domicile, age-standardised SAH incidence varied between 6.3-11.5/100,000 person-years and case fatality between 40 and 57%. Between 2001 and 2018, the SAH incidence of NZ decreased by 34% and the case fatality by 12%.

Interpretation

Since the incidence and case-fatality of SAH varies considerably between regions and ethnic groups, caution is advised when generalising findings from focused geographical locations for public health planning, especially in multi-ethnic populations.

Funding

NZ Health Research Council.

Sex-specific socioeconomic risk factors for spontaneous subarachnoid hemorrhage-a case-control study during the 5 years before ictus

Background

There is a difference in the incidence of spontaneous subarachnoid hemorrhage (SAH) between sexes, with the majority of cases occurring in female patients. Although this phenomenon has been studied from a medical perspective, the reasons for the predominance of female cases are still unclear. Non-medical factors, such as a patient's socioeconomic situation, can differ between female and male patients, with health implications. The aim of the study was to identify socioeconomic profiles for both sexes that may be vulnerable to developing SAH. This information could potentially be used for active preventive health efforts.

Methods

This study was based on a 7-year consecutive cohort of 890 patients with SAH treated at Uppsala University Hospital, along with a sex- and age-matched 5:1 control group from Statistics Sweden. The collected information included demographic data, income that was analyzed through "earnings" (EAs), which is defined as the sum of income and other economic compensations related to work, and "disposable income" (DI), which is the net amount that an individual can use. Pension and sickness-related absence from work were measured using early pension (EP), old age pension (OAP), sickness absence (SA), and disability pension (DP). Univariate and multivariate analyses were used.

Results

Among the women, the socioeconomic risk profile for SAH included lower education, unemployment, being registered as living single, residing in a sparsely populated municipality, and increased age. For the men, the risk profile included residing in a sparsely populated municipality and changes in civil status. Both women and men with SAH had lower EAs and DI compared to the controls. Notably, a significantly higher proportion of the women with SAH received DP compared to the controls.

Conclusion

Residing in a sparsely populated area was associated with an increased risk for SAH for both women and men. The women with SAH were more economically vulnerable, whereas the men faced a different type of vulnerability related to changes in civil status. We suggest that healthcare organizations use this information to identify individuals at risk and actively implement preventive measures according to stroke guidelines for both groups.

Temporal trends and practice variation in early repair of the ruptured aneurysm among patients with aneurysmal subarachnoid hemorrhage in the United States, 2012-2019

BACKGROUND

Early repair of the ruptured cerebral aneurysm (RRCA), preferably within 24 h of onset, is endorsed by clinical guideline as the preferred management strategy for patients with aneurysmal subarachnoid hemorrhage (aSAH). However, a comprehensive picture of this guideline-recommended usage in contemporary clinical practice is not available.

AIMS

This study aimed to characterize trends over time and practice variation in the implementation of an early RRCA strategy among patients with aSAH in a large, national representative data.

METHODS

Using data from the 2012-2019 National Inpatient Sample, we measured trends in the proportion of early RRCA, defined as within day 1 of admission, overall, and by demographic and geographical subgroups. In addition, we created multilevel regression models to quantify hospital-level variation in the early RRCA rates.

RESULTS

We identified 82,615 aSAH hospitalizations (mean age = 56.1 years; 68.9% women) undergoing RRCA and, among these, 84.0% (95% confidence interval (CI) = 83.4-84.7%) receiving early RRCA. The proportion of early RRCA increased steadily from 82.5% in 2012 to 85.8% in 2019 (p for trend <0.001). The proportion of patients receiving early RRCA across geographic regions ranged from 78.7% to 87.9%, with a median (interquartile range (IQR)) of 84.2% (83.0-86.1%). In contrast, the delivery of early RRCA varied widely among hospitals, with a median (IQR) rate of 86.1% (75.0-100.0%) and a range from 0% to 100.0%. The median odds ratio for the early use of RRCA treatment was 1.24 (95% CI = 1.21-1.27) in 2019, indicating 24% increased odds of implementing early RRCA if moving from a lower-use to a higher-use hospital.

CONCLUSIONS

Most patients in the United States with aSAH received early RRCA treatment and exhibited an upward trend over the recent 8-year period. However, substantial variation in access to early RRCA was observed across population subgroups, particularly at the hospital level. Future efforts are necessary to identify further sources of this variation and to develop initiatives that could represent an opportunity to optimize guideline-based quality of care in aSAH management.

DATA ACCESS STATEMENT

The data are available from the corresponding author upon reasonable request following completion of onboarding and verification procedures as specified by the HCUP.

Sex Differences in Case Fatality of Aneurysmal Subarachnoid Hemorrhage: A Systematic Review

INTRODUCTION

Aneurysmal subarachnoid hemorrhage (SAH) is more common in women than in men, contrary to most cardiovascular diseases. However, it is unclear whether the case fatality rate (CFR) of SAH also differs by sex. Thus, we performed a systematic review to address the relationship between sex and SAH CFRs.

METHODS

We conducted a systematic literature search in PubMed, Scopus, and Cochrane library databases. We focused on population-based studies that included both nonhospitalized and hospitalized SAHs and had either reported 1-month (28-31 day) SAH CFRs separately for men and women or calculated risk estimates for SAH CFR by sex. For quality classification, we used the Cochrane Collaboration Handbook and Critical Appraisal Skills Program guidelines. We pooled the study cohorts and calculated relative risk ratios (RRs) with 95% confidence intervals (CIs) for SAH death between women and men using a random-effects meta-analysis model.

RESULTS

The literature search yielded 5,592 initial publications, of which 33 study cohorts were included in the final review. Of the 33 study cohorts, only three reported significant sex differences, although the findings were contradictory. In the pooled analysis of all 53,141 SAH cases (60.3% women) from 26 countries, the 1-month CFR did not differ (RR = 0.99 [95% CI: 0.93-1.05]) between women (35.5%) and men (35.0%). According to our risk-of-bias evaluation, all 33 study cohorts were categorized as low quality. The most important sources of bias risks were related to the absence of proper confounding control (all 33 study cohorts), insufficient sample size (27 of 33 study cohorts), and poor/unclear diagnostic accuracy (27 of 33 study cohorts).

CONCLUSION

Contrary to SAH incidence rates, the SAH CFRs do not seem to differ between men and women. However, since none of the studies were specifically designed to examine the sex differences in SAH CFRs, future studies on the topic are warranted.

Risk factor synergism in aneurysmal subarachnoid hemorrhage: a cross-sectional study

BACKGROUND

Spontaneous subarachnoid hemorrhage (SAH) accounts for 5-10% of strokes but a disproportionately large amount of stroke-related morbidity. Several risk factors have been described, including smoking, hypertension, increasing age, and female sex.

METHODS

This cross-sectional study examined all patients with aSAH within a nationally representative catchment from 01/01/2017 to 31/12/2020. Patients with aneurysmal SAH were identified from multiple sources, including a prospective database and death records. The population was estimated from projections from a door-to-door census and risk factors from stratified random sampled surveys conducted on a yearly basis. Poisson regression models were used to estimate the incidence and incidence rate ratios (IRRs) for risk factors with 95% confidence intervals (95% CIs).

RESULTS

We identified 875 cases of aSAH in 11,666,807 patient-years of follow-up, which corresponded to a crude incidence of 7.5 per 100,000 patient-years (95% CI 7-8) and a standardized incidence of 6.1/100,000 (95% CI 5.6-6.5). Smoking was the strongest individual risk factor, with a standardized incidence of 24/100,000 (95% CI 20-27) in smokers compared with 2.6/100,000 (2.1-3.2) in non-smokers (age-adjusted IRR 9.2, 95% CI 6.3-13.6). Hypertension (age-adjusted IRR 3.1, 95% CI 2.2-4.3) and female sex (age-adjusted IRR 1.8, 95% CI 1.4-2.3) were also associated with increased incidence. The highest incidence was observed in hypertensive smokers (standardized incidence 63/100,000, 95% CI 41-84), who had a lifetime risk of aSAH of 6.7% (95% CI 5.4-8.1) after age 35. Compared with participants who were non-smokers without hypertension, the age-adjusted IRR in hypertensive smokers was 27.9 (95% CI 15.9-48.8).

CONCLUSION

Smoking is the most prominent individual risk factor for aSAH. Smoking and hypertension appear to interact to increase the risk of aSAH synergistically.

Case Fatality of Aneurysmal Subarachnoid Hemorrhage Varies by Geographic Region Within Finland: A Nationwide Register-Based Study

BACKGROUND AND OBJECTIVES

Previous studies have reported a substantial between-country variation in the case fatality rates (CFRs) of aneurysmal subarachnoid hemorrhage (SAH). However, contrary to comparisons among countries, nationwide comparisons within countries that focus on populations with equal access to health care and include out-of-hospital deaths in analyses are lacking. Thus, we aimed to investigate whether the SAH CFRs vary between geographic regions within Finland.

METHODS

We identified all hospitalized and nonhospitalized (sudden-death) cases with aneurysmal SAH in Finland during 1998-2017 through 2 externally validated nationwide registers. According to the municipality of residence, we divided the cases with SAH into 5 geographic regions: Southern, Central, Western, Northern, and Eastern Finland, each served by a University Central Hospital with a neurosurgical service. In addition to overall 30-day CFRs, we computed sudden death rates and 30-day CFRs after hospitalization for each region. Using logistic and Poisson regression models, we calculated regional age-adjusted, sex-adjusted, and year-adjusted odds ratios and annual percent changes with 95% CIs for CFRs.

RESULTS

During 1998-2017, we identified a total of 9,443 cases with SAH, of which 3,484 (36.9%) occurred in Southern Finland. In comparison with the overall 30-day CFR of Southern Finland (35.1%), the age-adjusted, sex-adjusted, and study year-adjusted odds of SAH death were 32% (16%-50%) higher in Central Finland (42.7%), 39% (23%-58%) higher in Eastern Finland (43.4%), and 52% (33%-74%) higher in Western Finland (47.1%). The regional differences were present among both sexes, in all age groups, in sudden death rates, and in 30-day CFRs after hospitalization. Between 1998 and 2017, the overall 30-day CFRs decreased in Central (2.4% [1.0%-3.8%] per year) and Southern (1.2% [0.2%-2.2%] per year) Finland, whereas CFRs remained stable in the other regions. In the last 4 years of the study period (2014-2017), Southern Finland had the lowest 30-day CFR (16.5%) among hospitalized patients.

DISCUSSION

SAH CFRs seem to vary significantly even within a country with relatively equal access to health care. Future studies with detailed individual-level data are needed to explore whether health inequities explain the reported findings.

Should individual timeline and serial CT/MRI panels of all patients be presented in acute brain insult cohorts? A pilot study of 45 patients with decompressive craniectomy after aneurysmal subarachnoid hemorrhage

PURPOSE

Our review of acute brain insult articles indicated that the patients' individual (i) timeline panels with the defined time points since the emergency call and (ii) serial brain CT/MRI slice panels through the neurointensive care until death or final brain tissue outcome at 12 months or later are not presented.

METHODS

We retrospectively constructed such panels for the 45 aneurysmal subarachnoid hemorrhage (aSAH) patients with a secondary decompressive craniectomy (DC) after the acute admission to neurointensive care at Kuopio University Hospital (KUH) from a defined population from 2005 to 2018. The patients were indicated by numbers (1.-45.) in the pseudonymized panels, tables, results, and discussion. The timelines contained up to ten defined time points on a logarithmic time axis until death ([Formula: see text]; 56%) or 3 years ([Formula: see text]; 44%). The brain CT/MRI panels contained a representative slice from the following time points: SAH diagnosis, after aneurysm closure, after DC, at about 12 months (20 survivors).

RESULTS

The timelines indicated re-bleeds and allowed to compare the times elapsed between any two time points, in terms of workflow swiftness. The serial CT/MRI slices illustrated the presence and course of intracerebral hemorrhage (ICH), perihematomal edema, intraventricular hemorrhage (IVH), hydrocephalus, delayed brain injury, and, in the 20 (44%) survivors, the brain tissue outcome.

CONCLUSIONS

The pseudonymized timeline panels and serial brain imaging panels, indicating the patients by numbers, allowed the presentation and comparison of individual clinical courses. An obvious application would be the quality control in acute or elective medicine for timely and equal access to clinical care.

Re-Evaluating Risk Factors, Incidence, and Outcome of Aneurysmal and Non-Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Subarachnoid hemorrhage (SAH) is one of the world's most life-threatening types of stroke. SAH can be classified into two main categories, aneurysmal (aSAH) and non-aneurysmal SAH (naSAH). In the present study, we aimed to prospectively evaluate SAH and its subcategories incidences, risk factors, complications, and outcomes in central Iran.

METHODS

All SAH patients diagnosed between 2016 and 2020 were included in Isfahan SAH Registry. Demographic, clinical characteristics, incidence rates (based on age categories), and laboratory/imaging findings were collected and compared between aSAH and naSAH subgroups. Complications during hospital stay and outcomes were also analyzed. Binary logistic regression analysis was performed to investigate the predictors of aSAH versus naSAH. Kaplan-Meier curves and Cox regression were used to evaluate the survival probability.

RESULTS

A total of 461 SAH patients were included through Isfahan SAH Registry. The SAH annual incidence rate was 3.11 per 100,000 person-years. aSAH had higher incidence rate than naSAH (2.08/100,000 vs. 0.9/100,000 person-years, respectively). In-hospital mortality was 18.2%. Hypertension (P = 0.003) and smoking (P = 0.03) were significantly associated with aSAH, whereas diabetes mellitus (P < 0.001) was more associated with naSAH. After Cox regression analysis, there were higher hazard ratios for reduced in-hospital survival in conditions including altered mental status, Glasgow Coma Scale ≤13, rebleeding, and seizures.

CONCLUSIONS

This study provided an updated estimation of SAH and its subgroups incidences in central Iran. Risk factors for aSAH are comparable to the ones reported in the literature. It is noteworthy that diabetes mellitus was associated with a higher incidence of naSAH in our cohort.

Adult-Onset Neuroepidemiology in Finland: Lessons to Learn and Work to Do

Finland is a relatively small genetic isolate with a genetically non-homogenous population. Available Finnish data on neuroepidemiology of adult-onset disorders are limited, and this paper describes the conclusions that can be drawn and their implications. Apparently, Finnish people have a (relatively) high risk of developing Unverricht-Lundborg disease (EPM1), Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), Spinal muscular atrophy, Jokela type (SMAJ) and adult-onset dystonia. On the other hand, some disorders, such as Friedreich's ataxia (FRDA) and Wilson's disease (WD), are almost absent or completely absent in the population. Valid and timely data concerning even many common disorders, such as stroke, migraine, neuropathy, Alzheimer's disease and Parkinson's disease, are unavailable, and there are virtually no data on many less-common neurological disorders, such as neurosarcoidosis or autoimmune encephalitides. There also appear to be marked regional differences in the incidence and prevalence of many diseases, suggesting that non-granular nationwide data may be misleading in many cases. Concentrated efforts to advance neuroepidemiological research in the country would be of clinical, administrative and scientific benefit, but currently, all progress is blocked by administrative and financial obstacles.

Will improved neuroradiology facilities debunk the reported rarity of intracranial aneurysms in Sub-Saharan Africa?

Background:

Intracranial aneurysms (IAN) are rare in the Sub-Saharan Africa unlike other parts of the world. The debate is whether the low frequency might be apparent because of the scarcity of advanced neuroimaging services, or real. This study investigated if improved imaging facilities would debunk the rarity of IAN in our subregion.

Methods:

This is a retrospective cohort study of prospectively recorded data of patients with subarachnoid hemorrhage (SAH) and IAN managed over 19 years (2003–2021), at the study center with a catchment population of over 47 million. The center witnessed progressive improvements in neuroimaging facilities: 2-Slice, 8-slice, and 64-slice computed tomography (CT) and 0.35T, 1.5T magnetic resonance imaging (MRI) during the period.

Results:

There were 241 cases of SAH, but only 166 aneurysms were confirmed in 158 patients. Between 2003 and 2008, only 27 IAN patients (4.5 IAN/year) were diagnosed. After introduction of CT angiography/magnetic resonance angiography MRA using 8-slice CT/0.35T magnetic resonance imaging (MRI), between 2009 and 2014, the frequency of IAN increased to 8/year. Between 2015 and 2018 after installation of a 64-slice CT in 2014, the IAN remained the same (8/year). MRI 1.5T was added in 2018, the frequency doubled to 17 cases/year. The females were more (67.7%), the mean age was 46.3 years, but peak incidence was the sixth decade. Internal carotid artery aneurysms including posterior communicating artery were the most common (43%) followed by ACA with anterior communicating artery (24%) and middle cerebral artery (20%). Multiple aneurysms were seen in ten patients.

Conclusion:

Improved neuroimaging between 2003 and 2021 did not debunk the rarity of IAN in our region.

Case Fatality in Patients With Aneurysmal Subarachnoid Hemorrhage in Finland: A Nationwide Register-Based Study

BACKGROUND AND OBJECTIVES

Although single-center studies have reported declining case fatality rates (CFRs) of aneurysmal subarachnoid hemorrhage (SAH), nationwide reports that also include sudden-death SAHs with long uninterrupted study periods have remained limited. Moreover, little is known about whether the time-dependent trends of SAH CFR differ by age and/or sex. Thus, we aimed to characterize the nationwide changes of SAH CFRs in Finland between 1998 and 2017.

METHODS

We used 2 externally validated nationwide registers to identify all hospitalized and nonhospitalized (sudden-death) aneurysmal SAH events in Finland during 1998-2017. In addition to overall 30-day CFRs, we determined annual proportions of sudden-death and 30-day CFRs among hospitalized patients with SAH. To estimate time-dependent trends, we calculated annual age-adjusted and sex-adjusted CFR changes (percent with 95% CIs).

RESULTS

Between 1998 and 2017, we identified 9,443 cases with SAH (57.6% women), of which 2,245 (23.8%) died before hospitalization and 3,715 (39.3%) died within 30 days after SAH. Among the 7,198 hospitalized patients with SAH, the 30-day CFR was 20.4%. During the study period, the overall age-adjusted and sex-adjusted CFR declined by an average of 1.8% (1.1%-2.6%) per year. The decreases were especially notable in the proportion of sudden deaths among middle-aged (aged 40-64 years) and older (aged 65 years or older) women (2.9% [1.1%-4.7%] and 2.3% [0.7%-4.0%] per year, respectively) and in the CFRs of hospitalized young (younger than 40 years) and middle-aged women (9.1% [2.3%-15.7%] and 4.3% [2.3%-6.5%] per year, respectively). On the contrary, the 30-day CFR of older (aged 65 years or older) hospitalized men increased by 3.5% (0.7%-6.3%) per year, while the proportions of older men who died before hospitalization remained unchanged.

DISCUSSION

The overall CFR of SAH seems to be decreasing, at least among women. The continued high CFR of hospitalized older men requires attention from clinicians and epidemiologists, especially if this trend is also common in other countries.

Aneurysmal subarachnoid haemorrhage in Indigenous and non-Indigenous Australians: A retrospective study assessing patient characteristics and outcome

INTRODUCTION

Smoking and hypertension are prevalent among Indigenous Australians (Aboriginal and Torres Strait Islanders). We investigated if these risk factors suggest a greater rate of aneurysmal subarachnoid haemorrhage in Indigenous Australians (IA) compared to non-IA.

MATERIALS AND METHODS

A retrospective cross-sectional study was performed on data retrieved from the Nationwide Hospital Morbidity Database for all aSAH cases in Australia between 2012 and 2018. Patient characteristics, radiological findings, aneurysm characteristics, treatment characteristics and discharge outcomes were assessed. Crude and age-adjusted incidences, trends of aSAH and case fatality rate over time were calculated.

RESULTS

A total of 12,286 patients were included (285 IA, 12,001 non-IA). Indigenous aSAH patients were significantly younger than non-IA, with 89.8 percent of IA younger than 65 years old (p < 0.001). Crude annual incidences were similar between the 2 cohorts, however age-adjusted incidence shows a RR = 1.4 at 45-59 years in IA patients, compared with their non-IA counterparts. 30-day mortality was similar between the two groups, at 25.3 and 26.9% for IA and non-IA groups, respectively.

CONCLUSION

This 10 year nationwide retrospective study highlights a disparity between the crude and age-adjusted incidence of aSAH in IA compared to non-IA.

Obesity Does Not Protect From Subarachnoid Hemorrhage: Pooled Analyses of 3 Large Prospective Nordic Cohorts

BACKGROUND

Several population-based cohort studies have related higher body mass index (BMI) to a decreased risk of subarachnoid hemorrhage (SAH). The main objective of our study was to investigate whether the previously reported inverse association can be explained by modifying effects of the most important risk factors of SAH-smoking and hypertension.

METHODS

We conducted a collaborative study of three prospective population-based Nordic cohorts by combining comprehensive baseline data from 211 972 adult participants collected between 1972 and 2012, with follow-up until the end of 2018. Primarily, we compared the risk of SAH between three BMI categories: (1) low (BMI<22.5), (2) moderate (BMI: 22.5-29.9), and (3) high (BMI≥30) BMI and evaluated the modifying effects of smoking and hypertension on the associations.

RESULTS

We identified 831 SAH events (mean age 62 years, 55% women) during the total follow-up of 4.7 million person-years. Compared with the moderate BMI category, persons with low BMI had an elevated risk for SAH (adjusted hazard ratio [HR], 1.30 [1.09-1.55]), whereas no significant risk difference was found in high BMI category (HR, 0.91 [0.73-1.13]). However, we only found the increased risk of low BMI in smokers (HR, 1.49 [1.19-1.88]) and in hypertensive men (HR, 1.72 [1.18-2.50]), but not in nonsmokers (HR, 1.02 [0.76-1.37]) or in men with normal blood pressure values (HR, 0.98 [0.63-1.54]; interaction HRs, 1.68 [1.18-2.41], P=0.004 between low BMI and smoking and 1.76 [0.98-3.13], P=0.06 between low BMI and hypertension in men).

CONCLUSIONS

Smoking and hypertension appear to explain, at least partly, the previously reported inverse association between BMI and the risk of SAH. Therefore, the independent role of BMI in the risk of SAH is likely modest.

Trends in Mortality after Intensive Care of Patients with Aneurysmal Subarachnoid Hemorrhage in Finland in 2003-2019: A Finnish Intensive Care Consortium study

Background

Previous studies suggest that case mortality of aneurysmal subarachnoid hemorrhage (aSAH) has decreased during the last decades, but most studies have been unable to assess case severities among individual patients. We aimed to assess changes in severity-adjusted aSAH mortality in patients admitted to intensive care units (ICUs).

Methods

We conducted a retrospective, register-based study by using the prospectively collected Finnish Intensive Care Consortium database. Four out of five ICUs providing neurosurgical and neurointensive care in Finland participated in the Finnish Intensive Care Consortium. We extracted data on adult patients admitted to Finnish ICUs with aSAH between 2003 and 2019. The primary outcome was 12-month mortality during three periods: 2003–2008, 2009–2014, and 2015–2019. Using a multivariable logistic regression model—with variables including age, sex, World Federation of Neurological Surgeons grade, preadmission dependency, significant comorbidities, and modified Simplified Acute Physiology Score II—we analyzed whether admission period was independently associated with mortality.

Results

A total of 1,847 patients were included in the study. For the periods 2003–2008 and 2015–2019, the mean number of patients with aSAH admitted per year increased from 81 to 123. At the same time, the patients’ median age increased from 55 to 58 years (p = 0.001), and the proportion of patients with World Federation of Neurological Surgeons grades I–III increased from 42 to 58% (p < 0.001). The unadjusted 12-month mortality declined from 30% in 2003–2008 to 23% in 2015–2019 (p = 0.001), but there was no statistically significant change in severity-adjusted mortality.

Conclusions

Between 2003 and 2019, patients with aSAH admitted to ICUs became older and the proportion of less severe cases increased. Unadjusted mortality decreased but age and case severity adjusted–mortality remained unchanged.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01420-z.