Incidence and prognosis of stroke in the Belluno province, Italy. First-year results of a community-based study

Case fatality and functional outcome after spontaneous subarachnoid haemorrhage: A systematic review and meta-analysis of time trends and regional variations in population-based studies

INTRODUCTION

A previous systematic review of population-based studies from 1973 to 2002 found a decrease in case fatality for spontaneous subarachnoid haemorrhage, but could not find a sufficient number of studies to assess changes in functional outcome. Since then, treatment has advanced distinctly. We assessed whether case fatality has decreased further and whether functional outcome has improved.

PATIENTS AND METHODS

We searched PubMed and Web of Science for new population-based studies using the same criteria as in our previous systematic review. We assessed changes in case fatality and functional outcome over time using linear regression.

RESULTS

We included 24 new studies with 827 patients and analysed 9542 patients described in 62 study periods between 1973 and 2017. Case fatality decreased by 0.3% (95% CI: -0.7 to 0.1) per year. In a sensitivity analysis excluding studies that did not provide 1-month outcome and outliers, the age and sex-adjusted decrease was 0.1% per year (95% CI: -0.9 to 0.6). The mean case fatality rate decreased from 47% (95% CI: 31-63) in the 1970s to 35% (95% CI: 30-39) in the 1990s, and remained stable in the 2000s (34%; 95% CI: 27-41) and 2010s (38%; 95% CI: 15-60). In 15 studies, the mean proportion of patients living independently increased by 0.2% per year (95%CI: -0.7 to 1.1) and the mean was 45% (95% CI: 39-50) in six studies that reported outcome after 12 months.

DISCUSSION AND CONCLUSION

From 1973 to 2017, the case-fatality rate of spontaneous subarachnoid haemorrhage declined overall by 13.5%, but remained stable over the last two decades. The data on time trends in functional outcome were inconclusive.

An Unusual Case of Thalamic Stroke in a Young Adult With Patent Foramen Ovale and Finasteride Use

Symptomatic cerebral infarcts with cryptogenic ischemic stroke pose diagnostic challenges due to unknown etiology. Notably, up to half of young individuals with cryptogenic stroke exhibit patent foramen ovale (PFO), while finasteride, which is used for male pattern baldness, elevates testosterone levels, potentially increasing the risk of thrombosis. Here, we present a case of thalamic infarction in a 21-year-old male devoid of cerebrovascular risk factors but with PFO and finasteride use. The patient presented with short-term memory issues, otherwise lacking medical history or substance use. Examination revealed neurological deficits, with imaging indicating a left thalamic infarct. Subsequent investigations identified PFO, prompting referral for closure, yielding symptomatic improvement. Furthermore, discontinuation of finasteride was advised due to its thrombotic association. Finasteride's inhibition of 5-alpha reductase 2 increases testosterone conversion to estrogen, potentially promoting thrombosis. Finasteride use can cause thrombotic events, emphasizing its risk. In conclusion, young embolic stroke patients warrant PFO evaluation alongside hypercoagulable workup, with closure benefiting those under the age of 55. Additionally, discontinuing finasteride may mitigate thrombosis risk.

Sex Differences in the Epidemiology of Intracerebral Hemorrhage Over 10 Years in a Population-Based Stroke Registry

BACKGROUND

We investigated incidence and outcome of spontaneous intracerebral hemorrhage (ICH) in a population-based stroke registry and provided data to inform on the figures of the disease in women and in men.

METHODS AND RESULTS

Our prospective population-based registry included patients with first-ever ICH occurring from January 2011 to December 2020. Incidence rates were standardized to the 2011 Italian and European population, and incidence rate ratios were calculated. Multivariate hazard ratios for 30-day and 1-year fatality were estimated with Cox regression, including components of the ICH score and sex. We included 748 first-ever ICHs (41.3% women). Women were significantly older than men at ICH onset (78.9±12.6 versus 73.2±13.6 years; P<0.001) and showed higher clinical severity on presentation (median National Institutes of Health Stroke Scale score, 11 [interquartile range, 6-20] versus 9 [interquartile range, 4-15], respectively; P=0.016). The crude annual incidence rate was 20.2 (95% CI, 18.0-22.6) per 100 000 person-years in women and 30.2 (95% CI, 27.4-33.2) per 100 000 person-years in men); incidence was lower in women versus men (incidence rate ratio, 0.67 [95% CI, 0.58-0.78]; P<0.001) and did not change over time in both sexes (P for trend=0.073 and 0.904, respectively). Unadjusted comparison showed higher 1-year case-fatality rates in women versus men (48.5% versus 40.1%; P=0.026). After adjusting for components of the ICH score, female sex lost significance as a predictor of mortality.

CONCLUSIONS

We found lower ICH incidence in women than in men. However, women showed a higher 1-year case-fatality rate versus men, which was likely related to older age at ICH onset and higher clinical severity. Identification of factors explaining the reported differences is important to develop targeted interventions.

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.

Epidemiology of intracerebral hemorrhage: A systematic review and meta-analysis

Background

Intracerebral hemorrhage (ICH) is associated with high mortality and disability rates. This study aimed to investigate the relationship between sex, age, study year, risk factors, bleeding site, median year of study, and the incidence of ICH.

Method

Literature on the incidence of ICH published on 1 January 1980 and 1 January 2020, was systematically retrieved from PubMed and Embase databases. The random-effects model and subgroup analysis were used to explore the relationship between the incidence of ICH and different ages, sex, bleeding sites, and risk factors.

Results

We summarized the epidemiological changes in ICH in the past 40 years according to 52 studies and found that the total incidence of ICH is 29.9 per 100,000 person-years (95% CI: 26.5–33.3), which has not decreased worldwide. The incidence of ICH in the Asian population is much higher than in other continents. In addition, the incidence of ICH increases with age and differs at the 85-year-old boundary. Men are more likely to develop ICH than women, and the basal ganglia region is the most common area for ICH. Of the 10 risk factors examined in this study, those with hypertension had the highest incidence of ICH, followed by those with excessive alcohol consumption and heart disease.

Conclusion

The prevention and treatment of ICH still need to be improved continuously according to age, sex, risk factors, and other factors, and targeted and normative strategies should be gradually developed in the future.

Global Stroke Statistics 2019

BACKGROUND

Data on stroke epidemiology and availability of hospital-based stroke services around the world are important for guiding policy decisions and healthcare planning.

AIMS

To provide the most current incidence, mortality and case-fatality data on stroke and describe current availability of stroke units around the world by country.

METHODS

We searched multiple databases (based on our existing search strategy) to identify new original manuscripts and review articles published between 1 June 2016 and 31 October 2018 that met the ideal criteria for data on stroke incidence and case-fatality. For data on the availability of hospital-based stroke services, we searched PubMed for all literature published up until 31 June 2018. We further screened reference lists, citation history of manuscripts and gray literature for this information. Mortality codes for International Classification of Diseases-9 and International Classification of Diseases-10 were extracted from the World Health Organization mortality database for each country providing these data. Population denominators were obtained from the World Health Organization, and when these were unavailable within a two-year period of mortality data, population denominators within a two-year period were obtained from the United Nations. Using country-specific population denominators and the most recent years of mortality data available for each country, we calculated both the crude mortality from stroke and mortality adjusted to the World Health Organization world population.

RESULTS

Since our last report in 2017, there were two countries with new incidence studies, China (n = 1) and India (n = 2) that met the ideal criteria. New data on case-fatality were found for Estonia and India. The most current mortality data were available for the year 2015 (39 countries), 2016 (43 countries), and 2017 (7 countries). No new data on mortality were available for six countries. Availability of stroke units was noted for 63 countries, and the proportion of patients treated in stroke units was reported for 35/63 countries.

CONCLUSION

Up-to-date data on stroke incidence, case-fatality, and mortality statistics provide evidence of variation among countries and changing magnitudes of burden among high and low-middle income countries. Reporting of hospital-based stroke units remains limited and should be encouraged.

Worldwide Incidence of Aneurysmal Subarachnoid Hemorrhage According to Region, Time Period, Blood Pressure, and Smoking Prevalence in the Population: A Systematic Review and Meta-analysis

Importance

Subarachnoid hemorrhage (SAH) from ruptured intracranial aneurysms is a subset of stroke with high fatality and morbidity. Better understanding of a change in incidence over time and of factors associated with this change could facilitate primary prevention.

Objective

To assess worldwide SAH incidence according to region, age, sex, time period, blood pressure, and smoking prevalence.

Data Sources

We searched PubMed, Web of Science, and Embase for studies on SAH incidence published between January 1960 and March 2017. Worldwide blood pressure and smoking prevalence data were extracted from the Noncommunicable Disease Risk Factor and Global Burden of Disease data sets.

Study Selection

Population-based studies with prospective designs representative of the entire study population according to predefined criteria.

Data Extraction and Synthesis

Two reviewers independently extracted data according to PRISMA guidelines. Incidence of SAH was calculated per 100 000 person-years, and risk ratios (RRs) including 95% CIs were calculated with multivariable random-effects binomial regression. The association of SAH incidence with blood pressure and smoking prevalence was assessed with linear regression.

Main Outcomes and Measures

Incidence of SAH.

Results

A total of 75 studies from 32 countries were included. These studies comprised 8176 patients with SAH were studied over 67 746 051 person-years. Overall crude SAH incidence across all midyears was 7.9 (95% CI, 6.9-9.0) per 100 000 person-years; the RR for women was 1.3 (95% CI, 0.98-1.7). Compared with men aged 45 to 54 years, the RR in Japanese women older than 75 years was 2.5 (95% CI, 1.8-3.4) and in European women older than 75 years was 1.5 (95% CI, 0.9-2.5). Global SAH incidence declined from 10.2 (95% CI, 8.4-12.5) per 100 000 person-years in 1980 to 6.1 (95% CI, 4.9-7.5) in 2010 or by 1.7% (95% CI, 0.6-2.8) annually between 1955 and 2014. Incidence of SAH declined between 1980 and 2010 by 40.6% in Europe, 46.2% in Asia, and 14.0% in North America and increased by 59.1% in Japan. The global SAH incidence declined with every millimeter of mercury decrease in systolic blood pressure by 7.1% (95% CI, 5.8-8.4) and with every percentage decrease in smoking prevalence by 2.4% (95% CI, 1.6-3.3).

Conclusions and Relevance

Worldwide SAH incidence and its decline show large regional differences and parallel the decrease in blood pressure and smoking prevalence. Understanding determinants for regional differences and further reducing blood pressure and smoking prevalence may yield a diminished SAH burden.

Intracerebral hemorrhage outcome: A comprehensive update

Non-traumatic intracerebral hemorrhage (ICH) is associated with a significant global burden of disease, and despite being proportionally less frequent than ischemic stroke, in 2010 it was associated with greater worldwide disability-adjusted life years lost. The focus of outcome assessment after ICH has been mortality in most studies, because of the high early case fatality which reaches 40% in some population-based studies. The most robust and consistent predictors of early mortality include age, severity of neurological impairment, hemorrhage volume and antithrombotic therapy at the time of the event. Long-term outcome assessment is multifaceted and includes not only mortality and functional outcome, but also patient self-assessment of the health-related quality of life, occurrence of cognitive impairment, psychiatric disorders, epileptic seizures, recurrent ICH and subsequent thromboembolic events. Several scores which predict mortality and functional outcome after ICH have been validated and are useful in the daily clinical practice, however they must be used in combination with the clinical judgment for individualized patients. Management of patients with ICH both in the acute and chronic phases, requires health care professionals to have a comprehensive and updated perspective on outcome, which informs decisions that are needed to be taken together with the patient and next of kin.

Time Trends in Atrial Fibrillation-Associated Stroke and Premorbid Anticoagulation: Population-Based Study and Systematic Review

Background and Purpose- Prevalence of atrial fibrillation (AF) is increasing, but the impact on overall burden of stroke is uncertain, as is the proportion that could be attributed to under anticoagulation. We did a population-based study of AF-associated stroke and a systematic review of time trends in other stroke incidence studies and of rates of premorbid anticoagulation. Methods- The proportion of incident strokes with associated AF was determined in the OXVASC (Oxford Vascular Study; 2002-2017) and in other prospective, population-based stroke incidence studies published before December 2017. Proportions were pooled by Mantel Haenszel methods, and the pooled percentage of cases with premorbid anticoagulation was determined. Analyses were stratified by the age of study population, mid-study year, country, and ethnicity. Results- Of 1928 patients with incident ischemic stroke in OXVASC, 629 (32.6%; 95% CI, 30.5-34.7) were AF associated, consistent with the pooled estimate from 4 smaller studies over the same study period (608/1948; 31.2%, 30.0-32.4; Phet=0.80). The pooled estimate from all studies reporting premorbid AF over 25 million person-years of observation (1960 onwards; 33 reports) was lower (18.6%, 16.8-20.3) and more heterogeneous (Phet<0.0001), but 62% of heterogeneity was explained by the age of study population, study period, country, and ethnicity. The proportion of incident strokes on premorbid anticoagulation increased over time, both for ischemic stroke in OXVASC (2002-2007: 15.1%, 2008-2012: 19.6%, and 2013-2017: 35.9%; Ptrend<0.0001), and across all studies (P=0.002), but the pooled estimates suggested substantial undertreatment even in the most recent periods (2001-2015: 25.7%, 21.1-30.3 and ≥2010: 31.6%, 18.2-44.9). Conclusions- About 1 in 3 incident ischemic strokes are still AF associated, due partly to low rates of anticoagulation for known prior AF, which therefore represents a major public health opportunity to reduce the burden of stroke.

Global stroke statistics

Background Up to date data on incidence, mortality, and case-fatality for stroke are important for setting the agenda for prevention and healthcare. Aims and/or hypothesis We aim to update the most current incidence and mortality data on stroke available by country, and to expand the scope to case-fatality and explore how registry data might be complementary. Methods Data were compiled using two approaches: (1) an updated literature review building from our previous review and (2) direct acquisition and analysis of stroke events in the World Health Organization (WHO) mortality database for each country providing these data. To assess new and/or updated data on incidence, we searched multiple databases to identify new original papers and review articles that met ideal criteria for stroke incidence studies and were published between 15 May 2013 and 31 May 2016. For data on case-fatality, we searched between 1980 and 31 May 2016. We further screened reference lists and citation history of papers to identify other studies not obtained from these sources. Mortality codes for ICD-8, ICD-9, and ICD-10 were extracted. Using population denominators provided for each country, we calculated both the crude mortality from stroke and mortality adjusted to the WHO world population. We used only the most recent year reported to the WHO for which both population and mortality data were available. Results Fifty-one countries had data on stroke incidence, some with data over many time periods, and some with data in more than one region. Since our last review, there were new incidence studies from 12 countries, with four meeting pre-determined quality criteria. In these four studies, the incidence of stroke, adjusted to the WHO World standard population, ranged from 76 per 100,000 population per year in Australia (2009-10) up to 119 per 100,000 population per year in New Zealand (2011-12), with the latter being in those aged at least 15 years. Only in Martinique (2011-12) was the incidence of stroke greater in women than men. In countries either lacking or with old data on stroke incidence, eight had national clinical registries of hospital based data. Of the 128 countries reporting mortality data to the WHO, crude mortality was greatest in Kazhakstan (in 2003), Bulgaria, and Greece. Crude mortality and crude incidence of stroke were both positively correlated with the proportion of the population aged ≥ 65 years, but not with time. Data on case-fatality were available in 42 studies in 22 countries, with large variations between regions. Conclusions In this updated review, we describe the current data on stroke incidence, case-fatality and mortality in different countries, and highlight the growing trend for national clinical registries to provide estimates in lieu of community-based incidence studies.

Changes in stroke incidence, outcome, and associated factors in Porto between 1998 and 2011

Objective

Year 2000 marked a turning point in stroke prevention and treatment in Portugal. In face of high incidence rates stroke awareness campaigns, close surveillance of vascular risk factors and implementation of hospital stroke units were advanced by the National Health Authorities. To understand the effect of such measures, we assessed changes in stroke incidence and short-term outcome using data from two community-based registers undertaken in Porto in 1998–2000 and 2009–2011.

Methods

We used standard diagnostic criteria and multiple overlapping sources of case-ascertainment for first-ever strokes. Short-term outcome was measured by the modified Rankin Scale; disabling stroke was defined whenever post-stroke mRS score>pre-stroke mRS and >1.

Results

Globally, 462 and 405 first-ever stroke cases were registered in 1998–2000 and 2009–2011, respectively. Stroke incidence decreased by 23%, from 261 to 203/100,000 after adjustment for the Portuguese population. Significant reduction was found in those aged <75 years (31%) and in women (32%). Incidence of disabling strokes was reduced by 29%. Fatal strokes decreased by 46%, while intracerebral hemorrhage decreased by 51%. Risk of disability from stroke decreased by 11% (RR = 0.89; 95%CI, 0.81–0.98) in 2009–2011, as found after adjusting for patient/stroke characteristics in a Poisson model. Moreover, when patients arrived hospital within 3 h from stroke onset, the risk of disabling stroke was 0.76 (95%CI, 0.67–0.87) in 2009–2011 vs. 1998–2000, compared to 1.03 (95%CI, 0.89–1.12) for late arrival.

Conclusion

Risk of stroke, mainly of hemorrhagic stroke, was substantially reduced over time. Timely action in acute phase was responsible for the decline in disability across periods.

Increased incidence of subarachnoid hemorrhage during cold temperatures and influenza epidemics

OBJECTIVE

This study investigated whether the increased incidence of aneurysmal subarachnoid hemorrhage (SAH) in winter is related to temperature or increased incidence of influenza. Such relationships may elucidate the pathogenesis of intracranial aneurysm rupture.

METHODS

A nationwide sample of 18,714 patients with SAH was linked with weekly temperature and influenza-like illness consultation data. Poisson regression analyses were used to calculate incidence density ratios (IDRs) with corresponding 95% CIs for the association of SAH incidence with temperature and influenza epidemics; IDRs were adjusted for study year (aIDR). In addition, SAH incidence data from 30 European population-based studies were linked with daily temperature data from the European Climate Assessment.

RESULTS

The aIDR for SAH during influenza epidemics was 1.061 (95% CI 1.022–1.101) in the univariable and 1.030 (95% CI 0.989–1.074) in the multivariable analysis. This association declined gradually during the weeks after epidemics. Per 1°C temperature drop, the aIDR was 1.005 (95% CI 1.003–1.008) in the univariable and 1.004 (95% CI 1.002–1.007) in the multivariable analysis. In the European population-based studies, the IDR was 1.143 (95% CI 1.129–1.157) per 1°C temperature drop.

CONCLUSIONS

The incidence of SAH is increased during cold temperatures and epidemic influenza. Future studies with individual patient data are needed to investigate causality between temperature or influenza and SAH.

Strokes in young adults: epidemiology and prevention

Strokes in young adults are reported as being uncommon, comprising 10%-15% of all stroke patients. However, compared with stroke in older adults, stroke in the young has a disproportionately large economic impact by leaving victims disabled before their most productive years. Recent publications report an increased incidence of stroke in young adults. This is important given the fact that younger stroke patients have a clearly increased risk of death compared with the general population. The prevalence of standard modifiable vascular risk factors in young stroke patients is different from that in older patients. Modifiable risk factors for stroke, such as dyslipidemia, smoking, and hypertension, are highly prevalent in the young stroke population, with no significant difference in geographic, climatic, nutritional, lifestyle, or genetic diversity. The list of potential stroke etiologies among young adults is extensive. Strokes of undetermined and of other determined etiology are the most common types among young patients according to TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria. Prevention is the primary treatment strategy aimed at reducing morbidity and mortality related to stroke. Therefore, primary prevention is very important with regard to stroke in young adults, and aggressive treatment of risk factors for stroke, such as hypertension, smoking, and dyslipidemia, is essential. The best form of secondary stroke prevention is directed toward stroke etiology as well as treatment of additional risk factors. However, there is a lack of specific recommendations and guidelines for stroke management in young adults. In conclusion, strokes in young adults are a major public health problem and further research, with standardized methodology, is needed in order to give us more precise epidemiologic data. Given the increasing incidence of stroke in the young, there is an objective need for more research in order to reduce this burden.

Current status of stroke epidemiology in Greece: a panorama

Although strokes have been documented since about 3 millennia, they remain today as one of the leading causes of mortality, as well as of subsequent serious long-term physical and mental morbidity, among patients in many different countries all over the world. Greece presents an increase in mortality rates according to World Health Organization, and this fact underlines the need for early diagnosis and treatment, as well as, the need to implement effective prevention strategies for strokes. This review makes an effort to describe the current status of stroke epidemiological features, as well as to present the risk factors prevalent in Greece. The incidence rate is 261-319/100,000 based on the recent population based registry. Stroke appears to be more prevalent in men than in women, and the mean age of stroke onset in Greece is at 70 years of age. Hypertension, atrial fibrillation, dyslipidaemia and diabetes mellitus are the major risk factors of stroke in the Greek population, while smoking is the most commonly documented modifiable risk factor in young adults with ischemic stroke. Similar to other parts of the world, ischemic stroke is the most common stroke type. The 28-day case fatality rate for men and women was 26.5%. The mean in-hospital cost per stroke patient was 3624.9 € and the mean rehabilitation cost of outpatients with stroke was 5553.3 €, while the cost proportion of hemorrhagic stroke is higher when compared to ischemic stroke. Stroke is a devastating condition with recognized challenges in identifying effective prevention programs. In Greece, limited data exists regarding the epidemiology of strokes. As a result, the need to conduct new studies and researches across the country is well documented.

Global stroke statistics

In many countries, stroke is a lower priority than other diseases despite its public health impact. One issue is a lack of readily accessible comparative data to help make the case for the development of national stroke strategies. To assist in this process, we need to have a common repository of the latest published information on the impact of stroke worldwide. We aim to provide a repository of the most current incidence and mortality data on stroke available by country and illustrate the gaps in these data. We plan to update this repository annually and expand the scope to address other aspects of the burden of stroke. Data were compiled using two approaches: (1) an extensive literature review with a major focus on published systematic reviews on stroke incidence (between 1980 and May 14, 2013); and (2) direct acquisition and collation of data from the World Health Organization to present the most current estimates of stroke mortality for each country recognized by the World Health Organization. For mortality, ICD8, ICD9, and ICD10 mortality codes were extracted. Using population denominators crude stroke mortality was calculated, as well as adjusting for the World Health Organization world population. We used only the most recent year reported to the World Health Organization. Incidence rates for stroke were available for 52 countries, with some countries having incidence studies undertaken in more than one region. When adjusted to the World Health Organization world standard population, incidence rates for stroke ranged from 41 per 100 000 population per year in Nigeria (1971-74) to 316/ 100 000/year in urban Dar-es-Salaam (Tanzania). Some regions had three to fivefold greater incidence than other countries. Of the 123 countries reporting mortality data, crude mortality was greatest in Kazhakstan (in 2003). In many regions data were very old or nonexistent. Such country-level data are important for citizens, clinicians, and policy makers so that local and global strategies to reduce the overall burden of stroke can be implemented. Through this first annual review of country-specific stroke epidemiology, we hope to promote discussion and provide insights into the worldwide burden of stroke.

Stroke types in rural and urban northern portugal: incidence and 7-year survival in a community-based study

BACKGROUND/AIM

Differences in stroke incidence and mortality between regions could stem from differences in the incidence of particular stroke types and long-term prognosis. The aim of this study was to investigate whether different risk profiles and stroke types underlie the difference in stroke incidence and patient long-term survival in rural and urban populations.

METHODS

All suspected first-ever-in-a-lifetime strokes occurring between October 1998 and September 2000 in 37,290 residents of rural municipalities and in 86,023 individuals living in the city of Porto were entered into a population-based registry. Standard definitions of stroke types and overlapping comprehensive sources of information were used for patient identification. Patients were examined by neurologists at 3 months, 1 year and 7 years after the index event.

RESULTS

From a total of 688 patients included (226 in rural and 462 in urban areas), 76.2% had an ischaemic stroke (IS; 75.3 vs. 77.9%), 16.1% a primary intracerebral haemorrhage (PICH; 16.3 vs. 14.6%) and 3.3% a subarachnoid haemorrhage (SAH; 2.7 vs. 3.7%); in 4.4% (4.9 vs. 4.1%), the stroke type could not be determined. The annual incidence rate per 1,000 was 2.13 (95% CI, 1.95-2.31), 0.45 (95% CI, 0.37-0.53), 0.09 (95% CI, 0.06-0.14) and 0.12 (95% CI, 0.08-0.17), respectively. The age-specific rural/urban incidence rate ratios for IS in the youngest group (<55 years) was 0.27 (95% CI, 0.11-0.69), increasing to 1.47 (95% CI, 1.07-2.01) for those aged 65-74 years and to 1.87 (95% CI, 1.39-2.52) for those between 75 and 84 years. Rural compared to urban patients with an IS were predominantly men, had a prevalence ratio (PR) of 1.28 (95% CI, 1.05-1.56), were 65 years or older (PR = 1.18; 95% CI, 1.08-1.30) and had in general a lower prevalence of risk factors. There was no evidence of rural/urban differences in 28-day case fatality for the stroke types, although IS tended to be less fatal among urban patients (10.3 vs. 13.1%), whereas PICH (33.3 vs. 24.2%) and SAH (35.3 vs. 16.7%) were less fatal among rural patients. Independently of rural/urban residence, predictors of poor survival after the acute phase (28 days) were age >65 years (HR = 3.57; 95% CI, 2.6-4.9), diabetes (HR = 1.5; 95% CI, 1.2-1.9), ischaemic heart disease (HR = 1.8; 95% CI, 1.3-2.6), atrial fibrillation (HR = 1.5; 95% CI, 1.1-2.0) and smoking habits (HR = 1.6; 95% CI, 1.1-2.3).

CONCLUSIONS

The age pattern of IS incidence marks the difference between rural and urban populations; the youngest urban and the oldest rural residents were at a higher risk. Although patients from rural areas were older, the relatively lower prevalence of simultaneously occurring risk and prognostic factors among them as well as the similar management of rural and urban patients may justify why rurality is not associated with long-term survival.

Epidemiology of stroke in Italy

This study reviews available data on stroke epidemiology in Italy. Data were identified through Medline/PubMed, Embase, and from reference lists, related articles, and citation lists of each of the retrieved papers. Nineteen papers were considered, referring to selected stroke-registers performed in seven different geographical areas: Acquaviva-Casamassima county, Aeolian Islands, Aosta district, Belluno district, L'Aquila district, Trasimeno area, and Vibo Valentia district. Registers covered a total population of 2 262 940 people, with a hospitalization rate from 82% to 98%. The mean age at stroke onset was 74·6 ± 1·1 years, 72·3 years in men and 76·6 years in women. Among all strokes: • 67·3-82·6% were classified ischemic • 9·9-19·6% as primary intracerebral hemorrhage • 1·6-4·0% as sub-arachnoid hemorrhage, and • 1·2-17·7% as undetermined. Annual incidence rates standardized to the Italian population ranged from 175/1 00 000 to 360/1 00 000 in men and from 130/1 00 000 to 273/1 00 000 in women. Thirty-day case-fatality rates for all strokes ranged from 18·1% to 33·0% while one-year case-fatality rates ranged from 37·9% to 40·2%. Data from selected Italian registers on stroke incidence and case-fatality indicate the great burden of the disease on our national healthcare system. The continuous implementation of preventive strategies, either population-based or addressed to the single patient at a high risk of stroke, is important to reduce the burden of the disease.

Stroke in the very old: a systematic review of studies on incidence, outcome, and resource use

Background and Purpose. Stroke incidence increases with age and is likely to increase in the aging populations. We investigated incidence, outcome, and resource use in very old subjects with stroke. Methods. We performed a systematic review of available data through electronic search of the literature databases and manual search of reference lists. Data were extracted for the age groups of over 80, 80 to 84 years old, and over 85. Overall incidence rates, expressed as the number of first strokes per 1000 person-years, were estimated using Poisson regression analysis. Odds ratios for the comparisons between subjects over and under 80 were calculated with the Mantel-Haenszel method. Results. We found a high incidence of stroke in the very old. The estimated incidence rates were 20.78 (95% CI 19.69 to 21.87) in subjects over 80, 17.23 (95% CI 15.97 to 18.49) for those 80 to 85 years old, and 20.78 (95% CI 16.74 to 23.78) for those over 85. Subjects over 80 contributed 29.95% of strokes; rates were similar among genders. Thirty-day case fatality rate and occurrence of dependency were higher in subjects over 80, although associated with less frequent hospital and stroke unit admission and less diagnostic resource use. Conclusions. The contribution of very old subjects to the global burden of stroke is relevant and may require efficient dedicated stroke services.

Epidemiology and etiology of young stroke

Introduction. Stroke in people under 45 years of age is less frequent than in older populations but has a major impact on the individual and society. In this article we provide an overview of the epidemiology and etiology of young stroke. Methods. This paper is based on a review of population-based studies on stroke incidence that have included subgroup analyses for patients under 45 years of age, as well as smaller community-based studies and case-series specifically examining the incidence of stroke in the young. Trends are discussed along with the relative frequencies of various etiologies. Discussion. Stroke in the young requires a different approach to investigation and management than stroke in the elderly given differences in the relative frequencies of possible underlying causes. It remains the case, however, that atherosclerosis contributes to a large proportion of stroke in young patients, thus, conventional risk factors must be targeted aggressively.

Incidence and prognosis of stroke in young adults: a population-based study in Ferrara, Italy

The reported annual incidence of juvenile stroke ranges from 9 to 47 cases per 100,000 inhabitants. We sought to estimate the incidence of first-ever stroke in young adults through a population-based stroke registry in a well-defined and stable population. We planned to collect all cases of new stroke in people aged 15-44 years in Ferrara, Italy, over the period 2002-2007. During the surveillance period, a first-ever stroke was diagnosed in 39 patients, giving a mean annual crude incidence rate of 12.1 cases per 100,000 person-years (95% CI 8.6-16.5), 9.1 when adjusted to the European population. The overall 30-day case fatality rate was 7.7, 21.4% for hemorrhagic stroke. The incidence rate was in the range of estimates detected in western countries. The case-fatality rate was lower than that reported in less recent studies. The stroke subtype predicted the probability of death and the outcome.

The effect of survival bias on case-control genetic association studies of highly lethal diseases

BACKGROUND

Survival bias is the phenomenon by which individuals are excluded from analysis of a trait because of mortality related to the expression of that trait. In genetic association studies, variants increasing risk for disease onset as well as risk of disease-related mortality (lethality) could be difficult to detect in genetic association case-control designs, possibly leading to underestimation of a variant's effect on disease risk.

METHODS AND RESULTS

We modeled cohorts for 3 diseases of high lethality (intracerebral hemorrhage, ischemic stroke, and myocardial infarction) using existing longitudinal data. Based on these models, we simulated case-control genetic association studies for genetic risk factors of varying effect sizes, lethality, and minor allele frequencies. For each disease, erosion of detected effect size was larger for case-control studies of individuals of advanced age (age >75 years) and/or variants with very high event-associated lethality (genotype relative risk for event-related death >2.0). We found that survival bias results in no more than 20% effect size erosion for cohorts with mean age <75 years, even for variants that double lethality risk. Furthermore, we found that increasing effect size erosion was accompanied by depletion of minor allele frequencies in the case population, yielding a "signature" of the presence of survival bias.

CONCLUSIONS

Our simulation provides formulas to allow estimation of effect size erosion given a variant's odds ratio of disease, odds ratio of lethality, and minor allele frequencies. These formulas will add precision to power calculation and replication efforts for case-control genetic studies. Our approach requires validation using prospective data.

Mild-to-moderate neurogenic pyrexia in acute cerebral infarction

BACKGROUND

Pyrexia is often associated with unfavorable stroke outcomes. However, limited information is available on the relationship between the causes of poststroke hyperthermia and stroke prognosis, especially for mild-to-moderate neurogenic pyrexia in acute cerebral infarction.

AIMS

To compare the differences in the clinical features and characteristics of pyrexia as well as its prognosis among acute cerebral infarction patients with mild-to-moderate neurogenic pyrexia, with infectious pyrexia, and without pyrexia. The focus was on mild-to-moderate neurogenic pyrexia.

METHODS

A total of 709 patients with acute cerebral infarction were prospectively recruited and their clinical data were analyzed.

RESULTS

No significant difference was detected in age, gender, history of smoking, hypertension, or diabetes among the 3 groups (p > 0.05). Patients with mild-to-moderate neurogenic pyrexia and those with infectious pyrexia had higher baseline National Institutes of Health Stroke Scale (NIHSS) scores (15.1 ± 6.7, p = 0.003; 14.3 ± 8.1, p = 0.002, respectively), lower 3-month Barthel index (BI) values (64.2 ± 40.7, p < 0.001; 61.9 ± 49.3, p < 0.001, respectively) and higher 3-month mortality rates (13%, p = 0.026; 16%, p < 0.001, respectively) than patients without pyrexia (NIHSS score 11.4 ± 7.9; BI 82.6 ± 39.8, and mortality rate 6%, respectively). No difference existed in these parameters between the 2 pyrexia groups (p > 0.05), but mild-to-moderate neurogenic pyrexia had an earlier onset and a shorter duration than infectious pyrexia (p < 0.001).

CONCLUSIONS

Acute cerebral infarction patients with mild-to-moderate neurogenic pyrexia had a similar prognosis compared to those with infectious pyrexia. Mild-to-moderate neurogenic pyrexia is possibly associated with stroke severity.

Incidence of stroke in young adults: a review

Introduction. Stroke in the young may have a dramatic impact on the quality of life in survivors. This study was aimed to evaluate incidence of first-ever stroke in the young by means of a systematic review. Materials and Methods. All papers on incidence of stroke in the young published after 1980, were identified by electronic search of Medline and manual search of reference lists. Only studies recruiting subjects under 44 years of age and with a lower age limit not higher than 20 years were included. Incidence rates were standardized to the 2000 European population according to the direct method. Poisson regression analysis was used to compare studies. Results. 29 studies including 3548 participants were identified. Incidence rates, after excluding a few outliers, ranged between 8.63 and 19.12 for crude rates and between 8.70 and 21.02 for standardized rates. Heterogeneity among studies was statistically significant but improved after excluding 4 studies. Few studies reported the proportions of stroke subtypes. Conclusions. Stroke in subjects under 45 years of age is not such a rare disease and requires specific preventive programs.

Time trends in outcome of subarachnoid hemorrhage: Population-based study and systematic review

BACKGROUND

Treatment of aneurysmal subarachnoid hemorrhage (SAH) has changed substantially over the last 25 years but there is a lack of reliable population-based data on whether case-fatality or functional outcomes have improved.

METHODS

We determined changes in the standardized incidence and outcome of SAH in the same population between 1981 and 1986 (Oxford Community Stroke Project) and 2002 and 2008 (Oxford Vascular Study). In a meta-analysis with other population-based studies, we used linear regression to determine time trends in outcome.

RESULTS

There were no reductions in incidence of SAH (RR = 0.79, 95% confidence interval [CI] 0.48-1.29, p = 0.34) and in 30-day case-fatality (RR = 0.67, 95% CI 0.39-1.13, p = 0.14) in the Oxford Vascular Study vs Oxford Community Stroke Project, but there was a decrease in overall mortality (RR = 0.47, 0.23-0.97, p = 0.04). Following adjustment for age and baseline SAH severity, patients surviving to hospital had reduced risk of death or dependency (modified Rankin score > 3) at 12 months in the Oxford Vascular Study (RR = 0.51, 0.29-0.88, p = 0.01). Among 32 studies covering 39 study periods from 1980 to 2005, 7 studied time trends within single populations. Unadjusted case-fatality fell by 0.9% per annum (0.3-1.5, p = 0.007) in a meta-analysis of data from all studies, and by 0.9% per annum (0.2-1.6%, p = 0.01) within the 7 population studies.

CONCLUSION

Mortality due to subarachnoid hemorrhage fell by about 50% in our study population over the last 2 decades, due mainly to improved outcomes in cases surviving to reach hospital. This improvement is consistent with a significant decrease in case-fatality over the last 25 years in our pooled analysis of other similar population-based studies.

The incidence of major stroke subtypes in southern Italy: a population-based study

BACKGROUND AND PURPOSE

Stroke is characterized by well-defined clinical major subtypes, but there are few studies on incidence rates, aetiologies and outcomes in population-based setting. We assessed the age/sex incidence of the major stroke subtypes in a region of Southern Italy.

METHODS

We established a multisource, prospective population-based register in Puglia, Southern Italy to identify all residents with a first-ever stroke between 1 January 2001 and 31 December 2002.

RESULTS

One hundred and twenty-seven first-ever strokes were diagnosed, and stroke subtype was defined in 119 cases. The incidence rates per 100 000 adjusted to the European population (AEP) were 112 for cerebral infarction (CI), 30 for intracerebral haemorrhage (IH), four for subarachnoid haemorrhage (SH) and nine for undetermined stroke (US). The incidence rates for CI, IH and US approximately doubled with each decade of life and were higher in men. AEP incidence rates for CI in the age groups 45-84 were lower compared to other studies, whilst the corresponding rates for IH were higher.

CONCLUSIONS

This population had a lower incidence of CI compared to other population-based studies from Northern Europe and the United States. Furthermore, with the projected increase in the segment of the very old in the general population, our data indicate that both CI and IH will dramatically increase in the near future.

Incidence, case fatality, and functional outcome of intracerebral haemorrhage over time, according to age, sex, and ethnic origin: a systematic review and meta-analysis

BACKGROUND

Since the early 1980s, imaging techniques have enabled population-based studies of intracerebral haemorrhage. We aimed to assess the incidence, case fatality, and functional outcome of intracerebral haemorrhage in relation to age, sex, ethnic origin, and time period in studies published since 1980.

METHODS

From PubMed and Embase searches with predefined inclusion criteria, we identified population-based studies published between January, 1980, and November, 2008. We calculated incidence and case fatality. Incidences for multiple studies were pooled in a random-effects binomial meta-analysis. Time trends of case fatality were assessed with weighted linear-regression analysis.

FINDINGS

36 eligible studies described 44 time periods (mid-year range 1983-2006). These studies included 8145 patients with intracerebral haemorrhage. Incidence did not decrease between 1980 and 2008. Overall incidence was 24.6 per 100 000 person-years (95% CI 19.7-30.7). Incidence was not significantly lower in women than in men (overall incidence ratio 0.85, 95% CI 0.61-1.18). Using the age group 45-54 years as reference, incidence ratios increased from 0.10 (95% CI 0.06-0.14) for people aged less than 45 years to 9.6 (6.6-13.9) for people older than 85 years. Median case fatality at 1 month was 40.4% (range 13.1-61.0) and did not decrease over time, and was lower in Japan (16.7%, 95% CI 15.0-18.5) than elsewhere (42.3%, 40.9-43.6). Six studies reported functional outcome, with independency rates of between 12% and 39%. Incidence of intracerebral haemorrhage per 100 000 person-years was 24.2 (95% CI 20.9-28.0) in white people, 22.9 (14.8-35.6) in black people, 19.6 (15.7-24.5) in Hispanic people, and 51.8 (38.8-69.3) in Asian people.

INTERPRETATION

Incidence of intracerebral haemorrhage increases with age and has not decreased between 1980 and 2006. Case fatality is lower in Japan than elsewhere, increases with age, and has not decreased over time. More data on functional outcome are needed.

FUNDING

Netherlands Heart Foundation.

Incidence and Case Fatality of Subarachnoid Haemorrhage in Northern Greece: The Evros Registry of Subarachnoid Haemorrhage

Background

Epidemiological data on subarachnoid haemorrhage incidence and case-fatality rates are scarce in the southeastern Mediterranean region. We conducted a population-based study in Evros Province, located in north-eastern Greece, to determine subarachnoid haemorrhage incidence over a 5-year period (2001–2005).

Methods

Evros Province has a well-defined, largely homogeneous population with healthcare organised around a single tertiary-care University Hospital. We organised a prospective computerised registry of permanent Evros residents admitted or transferred to our hospital with a diagnosis of subarachnoid haemorrhage. Standard World Health Organization definitions and overlapping case-finding methods were used to identify all cases of first ever in a lifetime subarachnoid haemorrhage in all age groups, occurring during the study period. The diagnosis was confirmed by computed tomography scan in all hospitalised cases. Sudden deaths attributable to subarachnoid haemorrhage were systematically recorded province-wide by our forensic department and are included in the study.

Results

During the 5-year period, 51 cases of subarachnoid haemorrhage were recorded (28 men, 23 women; mean age 59 ± 17 years). The crude annual incidence rates were 8·3/100000 persons (95% confidence interval: 5·5–12·0) for men, 7·5/100000 (4·8–11·3) for women and 7·9/100000 (5§9–10§4) for all subjects. The standardised incidence rates for groups aged 45–84 years in the European population were 9·3/100000 (5·8–12·8) for men, 6·5/100000 (3·7–9·4) for women and 7·9/100000 (5·7–10·2). The 28-day case-fatality rates for men, women and all subjects were 36% (21–54%), 35% (19–55%) and 35% (24–49%), respectively.

Conclusions

The incidence and case-fatality rate of subarachnoid haemorrhage haemorrhage in Greece appear to be similar to other developed countries. No gender differences in subarachnoid haemorrhage incidence and case-fatality rate were documented.

Changes in case fatality of aneurysmal subarachnoid haemorrhage over time, according to age, sex, and region: a meta-analysis

BACKGROUND

In a systematic review, published in 1997, we found that the case fatality of aneurysmal subarachnoid haemorrhage (SAH) decreased during the period 1960-95. Because diagnostic and treatment strategies have improved and new studies from previously non-studied regions have been published since 1995, we did an updated meta-analysis to assess changes in case fatality and morbidity and differences according to age, sex, and region.

METHODS

A new search of PubMed with predefined inclusion criteria for case finding and diagnosis identified reports on prospective population-based studies published between January, 1995, and July, 2007. The studies included in the previous systematic review were reassessed with the new inclusion criteria. Changes in case fatality over time and the effect of age and sex were quantified with weighted linear regression. Regional differences were analysed with linear regression analysis, and the regions of interest were subsequently defined as reference regions and compared with the other regions.

FINDINGS

33 studies (23 of which were published in 1995 or later) were included that described 39 study periods. These studies reported on 8739 patients, of whom 7659 [88%] were reported on after 1995. 11 of the studies that were included in the previous review did not meet the current, more stringent, inclusion criteria. The mean age of patients had increased in the period 1973 to 2002 from 52 to 62 years. Case fatality varied from 8.3% to 66.7% between studies and decreased 0.8% per year (95% CI 0.2 to 1.3). The decrease was unchanged after adjustment for sex, but the decrease per year was 0.4% (-0.5 to 1.2) after adjustment for age. Case fatality was 11.8% (3.8 to 19.9) lower in Japan than it was in Europe, the USA, Australia, and New Zealand. The unadjusted decrease in case fatality excluding the data for Japan was 0.6% per year (0.0 to 1.1), a 17% decrease over the three decades. Six studies reported data on case morbidity, but these were insufficient to assess changes over time.

INTERPRETATION

Despite an increase in the mean age of patients with SAH, case-fatality rates have decreased by 17% between 1973 and 2002 and show potentially important regional differences. This decrease coincides with the introduction of improved management strategies.

FUNDING

Netherlands Organisation for Scientific Research; ZonMw.

Worldwide stroke incidence and early case fatality reported in 56 population-based studies: a systematic review

This systematic review of population-based studies of the incidence and early (21 days to 1 month) case fatality of stroke is based on studies published from 1970 to 2008. Stroke incidence (incident strokes only) and case fatality from 21 days to 1 month post-stroke were analysed by four decades of study, two country income groups (high-income countries and low to middle income countries, in accordance with the World Bank's country classification) and, when possible, by stroke pathological type: ischaemic stroke, primary intracerebral haemorrhage, and subarachnoid haemorrhage. This Review shows a divergent, statistically significant trend in stroke incidence rates over the past four decades, with a 42% decrease in stroke incidence in high-income countries and a greater than 100% increase in stroke incidence in low to middle income countries. In 2000-08, the overall stroke incidence rates in low to middle income countries have, for the first time, exceeded the level of stroke incidence seen in high-income countries, by 20%. The time to decide whether or not stroke is an issue that should be on the governmental agenda in low to middle income countries has now passed. Now is the time for action.

Impact of functional status at six months on long term survival in patients with ischaemic stroke: prospective cohort studies

OBJECTIVE

To estimate the impact on long term survival of functional status at six months after ischaemic stroke.

DESIGN

Prospective cohort study. Settings Three cohorts: Oxfordshire community stroke project, Lothian stroke register, and the first international stroke trial (in the United Kingdom).

PARTICIPANTS

7710 patients with ischaemic stroke registered between 1981 and 2000 and followed up for a maximum of 19 years.

MAIN OUTCOME MEASURES

Functional status at six months after stroke assessed with modified Rankin scale or "two simple questions." Mortality during follow-up. Survival analysis with Kaplan-Meier curves, log rank test, and Cox's regression model.

RESULTS

In a combined analysis of all three cohorts, among patients who survived to assessment six months after the index stroke, the subsequent median length of survival among those independent in daily living and those dependent was 9.7 years (95% confidence interval 8.9 to 10.6) and 6.0 years (5.7 to 6.4), respectively. In a combined analysis of the Oxfordshire and Lothian cohorts, subsequent median survival fell progressively from 12.9 years (10.0 to 15.9) for patients with a Rankin score of 0-1 at six months after the stroke to 2.5 years (1.4 to 3.5) for patients with a Rankin score of 5. All previously stated differences in median survival were significant (log rank test P<0.001). The influence of functional outcome on survival remained significant (P<0.05) in each cohort after adjustment for relevant covariates (such as age, presence of atrial fibrillation, visible infarct on computed tomography, subtype of stroke) in a Cox's regression model.

CONCLUSION

Functional status six months after an ischaemic stroke is associated with long term survival. Early interventions that reduce dependency at six months might have positive effects on long term survival.

Incidence of subarachnoid haemorrhage: a systematic review with emphasis on region, age, gender and time trends

BACKGROUND AND AIM

To update our 1996 review on the incidence of subarachnoid haemorrhage (SAH) and assess the relation of incidence with region, age, gender and time period.

METHODS

We searched for studies on the incidence of SAH published until October 2005. The overall incidences with corresponding 95% confidence intervals were calculated. We determined the relationship between the incidence of SAH and determinants by means of univariate Poisson regression.

RESULTS

We included 51 studies (33 new), describing 58 study populations in 21 countries, observing 45,821,896 person-years. Incidences per 100,000 person-years were 22.7 (95% CI 21.9 to 23.5) in Japan, 19.7 (18.1 to 21.3) in Finland, 4.2 (3.1 to 5.7) in South and Central America, and 9.1 (8.8 to 9.5) in the other regions. With age category 45-55 years as the reference, incidence ratios increased from 0.10 (0.08 to 0.14) for age groups younger than 25 years to 1.61 (1.24 to 2.07) for age groups older than 85 years. The incidence in women was 1.24 (1.09 to 1.42) times higher than in men; this gender difference started at age 55 years and increased thereafter. Between 1950 and 2005, the incidence decreased by 0.6% (1.3% decrease to 0.1% increase) per year.

CONCLUSIONS

The overall incidence of SAH is approximately 9 per 100,000 person-years. Rates are higher in Japan and Finland and increase with age. The preponderance of women starts only in the sixth decade. The decline in incidence of SAH over the past 45 years is relatively moderate compared with that for stroke in general.

Epidemiology of stroke in Europe: Geographic and environmental differences

The development of stroke registries has allowed the accumulation of a wealth of data on the descriptive epidemiology of stroke and its evolution in space and in time. For instance, there has been an observed decrease of stroke incidence and mortality in Western Countries during the past 20 years. The use of brain imaging technologies including CT scan and MRI, along with improved cardiac and vascular imaging, has allowed better identification of risk factors for stroke. Hypertension remains the main risk factor for both ischemic and hemorrhagic strokes, and its treatment is effective in reducing first-ever and recurrent stroke incidence. Major medical progress has been achieved in the development of effective medications for hypertension control in the last 2 decades. Despite these advances, we observe large differences in the incidence and mortality rates of stroke throughout the European community. In this review we pose some questions regarding the possible reasons for these differences and we analyze the issue of environmental factors such as meteorological factors and pollution as stroke risk factors.

Evidence for Age-Dependent Education-Related Differences in Men and Women with First-Ever Stroke

Several studies have shown a relationship between low socioeconomic status, age and stroke mortality. However, there is lack of similar studies in relation to stroke incidence. All cases of first-ever stroke occurring in a population aged 35-85 years from the city of Umeå were collected from hospital-based registers during a 2-year study period (2000-2002), from death certificates and also from nursing homes during a 6-month period. The WHO definition of stroke was used. Register data served to analyze educational level. A total of 457 first-ever strokes (244 women and 213 men) were registered, corresponding to an overall annual incidence rate of first-ever stroke of 413.4 per 100,000. The incidence of first-ever stroke was significantly higher among low-educated compared to high-educated men and women. The highest stroke incidence was found among low-educated women aged 75-85 years. The educational-related differences in stroke incidence persisted in the oldest age group (75-85 years), also after controlling for sex and age. This is one of the first studies that analyzes first-ever stroke incidence also among elderly men and women (75-85 years) in relation to socioeconomic status. More community-based studies are needed in order to confirm the results.

Ethnic differences in stroke recurrence

OBJECTIVE

To determine whether stroke recurrence and the effect of recurrence on mortality differ by ethnicity.

METHODS

Using methods from the Brain Attack Surveillance in Corpus Christi project, we prospectively identified first-ever ischemic strokes from emergency department logs and hospital admissions (January 2000 to December 2004). Recurrent strokes and deaths were identified for the same period. Cumulative probability of stroke recurrence was estimated. Cox proportional hazards models were used to examine ethnic differences in recurrence and to examine the relation among ethnicity, recurrence, and mortality.

RESULTS

During the time interval, 1,345 first-ever ischemic strokes were validated. Median age of patients was 72 years; 53% were Mexican American (MA). There were 126 recurrent strokes. Cumulative risk for recurrence at 30 days and 1 year was 2.6 and 7.5%, respectively. MAs had higher risk for stroke recurrence (risk ratio, 1.57; 95% confidence interval, 1.05-2.34) compared with non-Hispanic white patients, adjusted for demographics, stroke risk factors, and stroke severity. Stroke recurrence was related to mortality to a similar extent across ethnic groups (non-Hispanic white patients: risk ratio, 3.32; 95% confidence interval, 2.07-5.32; MAs: risk ratio, 2.35; 95% confidence interval, 1.42-3.88).

INTERPRETATION

MAs had higher stroke recurrence risk compared with non-Hispanic white patients. Stroke recurrence had an important impact on mortality. Efforts to reduce stroke recurrence in MAs are needed.

Stroke incidence and prevalence in Europe: a review of available data

Reliable data on stroke incidence and prevalence are essential for calculating the burden of stroke and the planning of prevention and treatment of stroke patients. In the current study we have reviewed the published data from EU countries, Iceland, Norway, and Switzerland, and provide WHO estimates for stroke incidence and prevalence in these countries. Studies on stroke epidemiology published in peer-reviewed journals during the past 10 years were identified using Medline/PubMed searches, and reviewed using the structure of WHO's stroke component of the WHO InfoBase. WHO estimates for stroke incidence and prevalence for each country were calculated from routine mortality statistics. Rates from studies that met the 'ideal' criteria were compared with WHO's estimates. Forty-four incidence studies and 12 prevalence studies were identified. There were several methodological differences that hampered comparisons of data. WHO stroke estimates were in good agreement with results from 'ideal' stroke population studies. According to the WHO estimates the number of stroke events in these selected countries is likely to increase from 1.1 million per year in 2000 to more than 1.5 million per year in 2025 solely because of the demographic changes. Until better and more stroke studies are available, the WHO stroke estimates may provide the best data for understanding the stroke burden in countries where no stroke data currently exists. A standardized protocol for stroke surveillance is recommended.

Incidence, 30-day case-fatality rate, and prognosis of stroke in Iquique, Chile: a 2-year community-based prospective study (PISCIS project)

BACKGROUND

The epidemiology of stroke in Latin-American populations and variation of subtypes between communities are unclear. Our aim was to ascertain prospectively the incidence of first-ever stroke in the predominantly Hispanic-Mestizo population of Iquique, a city in the northern desert region of Chile.

METHODS

We prospectively identified all possible cases of stroke and transient ischaemic attacks between July 1, 2000, and June 30, 2002, from several overlapping sources. Patients were rapidly assessed by two field neurologists. Standard definitions for incident cases, stroke, transient ischaemic attack, pathological type, and infarction subtype were used. All cases identified were adjudicated by at least two stroke neurologists and followed up at 6 months. Incidence rates of first-ever strokes were calculated from the population of Iquique (214 526) according to the national census of 2002.

FINDINGS

Of 380 cases of stroke identified, 292 were incident. CT scans were done in 267 (91%) patients and the mean time to scan was 2.2 days. The hospital admission rate was 71% (207/292). The overall age-adjusted incidence rate of first-ever stroke was 140.1 per 100,000 (95% CI 124.0-156.2). The incidence rates per 100,000 according to pathological type were: infarcts 87.3, intracerebral haemorrhage 27.6, and subarachnoid haemorrhage 6.2. The 30 day and 6-month case-fatality rates were 23.3% and 33.0%, respectively.

INTERPRETATION

Our results show incidence rates of stroke similar to those reported in other community studies. Although the proportion of intracerebral haemorrhages was higher than reported in previous studies, the overall incidence was not, which could indicate a slightly lower incidence of ischaemic strokes in this population than in other countries. The prognosis was similar to that found in other population-based studies.

Stroke

Stroke is a major public-health burden worldwide. Prevention programmes are essential to reduce the incidence of stroke and to prevent the all but inevitable stroke epidemic, which will hit less developed countries particularly hard as their populations age and adopt lifestyles of the more developed countries. Efficient, effective, and rapid diagnosis of stroke and transient ischaemic attack is crucial. The diagnosis of the exact type and cause of stroke, which requires brain imaging as well as traditional clinical skills, is also important when it will influence management. The treatment of acute stroke, the prevention and management of the many complications of stroke, and the prevention of recurrent stroke and other serious vascular events are all improving rapidly. However, stroke management will only be most effective when delivered in the context of an organised, expert, educated, and enthusiastic stroke service that can react quickly to the needs of patients at all stages from onset to recovery.

Incidence of first-ever ischemic and hemorrhagic stroke in a well-defined community of southern Italy, 1993-1995

Most epidemiological surveys in the Italian population, have concentrated on areas of northern and central Italy. The incidence of the first-ever ischemic and hemorrhagic strokes in a well-defined population of the province of Foggia, a rural area of southern Italy, over a 3-year period has been investigated, to compare the occurrence of stroke by type in this and other areas. A retrospective study in a local health district (USL FG3) in the province of Foggia was conducted and all cases of first-ever cerebral infarction (CI) and intracerebral hemorrhage (ICH) in the local population (41 269) from January 1, 1993 to December 31, 1995 have been investigated. Case ascertainment was performed by a chart review in the two local hospitals and examination of death certificates. General practitioners were also asked to report on non-hospitalized cases suffering a stroke during the study period. Patients with recurrent stroke, unclassifiable stroke, transient ischemic attacks and subarachnoid hemorrhage were excluded. Risk factors for stroke and 30-day mortality were investigated. The rates were standardized to the Italian population (57 138 489, 1991 census). During the 3-year study period, 202 patients had a first-ever ischemic or hemorrhagic stroke (66 in 1993, 69 in 1994 and 67 in 1995). Of these, 174 (86.1%) had cerebral ischemia, accounting for 57, 60 and 57 cases in the three index years. The overall crude annual incidence of CI and ICH was 1.60, 1.67 and 1.62 of 1000 for 1993, 1994 and 1995, respectively. The corresponding standardized incidences rates were 2.0, 2.10 and 2.06 of 1000. The rate was 0.11 in patients <55 years of age, and 1.97, 7.01, 13.52, and 25.34 at ages 55-64, 65-74, 75-84, and 85+ years for the entire period; the 30-day mortality was 27.2, 21.7, and 15% for 1993, 1994, and 1995, respectively. Hypertension (45.9%), diabetes (26.4%) and atrial fibrillation (16.6%) were the most common risk factors. The incidence of CI and ICH was similar to that of most other Italian studies. It was constant during the 3-year period, and mostly involved older people.

Recurrence of intracranial aneurysms in autosomal-dominant polycystic kidney disease

BACKGROUND

The natural history of intracranial aneurysms (ICAs) in individuals with autosomal-dominant polycystic kidney disease (ADPKD) is poorly defined.

METHODS

We followed twenty ADPKD subjects, eleven with ruptured and nine with intact ICA, for 15.2 +/- 8.1 years (range, 6.0 to 33.2 years). Initial diagnosis was by four-vessel cerebral angiography in eighteen subjects. Follow-up examinations were four-vessel cerebral angiography in fourteen and magnetic resonance angiography (MRA) in six subjects. We examined the occurrence of new ICAs, an increase in size of existing ICAs, recurrent rupture or surgical intervention, and death.

RESULTS

Age at initial diagnosis of ICA was 37.7 +/- 10.4 years (range, 20.2 to 53.1 years). Seventeen subjects (85%) had an anterior and three (15%) had a posterior ICA at initial diagnosis. On restudy, five subjects (25%) had a significant change, consisting of new ICAs in a different location in all five and an increase in size of an existing ICA in two of the five. All subjects with ruptured ICA and one subject with intact ICA had undergone surgery at the time of initial diagnosis. Ten subjects (50%) underwent further surgery 8.1 +/- 6.1 years later (1.3 to 17 years). No subject died during follow-up and one subject experienced a recurrent RICA (RICA). We were unable to identify risk factors associated with development of a new ICA or increase in size of an existing ICA.

CONCLUSION

Individuals with ADPKD and ICA appear to be at moderate risk for new ICAs and increase in size of existing ICAs; mortality and risk of recurrent rupture, however, appear to be low.

Incidence, risk, and case fatality of first ever stroke in the elderly population. The Rotterdam Study

OBJECTIVE

To estimate the incidence, survival, and lifetime risk of stroke in the elderly population.

METHODS

The authors conducted a study in 7,721 participants from the population based Rotterdam Study who were free from stroke at baseline (1990-1993) and were followed up for stroke until 1 January 1999. Age and sex specific incidence, case fatality rates, and lifetime risks of stroke were calculated.

RESULTS

Mean follow up was 6.0 years and 432 strokes occurred. The incidence rate of stroke per 1,000 person years increased with age and ranged from 1.7 (95% CI 0.4 to 6.6) in men aged 55 to 59 years to 69.8 (95% CI 22.5 to 216.6) in men aged 95 years or over. Corresponding figures for women were 1.2 (95% CI 0.3 to 4.7) and 33.1 (95% CI 17.8 to 61.6). Men and women had similar absolute lifetime risks of stroke (21% for those aged 55 years). The survival after stroke did not differ according to sex.

CONCLUSIONS

Stroke incidence increases with age, also in the very old. Although the incidence rate is higher in men than in women over the entire age range, the lifetime risks were similar for both sexes.

Stroke epidemiology: a review of population-based studies of incidence, prevalence, and case-fatality in the late 20th century

This overview of population-based studies of incidence, prevalence, mortality, and case-fatality of stroke was based on studies from 1990. Incidence (first stroke in an individual's lifetime) and prevalence were computed by age, sex, and stroke type. Age-standardised incidence and prevalence with the corresponding 95% CI were plotted for each study to facilitate comparisons. The review shows that the burden of stroke is high and is likely to increase in future decades as a result of demographic and epidemiological transitions in populations. The main features of stroke epidemiology include modest geographical variation in incidence, prevalence, and case-fatality among the--predominantly white--populations studied so far, and a stabilisation or reversal in the declining secular trends in the pre-1990s rates, especially in older people. However, further research that uses the best possible methods to study the incidence, risk factors, and outcome of stroke are urgently needed in other populations of the world, especially in less developed countries where the risk of stroke is high, lifestyles are changing rapidly, and population restructuring is occurring.

Incidence of intracerebral and subarachnoid haemorrhage in southern Sweden

OBJECTIVES

Spontaneous intracranial haemorrhage-that is, mainly subarachnoid haemorrhage (SAH) and primary intracerebral haemorrhage (PICH)-constitutes an important part of all strokes. As previous epidemiological studies have demonstrated highly variable incidence rates, we conducted a large prospective investigation of all haemorrhagic strokes during a 1 year period.

METHODS

Twelve hospitals serving a defined population of 1.14 million in southern Sweden registered all cases with spontaneous intracranial haemorrhage, including those found dead outside hospitals, during 1996. All patients were examined with CT of the brain or underwent necropsy. Incidence rates adjusted to the Swedish population for age and sex, as well as location of haematoma and prevalence of risk factors were calculated.

RESULTS

A total of 106 patients with SAH and 341 patients with PICH were identified. The annual incidence/100 000 was 10.0 (6.4 for men and 13.5 for women) for SAH and 28.4 (32.2 for men and 24.7 for women) for PICH when adjusted to the Swedish population. Subarachnoid haemorrhage affected twice as many women as men. The incidence of both types of haemorrhage increased with advancing age, but in particular, this was the case for supratentorial PICH. Lobar haematomas were the most common (51.6%) type of PICH. Among patients with PICH, 37% had hypertension, 41% other vascular disease, and 12% were on oral anticoagulation. Among patients with SAH, 28% had hypertension and 18% vascular disease before the haemorrhage but no one was on treatment with oral anticoagulation.

CONCLUSIONS

The incidence of PICH was high, especially for the older age groups. PICH was, on average, three times as common as SAH. The study underscores the importance of PICH and SAH as significant stroke subgroups.

Stroke: epidemiology, clinical picture, and risk factors--Part I of III

The aim of this review is to present the current knowledge regarding stroke. It will appear in three parts (in part II the pathogenesis, investigations, and prognosis will be presented, while part III will consist of the management and rehabilitation). In the current part (I) the definitions of the clinical picture are presented. These include: amaurosis fugax, vertebrobasilar transient ischemic attack, and stroke (with good recovery, in evolution and complete). The role of the following risk factors is discussed in detail: age, gender, ethnicity, heredity, hypertension, cigarette smoking, hyperlipidemia, diabetes mellitus, obesity, fibrinogen and clotting factors, oral contraceptives, erythrocytosis and hematocrit level, prior cerebrovascular and other diseases, physical inactivity, diet and alcohol consumption, illicit drug use, and genetic predisposition. In particular, regarding the carotid arteries, the following characteristics are analyzed: atheroma, carotid plaque echomorphology, carotid stenosis, presence of ulcer, local variations in surface deformability, pathological characteristics, and dissection. Finally the significance of the cerebral collateral circulation and the conditions predisposing to cardioembolism and to cerebral hemorrhage are presented.

Undertreatment of hypertension in community-dwelling older adults: a drug-utilization study in Dicomano, Italy

OBJECTIVE

To define: (1) the prevalence of and (2) factors associated with undertreatment of hypertension in older persons; and (3) the prevalence of specific drug regimens and reasons for their selection.

PARTICIPANTS

Cross-sectional survey of persons aged > or =65 years living in Dicomano, Italy.

MAIN OUTCOME MEASURES

Prevalence of untreated and uncontrolled hypertension, both defined on the basis of two blood pressure (BP) cut-off points (> or =140/90 and > or =160/90 mm Hg) and of the presence of pharmacological treatment Predictors of undertreatment were analysed for the higher BP cut-off only.

RESULTS

Five hundred of 692 (72.3%) and 380/692 (54.9%) participants met the 140/90 and the 160/90 mm Hg BP criterion, respectively. Of the latter, 162 (42.6%) were untreated, 119 (31.3%) had uncontrolled and 99 (26.1%) controlled hypertension. Women [odds ratio (OR), 0.4; 95% confidence interval (CI), 0.2-0.7], participants with coronary artery disease (CAD) (OR, 0.2; 95% CI, 0.1-0.6), stroke (OR, 0.3; 95% CI, 0.1-0.7), and preserved cognitive status (Mini Mental State Examination score >21: 0.3; 95% CI, 0.2-0.7) were more frequently treated. Uncontrolled hypertension was less likely in women (OR, 0.5; 95% CI, 0.3-1.0) and CAD patients (OR, 0.3; 95% CI, 0.1-0.7). Angiotensin converting enzyme (ACE)-inhibitors (55%), calcium (Ca)-antagonists (31%) and diuretics (20%) were the drugs most commonly prescribed. ACE-inhibitors were preferred, and diuretics rarely used, in diabetic subjects. Ca-antagonists were used mostly in CAD participants.

CONCLUSIONS

Hypertension is undertreated in the majority of noninstitutionalized older adults, especially in men with impaired cognition and no vascular disease. Drug regimens are mostly based on ACE-inhibitors and Ca-antagonists, as a result of associated clinical conditions, requiring individualized treatment.