Community-based Stroke Register Research Articles

Incidence and relative risk of stroke in the diabetic and the non-diabetic population between 1998 and 2014: A community-based stroke register.

One major objective of the St. Vincent Declaration was to reduce excess risk of stroke in people with diabetes mellitus. The aim of this study is to estimate the trend of incidence and relative risk of stroke in the diabetic and the non-diabetic populations in Germany over a 17-year period. We estimated age–sex standardised incidence rates of all stroke and ischaemic stroke in people with and without diabetes based on an ongoing prospective community-based stroke register covering 105,000 inhabitants. Time trends were analysed using Poisson regression. In total, 3,111 individuals (diabetes: 28.4%, men 46.9%, mean age 73.1 years (SD 13.2)) had a first stroke, 84.9% of which were ischaemic stroke. Among people with diabetes we observed a significant reduction in all stroke incidence by 1.5% per year (relative risk: 0.985; 95% confidence interval 0.972–0.9995) Likewise, this incidence tended to decrease for ischaemic stroke by 1% per year (0.993; 0.979–1.008). In contrast, the incidence rate for all stroke remained nearly stable among people without diabetes (1.003; 0.993–1.013) and for ischaemic stroke (1.002; 0.991–1.013). The relative risk comparing diabetic and non-diabetic population decreased for all stroke (two percent annual reduction) but not for ischaemic stroke. Time trends were similar for both sexes regarding all and ischaemic strokes. We found a reduction in risk of stroke in the diabetic population while this rate did not materially change in the non-diabetic population.

Validation of the Swedish inpatient and cause-of-death registers in the context of stroke

Quality follow-up within stroke care is important in times when stroke prevalence is increasing and health care funds are limited. Administrative data, such as data from the inpatient register (IPR) and the cause-of-death register (CDR) are often used for this purpose, but the validity of such data has not been ascertained. During the year 1999-2000, a community-based stroke register was established in a Swedish municipality. Data from that register was compared with two administrative registers, the IPR and the CDR. Using multiple overlapping data sources, 377 patients with first-ever stroke were found in the community-based register. Forty-four of these (12%) were missing in the IPR/CDR. Non-hospitalized patients were less likely to be registered in the IPR/CDR, as were patients who were not initially treated in a stroke unit. Stroke severity was lower among non-registered patients. Thirty patients (8%) in the IPR/CDR were misclassified as stroke patients. Quality follow-up within stroke care could be biased or have low comparability, when administrative data are used. Great caution should be taken when data are derived from the inpatient and cause-of-death registers, and more validation work needs to be carried out in the context of stroke.

A Comparison of Characteristics and Resource Use Between In-hospital and Admitted Patients with Stroke

Although in-hospital stroke is not a common occurrence, it is important to identify what components of stroke care these patients receive. The aims of this study were to estimate the clinical characteristics, process of stroke care, and mortality in patients admitted to hospital with stroke compared with patients with in-hospital strokes. Data from a community-based stroke register (1995-2004) in an inner city multiethnic population of 271,817 in South London, United Kingdom, were analyzed. From a total of 2402 patients, 291 (12.1%) had in-hospital strokes. Patients with in-hospital strokes were more likely to be incontinent, be dysphagic, have a motor deficit, and have a low level of consciousness (P < .001) compared with admitted patients with stroke. Brain imaging was carried out more frequently in admitted patients with stroke (P < .001). Access to stroke unit care was higher in admitted patients with stroke (P < .001). In-hospital patients with stroke had a longer mean length of stay (55.9 days) compared with admitted patients with stroke (37.9 days, P < .001). There were no significant differences between the groups for receipt of physiotherapy or occupational therapy after discharge (P=.232) or receipt of speech and language therapy (P=.345). After adjustment of case mix variables, in-hospital patients with stroke were less likely to undergo imaging (odds ratio [OR]=0.54, 95% confidence interval [CI]=0.33-0.89, P=.015). In-hospital patients with stroke were less likely to be treated in a stroke unit (OR=0.33, 95% CI=0.22-0.50, P < .001) and prescribed antiplatelet therapy at 3 months (OR=0.51, 95% CI=0.30-0.88, P=.015). By 3 months, in-hospital patients with stroke were more likely to have died (P < .001), although this was not significant after case mix adjustment (OR=1.39, 95% CI=0.90-2.15, P=.135). This study demonstrated that in-hospital patients with stroke had worse stroke severity, and poorer access to a number of components of stroke care compared with admitted patients with stroke. All hospitals should include, in their stroke policies and guidelines, evidence-based pathways that prioritize the needs of patients who have a stroke while in hospital.

Case ascertainment in stroke studies: the risk of selection bias.

The purpose was to compare the completeness of case ascertainment in two stroke registers, one local population-based, the other a national quality register (Riks-Stroke), and to examine if patient characteristics could be affected by selection bias. By the way of linking and matching computer files, the completeness of case ascertainment was evaluated. In the local stroke incidence study 377 patients were included. Of them, 63% were reported to the hospital-based national quality register. The case-fatality was lower in the national register. A larger proportion of the patients in the national register appeared to have been treated in a stroke unit and undergone rehabilitation, and computerized tomography seemed to have been performed in a larger proportion. Because of selection bias, outcome data get skewed when case ascertainment does not embrace all stroke cases. A community-based stroke register is the golden standard when measuring stroke incidence.

Incidence, etiology and long-term prognosis of stroke

In Germany, basic data on stroke morbidity are lacking. So far only routine mortality statistics have provided information on epidemiology of stroke. Therefore, a population-based register of stroke was set up in Germany to determine incidence and case fatality in a defined German population. The Erlangen Stroke Register is a prospective community-based study among the 101,450 residents of the city of Erlangen, Bavaria, Germany. All identified cases of first-ever strokes were followed-up to 12 months from onset of stroke. During 2 years of registration, 354 first-ever-in-a-lifetime strokes (FELS) were registered. The diagnosis and stroke type were confirmed by CT scan in 95 % of cases. Fifty-one percent of all FELS occurred in the age group > 75 years of age. After age-adjustment to the German standard population, the incidence rate was 182 per 100,000 (200 per 100,000 for men and 170 per 100,000 for women). Overall case fatality at 28 days was 19.4 %, at 3 months it was 28.5 %, and at 1 year 37.3 %. The first prospective community-based stroke register in Germany including all age groups revealed incidence rates of stroke similar to those reported from other population-based studies in western industrialized countries.

High Incidence Rates of Stroke in Örebro, Sweden: Further Support for Regional Incidence Differences within Scandinavia

Background and Purpose: As a basis for comparison of differences in stroke incidence in Scandinavian countries, a community-based stroke register was established in Örebro in the centre of Sweden. Methods: All first-ever cases of stroke were registered during a 12-month period 1999–2000. The study population was 123,503. The WHO definition of stroke was used. Cases were searched inside as well as outside hospital. Multiple overlapping sources and ‘hot pursuit’ technique were used in the process of case ascertainment. Results: 388 cases of first-ever stroke were found, corresponding to a crude incidence rate of 314 (95% CI, 283–348) per 100,000 per year, 337 (95% CI, 294–386) for females, and 289 (95% CI, 248–336) for males. Adjusted to the European population, the corresponding rates were 254 (95% CI, 227–284) per 100,000 per year, 273 (95% CI, 238–311) for females and 232 (95% CI, 206–261) for males. The overall 28-day case-fatality rate was 19% (95% CI, 15–23). The case-fatality rates for the different subtypes of stroke were as follows: brain infarction, 10%; intracerebral haemorrhage, 20%; subarachnoidal haemorrhage 45%, and undetermined pathological type 56%. Conclusions: The present study as well as other studies in northern and middle Scandinavia show significantly higher incidence rates than studies from other regions. The crude incidence rate, reflecting the age distribution of the population, is even higher, indicating a burden to the community that is rather increasing than decreasing.

The inter- and intraobserver reliabilities of a new classification system for ischaemic stroke: the South London Stroke Register

Objectives: This study aims to determine the inter- and intraobserver reliabilities of an aetiological classification devised as part of a community-based stroke register. Methods: Patients with first-ever acute ischaemic stroke were clinically assessed and received investigation according to a set protocol. Results of the clinical assessment and investigations were used to determine an aetiological stroke subtype for each patient by observer 1. Aetiological subtypes consisted of extracranial large artery atherosclerosis (LAAec), intracranial large artery atherosclerosis (LAAic), high-risk cardioembolism (CH), medium-risk cardioembolism (CM), small vessel occlusion (SVO), other aetiology (OTH), no aetiology identified (NA) and multiple probable or multiple possible aetiology (MPA). The same data were distributed to a further four observers along with the criteria for the classification system. Two of the observers were retested on the same patients after of period of 8 weeks. Inter- and intraobserver agreement was determined using the kappa statistic, which gives the chance-adjusted percentage agreement. Results: Forty-five consecutive patients were included. The overall kappa statistic for ischaemic stroke was 0.91 indicating excellent agreement. Kappa statistics were highest for the more frequent subtypes of SVO (0.97) and CH (0.97). Substantially high kappa statistics were also obtained for the less-frequent categories of LAAec (0.91), CM (0.84), NA (0.89) and MPA (0.87). A low kappa statistic was obtained for the category OTH (0.16), which had a low frequency of reporting, indicating poor agreement. The kappa statistic for probable categories was higher than the kappa statistic for all stroke subtypes at 0.96. Intraobserver agreement between first and second assignments of subtype diagnoses for both observers reached excellent agreement with kappa statistics of 0.83 and 0.85. Conclusion: The aetiological classification system, designed for use in the investigation of the epidemiology, stroke subtype and their relation to the natural history of stroke in a multiethnic inner city population, allows high inter- and intrarater agreements of subtype diagnosis.

Stroke Risk from Multiple Risk Factors Combined with Hypertension: A Primary Care Based Case-control Study in a Defined Population of Northwest England

PURPOSE: To examine how hypertension interacts with other known risk factors in affecting the risk of stroke in a primary care based setting. METHODS: Cases were patients with first-ever stroke identified from the community-based stroke register in 1994–95 in northwest England. Two controls per case were randomly selected from the same primary care site and matched by age and sex. Information on predefined risk factors was extracted from medical records. RESULTS: 267 cases and 534 controls were included. Adjusted odds ratio (OR) for stroke from hypertension was 2.6 (95% confidence interval: 1.7–3.9). In hypertensives who were current smokers, risk of stroke was increased 6 fold OR = 6.1 2.7–13.7 as compared to non-smokers without hypertension. Hypertensives who had a preexisting history of myocardial infarction or obesity or diabetes had 3 fold higher risks of stroke. Subjects with hypertension and with a history of transient ischemic attack or atrial fibrillation had ⩾ 8 fold excess risk of stroke. Among them, the risk was greater in those with poorly controlled or untreated hypertension OR = 13.2 2.6–67.0 and in those with well or moderately controlled OR = 5.2 1.6–17.2 as compared to subjects without both risk factors. There appeared to be a steady increase in risk of stroke according to the number of risk factors present, particularly in hypertensive subjects. CONCLUSIONS: Stroke risks in hypertensives associated with combinations of other risk factors appeared to follow an additive model. Subjects with multiple risk factors should be targeted in order to reduce the overall risk for stroke.

A prospective community-based study of stroke in Germany--the Erlangen Stroke Project (ESPro): incidence and case fatality at 1, 3, and 12 months.

In Germany, basic data on stroke morbidity are lacking. If a population-based register in former East Germany is excluded, only routine mortality statistics have thus far provided information on epidemiology of stroke. Therefore, a population-based register of stroke was set up in Southern Germany to determine incidence and case fatality in a defined German population. The Erlangen Stroke Project (ESPro) is a prospective community-based study among the 101 450 residents of the city of Erlangen, Bavaria, Germany. Standard definitions and overlapping case-finding methods were used to identify all cases of first-ever stroke in all age-groups, occurring in the 2 years of registration (April 1, 1994, to March 31, 1996). All identified cases of first-ever strokes were followed up at 3 and 12 months from onset. During 2 years of registration, 354 first-ever-in-a-lifetime strokes (FELS) were registered. The diagnosis and stroke type were confirmed by CT scan in 95% of cases. Fifty-one percent of all FELS occurred in the age group >/=75 years of age. The crude annual incidence rate was 1.74 per 1000 (1.47 for men and 2.01 for women). After age-adjustment to the European population, the incidence rate was 1.34 per 1000 (1.48 for men and 1. 25 for women). The annual crude incidence rate of cerebral infarction was 1.37/1000, intracerebral hemorrhage 0.24/1000, subarachnoid hemorrhage 0.06/1000, and unspecified stroke 0.08/1000. Overall case fatality at 28 days was 19.4%, at 3 months it was 28.5%, and at 1 year 37.3%. The first prospective community-based stroke register including all age groups in Germany revealed incidence rates of stroke similar to those reported from other population-based studies in western industrialized countries, but lower than that observed in former East Germany.

Trends in case-fatality of stroke in Finland during 1983 to 1992.

Stroke mortality has been declining in Finland during the past 20 years. It is not known, however, whether this favorable development is attributable to the decline in the incidence or case-fatality of stroke. For this reason we examined the trends in case-fatality of stroke, including trends by subtype of stroke. The analyses were carried out using data of the community-based FINMONICA Stroke Register, which was operating in three geographic areas of Finland during 1983 to 1992. All stroke events (n = 11,171) in persons aged 35 to 74 years were included in this register. The 28-day case-fatality of stroke fell yearly by 3.6% (P = .01) in men and by 2.6% (P = .2) in women. At the end of the study period, the average 28-day case-fatality of all strokes was 20% in men and 21% in women. Considerable differences by subtype of stroke were observed. The 28-day case-fatalities at the end of the study period were in men-56% for subarachnoid hemorrhage, 42% for intracerebral hemorrhage, and 14% for cerebral infarction. In women, the corresponding figures were 49%, 49%, and 14%. The 28-day case-fatality of subarachnoid hemorrhage did not change during the study period, but for intracerebral hemorrhage, a significant decline was observed in men and there was a declining trend also in women. The 28-day case-fatality of cerebral infarction declined significantly in both genders. With the exception of subarachnoid hemorrhage, the 28-day case-fatality of stroke has fallen in Finland. It is likely that this fall has contributed to the decline in stroke mortality.

A community based stroke register in a high risk area for stroke in north west England.

STUDY OBJECTIVE: To develop a community based stroke register to assess the magnitude of the problem of stroke in an entire health district in a high risk area for stroke....

Epidemiology of Stroke in Kaunas, Lithuania

In Lithuania, only routine mortality statistics have thus far provided data on the epidemiology of stroke. This study aims to assess the mortality, incidence, and case-fatality rate of stroke in the city of Kaunas, Lithuania, during 1986 to 1988. A community-based stroke register was set up in 1986 to collect data on all suspected events of acute stroke that occurred in the population aged 35 to 64 years permanently residing in Kaunas. Crude and age-standardized attack rates, incidence, mortality, and case-fatality rates were calculated for the period studied. Among men, the average age-standardized incidence of stroke (referring to first-ever events) was 230/100,000, the attack rate (all events) was 300/100,000, and the mortality from all strokes was 68/100,000. Among women, the corresponding rates were 131/100,000, 154/100,000, and 35/100,000, respectively. Of 973 acute stroke events registered, 80% were first-ever strokes. The age-adjusted 28-day overall case-fatality rate and the case-fatality rate of first-ever stroke were 23.3% and 19.8% in men and 21.8% and 21.3% in women, respectively. The findings from this first assessment of the incidence and mortality of stroke show that in the mid-1980s both were high in Kaunas compared with other countries. The case-fatality rate was similar to that reported for most other European countries. Further investigations are being carried out to assess the trends in mortality, incidence, and risk factors of stroke in the Kaunas population.

Depressive disorders in long-term survivors of stroke. Associations with demographic and social factors, functional status, and brain lesion volume.

Sixty surviving patients from a community-based stroke register who had computerised tomography (CT) scan evidence of a single brain lesion were interviewed three to five years after their first ever stroke. Depression (DSM-III-R major depression, partially resolved major depression, and dysthymia) was present in 11 (18%) of the patients and was associated with impaired physical and cognitive functioning, greater age, residence in an institution, absence of a close personal relationship, and larger original brain lesion. Of these variables, only functional dependence (odds ratio 16.4; confidence interval 1.6-170), larger lesion volume (6.6; 1-50), and female sex (8; 1.1-56) remained significantly associated with depression after controlling for all other variables. We conclude that depression in long-term survivors of stroke has many of the same associations as depression in non-stroke elderly populations. Depression in long-term stroke survivors may also be associated with larger original brain lesions, although this requires confirmation in a prospective study.

Long-term risk of recurrent stroke after a first-ever stroke. The Oxfordshire Community Stroke Project.

There have been few community-based studies of long-term prognosis after acute stroke. This study aims to provide precise estimates of the absolute and relative risks of stroke recurrence in an unselected cohort of patients with a first-ever stroke. Six hundred seventy-five patients were registered in a community-based stroke register (the Oxfordshire Community Stroke Project) and prospectively followed for up to 6.5 years. Their relative risk of recurrent stroke was calculated using age- and sex-specific incidence rates for first stroke in Oxfordshire. One hundred eighty recurrent episodes of stroke were identified, of which 135 were first recurrences. Given survival, the actuarial risk of suffering a recurrence was 30% (95% confidence interval, 20% to 39%) by 5 years, about nine times the risk of stroke in the general population. The risk was highest early after the first stroke: 13% (95% confidence interval, 10% to 16%) by 1 year, 15 times the risk in the general population. After the first year the average annual risk was about 4%. The risk of stroke recurrence did not appear to be related to age or pathological type of stroke. The absolute and relative risks of recurrent stroke are highest early after the first stroke but remain elevated for several years thereafter. Efforts at secondary prevention should be initiated as soon as possible and continued for several years to gain greatest benefit.

Stroke Incidence and Case Fatality in Finland and in Akita, Japan: A Comparative Study

The incidence and case fatality of stroke from 1983 to 1985 from the community-based stroke register of the FINMONICA study in Finland were compared with the corresponding rates in the hospital-based register of Akita in Japan collected during 1984-1986. The comparability of the two registers was assessed, and case fatality was compared only in hospitalized cases. In Akita, the age-standardized incidence of cerebral haemorrhage in people aged 25-74 was twice that in FINMONICA, while the reverse was true for incidence of cerebral infarction. Case fatality from stroke within 48 h of onset was higher in FINMONICA than in Akita in each stroke subtype. The incidence and mortality of subarachnoid haemorrhage were similar in the two populations. The differences in early case fatality are probably due to dissimilarities in the severity of the stroke attacks rather than discrepancies in early treatment. Coding practices and also a more unlikely selection bias due to the differential use of computerized brain tomography in the two countries may play a role in differences in incidence and case fatality between these two countries.

Stroke mortality and case-fatality rates in three geographic areas of Finland from 1983 to 1986.

Our aim was to describe the mortality and early case-fatality rates of stroke in three geographic areas of Finland during 1983 to 1986 by means of a community-based stroke register and to estimate the accuracy of registration of stroke deaths in the official statistics compared with the FINMONICA stroke register. Annual and average mortality and case-fatality rates of stroke were derived from data collected in the FINMONICA stroke register during 1983 to 1986. Age-specific and age-standardized rates were calculated for the three areas, and the results were compared with the official mortality statistics and with the case-fatality figures published previously in the literature for Finland and elsewhere. Mortality from stroke in the three FINMONICA areas was between 73 and 90 per 100,000 per year among men aged 25 to 74 years and between 42 and 55 per 100,000 per year among women in the same age group. Average case-fatality was similar in the three areas and globally high: 20% to 27% in men and 24% to 28% in women. Approximately half of the fatal strokes occurred within less than 2 days from the onset of the attack, and a further 25% within the first week. Hemorrhagic strokes accounted for 54% to 81% of all fatal strokes occurring in less than 2 days among men, while among women the corresponding proportions varied in the three areas between 35% and 74%. Of cerebral infarctions, approximately 28% to 37% among men and 19% to 20% among women were fatal within less than 2 days. Although the number of fatal strokes was similar in both the FINMONICA register and official mortality statistics, only 82% to 85% of the stroke cases were common in both registers; a further 13% to 14% of the cases classified as stroke deaths in the FINMONICA register could also be found in the official mortality statistics, but the underlying cause of death was something other than stroke. The reliability of the Finnish official mortality statistics with regard to stroke deaths is reasonably good in aggregate numbers, but at the individual level considerable discrepancies seem to occur. Mortality from stroke in Finland has not declined further after 1979 and remains high internationally. Early case-fatality of stroke also seems higher in Finland than in most other countries. We believe that both the high incidence of stroke and the severity of the attacks are contributing to mortality and case-fatality rates of stroke in Finland.

Long-term survival after first-ever stroke: the Oxfordshire Community Stroke Project.

There have been relatively few community-based studies of long-term prognosis after acute stroke. This study aimed to provide precise estimates of the absolute and relative risks of dying in an unselected cohort of patients with a first-ever stroke. Six hundred seventy-five patients were registered by a community-based stroke register (the Oxfordshire Community Stroke Project) and prospectively followed up for up to 6.5 years. Their relative risk of death was calculated using age- and sex-specific mortality rates for Oxfordshire. During the first 30 days, 129 (19%) patients died. Patients who survived at least 30 days after a first-ever stroke thereafter had an average annual risk of death of 9.1%, 2.3-fold the risk in people from the general population. Although the absolute (about 15%) and relative (about threefold) risks of death were highest in these 30-day survivors over the first year after the stroke, they were at increased risk of dying over the next few years (range of relative risk for individual years, 1.1-2.9). Predictably, older patients had a worse absolute survival but, relative to the general population, stroke also increased the relative risk of dying in younger patients. During the first 30 days stroke accounts for most deaths; after this time nonstroke cardiovascular disease becomes increasingly important and is the most common cause of death after the first year. These data highlight the importance of long-term secondary prevention of vascular events in stroke patients, targeted as much at the cardiovascular as at the cerebrovascular circulation.

Primary Intracerebral Haemorrhage in the Oxfordshire Community Stroke Project

In a community-based stroke register we identified 675 patients with first-ever stroke. Sixty-six (10%) due to primary intracerebral haemorrhage giving a crude incidence of 0.16/1,000/year (age adjusted to England and Wales population = 0.23/1,000/year). The site of the haemorrhage was lobar in 36%, basal ganglionic in 27%, cerebellar in 11 %, massive supratentorial in 9%, brain stem in 3% and unknown in 14%. Intraventricular haemorrhage was least common in the lobar group (13%) but occurred in 29% overall. The clinical presentation and features depended upon the site and size of the haematoma. Hypertension preceded the stroke in 58%, other aetiologies were uncommon.

The FINMONICA Stroke Register. Community-based stroke registration and analysis of stroke incidence in Finland, 1983-1985.

In the early 1980s, a standardized community-based stroke register was started in three geographic areas in Finland: North Karelia and Kuopio in eastern Finland and Turku/Loimaa in southwestern Finland. The results from the first 3 years, 1983-1985, confirmed the high incidence of stroke in Finland. The incidence of stroke was higher in eastern Finland than in the southwestern part of the country. The age-standardized annual incidence among men aged 25-74 years varied from 206 per 100,000 population in southwestern Finland to 322 per 100,000 population in the province of Kuopio in eastern Finland. Among women aged 25-74, incidence was 119 and 187 per 100,000 population in these two areas, respectively. The age-standardized male:female ratio in incidence was 1.7, slightly higher than that previously reported in Finland. Out of 3,574 stroke events registered, 78% were first events without a history of previous stroke. People aged 65-74 years accounted for 45% of all events among men and 62% of all events among women. The authors' experience shows that the geographic variation in stroke incidence and attack rates is difficult to assess even within a country with a relatively uniform health care system. Rigorous standardization and quality control is needed for the assessment of long-term trends; this is the primary goal of the FINMONICA Stroke Register. The findings of this study suggest that the incidence of stroke is still high in Finland, although mortality from stroke has steeply declined during the past 15-20 years. The number of stroke survivors in Finland may actually be increasing. Since the occurrence of stroke is high in Finland as compared with other countries, intensified primary and secondary prevention measures are needed to reduce it.

Diurnal and seasonal variations in the occurrence of stroke: a community-based study.

Several hospital-based studies suggest a circadian rhythm for stroke, with a peak of onset in the morning. To verify whether these results could be confirmed in a community-based study, we used data from the SEPIVAC, a community-based stroke register in Umbria, Italy. Cerebral infarctions (48%), primary intracerebral hemorrhages (54%), subarachnoid hemorrhages (53%) and 'not known' strokes (51%) were all more common between 6 a.m. and noon, and this peak was still present when strokes recognized on awakening were evenly redistributed over the sleep period. Looking at the subgroups of cerebral infarction, lacunar syndromes were more common during sleep. Cerebral infarctions were more frequent during winter, and primary intracerebral hemorrhages during autumn.