Incidence Of First-ever Stroke Research Articles

Cost of stroke in Sweden: an incidence estimate.

To estimate the excess cost of stroke in Sweden and the potential costs that could be avoided by preventing first-ever strokes. We adopted the incidence approach for estimating the present value of both direct and indirect costs. Data on mortality, stroke recurrence, and inpatient care were estimated from a national register of patient data with a four-year follow-up period. To estimate costs for social services, we used survey data on living conditions before stroke onset and at three and at twenty-four months. Costs for outpatient visits, rehabilitation, drugs, and production losses due to premature death and early retirement were estimated on the basis of both published and nonpublished sources. Lifetime costs were based on life tables adjusted for excess mortality of stroke, and costs in year 4 were extrapolated to subsequent years. The present value direct cost for an average stroke patient is SEK513,800 (USdollars 56,024 or Euro60,825). The corresponding indirect cost is SEK125,110 (USdollars13,640 or Euro14,810). Almost 45 percent of the direct costs were attributable to social services. Women had higher costs than men, and costs for survivors increased with age due to social services. With an incidence of 213 first-ever strokes per 100,000 individuals, the total excess direct and indirect cost of stroke would be SEK12.3 billion (approximately US$1.3 billion or Euro1.5 billion). Hence, there are large potential cost offsets both in the health-care sector and in the social service sector if the incidence of first-ever stroke could be reduced.

Change in stroke incidence, mortality, case-fatality, severity, and risk factors in Oxfordshire, UK from 1981 to 2004 (Oxford Vascular Study)

The incidence of stroke is predicted to rise because of the rapidly ageing population. However, over the past two decades, findings of randomised trials have identified several interventions that are effective in prevention of stroke. Reliable data on time-trends in stroke incidence, major risk factors, and use of preventive treatments in an ageing population are required to ascertain whether implementation of preventive strategies can offset the predicted rise in stroke incidence. We aimed to obtain these data. We ascertained changes in incidence of transient ischaemic attack and stroke, risk factors, and premorbid use of preventive treatments from 1981-84 (Oxford Community Stroke Project; OCSP) to 2002-04 (Oxford Vascular Study; OXVASC). Of 476 patients with transient ischaemic attacks or strokes in OXVASC, 262 strokes and 93 transient ischaemic attacks were incident events. Despite more complete case-ascertainment than in OCSP, age-adjusted and sex-adjusted incidence of first-ever stroke fell by 29% (relative incidence 0.71, 95% CI 0.61-0.83, p=0.0002). Incidence declined by more than 50% for primary intracerebral haemorrhage (0.47, 0.27-0.83, p=0.01) but was unchanged for subarachnoid haemorrhage (0.83, 0.44-1.57, p=0.57). Thus, although 28% more incident strokes (366 vs 286) were expected in OXVASC due to demographic change alone (33% increase in those aged 75 or older), the observed number fell (262 vs 286). Major reductions were recorded in mortality rates for incident stroke (0.63, 0.44-0.90, p=0.02) and in incidence of disabling or fatal stroke (0.60, 0.50-0.73, p<0.0001), but no change was seen in case-fatality due to incident stroke (17.2% vs 17.8%; age and sex adjusted relative risk 0.85, 95% CI 0.57-1.28, p=0.45). Comparison of premorbid risk factors revealed substantial reductions in the proportion of smokers, mean total cholesterol, and mean systolic and diastolic blood pressures and major increases in premorbid treatment with antiplatelet, lipid-lowering, and blood pressure lowering drugs (all p<0.0001). The age-specific incidence of major stroke in Oxfordshire has fallen by 40% over the past 20 years in association with increased use of preventive treatments and major reductions in premorbid risk factors.

Incidence and case fatality rates of first-ever stroke in a black Caribbean population: the Barbados Register of Strokes.

Estimation of stroke incidence among black populations outside the USA and the UK has been hampered by the lack of community-based studies. We aimed to document the incidence of first-ever stroke in Barbados, a Caribbean island with a population of 268,000 people. A national community-based prospective register of first-ever strokes, using multiple overlapping sources of notification, was established. During the first year, 352 patients (95.2% black) were registered, 142 males and 210 females (59.7%), with a mean age of 72.5 years (range 24 to 104; SD 14.8). Cerebral infarction (IS) occurred in 81.8%, intracerebral hemorrhage (ICH) in 11.9%, subarachnoid hemorrhage (SAH) in 2.0%, whereas 4.3% of strokes were unclassified (UC). The crude annual incidence rate for the black population was 1.40 (95% CI: 1.25,1.55) per 1000 (1.35 standardized to the European population) for all strokes, 1.20 (1.07,1.34) for IS, 0.18 (0.12,0.23) for ICH, and 0.03 (0.01,0.05) for SAH. Lacunar infarction (LACI) accounted for 50.7% of IS among the black population, whereas 15.6% and 26.8% were caused by total anterior circulation infarction (TACI) and partial anterior circulation infarction (PACI), respectively. At 7 and 28 days, respectively, case fatality rates for blacks were 13.1% and 27.8% for all strokes, 46.3% and 58.5% for ICH, 7.6% and 21.7% for IS, 32.6% and 65.1% for TACI, and 2.1% and 9.0% for LACI. Stroke incidence among the black population of Barbados is lower than among African-origin populations in the USA and UK. Lacunar infarction is the predominant stroke subtype.

Acute stroke in the very elderly: epidemiological features, stroke subtypes, management, and outcome in Martinique, French West Indies.

Stroke incidence increases with increasing age and has an impact on daily living in many areas. With increasing life expectancy, old people will constitute the majority of stroke victims. We present the first stroke study focusing on very old patients in a black Caribbean population (Martinique, French West Indies). All Martinican patients suffering from their first-ever stroke during 1 calendar year between June 1, 1998, and May 31, 1999, were included. Epidemiological, clinical, neuroimaging, management, and outcome data during the first month were collected and compared between very old patients (>or=85 years) and patients aged <85 years. One hundred patients aged >or=85 years and 480 patients aged <85 years were included (sex ratio, women/men, 2.84 and 0.85, respectively; mean+/-SD age, 88.8+/-3.6 and 65.8+/-13.3 years, respectively). The incidence of first-ever stroke was 1.64/1000 per year in the Martinique population and 18.2/1000 per year in patients aged >or=85 years. Elderly patients showed a significantly lower proportion of diabetes (19.1% versus 32.2%; P=0.012) and smoking (0% versus 8.4%; P=0.004) and a higher proportion of peripheral artery disease (23.4% versus 11.4%; P=0.002). Prevalence of hypertension was identical in the 2 groups (70%). There were no significant differences in stroke types or ischemic stroke subtypes between the 2 groups. Active medical care was poorer in older than in younger patients (hospitalization rate, 89% versus 94.4%; admission to neurological ward, 8% versus 23.8%; rate of performance of a CT scan, 82% versus 94%). The 30-day case fatality rate was approximately twice as high in elderly patients (31% versus 16.7%; P=0.0009), and disability (Rankin Scale score >or=3) in survivors was markedly higher (78% versus 48%; P<0.0001). In Martinique, the incidence of first-ever stroke in very old black Caribbean patients seems similar to that in white patients. They have the same pathological type and subtype of stroke as do young patients. The poorer stroke outcome found in the elderly during the first month may be related in large part to less active management than in younger patients.

Trends in Stroke Incidence and 10-Year Survival in Söderhamn, Sweden, 1975-2001

Stroke mortality rates have declined in many countries. Stroke incidence rates have also declined, but not to the same extent and not always in parallel with stroke mortality. The aim of the present study was to investigate trends in stroke incidence and long-term survival in a Swedish population. A population-based survey of the incidence of first-ever stroke was performed prospectively in the periods 1975 to 1977, 1983 to 1986, and 1987 to 1990. Case fatality ratios and survival rates were followed to 2001. Crude incidence rates increased between 1975 to 1977 and 1983 to 1986, but age- and sex-adjusted incidence rates were stable during the whole period of 1975 to 1990. The incidence of intracerebral hemorrhage decreased by approximately two thirds, whereas the incidence of mild brain infarction almost doubled. The case fatality ratio at 28 days did not change, but the 10-year survival ratio increased from 13% to 35%. Mean survival time increased significantly among patients with intracerebral hemorrhage and brain infarction but not among patients with subarachnoidal hemorrhage or stroke of undetermined origin. Stroke incidence and short-term case fatality did not change between 1975 and 1990 in the Söderhamn population. Long-term survival after stroke, on the other hand, has continued to improve to 2001. The implication of these changes is that the burden of stroke is likely to increase unless strokes are becoming less severe.

Proportion of Older People in the Community as a Predictor of Increasing Stroke Incidence

Objectives: To compare stroke incidence rates among comparable registries and to make correlations with aging of the resident populations. Methods: This correlation study included all comparable stroke registries maintained in industrialized countries (Italy, France, United Kingdom, Denmark, Norway, United States, and Australia). Eleven community-based stroke registries with similar high proportions of radiologically confirmed diagnoses based on standard definitions were identified. Incidence rates of first-ever stroke from the prospective L’Aquila registry and from the other registries were compared after age and sex standardization to the 1996 European population. The rates were then correlated with the proportion of individuals aged 65 and over in the corresponding resident populations by means of the Poisson regression analysis. Results: In the L’Aquila registry, the crude annual incidence of first-ever stroke was 281/100,000 (95% confidence interval 271–293) based on 2,515 patients included during a 3-year period. The rate standardized to the European population was 249/100,000. Standardized incidence ratios indicated a significant excess of first-ever strokes in the L’Aquila registry up to 51% with respect to most of the compared studies. A significant correlation was also found between crude (p < 0.0001) and standardized (p = 0.0012) stroke incidence rates and proportions of individuals aged 65 and over in the different populations. Conclusions: The L’Aquila experience suggests that any further aging of a population will increase the stroke occurrence for both the reasons of a direct and predictable effect of the growing proportion of elderly individuals within that population and a disproportionately increased stroke risk in the older age groups.

Stroke in young adults in the community-based L'Aquila registry: incidence and prognosis.

Stroke type in the young may influence the outcome and may have a dramatic impact on the quality of life in survivors. This study aimed to evaluate the incidence and prognosis of first-ever stroke in the young and to make comparisons with older patients within a well-defined population. All first-ever strokes occurring in the L'Aquila district, central Italy, were traced by active monitoring of inpatient and outpatient health services. Incidence rates were standardized to the 1996 European population according to the direct method. Long-term survival was estimated by the Kaplan-Meier method; outcome in survivors was evaluated by the modified Rankin scale. Of 4353 patients who had a first-ever stroke, 89 patients <45 years of age (55 men and 34 women) (2%) were identified in a 5-year period. Mean age+/-SD was 36.1+/-8.1 years. Twenty patients (22.5%) had a subarachnoid hemorrhage, 18 (20.2%) an intracerebral hemorrhage, and 51 (57.3%) a cerebral infarction. The corresponding proportions in patients >45 years of age were 2.4%, 13.3%, and 83.1%. Neuroimaging studies of the brain detected 14 intracranial aneurysms and 6 arteriovenous malformations in 20 of 38 patients (52.6%) with either subarachnoid (n=17) or intracerebral (n=3) hemorrhage. The crude annual incidence rate was 10.18/100,000 (95% CI, 8.14 to 12.57) and 10.23/100,000 when standardized to the 1996 European population. The 30-day case-fatality rate was 11.2% (95% CI, 6.2 to 19.4). Patients with subarachnoid hemorrhage had the highest proportion of good recovery (60%), patients with intracerebral hemorrhage had the highest mortality (44%), and patients with cerebral infarction had the highest proportion of severe disability (47%). Stroke patients <45 years of age showed a disproportionate cumulative high prevalence (42.7%) of subarachnoid and intracerebral hemorrhage with respect to older patients (15.7%), mainly (52.6%) due to aneurysms and arteriovenous malformations. Therefore, screening procedures and preventive strategies in the young should also be addressed to subjects at risk of subarachnoid and intracerebral hemorrhage.

Increased stroke incidence in Lund-Orup, Sweden, between 1983 to 1985 and 1993 to 1995.

Some studies suggest that the incidence of stroke may continue to change. We examined recent temporal trends in a defined geographical area of southern Sweden. Medical records at the University Hospital of Lund (hospital district population 224 126 in 1993) were retrospectively screened for possible first-ever strokes during 1993 to 1995. Included patients were classified into pathological subtypes (cerebral infarction, intracerebral hemorrhage, subarachnoid hemorrhage, and undetermined pathological type) and according to the Oxfordshire Community Stroke Project (OCSP) classification system. Stroke patients from a previous study from 1983 to 1985 in the same area were reevaluated with the same criteria. Epidemiological data for the 2 time periods were compared. There were 998 patients with first-ever stroke in 1983 to 1985 and 1318 in 1993 to 1995. The total incidence rate per 100 000 person-years (age-adjusted to the European population) increased from 134 (95% confidence limits [CL] 126 to 143) to 158 (95% CL 149 to 168). The incidence rate for patients <75 years of age increased from 94 (95% CL 85 to 103) in 1983 to 1985 to 117 (95% CL 108 to 127) in 1993 to 1995, whereas the incidence rate for patients >/=75 years was stable. The age-adjusted incidence rates for the OCSP subtypes lacunar and posterior circulation syndromes increased significantly, by 30% and 55%, respectively. A marked increase in the incidence of first-ever stroke was observed, surprisingly mainly confined to people <75 years of age. The underlying causes of this increase must be explored in future studies.

Stroke incidence and survival in three Sicilian municipalities. Sicilian Neuro-Epidemiologic Study (SNES) Group.

We investigated the incidence of first-ever stroke in three Sicilian municipalities over the years 1984-1987. Case ascertainment involved two approaches: a door-to-door two-phase prevalence survey and a study of death certificates. Only first-ever strokes occurring within the study time interval were included, and diagnoses were based on specified criteria. We found 138 subjects who had experienced a first stroke over 73 488 person-years; the average incidence rate (new cases per 1000 population per year) was 1.9 overall, 1.7 in men, and 2.1 in women. Incidence increased steeply with age and was similar in men and women. Incidence was similar in the three study municipalities. The overall case-fatality rate was 35% at 30 days and 22% at one week. Survival after stroke was similar in men and women but better in younger compared to older stroke patients. Comparisons with previous studies suggest the absence of major geographic variations in stroke incidence within Italy.

Looking beyond first-ever stroke incidence

Looking beyond first-ever stroke incidence

High stroke incidence in the prospective community-based L'Aquila registry (1994-1998). First year's results.

Changes in stroke incidence are likely to occur as a consequence of aging of the population, but evidence for this hypothesis is lacking. A prospective community-based registry of first-ever strokes (1994 to 1998) classified according to the International Classification of Diseases, 9th Revision (ICD-9) was established in the L'Aquila district, central Italy, with a total population of 297,838 (1991 census). Patients were identified by active monitoring of multiple sources, including general practitioners. In 1994, 819 patients (398 men and 421 women; mean +/- SD age, 74.8 +/- 11.3 years) suffered from a first-ever stroke. Eighty-nine percent of the patients had neuroimaging studies of the brain and were reclassified with the recent Application of the International Classification of Diseases to Neurology (ICD-10 NA). The occurrence of subarachnoid hemorrhage, intracerebral hemorrhage, cerebral infarction, and ill-defined events was 2.9%, 14.9%, 80.2%, and 2.0%, respectively. Crude annual incidence of first-ever stroke was 2.75/1000 (95% confidence interval [CI], 2.57 to 2.94) and 24.23/1000 (95% CI, 21.65 to 27.10) in patients older than 80 years. Incidence rates were higher in men and steeply increased with age. The standardized rate was 2.37/1000 for the Italian and 2.28/1000 for the European population. The 30-day case-fatality rate was 25.6% (95% CI, 22.8% to 28.7%). The occurrence of death, disability, and full recovery at 1 year was 36.9%, 38.9%, and 24.2%, respectively. No differences were found in stroke incidence and case-fatality according to income and urban or rural residences. In our population-based study, we found a high stroke incidence notably in the older age subgroups, suggesting that rather than declining, stroke is only being postponed until later in life.

Stroke epidemiology in Novosibirsk, Russia: a population-based study.

To determine first-ever stroke incidence, 30-day case-fatality rates, and frequency of various risk factors among patients with stroke in Novosibirsk, Russia, during 1992. A population-based study of an administratively defined district of Novosibirsk was conducted to identify residents with a first-ever stroke that occurred between Jan. 1, 1992, and Dec. 31, 1992. For case ascertainment, mortality statistics, death certificates, hospital registrations, outpatient clinical data, and all ambulance calls for the study area were reviewed. Patients with stroke or suspected stroke were examined and interviewed by a cerebrovascular neurologist, and the type of stroke was determined. During the 12-month study period, 366 patients with first-ever stroke were registered. A diagnosis of cerebral infarction or intracerebral hemorrhage was confirmed by computed tomography or autopsy in 42% of cases. The diagnosis of subarachnoid hemorrhage was established by cerebrospinal fluid examination in all 14 cases. The age- and sex-adjusted annual incidence rate for stroke was 232 per 100,000. The distribution of incidence cases by diagnostic category was as follows: cerebral infarction, 87.7%; intracerebral hemorrhage, 8.5%; and subarachnoid hemorrhage, 3.8%. The overall 30-day case-fatality rate for stroke was 22.4%. Hypertension, angina pectoris, and cigarette smoking were the most frequent risk factors in patients with stroke in Novosibirsk. The incidence rate of first-ever stroke in Novosibirsk, Russia, is one of the highest in the world, but the 30-day case-fatality rates are similar to those in other populations.

A prospective community-based study of stroke in Warsaw, Poland.

Poland is a country with high morbidity and mortality rates from cardiovascular diseases. No recent studies have evaluated the contribution of cerebrovascular diseases to this morbidity and mortality. Our aim was to accurately determine stroke incidence rates in Warsaw, Poland. A 2-year prospective and population-based stroke registry was maintained for health care units 2 and 3 in Warsaw, Poland (population, 182,285). Case subjects were ascertained by surveying hospital admissions, outpatient visits, and death certificates. During the 2 years of the study (1991 to 1992), 633 cases of first-event strokes were registered, 462 of which were first ever in a lifetime. Computed tomography or necropsy was performed in 72% of first-ever stroke cases. The crude annual incidence rate for first-ever stroke was 127/100,000 (95% confidence intervals, 111 to 145); the rate standardized to the European population was 111 (95% confidence intervals, 96 to 128). Our incidence rates for first-event strokes were found to be in the middle of the range among other first-event studies. When comparing our first-ever stroke incidence rates with those of comparable studies performed throughout Europe, they were found to be similar for groups aged younger than 65 years but lower in the older age groups. The distribution of ischemic and hemorrhagic stroke subtypes was similar to that of other countries. This first population-based prospective stroke registry in Poland showed that incidence rates were not high compared with other studies throughout Europe and the world. These stroke incidence rates are not a large contributing factor to high cardiovascular morbidity rates in Poland.

Event, incidence, and fatality rates of cerebrovascular diseases in Enköping-Håbo, Sweden, 1986-1988

In order to study the need for medical care among elderly stroke patients, a prospective registration of cerebrovascular diseases started on January 1, 1986 in Enköping-Håbo health service district, Sweden. This article reports the design of the stroke register and the registration procedures, the annual events of stroke, both first-ever and recurrent, during 1986-1988 and the fatality rate with special regard to the very old population. The annual incidence of first-ever stroke was 0.33/1,000 among persons younger than 65 years of age, 10.6/1,000 among persons aged 65-84 years, and 34.5/1,000 among persons aged 85 years and older. The fatality rate of first-ever strokes was 7.5% within one month for persons younger than 65 years of age, 20.3% in the age-group 65-84 years, and 41% for the population 85 years and older. These results are compared with a similar Swedish study from Söderhamn and four comparable international studies. The results from this study gave a basis for designing special care programs in hospital and in home-care also for old stroke patients.

Increasing incidence of stroke among Swedish women.

The incidence of stroke and transient ischemic attack was studied prospectively in the municipality of Söderhamn, Sweden, during the periods 1975-1978 and 1983-1986. A total of 723 cases of stroke and 111 cases of transient ischemic attack were registered during the two periods. The number of first-ever strokes increased by 28% between the 1970s and the 1980s, while the annual incidence of first-ever stroke rose from 2.90 to 3.53/1,000 (p less than 0.02). Female incidence increased by 38%, from 2.62 to 3.62/1,000 (p less than 0.05) between the study periods. Male incidence, however, changed nonsignificantly from 3.19 in the first period to 3.43 in the second. In 1975-1978, male incidence was four times greater than that of females up to 65 years of age, but the distribution became balanced in 1983-1986, when the increment of female incidence was 47% in the group 25-44 years old and 232% (p less than 0.05) in the group 45-64 years old. The annual incidence of first-ever transient ischemic attack was 0.43/1,000 in men and 0.48/1,000 in women in 1975-1978. The corresponding rates for 1983-1986 were 0.56 and 0.45/1,000, respectively. These changes were not significant. The cause of the increase in the incidence of stroke among women has not been established.