Monitoring stroke. An international challenge

30-Year Trends in Stroke Rates and Outcome in Auckland, New Zealand (1981-2012): A Multi-Ethnic Population-Based Series of Studies

Background

Insufficient data exist on population-based trends in morbidity and mortality to determine the success of prevention strategies and improvements in health care delivery in stroke. The aim of this study was to determine trends in incidence and outcome (1-year mortality, 28-day case-fatality) in relation to management and risk factors for stroke in the multi-ethnic population of Auckland, New Zealand (NZ) over 30-years.

Methods

Four stroke incidence population-based register studies were undertaken in adult residents (aged ≥15 years) of Auckland NZ in 1981–1982, 1991–1992, 2002–2003 and 2011–2012. All used standard World Health Organization (WHO) diagnostic criteria and multiple overlapping sources of case-ascertainment for hospitalised and non-hospitalised, fatal and non-fatal, new stroke events. Ethnicity was consistently self-identified into four major groups. Crude and age-adjusted (WHO world population standard) annual incidence and mortality with corresponding 95% confidence intervals (CI) were calculated per 100,000 people, assuming a Poisson distribution.

Results

5400 new stroke patients were registered in four 12 month recruitment phases over the 30-year study period; 79% were NZ/European, 6% Māori, 8% Pacific people, and 7% were of Asian or other origin. Overall stroke incidence and 1-year mortality decreased by 23% (95% CI 5%-31%) and 62% (95% CI 36%-86%), respectively, from 1981 to 2012. Whilst stroke incidence and mortality declined across all groups in NZ from 1991, Māori and Pacific groups had the slowest rate of decline and continue to experience stroke at a significantly younger age (mean ages 60 and 62 years, respectively) compared with NZ/Europeans (mean age 75 years). There was also a decline in 28-day stroke case fatality (overall by 14%, 95% CI 11%-17%) across all ethnic groups from 1981 to 2012. However, there were significant increases in the frequencies of pre-morbid hypertension, myocardial infarction, and diabetes mellitus, but a reduction in frequency of current smoking among stroke patients.

Conclusions

In this unique temporal series of studies spanning 30 years, stroke incidence, early case-fatality and 1-year mortality have declined, but ethnic disparities in risk and outcome for stroke persisted suggesting that primary stroke prevention remains crucial to reducing the burden of this disease.

Ischemic stroke incidence in Santa Coloma de Gramenet (ISISCOG), Spain. A community-based study

Background

In Spain, stroke is one of the major causes of death and the main cause of severe disability in people over 65 years. We analyzed the incidence of ischemic stroke, stroke subtypes, case fatality and disability at 90 days after the event in a Spanish population.

Methods

A prospective community-based register of ischemic strokes was established in Santa Coloma de Gramenet (Barcelona) [116,220 inhabitants of all ages, according to the municipal census of December 31,2001], from January 1 to December 31, 2003.

Standard definitions and case finding methods were used to identify all cases in all age groups. Every patient underwent a complete clinical evaluation and systematic tests including neuroimaging (CT/MRI) and vascular studies (carotid duplex ultrasound intra and extracranial and MR angiography).

Results

Over a one year period, 196 ischemic strokes were registered [107 men; median age = 76 years (range 39–98)], being the first event in 159 patients (81.1%) and a recurrent stroke in 37 (18.9%). After age-adjustment to the European population, the incidence of ischemic stroke per 100,000 inhabitants was 172 (95% CI, 148–196); 219 (176–261) in men and 133 (105–160) in women, with an annual incidence for first ischemic stroke of 139 (118–161); 165 (128–201) in men and 115 (89–140) in women. The incidence of stroke increased with age.

Stroke subtypes (TOAST classification criteria) were lacunar in 28.8%, atherothrombotic in 18.6%, cardioembolic in 26.6% and undetermined in 26.0% of patients. At 90 days, the case-fatality was 12%, and among survivors, moderate-to-severe disability was present in 45 % at 3 months.

Conclusion

This prospective community-based study shows one of the lowest incidences of stroke in Europe, as well as one of the lowest case fatality and disability rates at 90 days after stroke.

Incidence, comorbidity, case fatality and readmission of hospitalized stroke patients in Canada

BACKGROUND

Stroke is a leading cause of death and disability, and poses a significant burden of care for those who survive.

OBJECTIVES

To estimate the incidence of hospitalization for stroke and describe the impact of age, sex and comorbidity on in-hospital mortality, length of stay and readmission rates.

METHODS

Health insurance numbers were used to link acute care hospitalizations across Canada in 1999/2000 for stroke patients with no discharges for a stroke within the preceding five years. Patients were followed up for one year from the date of their initial admission.

RESULTS

The numbers of men (15,367) and women (16,740) in the study were similar. The incidence of all types of stroke (International Classification of Diseases, ninth revision, codes 430, 431 and 434/436) for hospitalized men and women was 14.4 per 10,000, with a 15-fold rise from 8.7 for the age group of 45 to 64 years to 131.9 per 10,000 for the age group 80 years and older. For the index episode, stroke patients spent an average of 21.0 days in the hospital, and 18.2% died in the hospital within 28 days. Of those who survived the first episode, 10.3% were readmitted to the hospital within one year with a recurrent stroke, and overall 37.1% were readmitted for any cause (including stroke). Among these stroke patients, hypertension was codiagnosed in 35%; diabetes in 17%; arrhythmia in 15%; ischemic heart disease in 13.6%; and congestive heart failure in 5%.

CONCLUSIONS

Hospital records linked by patient identification can produce more accurate national estimates of patients hospitalized with stroke than any current countrywide surveillance system.

Evaluation of postural stability in the elderly with stroke

OBJECTIVE

To compare clinical and biomechanical measures of balance in elderly stroke patients with those of healthy elderly people.

DESIGN

Two-group comparison design.

SETTING

Laboratory environment.

PARTICIPANTS

Fifteen poststroke patients and 15 healthy age-matched older adults (N=30).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The biomechanical variable COP-COM, which represents the distance between the center of pressure (COP) and the center of mass (COM) in terms of root mean square. The mean of 4 trials of the COP-COM variable for each test condition was used for statistical analysis. Furthermore, the different systems (sensory, motor, central processor) related to postural stability were evaluated.

RESULTS

Statistical significance of the COP-COM variable was larger in the stroke group than in healthy subjects, in both the anteroposterior (AP) and mediolateral (ML) directions. Furthermore, statistically, stroke subjects showed amplitudes of the COP-COM variable that were significantly larger in the eyes-closed condition. The significant negative correlation demonstrated between COP-COM amplitude and the balance scales (Berg, Tinetti) indicated that the patients with larger COP-COM amplitudes had lower clinical balance score. Furthermore, correlation coefficient scores between COP-COM variables in both AP and ML directions and motor performance using Fugl-Meyer Assessment (rho=-.53, rho=-.51, respectively) and reaction time (rho=-.53, rho=-.44, respectively) were significant. Vibration (rho=.41) and touch-pressure (rho=.42) perception thresholds correlated significantly only in the AP direction.

CONCLUSIONS

Evaluating postural stability with COP-COM variable provided an accurate measure of postural stability in poststroke elderly people. Furthermore, postural stability in quiet stance, as measured by COP-COM amplitude, was related to functional measures of balance as well as physiologic factors relating to balance, such as visual conditions, lower-extremity peripheral sensibility, motor recovery, and simple reaction time.

Anticoagulants for acute ischaemic stroke

BACKGROUND

Most ischaemic strokes are caused by blood clots blocking an artery in the brain. Clot prevention with anticoagulant therapy could have a significant impact on patient survival, disability and stroke recurrence.

OBJECTIVES

The objective of this review was to assess the effect of anticoagulant therapy versus control in the early treatment of patients with acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched 30 October 2003). For previous updates of this review, we searched the register of the Antithrombotic Trialists' (ATT) Collaboration, consulted MedStrategy (1995), and contacted relevant drug companies.

SELECTION CRITERIA

Randomised trials comparing early anticoagulant therapy (started within two weeks of stroke onset) with control in patients with acute presumed or confirmed ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Twenty-two trials involving 23,547 patients were included. The quality of the trials varied considerably. The anticoagulants tested were standard unfractionated heparin, low-molecular-weight heparins, heparinoids, oral anticoagulants, and thrombin inhibitors. Based on nine trials (22,570 patients) there was no evidence that anticoagulant therapy reduced the odds of death from all causes (odds ratio (OR) = 1.05, 95% confidence interval (CI) 0.98 to 1.12) at the end of follow-up. Similarly, based on six trials (21,966 patients), there was no evidence that anticoagulants reduced the odds of being dead or dependent at the end of follow-up (OR = 0.99; 95% CI 0.93 to 1.04). Although anticoagulant therapy was associated with about 9 fewer recurrent ischaemic strokes per 1000 patients treated (OR = 0.76; 95% CI 0.65 to 0.88), it was also associated with a similar sized 9 per 1000 increase in symptomatic intracranial haemorrhages (OR = 2.52; 95% CI 1.92 to 3.30). Similarly, anticoagulants avoided about 4 pulmonary emboli per 1000 (OR = 0.60, 95% CI 0.44 to 0.81), but this benefit was offset by an extra 9 major extracranial haemorrhages per 1000 (OR = 2.99; 95% CI 2.24 to 3.99). Sensitivity analyses did not identify a particular type of anticoagulant regimen or patient characteristic associated with net benefit.

REVIEWERS' CONCLUSIONS

Immediate anticoagulant therapy in patients with acute ischaemic stroke is not associated with net short- or long-term benefit. The data from this review do not support the routine use of any type of anticoagulant in acute ischaemic stroke. People treated with anticoagulants had less chance of developing deep vein thrombosis (DVT) and pulmonary embolism (PE) following their stroke, but these sorts of blood clots are not very common, and may be prevented in other ways.

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.

High early case fatality after ischaemic stroke in Poland: exploration of possible explanations in the International Stroke Trial

PURPOSE

To determine why Polish patients included in the International Stroke Trial (IST) had a higher early case fatality than patients from other countries.

METHODS

Of 19,435 patients randomised to IST, 17,370 had CT or autopsy-confirmed ischaemic stroke. We compared the baseline clinical state and 14-day case fatality of patients randomised in Polish centres with those from all other IST countries. We examined: age, gender, presence of atrial fibrillation (AF), conscious level, neurological deficit, cause of death and aspirin use in the 3 days before stroke.

RESULTS

In Poland, the 14-day case fatality rate was significantly higher than in other IST countries (13% vs. 9.6%; odds ratio, OR, 1.5, 95% confidence interval, CI, 1.2-1.9). In Poland, a significantly higher proportion of deaths was attributed to coronary heart disease (2.5% vs. 0.7%) and pulmonary embolism (1.0% vs. 0.4%). Polish patients had higher percentage of AF and drowsiness, but were younger. When these factors were adjusted for, Polish patients still had approximately a 57% higher risk of death within 14 days compared with other countries. A logistic regression analysis revealed that an increased risk of death within 14 days in Poland compared to other IST patients was present among patients younger than 75 years (OR 1.7; 95% CI 1.3-2.4), females (OR 1.8; 95% CI 1.3-2.5), patients who were alert at onset (OR 2.4; 95% CI 1.7-3.4), with partial anterior circulation syndrome (PACS) (OR 2.0; 95% CI 1.4-2.8) or lacunar syndrome (LACS) (OR 2.4; 95% CI 1.1-5.0) and without AF (OR 1.8; 95% CI 1.3-2.4). Polish patients were less likely to have been on aspirin before their stroke than other countries (7.6% vs. 20.8%).

CONCLUSION

The 14-day case fatality was significantly higher in Poland than in other countries in IST. Part of the increase was due to greater stroke severity in the Polish patients. However, differences persisted even after adjustment for baseline stroke severity. Several factors may have contributed the excess: poor attention to treatment of cardiovascular disease, less attention to treatment of secondary complications of stroke and some other--as yet unidentified--factor specific to Poland.

The Perugia hospital-based Stroke Registry: report of the 2nd year

This study reports the characteristics of stroke patients admitted to our hospital in the period Jan 1st, 1998-Dec 31st 1999. Seven hundred and ninety seven consecutive subjects (412 males; mean age 71 +/- 13 years) with a first-ever stroke were registered. Two-thirds of patients (65%) were admitted to the Stroke Unit (SU). The remaining part was managed in six general medicine wards (GM) or other services [neurosurgery and intensive care units (ICU+ NS)]. Ischemic stroke occurred in 534 subjects (67%). The high prevalence (30.1%) of haemorrhages can be partly explained by the presence of specialized neurosurgical services. Athero-thrombotic infarctions occurred in 21.7% of patients, lacunar in 24.7%, cardioembolic in 18.1%, other determined in 6.1%, and other undetermined in 27.5%. Overall hospital mortality was 10%. In cerebral hemorrhage mortality was 18% (44/240) vs. 6.3% (32/534) in ischemic stroke (p < 0.05). The distribution of stroke types and mortality was similar to other previous reports.

Heart disease contributes to high stroke mortality in Poland

CONTEXT

The case-fatality rate for ischemic stroke in Poland are 3 times higher than in the United States. The reason for this difference is uncertain.

OBJECTIVE

To explore whether cardiac comorbidity contributes to high case-fatality rates for ischemic stroke in Poland.

DESIGN

Prospective collection of data on ischemic stroke by using a structured data collection instrument.

SETTING

A regional neurological hospital in Warsaw.

INTERVENTION

Standard medical care was provided to all ischemic stroke patients.

OUTCOME MEASURE

Survival at 30 days, stroke lesion size and location by computerized tomographic scan, stroke syndrome.

RESULTS

252 patients with ischemic stroke were registered. Overall 30-day case-fatality rate was significantly higher in the group of patients with atrial fibrillation (AF) (28.6% v 13.9%) and congestive heart failure (CHF) (29.1% v 12.7%) than in those without these comorbidities. In patients with either AF or CHF, ischemic lesions seen on computed tomography (CT) scans were more likely to be very large (occupying more than 1 lobe) and were more likely to involve both superficial and deep structures of the brain. Large hemispheric syndromes were more likely in patients with AF (38.5% v 18.5%) and CHF (33.8% v 18.9%) than in those without these comorbidities.

CONCLUSIONS

Strokes caused by CHF or AF tend to be larger and are more likely to lead to death. The high prevalence of cardiac disease may be one cause of high stroke mortality in Poland.

High case-fatality rates in the Warsaw stroke registry

We studied 1-year survival in 297 patients with first-even-in-lifetime ischemic stroke (FEL-IS) selected from a population-based study of stroke in the Mokotow district of Warsaw. Case fatality rates were 29% at 30 days and 51% at 1 year. These case fatality rates are significantly higher than in other industrialized countries. Early deaths were primarily caused by neurological sequelae of stroke or complications of immobility, whereas late deaths (>30 days) were primarily caused by stroke recurrence or complications of immobility. Predictors of survival were analyzed by life table methods. Adverse predictors of 1-year survival included greater age, low activities of daily living scores, atrial fibrillation, greater weakness, congestive heart failure, and untreated hypertension. Patients with stroke recurrence were more likely to die in the first year. We hypothesize that stroke severity contributes to high case-fatality rates by increasing death caused by both direct neurological sequelae and complications of immobility. Medical comorbidity probably contributes to high case-fatality rates in Poland by increasing stroke recurrence rates and by increasing deaths caused by immobility. We hypothesize that high case-fatality rates in Poland could be reduced by improved rehabilitation of stroke patients to avoid deaths caused by immobility and by better control of medical comorbidity in stroke patients.