Trends in Incidence and Outcome of Stroke in Perth, Western Australia During 1989 to 2001

Abstract

Background and Purpose-We studied temporal trends in major stroke outcomes in Perth, Western Australia (WA), comparing 3 12-month periods, roughly 5 years apart, between 1989 and 2001. Methods-The Perth Community Stroke Study (PCSS) used uniform definitions and procedures in a representative segment (approximately 143 000 people in the year 2000) of Perth, WA. Crude and age-standardized incidence and 28-day case fatality for stroke in the different study periods were compared using Poisson regression. We also undertook temporal comparisons of severity, risk factors, and management of stroke to define the basis for any changes in rates. Data are reported with 95% confidence intervals (CI). Results-There were 251, 213, and 183 first-ever strokes identified in the first, second, and third study periods, respectively, reflecting significant declines in stroke rates overall, for major age groups, and for both ischemic stroke and intracerebral hemorrhage. The decline in rates was greater in men than women. Compared with the 1989 to 1990 period, sex-and age-adjusted rates declined by 25% (95% CI 10% to 37%) in 1995 to 1996, and by 43% (95% CI 31% to 53%) in 2000 to 2001, corresponding to a 5.5% average annual decrease overall. There were correspondingly significant reductions in the frequencies of key risk factors among cases. However, early case fatality remained stable, both overall and for major pathological subtypes of stroke. Conclusions-These data confirm significant declines in the incidence of stroke on the western side of Australia, coincident with some improvement in the vascular risk profile of cases in the population. Decreasing risk rather than improving survival appears to be the main driver of falling mortality from stroke in this population. (Stroke. 2008;39: 776-782.)

Time trends in outcome of subarachnoid hemorrhage

“…13,14,16,[19][20][21]36 Data from the Perth Community Stroke Study from June 1995 to June 1996 19 were published separately from data from December 1996 to February 1998, 29 but these were combined for this analysis because the periods of study were so close. A pooled analysis of time trends within study populations, based on the difference in 1-month casefatality taken from the 2 furthest available timepoints (figure 2), demonstrated a 0.9% reduction in casefatality per annum (0.2-1.6, p ϭ 0.01).…”

“…All studies demonstrated a trend of declining case-fatality rates over time, and the rate of that decline was similar to the results of the weighted linear regression analysis from all studies, with the exception of the Valle d'Aosta study and the Perth Community Stroke Study, which had very small numbers of cases of SAH in at least 2 of the periods examined. 19,20,29 DISCUSSION Although a significant reduction in the incidence of SAH has not occurred in the last 25 years in our Oxfordshire population, mortality has halved largely due to improved survival among hospitalized patients, without a corresponding increase in the proportion of survivors with severe disability. Further evidence of improved outcome after SAH comes from our meta-analysis of time trends in casefatality within other population-based studies showing a 0.9% absolute annual reduction in crude 30-day case-fatality rates, and a similar sized reduction in case-fatality in a meta-analysis of all population-based studies that measured casefatality at more than one timepoint within the same population.…”

“…The majority of data in the pooled analysis come from the Auckland 13,29 and Northern Swedish populations, 16 with the latter study showing a significant decline in case-fatality. Smaller studies including the Perth Community Stroke Study (1989 -2001), 19,29 the Lund Registry, 21 and the Valle d'Aosta study (1989 -1997) 20 also reported reductions in case-fatality of around 40%, but were not adequately powered to show a significant fall, and the South London Stroke Registry 36 may not have covered a long enough period of time to examine the cumulative effect of changes in SAH management.…”

Increased Stroke Burdens Among the Low-Income Young and Middle Aged in Rural China

“…[2][3][4][5][6] Studies have demonstrated decreasing trends in incidence for both ischemic stroke (IS) and hemorrhagic stroke in developed countries. 4,[7][8][9] However, the incidence of hemorrhagic stroke has increased in those aged <35 to 44 years in Chinese Hong Kong. 10 Individuals between the ages of 35 and 64 years, who comprise the main labor force, account for 43.5% of the population in rural China.…”

Treatment of Risk Factors to Prevent Stroke

“…Treatment of risk factors is essential to prevent the first and subsequent stroke of all types, including ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage [1,2]. The reduction in stroke incidence in Western countries for the past several decades has been attributed to better treatment of risk factors [3,4]. The Framingham study was the first major epidemiological study that identified specific risk factors associated with cardiovascular disease.…”