Stroke incidence rates were unchanged, while fatality rates declined, during 1971-1987 in Göteborg, Sweden

Trends in stroke mortality and incidence in Finland in the 1970s and 1980s

This article presents trends in stroke mortality and incidence in Finland among people aged 25 to 74 years. Between 1971 and 1980, stroke mortality declined steeply: 4.1% per year among men and 5.5% per year among women. Between 1981 and 1991 the decline was smaller; about 2.2% per year in men and 2.8% per year in women. The North Karelia stroke register showed that stroke mortality declined in men from 155 per 100,000 per year in 1972 to 1973, to 87 per 100,000 per year in 1982 to 1983, and in women from 114 to 44 per 100,000 per year. A slight decline in mortality was observed during the 1980s in men, but not in women. The incidence of stroke also declined in North Karelia during the 1970s, from 328 to 248 per 100,000 per year in men, and from 230 to 141 per 100,000 in women. In the FINMONICA stroke register, the average rate of decline in incidence of stroke between 1983 and 1989 was 1.7% per year in men and 1.8% per year in women. Declines in incidence and mortality from subarachnoid hemorrhage were observed in both men and women; nevertheless it was the decline in cerebral infarction that accounted for most of the changes since about 80% of all strokes are cerebral infarctions. In conclusion, despite steep falls in stroke mortality and incidence in the 1970s, stroke mortality is still high in Finland compared with other nations. During the 1980s, the decline in stroke mortality was less and incidence leveled off until it resumed from 1987 to 1989.(ABSTRACT TRUNCATED AT 250 WORDS)

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

BACKGROUND AND PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Stroke trends in an aging population. The Technology Assessment Methods Project Team

BACKGROUND AND PURPOSE

Trends in stroke incidence and survival determine changes in stroke morbidity and mortality. This study examines the extent of the incidence decline and survival improvement in the Netherlands from 1979 to 1989. In addition, it projects future changes in stroke morbidity during the period 1985 to 2005, when the country's population will be aging.

METHODS

A state-event transition model is used, which combines Dutch population projections and existing data on stroke epidemiology. Based on the clinical course of stroke, the model describes historical national age- and sex-specific hospital admission and mortality rates for stroke. It extrapolates observed trends and projects future changes in stroke morbidity rates.

RESULTS

There is evidence of a continuing incidence decline. The most plausible rate of change is an annual decline of -1.9% (range, -1.7% to -2.1%) for men and -2.4% (range, -2.3% to -2.8%) for women. Projecting a constant mortality decline, the model shows a 35% decrease of the stroke incidence rate for a period of 20 years. Prevalence rates for major stroke will decline among the younger age groups but increase among the oldest because of increased survival in the latter. In absolute numbers this results in an 18% decrease of acute stroke episodes and an 11% increase of major stroke cases.

CONCLUSIONS

The increase in survival cannot fully explain the observed mortality decline and, therefore, a concomitant incidence decline has to be assumed. Aging of the population partially outweighs the effect of an incidence decline on the total burden of stroke. Increase in cardiovascular survival leads to a further increase in major stroke prevalence among the oldest age groups.