Increasing stroke incidence and decreasing case fatality, 1989-1998: a study from the stroke register in Malmö, Sweden

Abstract

Background and purpose: Although the incidence of and mortality from myocardial infarction (MI) have declined in most industrialized countries, incidence studies of stroke have shown less consistent trends. This study examines time trends in the incidence of stroke and case fatality rates in relation to socioeconomic circumstances and history of MI.

Methods: Stroke incidence in the city of Malmö, Sweden (250,000 citizens), has been continuously monitored since 1989. All patients 50 to 79 years of age who experienced a first-ever stroke between 1989 and 1998 were included.

Results: We included 3621 patients (1969 men, 1652 women). The age-standardized incidence was 647 per 100,000 persons-years for men and 400 per 100,000 persons-years for women. The annual increase-3.1% in men (P<0.05) and 2.9% in women (P<0.05)-was more pronounced in the younger age groups and was lowest in areas with poor socioeconomic circumstances. We found that 13% of the men and 6% of the women had a history of MI; this proportion was stable over the study period. The average case fatality rates in 1989 to 1998 were 10% for men and 9.3% for women. Rates remained stable for men but declined significantly in women (odds ratio per year, 0.895; 95% confidence interval, 0.84 to 0.95).

Conclusions: In this urban population, stroke incidence increased between 1989 and 1998. The rate of increase tended to be lower in residential areas with least favorable socioeconomic circumstances. The proportion with a history of MI remained unchanged during the study period. There has been significant improvement in the case fatality rate in women but not in men.