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

Stroke risk factors have been shown to change with time in several places; simultaneously, stroke incidence rates have increased in some and decreased in other places. In Göteborg, Sweden, cardiovascular epidemiological research has included stroke registration since 1971. From these data on stroke, incidence and fatality rates from a 17-year period are given.

During the period 1971-1987 all cases of stroke occurring in people aged 15-65 years in the city of Göteborg were uniformly recorded, with an estimated case detection rate of 90% or more.

Age-adjusted incidence rates of first-ever stroke by sex did not change during the period. Age-specific rates and rates for individual types of stroke (subarachnoid hemorrhage, intracerebral hemorrhage, and cerebral infarction-unspecified stroke combined) were also largely unchanged. A slight increase in the incidence rate of intracerebral hemorrhage may be due to better detection after computed tomography came into use in 1976. Stroke fatality rates declined through the whole period in both sexes and all age groups, markedly so for intracerebral hemorrhage and subarachnoid hemorrhage.

This conforms with vital statistics for Göteborg and for Sweden of declining stroke mortality during the period. The decline in stroke fatality rates may be related to decreases in smoking habits and blood pressure together with an increase in the percentage of people on antihypertensive treatment among middle-aged men, and to some extent even middle-aged women, reported from the same population. Why stroke incidence rates did not decline concomitantly is unexplained.