Objectives: Declining case fatality in acute stroke has been reported from many western countries. The aim of this study was to explore in what subset of patients the decline in case fatality has occurred.
Setting: In a population-based study, acute stroke events were recorded in the age group 25-74 years in northern Sweden during the years 1985-1993 within the framework of the WHO MONICA Project.
Subjects: In total 3486 men and 2212 women with a first-ever stroke (except subarachnoid haemorrhage) were included.
Main outcome: Change in stroke incidence, case fatality and neurological deficits at onset over a 9-year period.
Results: The incidence (first-ever stroke) did not change over the years, while the overall case fatality decreased from 18.2% in 1985-1987 to 13.5% in 1991-1993. In both men and women with non-haemorrhagic stroke, a trend was seen towards an increasing incidence of mild stroke events over the years. In both sexes, a significant decline in case fatality was seen in patients with minor deficits at onset, while no change in case fatality was seen in patients with extensive deficits. There was no change in incidence of intracerebral haemorrhage, but the case fatality in patients with intracerebral haemorrhage declined significantly from 36% to 29% during the study period.
Conclusions: A declining case fatality was observed in both men and women. Among patients with non-haemorrhagic stroke, the decline was confined to patients with minor deficits. The declining case fatality can be attributed both to a shift in the severity towards more patients presenting with mild symptoms, and an improved prognosis in patients with minor deficits at onset, probably because of improved medical management.