Epidemiology of stroke in Lund-Orup, Sweden, 1983-85. Incidence of first stroke and age-related changes in subtypes.

The incidence of stroke in the hospital district of Lund-Orup (total population 200,191), the local uptake area of the University Hospital, Lund, was studied. Between January 1, 1983 and December 31, 1985, there were 1054 cases of first stroke. Age adjusted (to Swedish Dec 1983 population) incidence rates were 221.2 for males, 195.8 for females, and 208.3 for total population (per 100,000 and year). Case-fatality ratio by 30 days was 17.5%. Atherothrombotic infarction was the most common subtype (58.4%), followed in frequency by cardiac embolism (30.6%), intracerebral hemorrhage (8.3%) and subarachnoid hemorrhage (2.7%). The most important change in the distribution of subtypes with age was an increase in the proportion of cardiac embolism from 13% in the youngest to 44% in the oldest age groups. The present study underscores the importance of careful determination of subtypes of stroke in future epidemiological studies.