Secular trends in stroke in the Framingham study

Trends in stroke incidence, prevalence, fatality, and severity were examined in Framingham Study subjects, aged 55 to 64, during 3 successive decades beginning in 1953, 1963, and 1973. There was no significant decline in incidence or prevalence of total stroke and transient ischemic attacks (TIAs). In women, but not men, incidence of completed ischemic stroke declined significantly. Stroke severity did decrease significantly and severe neurologic deficit was less frequent in later decades; fewer patients with stroke were unconscious on admission to the hospital. There was no substantial change in the case mix and no significant decline in hemorrhage to account for the decline in severity. The proportion of isolated TIAs increased significantly over the 30 years studied, yielding an apparent decline in case-fatality rates, which was significant only in men. Secular trends in stroke incidence and fatality did not follow a clear pattern. There was a significant decline in stroke severity, but incidence of infarction fell only in women. The decline in total case-fatality rate occurred only in men, resulting largely from an increased incidence of isolated TIAs.