Stroke Definition and Assessment
Stroke was defined in both studies according to the World Health
Organization diagnostic criteria as rapidly developing clinical signs
of focal (at time global) disturbance of cerebral function lasting >24
hours or leading to death with no apparent cause other than that of
vascular origin.6 Only first-ever symptomatic stroke in a lifetime was
considered for this study and was classified as ischemic stroke, spontaneous
intracerebral hemorrhage, or undetermined stroke. Ischemic
stroke subtypes were defined as lacunar stroke, cardioembolic stroke,
and nonlacunar noncardioembolic stroke. Stroke severity was quantified
by the means of the National Institutes of Health Stroke Scale
(NIHSS) score obtained at the first clinical examination. In a small
number of cases, in which patients presented late or were assessed
elsewhere for events occurring on vacation, NIHSS score was estimated
on the basis of the review of the clinical history and medical
records. Such a retrospective evaluation of the NIHSS score has been
reported to be valid.11 For this study, minor was defined as a stroke
with an NIHSS score of 0 to 2.