Reliable data of the clinical burden of minor stroke are
important given the high risk of recurrent stroke,1 the
impact on cognitive function,2 fatigue and depression,3 and
the implications for clinical service provision. Reliable and
comparable ascertainment of minor stroke is also important
in geographical and temporal comparisons of incidence and
severity of stroke. However, relatively little is known about
the population-based epidemiology of minor stroke. Reliable
data should come from stroke incidence studies that meet the
ideal criteria for methodology,4,5 including complete prospective
case ascertainment in a well-defined population based on
multiple overlapping source of information, a standard World
Health Organization definition of stroke,6 and presentation of
rates by age and sex, but achieving complete case ascertainment
is difficult in patients with minor stroke who are usually
less likely to seek medical attention urgently and who are
often coded as transient ischemic attack (TIA) in administrative
databases.7,8
Although differences between stroke incidence studies in
the underlying health care system and patients’ attitude toward
seeking medical attention could result in discrepancies in
reported incidence of minor stroke, the systematic assessment
of all patients coded as TIA could be a major determinant
of completeness of ascertainment. To test this hypothesis,
we compared incidence of stroke, stratified by severity, in 2
similar high-quality population-based registries (Dijon Stroke Registry and the Oxford Vascular [OXVASC] Study); only 1
of which included systematic face-to-face clinic assessment of
all patients coded as TIA.