Few studies have compared the incidence and outcome of stroke in black and white people from the same population. Two population based stroke registers in US cities1 2 and one in the United Kingdom (the south London stroke register)3 found twice the incidence of stroke adjusted for age and sex in black people than in white people. Adjusting for socioeconomic status in the south London register attenuated but did not abolish this excess.3 None of these registers has found a significant difference between black people and white people in survival after stroke, and all have therefore attributed the excess mortality in black people to a higher incidence of stroke.2^–4

The south London register now includes more than 2000 patients with a first ever stroke over seven years and has accrued 6000 person years of follow-up.5 Such studies are rare these days even in the UK, whose universal healthcare system makes it an ideal location for …