Race/Ethnicity Epidemiological studies support racial and ethnic differences in the risk of stroke.35 and some Hispanic/Latino have a higher incidence of all stroke types and higher mortality rates compared with whites. This is particularly true for young and middle-aged blacks, who have a substan- tially higher risk of subarachnoid hemorrhage (SAH) and ICH than whites of the same age.36,37 In the Atherosclerosis Risk in Communities (ARIC) study, blacks had an incidence of all stroke types that was 38% (95% confidence interval [CI], 1.01 1.89) higher than that of whites.42 American Indians have an incidence rate for stroke of 679 per 100000 person-years, which is high relative to non-Hispanic whites.43 It remains unclear whether these racial differences are genetic, environmental, or an interac- tion between the two. 