Subarachnoid hemorrhage incidence among whites, blacks and Caribbean Hispanics: The Northern Manhattan study

American blacks and Hispanics may have a greater incidence of subarachnoid hemorrhage (SAH) than whites, but incidence data are scant. We used an active hospital and community surveillance program and autopsy reports to identify incident SAH cases among white, black and Hispanic adults living in Northern Manhattan between July 1993 and June 1997. The annual incidence adjusted for age and sex to the 1990 US Census was 9.7 per 100,000 (95% CI 7.5-12.0). Compared with whites (9 cases, age- and sex-adjusted annual incidence 8.2 per 100,000), the rate ratio of SAH was 1.3 (95% CI 0.7-2.4) for Hispanics (34 cases, incidence 10.9), and 1.6 (95% CI 0.8-2.8) for blacks (9 cases, incidence 12.8). The 30-day case fatality rate was 26%. Risk of death increased significantly with age and severity at onset but was not influenced by gender or race-ethnicity. Non-traumatic subarachnoid hemorrhage (SAH) is most frequently caused by rupture of an aneurysm and accounts for 5-10% of all strokes [1]. Blacks in Greater Cincinnati have increased SAH incidence compared with whites [2]. Studies from Texas and New Mexico suggest that Mexican-Americans may have a higher rate of SAH than non-Hispanic whites; however, only one study demonstrated statistical significance [3, 4]. Our objective is to report the population-based incidence and the 30-day case fatality rate after SAH for Caribbean Hispanic, black and white residents of Northern Manhattan.