Incidence of spontaneous subarachnoid hemorrhage among Hispanics and non-Hispanic whites in New Mexico.

BACKGROUND AND PURPOSE

There are differences in cerebrovascular disease incidence between racial and ethnic groups. Little is known about cerebrovascular disease among Hispanics living in the southwestern United States as compared to non-Hispanic whites. This is the first study which measures and compares the incidence of spontaneous subarachnoid hemorrhage (SAH) among Hispanics and non-Hispanic whites living in Bernalillo County, New Mexico. This information may help reduce the risk and incidence of SAH.

METHODS

Medical records of all possible cases of spontaneous SAH occurring during a two-year period (January 1, 1993 to December 31, 1994) among residents of Bernalillo County, New Mexico, were reviewed in all local hospitals. Hospital records were identified by ICD-9-CM codes. Medical examiner records were also reviewed for additional SAH cases occurring during the same time period. The 1990 U.S. census provided the population base.

RESULTS

There were 22 spontaneous SAHs among 267,965 non-Hispanic whites and 25 spontaneous SAHs among 178,310 Hispanics. Incidence of SAH increased with age in both groups. The age- and sex-adjusted total annual incidence of SAH per 100,000 people was 3.73 among non-Hispanic whites and 9.19 among Hispanics (relative risk for Hispanics 2.46, 95% confidence interval 1.37-4.43, P = 0.003). The incidence rates among men and women were not significantly different in either ethnic group.

CONCLUSIONS

The incidence of SAH among Hispanic residents of Bernalillo County, New Mexico, is approximately two and a half times higher than that among non-Hispanic whites. This suggests a higher prevalence or a greater tendency to rupture of berry aneurysms among Hispanics as compared to non-Hispanic whites. The reasons for this difference require further investigation.