Ethnic differences in stroke mortality between non-Hispanic whites, Hispanic whites, and blacks. The National Longitudinal Mortality Study

Abstract

Background and purpose: Although US blacks are known to have an excess stroke mortality compared with US whites, little is known about the stroke burden of the Hispanic white population. This report will provide estimates of the relative burden of stroke mortality in the US black and Hispanic population relative to the white population and examine the consistency of this relation across age.

Methods: Data were from participants aged > 45 years from the National Longitudinal Mortality Study. There were 1844 stroke deaths among 239,734 non-Hispanic whites, 46 deaths among 12,527 Hispanic whites, and 234 deaths among 23,468 black participants. Standard statistical methods were used to examine the ethnic differences in stroke mortality.

Results: The hazard ratios for black men and women (relative to non-Hispanic whites) were nearly identical, at > 4.0 at age 45 but marginally < 1.0 by age 85. For both Hispanic men and women, the hazard ratios (relative to non-Hispanic whites) were approximately 1.0 at age 45 but were marginally significantly < 1.0 at older ages. The ethnic differences in stroke death rates reveal differences in age distributions of age at fatal stroke between these groups. Approximately 6% of fatal strokes for non-Hispanic whites occurred before age 60, whereas > 15% occurred in both Hispanic whites and blacks.

Conclusions: These results suggest that (1) for Hispanics, stroke risk is similar to that for non-Hispanic whites at young ages but is marginally lower at older ages, (2) the excess stroke mortality in blacks mainly occurs at younger ages (between 45 and 55 years), and (3) the relation between stroke risk for blacks and Hispanics relative to whites is similar by sex. The impact of age on relative stroke mortality would argue against simple age adjustment for describing ethnic differences in stroke mortality. Finally, proportionally, more strokes occur at older ages in non-Hispanic whites than in either US blacks or Hispanic whites.