Decline in US Stroke Mortality

Abstract

Background and Purpose — Although stroke mortality rates have declined rapidly over the past 30 years, the decline has slowed to a plateau. Here, we assess whether the race-sex-region groups have participated equally in this decline and whether there are groups in which stroke mortality rates are still declining, and we predict how these rates will eventually differ. Methods — Data on stroke mortality in the United States between 1968 and 1996 were analyzed in a 3-step procedure: (1) we calculated “crude” age-adjusted stroke mortality rates by race, sex, and county; (2) we “smoothed” the rates across counties and years; and (3) we fit a model to describe the temporal pattern. From this model we calculated the percent decline in stroke mortality, the anticipated additional decline (thereby identifying regions that will continue to decline), and the anticipated eventual stroke mortality rates. Results — Maps by race-sex-region group describe the above parameters. White men have experienced the largest decline in stroke mortality, and black men have seen the smallest. Generally, stroke mortality appears to still be slowly declining for blacks but not for whites. Geographic differences in stroke mortality are predicted to persist. Conclusions — The analysis suggests that the Deep South (Alabama and Mississippi) will fall from the stroke belt and be replaced by other regions (notably Oregon, Washington, and Arkansas). New York City and southern Florida had low stroke mortality rates in 1968, have experienced large declines, and continue to experience declines, resulting in even larger relative heterogeneity of stroke mortality rates. The reasons for these differences in the pattern of the decline in stroke mortality are not understood.