The geography of stroke mortality in the United States and the concept of a stroke belt

DJ Lanska, LH Kuller - Stroke, 1995 - Am Heart Assoc
DJ Lanska, LH Kuller
Stroke, 1995Am Heart Assoc
Since at least 1940 there has been a consistent pattern of marked geographic variation in
stroke mortality rates within the United States. 1 2 3 Very high rates are reported in the
Southeast, and particularly the southeast coastal plain, while very low rates are reported in
the Mountain census division and along the northern Atlantic coast. 1 2 3 These general
patterns of geographic variation have been observed for both sexes and for whites and
nonwhites, although stroke rates have been consistently declining in all geographic areas of …
Since at least 1940 there has been a consistent pattern of marked geographic variation in stroke mortality rates within the United States. 1 2 3 Very high rates are reported in the Southeast, and particularly the southeast coastal plain, while very low rates are reported in the Mountain census division and along the northern Atlantic coast. 1 2 3 These general patterns of geographic variation have been observed for both sexes and for whites and nonwhites, although stroke rates have been consistently declining in all geographic areas of the continental United States over this interval. 1 Comparable age-adjusted and race-and sex-specific data for earlier periods are not available because (1) tabulations of deaths are limited to the Death Registration Area, which did not include all of the coterminous United States until 1933, 4 5 6 and (2) US mortality data were first cross-tabulated by age, race, sex, cause of death, and state in 1937. Nevertheless, age-adjusted stroke mortality rates for whites suggest that the current spatial distribution of stroke mortality was not in place in 1920; instead, the high-rate states were apparently concentrated in the northeastern United States. 3 From 1920 through 1933, rates declined considerably in all states but particularly in the Northeast, shifting the distribution of excess stroke mortality southward. By 1940, rates had declined further but least in the Southeast, leaving this area with an excess of stroke mortality that has persisted for half a century.
The nonrandom distribution of stroke mortality across the United States; the persistence of the pattern over more than five decades; the similarity of the pattern for different age, race, and sex groups; the fact that the pattern is not delimited by county, state, or other political administrative boundaries; and the extreme magnitude of the differences between rates in high-and low-rate areas suggest that the geographic pattern of stroke mortality rates is not an artifact of different diagnostic and reporting practices. 1 Furthermore, in the 1960s, national cooperative studies confirmed the apparent large differences in stroke mortality rates between geographic areas in the United States. 7 8 These large variations in mortality rates could not be explained by (1) differences in certification practices (such as the choice of underlying cause of death when multiple causes contributed to death),(2) the frequency with which clinical stroke diagnoses were listed on the certificates,(3) differences in the accuracy of diagnosis of stroke, or (4) variations in the standards of medical care. 7 8 9 10 11 Furthermore, the large regional differences in stroke mortality parallel geographic differences in stroke incidence 12 and in hospital utilization rates for stroke. 2
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