EFFECTS OF INTERSTATE MIGRATION ON THE GEOGRAPHIC-DISTRIBUTION OF STROKE MORTALITY IN THE UNITED-STATES

Background and Purpose This study examines the effects of lifetime net interstate migration on the geographic distribution of stroke mortali ty in the United States. Methods National Center for Health Statistics and Bureau of the Census data were used to map the geographic distrib ution of age-adjusted, race-, and race/sex-specific stroke mortality r ates by interstate migration status for natives, outmigrants, nonmigra nts, inmigrants, and residents in the United States for 1979 to 1981. Results High age-adjusted stroke mortality rates were significantly cl ustered in the southeastern United States for both whites and blacks; in addition, for whites, low-rate states were concentrated in some Mou ntain and northeastern states. Migrant status did not change this larg e-scale pattern, but individual states showed significant migration ef fects, which varied in magnitude and direction. Among whites, states t hat benefited from migration, with markedly lower stroke mortality rat es among residents than natives, included Arizona, Colorado, District of Columbia, and Florida, whereas states that suffered from migration included California, Idaho, Montana, North Dakota, Nevada, and Oklahom a. Among blacks, only Colorado showed an apparent large benefit from m igration, whereas 21 states suffered from migration. Conclusions Altho ugh the overall large-scale spatial distribution of resident stroke mo rtality rates cannot be explained by migration effects, some individua l states had rates that were strongly influenced by migration. Pattern s of mortality among migrant groups in Sun Belt retirement destination states probably result from differential selection effects for retire ment migration in older adults. Patterns of mortality for black migran ts to the North are probably influenced by ''carryover'' effects from their origin states.