Nationwide Cerebrovascular Disease Morbidity Study

Previous studies have noted that the geographic differences in stroke mortality among areas of the United States were not due to artifacts of certification practices or accuracy of the diagnosis. A study of hospitalized stroke patients was completed in order to determine whether the mortality differences were due to a higher incidence or case fatality following a stroke in areas with high stroke death rates. Eight of the nine areas that participated in the Nationwide Mortality Study were included in this study. A total of 2,619 stroke cases were ascertained including 1,631 (62.3%) who were alive at the time of hospital discharge, 937 (35.8%) dead at discharge, 46 (1.7%) who were discharged alive but died outside of the hospital, and five (0.2%) who were dead at discharge and certified by the medical examiner. The incidence of stroke was higher in the high stroke death rate areas especially for men. The ratio of the incidence of stroke in men as compared to women was higher in the younger age groups (45–54, 55–64) and in the high-incidence as compared to low-incidence areas. The case-fatality percentage was lowest in Denver and highest in South Carolina. Presence of coma on admission was the principal determinant of subsequent mortality in all areas. Finally, there was no consistent difference in the distribution of symptoms of stroke among the areas, and diagnostic procedures were performed more often in urban than rural areas. Approximately 80% of the stroke cases could be substantiated by either an autopsy verifying diagnosis, arteriography, hemorrhagic spinal fluid, hemiplegia or coma on admission. Several hypotheses to explain the differences have been suggested as well as the need for new information.