A comparison of trends in mortality from stroke in the United States and Rochester, Minnesota.

More uniform methods of diagnosis and determination of the cause of death result in greater reliability of trends in mortality from stroke. In all categories of stroke except subarachnoid hemorrhage, the mortality rates in Rochester, Minnesota, are lower and show a more rapid decline with time than in the United States as a whole. The differential between the rates for United States white population and the Rochester population is most evident in the older age groups. This difference may be due to the effects of revisions in the International Classification of Disease and/or to the assignment of nonstroke deaths to stroke causes in the United States as a whole to a greater extent than in Rochester. Whether different patterns of medical care affect the trends in stroke mortality has not been determined. The trends in mortality from various categories of stroke in Rochester are reliable because some of the inconsistencies of diagnosis, assignment of cause of death, and coding changes have been overcome. The decline in mortality rates for Rochester corresponds well with decreasing incidence rates and lack of change in case fatality rates previously reported.