摘要：A cohort study is one of the most important methods of investigating epidemiologically the etiological significance of possible risk factors on the occurrence of stroke. The Adult Health Study of the Radiation Effects Research Foundation, which began in 1958 under the aegis of the Atomic Bomb Casualty Commission, is one of a series of epidemiologic studies of the late effects of exposure to ionizing radiation on the atomic bomb survivors in Hiroshima and Nagasaki. This cohort study provides a wealth of information on changes in the incidence over time in cardiovascular diseases, including ischemic heart disease and stroke. When the study began, the population at risk of a stroke was about 16, 500 individuals who were free of cerebrovascular disease at the time of their first medical examination. During 26 years of follow-up, 865 cases of definite or probable strokes have been ascertained. When the cases were classified into strokes arising from cerebral hemorrhage, on the one hand, and cerebral infarction, on the other, age-adjusted incidence rates revealed a declining trend for both types, but especially for cerebral hemorrhage. The results of a multivariate analysis of risk factors showed that hypertension was the most significant predictor of stroke. It appears, however, that stroke occurrence in Japan varies with life style changes in accordance with the results from a comparative study of Japanese men living in Japan and in Hawaii.
