The epidemiology of cerebral vascular disease in Canada: an analysis of mortality data.

Mortality data for cerebral vascular disease in Canada and its provinces were analysed as an initial approach to the understanding of the epidemiology of this disease. Since 1950, there has been a decline in mortality attributed to vascular lesions of the central nervous system. This decline has been more pronounced in females. Five-year average age-sex-specific rates (1960-64) showed an almost constant proportional increase with age. The highest mortality rates tended to occur in the Eastern Provinces.From 1950 to 1964 there was a 21% decline in mortality due to intracranial hemorrhage and a concomitant 53% decline in mortality attributed to hypertensive disease. Over the same period there was a 24% increase in mortality attributed to cerebral embolism and thrombosis, and an 8% increase in mortality due to arteriosclerotic heart disease. Areal correlations offered only inconsistent support for the hypothesis that these associated trends are due to common etiologic determinants.Evidence presently available does little to clarify to what extent these trends and differences can be attributed to coding, certification and diagnostic practices, and to what extent to changing and differing incidence and prognosis.