HOSPITALIZATION AND CASE-FATALITY RATES FOR STROKE IN CANADA FROM 1982 THROUGH 1991 - THE CANADIAN COLLABORATIVE STUDY-GROUP OF STROKE HOSPITALIZATIONS

Background and Purpose The purpose of this study was to estimate rates of hospitalization and in-hospital case-fatality for cerebral infarct ion and intracerebral hemorrhage in Canada and to describe variation i n rates by age, sex, and calendar period. Methods Data were obtained f rom hospitalization databases for each of Canada's 10 provinces for th e 10 fiscal years of 1982 through 1991. All hospitalizations of person s 15 years of age or older with a primary diagnosis at discharge coded 431, 434, or 436 according to the International Classification of Dis ease, 9th Revision, were included. Rates per 100 000 population were c alculated for intracerebral hemorrhage and cerebral infarction, for me n and women, and for five age groups. Annual age- and sex-specific, 30 -day, in-hospital case-fatality rates were also calculated. Results A total of 335 283 discharges for stroke were enumerated over the 10-yea r period (309 631 cerebral infarctions and 25 652 intracerebral hemorr hages). A significant decline of approximately 1% per year was observe d for the rate of cerebral infarctions. For hemorrhages, the reverse w as seen. For men there was a 44% increase over the 10-year period, and for women there was a 34% increase. In-hospital case-fatality rates f or cerebral infarctions increased with age but did not differ by sex w hen age was considered. For the five age groups of 15 to 54, 55 to 64, 65 to 74, 75 to 84, and greater than or equal to 85 years, rates were 6%, 8%, 12%, 18%, and 27%, respectively. For intracerebral hemorrhage , the in-hospital case-fatality rates declined significantly over time from approximately 36% to 29%, 55% to 37%, 49% to 41%, 66% to 45%, an d 72% to 59% for the five age groups, respectively. Conclusions The po ssibility that these changes are artifactual could not be ruled out, b ut because there is no obvious risk in assuming that they are not, it would be prudent to investigate their causes further.