Trends in incidence and mortality from acute myocardial infarction in Nova Scotia and Saskatchewan 1974 to 1985. The Nova Scotia-Saskatchewan Cardiovascular Disease Epidemiology Group.
OBJECTIVE
To compare trends in incidence and case fatality of acute myocardial infarction (AMI) in Nova Scotia and Saskatchewan, provinces with the highest and lowest rates, respectively.


METHODS
Provincial hospital separation files were linked with mortality files and searched to identify incident cases in 1977, 1981 and 1985. The diagnoses were validated on a random sample of hospital charts with discharge codes 410 and 411 to 414 of the International Classification of Diseases of the World Health Organization.


RESULTS
In spite of persisting differences between Nova Scotia and Saskatchewan, standardized AMI mortality and incidence rates in males and females have decreased, although at a slower rate in Saskatchewan. In both provinces the greatest decrease has occurred in male deaths prior to any hospital admission--likely representing cases of sudden death. Excess mortality in Nova Scotia is due predominantly to out-of-hospital deaths. Case fatality rates have declined in both provinces. The proportion of definite and possible AMI was similar in Nova Scotia and Saskatchewan in 1977, but not thereafter.


CONCLUSIONS
Along with a decline in ischemic heart disease mortality, there appears to be a decline in AMI incidence in Nova Scotia. Parallel studies of risk factor changes, interventive care and access to care are required to explain the observed phenomena.
D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008498:Medical Record Linkage; D008875:Middle Aged; D009026:Mortality / Q000639:trends; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000401:mortality; D009674:Nova Scotia / Q000453:epidemiology; D012008:Recurrence; D012525:Saskatchewan / Q000453:epidemiology; D012737:Sex Factors