Trends in ischemic heart disease mortality and morbidity in Perth Statistical Division

Trends in mortality from Ischemic Heart Disease (IHD) and other principal causes of death, and in hospital admission rates for Acute Myocardial Infarction (AMI) have been studied in residents aged 35-64 years of the Perth Statistical Division for the period 1968-1982. Death rates were based on data abstracted from official statistics or computer tapes of unit death records. Hospital admission rates were derived from the computer tapes of the Western Australian Hospital Inpatient Survey, 1968-1982. Since 1968, mortality from IHD has fallen in the Perth Statistical Division in both males and females by 30% and 33%, respectively. This fall has occurred principally in deaths occurring out-of-hospital and has been accompanied by similar falls in mortality from other vascular diseases and in total mortality. Hospital admission rates for Acute Myocardial Infarction (AMI) in the Perth Statistical Division have fallen since 1971 by 17% in males and 27% in females. These findings taken together suggest that the improvement in IHD mortality in Western Australia has been due mainly to a fall in the incidence of acute manifestations of IHD (sudden death and AMI), rather than improvements in case fatality. The possible underlying mechanisms responsible for this are discussed.