Trends in coronary heart disease in Queensland, 1971-1980. An interpretation.

Routine data on mortality and hospital activity were used to estimate changes in coronary heart disease mortality, case fatality, and hospitalizations in the Australian state of Queensland over the decade 1971-1980. Acute myocardial infarction (International Classification of Diseases (ICD) 410) and other ischemic heart disease (ICD 411-414) were considered separately. For acute myocardial infarction, age-adjusted total mortality declined by about one fourth in both men and women; in-hospital mortality decreased somewhat more and deaths out of hospital correspondingly less. The age-adjusted case fatality ratio fell by the same amount (29%), in both sexes. Similar trends occurred at all ages. Admission rates decreased 11% in men and 18% in women. Similar patterns were evident for other ischemic heart disease except for admissions, which rose 23% among men and remained at the same level in women. These findings suggest that both declining incidence, particularly in the form of fewer deaths out of hospital, and improvements in care may have contributed to the general decline in coronary heart disease mortality in this community. Without direct measures of incidence or changing disease severity, the relative contributions of each factor cannot be examined.