title: Trends in in-hospital mortality following acute myocardial infarction (AMI) in Victoria, 1987-1994.
abstract: BACKGROUND
  Death rates from coronary hearts disease have exhibited remarkable declines in most industrialised countries. Cardiovascular mortality has been the subject of extensive research and we considered it important to analyse recent local population based data on hospital outcomes of acute myocardial infarction (AMI).
  
  
  OBJECTIVE
  To document the trends in in-hospital mortality from AMI in Victoria from 1987-1994.
  
  
  METHODS
  This was a retrospective analysis of data from the Victorian Inpatient Minimum Database relating to all public acute care hospitals. All separations recording a principal diagnosis 410 (AMI) were selected. Changes in distribution of AMI separations, in-hospital mortality, and changes in length of stay were examined.
  
  
  RESULTS
  The mean age of women admitted was 72 years compared with 64 years for men. Women comprised around a third of the overall sample but the proportion varied from 13% in those under 50 years to 57% among those aged 80 years and over. A striking decline in mortality was observed throughout the eight year period. The relative age adjusted decline was 33.5% (40% in males and 26% in females) with rates remaining higher in women. This decline occurred despite the increasing representation of those aged over 80 years. There was a significant decline in the mean length of stay (1.8 days) over the eight year period but this is likely to have had only minimal impact on mortality rates.
  
  
  CONCLUSIONS
  We have documented welcome declines in in-hospital mortality from AMI that are not an artefact of declining lengths of stay. Our observations parallel those in similar overseas studies. Large changes in medical management have taken place from the mid 1980s and may be partly responsible, but a change in disease process cannot be ruled out.
authors.affiliation: Public Health Branch, Department of Human Services, Melbourne, Vic.
authors.forename: D
authors.initials: D
authors.lastname: O'Hara
authors.forename: I
authors.initials: I
authors.lastname: McDonald
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001315:Australia / Q000453:epidemiology; D003627:Data Interpretation, Statistical; D005260:Female; D017052:Hospital Mortality / Q000639:trends*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality*; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends