Time trends of myocardial infarction 28-day case-fatality in the 1990s: is there a contribution from different changes among socioeconomic classes?
OBJECTIVE
Almost two-thirds of the coronary death rate decrease in the northern Italian Brianza MONICA male population, between 1993-4 and 1997-8, are attributable to a reduction in 28-day myocardial infarction (MI) case-fatality. The present paper investigates the factors associated with MI case-fatality decrease and in particular the role of socio-occupational classes (SOCs).


METHODS
Standardised information on acute coronary care and intervention before and during the hospitalisation was collected for all coronary events (n = 1817) registered in 1993-4 and in 1997-8 among 35-64-year-old male residents in Brianza. Deaths within 28 days after MI were carefully investigated. Five SOCs were defined adopting the Erikson-Goldthorpe-Portocarero method. Differences in 28-day MI case-fatality and in acute phase intervention and treatment over time and among SOCs in each period were assessed.


RESULTS
28-day MI case-fatality reduction (27.2%) can be mainly attributed to a decreased proportion of MI events that were fatal before reaching the hospital. In the lower SOCs significant changes in MI case-fatality were detected between 1993-4 and 1997-8. Differences in acute phase intervention and treatment between the periods were observed. SOC differences both in prevalence of out-of-hospital cardiac arrest and in the pre-hospital qualified intervention score were detected in the first period only.


CONCLUSIONS
In the study population MI case-fatality reduction can be mainly attributed to a more effective and prompt management before hospitalisation and to an improvement in acute treatment during hospitalisation. This enhancement is made available to the whole population overtaking social differences.
Fornari
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Centro di Studio e Ricerca sulla Patologia Cronico-Degenerativanegli Ambienti di Lavoro, Dipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università degli Studidi Milano-Bicocca, Monza, Italy.
Cesana
G C
GC
Chambless
L E
LE
Corrao
G
G
Borchini
R
R
Madotto
F
F
Ferrario
M M
MM
D000328:Adult; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000628:therapy; D012042:Registries; D012307:Risk Factors; D012923:Social Class; D013997:Time Factors; D055815:Young Adult