Geographical pattern of female deaths from myocardial infarction in an urban population: fatal outcome out-of-hospital related to socio-economic deprivation.

OBJECTIVE: This study of myocardial infarction (MI) amongst urban women has sought to assess whether there are differences in fatal outcome, in-hospital respectively out-of-hospital, between residential areas defined in terms of socio-economic circumstances.
DESIGN: Register-based surveillance study 1986-95.
SETTING: Seventeen residential areas in the city of Malmö, Sweden.
SUBJECTS: Women 20-74 years of age. MAIN OUTCOME MEASURES: Differences in fatal outcome, in-hospital respectively out-of-hospital, between residential areas were expressed in terms of age-adjusted odds ratios (ORs), calculated by means of logistic regression. Socio-economic circumstances in the areas were expressed in terms of a composite score.
RESULTS: Between residential areas there were marked and statistically significant differences in incidence (range 124-328/10(5), P < 0.001, d.f.=16) and mortality (range 38-132/10(5), P < 0.005, d.f.=16). Area rates of mortality covaried with incidence (r=0.85, P < 0.001) and with odds ratios of fatal outcome out-of-hospital (r=0.52, P=0.031) but not in-hospital. The odds ratios of fatal outcome out-of-hospital decreased in a statistically significant stepwise fashion from areas in the lowest socio-economic quintile (reference) to areas in the highest socio-economic quintile (OR: 0.67, 95% CI: 0.48-0.94). There was no corresponding association with the odds ratios of fatal outcome in-hospital.
CONCLUSIONS: The high rate of mortality from MI amongst women in areas with deprived socio-economic circumstances was related to deaths occurring out-of-hospital. In order to assess the preventive potential there is a need for further studies that may clarify to what extent the association with socio-economic circumstances can be explained by other factors and conditions known to influence the probability of survival.