Intra-urban variations in incidence and mortality in myocardial infarction. A study from the myocardial infarction register in the city of Malmö, Sweden

Abstract

Aim: To assess to what extent intra-urban variations and time trends of mortality in ischaemic heart disease are related to incidence of disease.

Methods and results: Incidence and mortality data were retrieved from the myocardial infarction register in Malmö. Age- and sex-adjusted incidence varied between the 17 city areas from 469 to 681/10(5) (P=0.003), and mortality from 286 to 446/10(5) (P=0.017). Socio-demographic risk factors for ischaemic heart disease were more prevalent in high rate areas. About 70% of the variance in mortality was explained by the variance in incidence. From 1986 to 1992, incidence declined by 3.6%/year in men (P=0.004) and by 0.9%/year in women (P=0.31). Mortality decreased by 4.1%/year in men (P=0.01) and by 1.9%/year in women (P=0.15). Incidence and mortality changes were statistically significant only in men>65. In younger age groups, incidence and mortality decreased in men but increased in women.

Conclusions: In this urban population, there were large intra-city differences in mortality from ischaemic heart disease. During the period 1986 1992 there was a parallel decline in mortality and incidence. There were, however, substantial variations both in terms of residence and subject.