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

Abstract

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