Geographical variation and time trends in the attack rate of coronary heart disease in five Swedish cities

Abstract

Based upon community myocardial infarction (MI) records in five Swedish cities, geographical variation and time trends in the attack rate of fatal and non‐fatal MI have been evaluated. During the study period 1975–1982, a total of 7699 events were registered among men and 1823 events among women. The mean annual mortality was highest in the north, and a declining gradient in mortality was observed from the northern to the southern part of the country. The out‐of‐hospital death rate was highest in the north, while no difference in in‐hospital mortality was observed. However, the geographical variation in the morbidity of MI was less consistent. Changes over time generally followed the same pattern in all cities. The attack rate of fatal and non‐fatal MI tended to decline among women and men aged 60–64 years. The pattern was less consistent among younger men. Among women aged 50–59 years the mortality remained unchanged, but the attack rate of non‐fatal MI increased in all cities. This increase was not explained by inclusion of less severe infarctions. A considerable proportion, about 85%, were recorded as primary events, emphasizing the possible role of primary prevention in obtaining a decrease in the incidence of the disease. The results of this study support previous findings of an important regional difference in the mortality of MI in Sweden. However, the magnitude of the regional variation in the incidence of coronary heart disease might be overestimated if only the mortality pattern is studied.