Increasing incidence and mortality from myocardial infarction in Stockholm county.

A study was undertaken to examine trends in the incidence and mortality of myocardial infarction in Sweden. All cases (n = 19908) of myocardial infarction diagnosed in the population of Stockholm county during 1974-80 were identified by means of the cause of death register and the inpatient care register. Information on patients at risk was obtained from the civil registration system. The relative risk of developing, or dying of, myocardial infarction in one specific year, compared with the average for the whole period, was taken as the basis for describing the trends. For men in Stockholm the incidence as well as the mortality was appreciably increased; the annual increase in incidence was 3% and in mortality 4%. There were no signs of decreasing lethality. For women there was an appreciable increase in incidence; for mortality the result was less specific but was compatible with an increase. The observed increases in incidence and mortality appeared to be real and were probably not due to an increasing tendency for patients to seek hospital treatment or for doctors to make the diagnosis. The reason for the increase is unknown.