Prevalence of angina pectoris and myocardial infarction in a general population sample of Swedish men.

A primary preventive trial against cardiovascular diseases has been in progress since 1970 in Göteborg, Sweden. The study population comprises all men in the city born in 1915-22 and 1924-25, a total of about 30 000 men. One third of this population constitutes the intervention group. The prevalence of angina pectoris and myocardial infarction among men aged 47-53 years has been studied in this group. The cases were identified by means of a postal questionnaire, direct interview at screening examination and by clinical examination. A validation of the postal questionnaire technique gave a sensitivity of 74% and a specificity of 94%. The minimum prevalence of angina pectoris amounted to 4.3% and the prevalence of myocardial infarction to 1.6%. In the angina series, 22% had suffered a myocardial infarction that preceded angina pectoris in 9%.