A prospective study on the relationship between aspirin use and heart attacks by the Physicians' Health Study Research Group at Harvard Medical School is presented below. The Physicians' Health Study was a 5-year randomized study of whether regular aspirin intake reduces risk of myocardial infarction or heart attack. Every other day, physicians participating in the study took either one aspirin tablet or a placebo. The study was blind those in the study did not know whether they were taking aspirin or a placebo. Of the 11,034 physicians taking a placebo, 189 suffered heart attacks over the course of the study, whereas of the 11,037 taking aspirin, 104 had heart attacks. Can we say that the intake of aspirin appears to diminish the risk of myocardial infarction? Myocardial Infarction Group Total Yes No Placebo 189 10845 11034 Aspirin 104 10933 11037 Total 293 21778 22071 Let patients taking placebo be the first group and those taking aspirin in the second group