Validation of self-reported history of acute myocardial infarction: experience of the Minnesota Heart Survey Registry.

Accurate separation of new cases of acute myocardial infarction from prevalent cases is critical for assessing trends in morbidity in population-based studies. This report presents data on the validity of self-reported history of previous acute myocardial infarction among 3,703 patients admitted to a coronary care unit with suspicion of acute myocardial infarction. We substantiated the history of a prior event for 60% of those who reported one (629 of 1,053) and found 40% to be false-positive histories. Much of the false-positive reporting was related to previous cardiac hospitalizations, predominantly (40%) for unstable angina.