Coronary heart disease in residents of Rochester, Minnesota, 1950-1975. I. Background and study design.

The unique medical data resource for the population of Rochester, Minnesota, is centered on the records of the Mayo Clinic and the Olmsted Medical and Surgical Group, which for several decades have provided nearly all medical care in this community. This resource has been utilized in a study of the incidence rates and secular trend in coronary heart disease for the period 1950-1975 among residents of Rochester. A total of 3,080 patients fulfilled the clinical and other criteria for inclusion in this study. The patients, classified by initial manifestation of coronary heart disease, consisted of 1,321 with myocardial infarction, 1,215 with angina pectoris, and 544 with sudden unexpected death. In this paper the background, clinical definitions, and study design are presented.