The CPPT was part of the Institute's Lipid Research Clinic Program under the Lipid Metabolism Branch, DHVD, NHLBI. Twelve lipid research clinics in the United States and Canada participated in this trial, as well as a coordinating center, a central electrocardiographic laboratory, central lipid and clinical chemistry laboratories, a nutrition coding center, and a group of consultants on recruitment and adherence. This program's objectives included the development of standardized methods and definitions for the diagnosis of hyperlipoproteinemia and the performance of a series of collaborative studies of the prevalence and natural history of this disorder, as well as the design and implementation of the Coronary Primary Prevention Trial.