C2: a data base management system developed for the Coronary Artery Surgery Study (CASS) and other clinical studies

For the Coronary Artery Surgery Study (CASS), large variable amounts of data on different form-types are collected on many different patients. In this paper, we describe C2, a "state-of-the-art" command-oriented data base system developed in response to the needs of maintaining a large complex data base and performing subsequent analyses on a large number of studies. C2 provides a friendly, interactive interface with the researcher as well as a powerful method for data extraction, data transformation, and the merging of files from the CASS data base.