Combining multiple data bases for outcomes assessment.

Often, information from a single database cannot answer important clinical outcomes or research questions. This article describes efforts to link multiple databases to extract useful health care information. One project, conducted by the Keystone Peer Review Organization (KePRO), focused on the number of combined right and left heart catheterizations done in patients, who were admitted to the hospital for a diagnostic left heart catheterization, for primary coronary artery disease. The study linked data from hospital billing records, patient records, and insurance companies' records. Another effort involves two studies of Acute Myocardial Infarction (AMI) by KePRO and Pennsylvania Health Care Cost Containment Council. The final case study describes the Crash Outcomes Data Evaluations Systems (CODES) project, conducted by the Pennsylvania Department of Health. To determine if seat belts help to prevent injuries, cut costs, and save lives, it was necessary to build a complete record across multiple sights of care from the crash until final outcome. These examples illustrate the challenges and the advantages of using multiple databases to assess health care outcomes.