Use of computerized databases to survey drug utilization in relation to diagnoses

Many studies of drug utilization have suffered from the absence of information on the indications for therapy. A few data sets on drug utilization are available which include indication information. In addition, a number of computerized collections of medical billing data now exist in North America which can be used for such studies. These include data from the Kaiser Permanente Medical Plan; the Group Health Cooperative of Puget Sound; the Commission on Professional and Hospital Activities' Professional Activity Study; the U.S. state of Rhode Island; the Saskatchewan Health Plan in Canada; and Medicaid, the state run but federally financed health insurance plan for economically or medically needy individuals in the United States. These databases have a number of general advantages and disadvantages, which are reviewed. In addition, the differences among these databases are also explored. Finally, examples are presented demonstrating how these databases can be used for: 1) descriptive research on drug utilization, 2) evaluating the appropriateness of drug utilization, and 3) interventions designed to improve the appropriateness of prescribing.