Abstract
Under proposals for national health insurance reform in the USA, employers and purchasing cooperatives will have to measure the quality of health care services. Their need for data systems upon which to base their decisions has stimulated dramatic innovation and rapid change in how health care information is collected, integrated from multiple sources, and reported. To make administrative data useful for quality measurement, careful attention must be given to information about: medical care utilization; patient characteristics; provider characteristics; and health plans. In this paper, we describe the extent to which this information is included in existing administrative datasets. We then suggest how planned datasets should be designed so they can be used to assess the quality of health care.