Profiling primary care physicians for a new managed care network.

We developed methods for comparing physicians who would be selected to participate in a major employer's self-insurance program. These methods used insurance claims data to identify and profile physicians according to deviations from prevailing practice and outcome patterns, after considering differences in case-mix and severity of illness among the patients treated by those providers. The discussion notes the usefulness and limitations of claims data for this and other purposes. We also comment on policy implications and the relationships between our methods and health care reform strategies designed to influence overall health care costs.