The Dartmouth data: moving from analysis to action

The work of Jack Wennberg and colleagues on variations in medical practice and outcomes has clarified our understanding of the relationships between supply, costs, and quality of medical care. Variations persist, however, in spite of our knowledge of them. Progress in reducing these variations will require technical, political, and regulatory solutions to problems surrounding financial incentives and health care delivery. Wennberg's paper uses Medicare claims data to focus on specific providers rather than geographic regions. However, "real-time" availability of such data is necessary to maximize their usefulness, and collective action will be required to overcome obstacles to that goal.