If you or someone you know experiences an acute myocardial infarction (AMI), it is natural to want to be treated at a “high-quality” hospital. Yet how does one know which hospitals measure up? In the past, objective information was scarce, and a hospital's reputation might well reflect the quantity of marble in its lobby rather than any true evidence of quality. But the world is changing, and the past decade has seen a proliferation of information aimed at helping consumers select among health care providers (hospitals and physicians). Ratings, rankings, and scorecards are now published by a variety of organizations, including federal and state agencies, nonprofit accrediting organizations, commercial companies, and the media. Although consumers might reasonably expect such information to be reliable, relatively little is known about the comparative accuracy or consistency of these alternative quality measurement systems.