Thousands of individual U.S. hospitals will have their ultimate test of competence revealed on the Web -- whether their patients live or die. The Hospital Compare page, maintained by the Centers for Medicare & Medicaid Services (CMS), has begun displaying actual hospital death rates for heart attack, heart failure, and pneumonia patients.

Previously, only relative performance had been shown; the page formerly showed only whether mortality at a particular hospital was about the same as the national average, better than average, or worse than average.

The rates are adjusted to take risk factors such as age, heart problems, and existing conditions into account.