The 30-day Risk-Adjusted Death (Mortality) Rates are produced using a complex statistical model, that relies on Medicare claims and enrollment information. The model predicts patients deaths for any cause within 30 days of hospital admission for heart failure, whether the patients die while still in the hospital or after discharge. Thirty-day mortality is used because this is the time period when deaths are most likely to be related to the care patients received in the hospital. Deaths that occur outside the hospital within 30 days are included along with deaths that occur in the hospital, because some hospitals discharge patients sooner that others.

These comparisons take into account how sick patients were before they were admitted to the hospital and differences in death rates that might be due to chance.

Hospitals in the Better Than U.S. National Rate category have risk-adjusted 30-day death (mortality) rates that are lower then the U.S. National rate, and we can be 95% certain that this difference is not due to chance.

Many hospitals in the No Different Than U.S. National Rate category have risk-adjusted 3-day death (mortality) rates that are about the same as the U.S. National rate. Other hospitals in this category have rates that are higher or lower than the U.S. National rate, but we cannot be 95% certain that these differences are not due to chance. One cannot be certain about differences when a hospital has very few relevant patients.

Hospital in the Worse Than U.S. National Rate category have risk-adjusted 30-day death (mortality) rates that are higher than the U.S. National rate, and we can be 95% certain that this difference is not due to chance.