Quality Definitions and Methodology

Outcome measures indicate what happened after patients with certain conditions received hospital care. The mortality rates focus on whether patients died within 30 days of their hospitalization. The rates of readmission focus on whether patients were hospitalized again within 30 days. Mortality rates and rates of readmission are indications of a hospital’s effectiveness in preventing complications, instructing patients at discharge, and enabling patients to make a smooth transition to their home or another setting such as a nursing home.

The hospital mortality rates and rates of readmission are based on people with Medicare who are 65 and older. These rates are calculated using Medicare enrollment and claims records, and a complex statistical procedure. The mortality rates and rates of readmission are "risk-adjusted" (i.e. the calculations take into account how sick patients were when they went in for their initial hospitalization). When the rates are risk-adjusted, it helps make comparisons more meaningful.

Mortality Rates

Mortality models estimate hospital-specific, risk-standardized, all-cause 30-day mortality rates for patients hospitalized with a principal diagnosis of heart attack, heart failure, and pneumonia. All-cause mortality is defined as death from any cause within 30 days after the add link here index admission date, regardless of whether the patient dies while still in the hospital or after discharge. For each condition, the risk-standardized ("adjusted" or "risk-adjusted") hospital mortality rate can be used to compare performance. The mortality measures for heart attack, heart failure, and pneumonia have been endorsed by the National Quality Forum (NQF), the non-profit public-private partnership organization that endorses national healthcare performance measures.

A hospital’s mortality rates are compared with U.S. National rates to determine whether patients admitted to the hospital have mortality rates that are lower (better) than the U.S. National rate, about the same as the U.S. National rate, or higher (worse) than the U.S. National rate, given how sick they were when they were admitted to the hospital. For some hospitals, the number of cases is too small (fewer than 25) to reliably tell how well the hospital is performing, so no comparison to the national rate is shown.

Readmission Rates

Readmission rates are calculated from Medicare data and do not include people in Medicare Advantage plans or people who do not have Medicare. A “readmission” occurs when a patient who had a recent hospital stay needs to go back into a hospital again within 30 days of their discharge. Patients may have been readmitted back to the same hospital or to a different hospital or acute care facility. They may have been readmitted for the same condition as their recent hospital stay, or for a different reason.

Readmission rates are calculated for a hospital’s heart attack patients, heart failure patients, and pneumonia patients. Rates of admission are risk-adjusted to take into account how sick patients were before they were first admitted to the hospital.

The report also shows how a hospital’s rates of readmission compare to the U.S. National Rate. For some hospitals, the number of cases is too small (fewer than 25) to reliably tell how well the hospital is performing, so no comparison to the national rate is shown.