30-day death (mortality) rates
The death (mortality) rates are estimates of deaths in the 30 days after either:
- Entering the hospital for a specific condition; or
- Having a coronary artery bypass graft (CABG) surgery.
Deaths can be for any reason, and can occur in the hospital or after discharge.
Death rates are measured within 30 days, because deaths after a longer time period may have less to do with the care the hospital provided and more to do with other complicating illnesses, patients’ own behavior, or other care services patients received after they leave the hospital.expand
Which patients are included
The death rates include hospitalizations for Medicare beneficiaries 65 or older who were enrolled in Original Medicare for 12 months before their hospital admission. The death rates do not include patients who left the hospital against medical advice.
Where the information comes from
Medicare calculates hospital-specific death rates for each hospital using Medicare claims data and eligibility data. The heart attack, heart failure, and pneumonia mortality measures also include VHA data. Using claims and eligibility data makes it possible to calculate death rates without having to review medical charts or requiring hospitals to report additional information. Medicare conducted research during the development of the initial death measures, which showed that measures that use claims data performed well compared to measures that use information from medical charts when estimating death rates.
To accurately compare hospital performance, the death measures adjust for patient characteristics that may make death more likely. These characteristics include the patient’s age, past medical history, and other diseases or conditions (comorbidities) the patient had when they were admitted that are known to increase the patient’s chance of death.
The statistical model used to calculate death measures confirms the estimated rates are precise, and provides the interval estimates for each hospital’s rates. The upper and lower boundaries of an interval estimate represents a range in which there is 95% certainty the true results lie.
Hospital Performance Categories
To assign death performance categories, the hospital’s interval estimate is compared to the national death rate. The table below describes the performance categories and classification criteria in detail:
|Mortality Measure Performance Categories|
|Category||Better than the national rate||No different than the national rate||Worse than the national rate||The number of cases is too small|
|Criterion||The entire 95% interval estimate surrounding the hospital’s rate is lower than the national rate.||The 95% interval estimate surrounding the hospital’s rate includes the national rate.||The entire 95% interval estimate surrounding the hospital’s rate is higher than the national rate.||Fewer than 25 cases|
For more detail on how death rates are calculated, please refer to QualityNet - Mortality Measures- Opens in a new windowExit Disclaimer - Opens in a new window. For other questions regarding the mortality measures, please email firstname.lastname@example.org.Exit Disclaimer - Opens in a new window