Medicare Analysis Shows Hospitals Can Lower Mortality and Readmission Rates

February 13, 2013

NEW HAVEN, CT– An analysis of Medicare data suggests that hospitals won't offset improvements in 30-day mortality rates with an increase in the 30-day rate of hospital readmissions [1]. In patients with acute MI and pneumonia, risk-standardized mortality and hospital readmission rates were not significantly associated with each other, while there was only a weak association for patients with heart failure.

The bottom line, according to lead investigator Dr Harlan Krumholz (Yale University, New Haven, CT), is that hospitals can and should be aiming to improve both mortality and hospital readmission rates in these patients.

To heartwire , Krumholz said the weak relationship between readmissions and mortality in heart-failure patients is an unusual finding, "that it sticks out," but he believes that it might be more a chance than real finding, especially since the inverse relationship between mortality and readmission was evident only in hospitals with risk-standardized mortality rates in the lower range (<11%).

"In the end, we saw virtually no association for pneumonia and MI and this very weak association for heart failure," said Krumholz. "I think we've dispelled the concern that your performance on mortality dictates your performance on readmissions. We showed that there are a lot of hospitals around the country that excel in both."

The new analysis is published February 12, 2013 in the Journal of the American Medical Association.

Does Low Mortality Mean Higher Readmission Rates?

In 2007 and 2008, the Centers for Medicare and Medicaid Services (CMS) began to publicly report 30-day risk-standardized all-cause mortality rates for patients with acute MI, heart failure, and pneumonia. In 2009, the CMS expanded public reporting to include risk-standardized readmission rates for acute MI, heart failure, and pneumonia. Public reporting on these two outcomes has led to some concern that mortality and hospital readmissions might have an inverse relationship, with hospitals that have lower mortality rates having higher rates of hospital readmissions because these sicker patients were treated successfully and later discharged.

"When the Affordable Care Act was passed, they incorporated financial incentives into the bill and have associated them with these measures," said Krumholz. "So it's kind of put hospitals on notice, and one of the concerns is that if you excel in mortality it might put you at a disadvantage for readmissions. If you help save more people, the concern was that the ones you're sending home might be sicker than they otherwise might have been."

Given the financial penalties associated with the 30-day mortality and readmission rates and the concerns associated with the publicly reported performance measures, Krumholz and colleagues attempted to examine the correlation between the two outcomes in Medicare fee-for-service beneficiaries discharged from the hospital with acute MI, heart failure, and pneumonia. In total, 4506 hospitals treating acute MI patients, 4767 hospitals treating heart-failure patients, and 4811 hospitals treating pneumonia cases were included in the analysis.

The mean risk-standardized mortality rates were 16.6% for acute MI, 11.2% for heart failure, and 11.6% for pneumonia. The mean risk-standardized readmission rates for the same conditions were 19.9%, 24.6%, and 18.2%. The Pearson correlation between the mortality and readmission rates was 0.03 for acute MI, -0.17 for heart failure, and 0.002 for pneumonia. The negative linear association was statistically significant only for heart failure, and, as the researchers point out in the paper, the shared variance between risk-standardized mortality and readmission was only 2.9%.

For acute MI, 381 hospitals were in the top-performing quartiles of both measures, with lower rates of mortality and readmission. Similarly, 259 hospitals were in the top-performing quartiles for both measures with pneumonia patients, and 307 hospitals exceled in lowered mortality and readmission for heart-failure patients.

To heartwire , Krumholz said that mortality rates are most likely "front-loaded," with events affected by lifesaving therapies and other measures initiated in the hospital within the first day or two. In contrast, readmission rates are often affected by how strong the patient is when sent home, a factor that is affected by transitional care and outpatient services. "For me, the bottom line is that we have to get hospitals to excel in both, and the empiric data are showing that we can," he said.