Weak Link Found Between Readmissions, Mortality

Hospital and policy leaders who complain that federal penalties for higher 30-day readmissions may have the unintended consequence of leading to more patient deaths, or that liberal readmissions practices actually prevent mortality, are largely incorrect.

That's the conclusion from Yale University School of Medicine readmission expert Harlan Krumholz, MD, and colleagues, as reported in Wednesday's Journal of the American Medical Association.

"Some researchers have raised concerns that hospital mortality rates and readmission rates might have an inverse relationship, such that hospitals with lower mortality rates are more likely to have higher readmission rates," Krumholz and colleagues wrote. "Interventions that improve mortality might also increase readmission rates by resulting in a higher-risk group being discharged from the hospital."

Additionally, there have been concerns that measuring either readmissions or measuring mortality means measuring basic quality of care, and that measuring both would be redundant.

And there are concerns that readmissions "could be 'adversely' affected by a competing risk of death—a patient who dies during the index episode of care can never be readmitted," wrote Eiran Z. Gorodeski, MD, and colleagues in a 2010 article in the New England Journal of Medicine.

"If a hospital has a lower mortality rate, then a greater proportion of its discharged patients are eligible for readmission. As such, to some extent, a higher readmission rate may be a consequence of successful care," Gorodeski wrote.

But after studying Medicare fee-for-service beneficiaries admitted between July 1, 2005 and June 30, 2008 for treatment of congestive heart failure, pneumonia or heart attack, Krumholz and colleagues concluded that 30-day readmission rates "were not associated" with mortality rates for patients admitted for heart attack or pneumonia, and were "only weakly associated within a certain range" for patients admitted for heart failure.

"We show that hospitals can do well on both measures, with many hospitals having low risk-standardized mortality rates and risk-standardized readmission rates," Krumholz wrote.

Concerns have been raised for two other reasons. First, the Centers for Medicare & Medicaid Services' rules assess financial penalties of up to 3% for hospital with higher rates of readmissions, but punish hospitals with higher mortality by withholding incentive pay amounting to a maximum of only 25% of 1.25% in incentive payment, starting this October.

Second, several large hospitals with good reputations but high readmission rates also had lower-than-average or average 30-day mortality rates.

Krumholz and co-authors emphasized that readmission measures and mortality measures "convey distinct information."

One caveat about the study is that data was collected prior to the passage of the Patient Protection and Affordable Care Act of 2010, which legislated two separate payment incentives for reducing readmissions and mortality within 30 days of discharge, penalties that took effect for the first time only four months ago. 

Whether data collected since then will change these results remains to be seen.