A study of over 3 million hospital admissions reveals that there is no significant association between hospital readmission and mortality rates among Medicare patients who suffer from heart attack, heart failure or pneumonia.

The researchers, who published their findings in a recent issue of JAMA, did not find any evidence to suggest that a hospital’s mortality rate in 30 days has any link to its readmission rate in 30 days.

Improving overall hospital care is vital for policy makers. For this reason a few years ago, The Centers for Medicare & Medicaid Services (CMS) began publishing the hospital 30-day risk-standardized mortality rates (RSMRs) and risk-standardized readmission rates (RSRRs) for patients with acute myocardial infarction (heart attack), heart failure, and pneumonia.

According to the background information of the article:

“Some researchers have raised concerns that these rates might have an inverse relationship, such that hospitals with lower mortality rates are more likely to have higher readmission rates. “Interventions that improve mortality might also increase readmission rates by resulting in a higher-risk group being discharged from the hospital. Conversely, the measures could provide redundant information.

Limited information exists about this relationship, an understanding of which is critical to measurement of quality, and yet questions surrounding an inverse relationship have led to public concerns about the measures.”

The research team, led by Harlan M. Krumholz, M.D., S.M., of the Yale University School of Medicine, evaluated the association between RSMRs and RSRRs among Medicare fee-for-service beneficiaries discharged between July 2005 and June 2008. This included a total of:

  • For heart attack – 4,506 hospitals with 590,809 admissions for mortality and 586,027 readmissions
  • For heart failure – 4,767 hospitals with 1,161,179 admissions for mortality and 1,430,030 readmissions
  • For pneumonia – 4,811 hospitals with 1,225,366 admissions for mortality and 1,297,031 readmissions

The RSMRs and RSRRs were:

  • Heart attack – RSMR 16.6 percent, RSRR 19.9 percent
  • Heart failure – RSMR 11.17 percent, RSRR 24.56 percent
  • Pneumonia – RSMR 11.64 percent, RSRR 18.22 percent.

For heart attack there was a correlation between RSMRs and RSRRs of 0.03, for heart failure it was -0.17 and for pneumonia it was 0.002.

These results indicate that there is not a strong association between mortality and hospital readmission rates among heart attack, heart failure and pneumonia patients.

The authors concluded:

“In a national study of the CMS publicly reported outcomes measures, we failed to find evidence that a hospital’s performance on the measure for 30-day RSMR is strongly associated with performance on 30-day RSRR. For AMI and pneumonia, there was no discernible relationship, and for HF, the relationship was only modest and not throughout the entire range of performance.”

A previous investigation, published in CMAJ (Canadian Medical Association Journal), showed that hospital readmission rates are not an accurate indicator of quality of hospital care.

Written by Joseph Nordqvist