Use of in-hospital mortality to assess ICU performance may bias quality measurement

May 21, 2012, American Thoracic Society

In-hospital mortality for ICU patients is often used as a quality measure, but discharge practices may bias results in a way that disadvantages large academic hospitals, according to a recently conducted study.

"Hospitals differ in the number of they transfer to other hospitals or post-acute care facilities," said lead author Lora Reineck, MD, post-doctoral fellow at the University of Pittsburgh School of Medicine. "These differences can affect in-hospital measurement if some hospitals discharge patients more frequently or earlier than others, since in these cases the mortality burden is shifted to other facilities. While it's known that discharge practices alter in-hospital ICU mortality measurement, it was previously unknown whether this effect is uniform across hospitals or whether certain types of hospitals are more affected than others."

The results will be presented at the ATS 2012 International Conference in San Francisco.

"We found that this 'discharge bias' disproportionally hurts large hospitals and academic hospitals, which frequently accept many patients in transfer from other hospitals," said Dr. Reineck. "Hospitals that care for a large number of patients insured through health maintenance organizations (HMOs) are also affected, since these organizations typical restrict transfers. Mortality measures tied to a specific time point, such as 30-day mortality, are less biased by discharge practices but are harder to calculate."

In recent years, quality measures have increasingly been publicly reported and tied to through pay-for-performance. It is important that these accurately assess performance and are not flawed by . According to Dr. Reineck, "our study reveals that large academic hospitals, as well as hospitals with a high proportion of commercial HMO patients, are more negatively affected by using in-hospital ICU mortality compared to 30-day mortality than other hospitals. Accounting for this bias might prevent these hospitals from being unfairly penalized in public reporting or pay-for-performance programs."

The retrospective cohort study used data on 43,830 ICU patients admitted to 134 hospitals in Pennsylvania in 2008. Discharge bias was defined as 30-day mortality minus in-hospital mortality; greater discharge bias makes a appear of relatively higher quality.

Mean risk-adjusted hospital-specific 30-day and in-hospital mortality rates were 13.1 ± 1.6% and 9.6 ± 1.3%, respectively, resulting in a mean hospital-specific discharge bias of 3.5% ± 1.3%. Discharge bias was greater in small hospitals, non-teaching hospitals, and hospitals with fewer commercial HMO patients, thereby making these facilities appear relatively better in quality compared to large teaching hospitals or those with a high proportion of commercial HMO patients. Hospital rank was greatly affected by discharge bias, with 29.1% of hospitals increasing in rank by at least one quartile and 26.9% decreasing in rank by at least one quartile. Large teaching hospitals and hospitals with the highest proportion of patients with commercial HMO insurance were more likely to decrease in rank than small, non-teaching hospitals or hospitals with a lower proportion of commercial HMO patients.

"State and national programs that use in-hospital mortality to benchmark hospitals should note how discharge bias unfairly disadvantages certain types of hospitals," concluded Dr. Reineck. "Discharge bias must be accounted for to prevent unfair performance assessments."

Future studies are planned to assess the effects that using this measure in public reporting has on outcomes of ICU patients.

Explore further: Hospital readmission rates not accurate measure of care quality

Related Stories

Hospital readmission rates not accurate measure of care quality

August 22, 2011
Avoidable readmissions after discharge from hospital are fairly uncommon and are not an accurate measure of quality of care, found a study in CMAJ (Canadian Medical Association Journal).

Death rate measure used to judge hospital quality may be misleading

January 3, 2012
Hospitals, health insurers and patients often rely on patient death rates in hospitals to compare hospital quality. Now a new study by researchers at Yale School of Medicine questions the accuracy of that widely used approach ...

Higher-spending hospitals have fewer deaths for emergency patients

April 3, 2012
Higher-spending hospitals do have better outcomes for their emergency patients, including fewer deaths, according to a Vanderbilt study released as a working paper through the National Bureau of Economic Research.

Recommended for you

Best of Last Year—The top Medical Xpress articles of 2017

December 20, 2017
It was a good year for medical research as a team at the German center for Neurodegenerative Diseases, Magdeburg, found that dancing can reverse the signs of aging in the brain. Any exercise helps, the team found, but dancing ...

Pickled in 'cognac', Chopin's heart gives up its secrets

November 26, 2017
The heart of Frederic Chopin, among the world's most cherished musical virtuosos, may finally have given up the cause of his untimely death.

Sugar industry withheld evidence of sucrose's health effects nearly 50 years ago

November 21, 2017
A U.S. sugar industry trade group appears to have pulled the plug on a study that was producing animal evidence linking sucrose to disease nearly 50 years ago, researchers argue in a paper publishing on November 21 in the ...

Female researchers pay more attention to sex and gender in medicine

November 7, 2017
When women participate in a medical research paper, that research is more likely to take into account the differences between the way men and women react to diseases and treatments, according to a new study by Stanford researchers.

Drug therapy from lethal bacteria could reduce kidney transplant rejection

August 3, 2017
An experimental treatment derived from a potentially deadly microorganism may provide lifesaving help for kidney transplant patients, according to an international study led by investigators at Cedars-Sinai.

Exploring the potential of human echolocation

June 25, 2017
People who are visually impaired will often use a cane to feel out their surroundings. With training and practice, people can learn to use the pitch, loudness and timbre of echoes from the cane or other sounds to navigate ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.