(Reuters) - One out of every 10 people who get a stent inserted to open up blocked arteries ends up back in the hospital within 30 days, suggests a new study that also found the readmitted patients are more likely to die in the next year.

Readmission rates are now publicly reported by the Centers for Medicare and Medicaid Services and are one performance measure used to determine how well a hospital is doing at treating its heart patients.

The study suggests that at least some of the factors related to a patient's chance of going back to the hospital, including the severity of the diseases they had to begin with, cannot necessarily be changed by better care.

Still, researchers said the findings give hospitals a place to start in addressing those extra risks and making sure that each patient has the right tools to prevent another costly hospital stay when they go home.

Many hospitals until recently have not focused on transitions to the outpatient environment, said Dr. Adrian Hernandez, from the Duke University School of Medicine in Durham, North Carolina, who wrote a commentary accompanying the study in the Archives of Internal Medicine.

When a patient's leaving the hospital, it's really important for not just the patient but the family...to understand what they had done and what they need to know about the disease and their medication.

Researchers tracked close to 13,000 patients who had one or more elective or emergency stent procedures over a 10-year period at a single hospital in Rochester, Minnesota. (For the full study, see bit.ly/fO01ME)

Just under 10 percent of patients were readmitted to the hospital within the month afterward with heart-related or other complications.

Women, as well as people with kidney and lung diseases or cancer all had a 30 to 90 percent higher risk of ending up back in the hospital compared to other heart patients.

REWARDING HOSPITALS

Procedural complications such as bleeding and heart attacks, as well as a longer hospital stay, were also linked with higher chances of readmission.

Between seven and eight percent of patients who were readmitted died within a year -- a rate that was 40 percent higher than patients who didn't have another hospital stay.

The higher mortality among readmitted patients was probably because they were sicker to begin with, or because of hospital errors that may have led to their readmission in the first place, Hernandez told Reuters Health.

A research letter published by Italian cardiologists alongside the new study also looked at readmission rates and reasons at northern Italian institutions.

The researchers found that among patients with a particularly dangerous type of heart attack, known as ST-segment elevation myocardial infarction, between seven and 20 percent of those who got stents were readmitted for repeat procedures, or with a heart attack or major bleeding within three years. Nearly 18 percent died during that period.

In the United States, performance measures such as rehospitalization of heart patients are being targeted as ways to financially reward the hospitals with better outcomes.

Readmission rates have been publicly reported by Medicare and advocated as measures of care quality based on the presumption that many of these early re-hospitalizations are preventable, said Dr. Gregg Fonarow, a cardiologist at the David Geffen School of Medicine at the University of California, Los Angeles, in an email to Reuters Health.

This new study, however, shows that there are relatively few early rehospitalizations that are directly related to the (stent) procedure, added Fonarow, who was not involved in the research.

That does not mean a hospital's readmission rates are not one fair way to assess its quality of care, argued one of the study's authors, Dr. David Holmes, from the Mayo Clinic in Rochester.

We're not going to change the fact that they're a woman, but we could then be on the lookout for things that might affect them, for example whether they're taking enough medications and the right ones, he told Reuters Health.

Holmes added that readmission numbers can get at whether or not patients were sent home too early to begin with, how well doctors treated all the problems, heart and otherwise, that patients had coming in, and whether they were taught about next steps when they left. Those include coming back in for outpatient check-ups and blood work.

As a quality indicator, I think that (rehospitalization) is a very reasonable thing, Holmes said. It does not answer all the questions.

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