Just because a patient has had a heart attack, or a flare-up of chronic heart or lung disease, doesn't mean the next stop should be an intensive care unit, a new study suggests.

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If the patient is critically ill, of course, the ICU is the best place. But for people in less dire condition, an ICU stay may not increase their chances of survival, and it costs more, the research finds.

Across the country, hospitals vary widely in what they do with such patients, and doctors have little evidence to guide them. The new study could help lay the groundwork for more effective — and cost-effective — use of ICU care for these cases.

A University of Michigan Institute for Healthcare Policy and Innovation team published the work in the Annals of the American Thoracic Society. The work is based on an analysis of more than 1.5 million Medicare records.

"ICU care can save lives, but it is also very costly," says lead author Thomas Valley, M.D., M.Sc., a pulmonary and critical care researcher at the U-M Medical School. "Our results highlight that there is a large group of patients whose doctors have trouble figuring out whether the ICU will help them or not."

The data came from people who were hospitalized for a flare-up of chronic obstructive pulmonary disease (COPD) or heart failure or for a heart attack over a three-year period. The researchers tracked how close the patients lived to the hospital where they were treated and how often those hospitals admitted such patients to ICUs or general wards.

The researchers zeroed in on those patients who were probably admitted to an ICU solely because they lived near a hospital that tended to send more of such patients to ICU beds. In other words, those patients were in the "margin" or "bubble" between clearly needing an ICU and clearly being able to be cared for in a general inpatient unit.

In all, about 1 in 6 patients in the study met this description. But the researchers found that despite getting ICU-level care, the patients were no less likely to have died within 30 days of their hospital stay than patients who stayed in a general hospital bed.

One thing that was different: the cost of their care, at least for the patients with heart attack or heart failure.

Those who stayed in an ICU racked up hospital bills several thousand dollars higher than those cared for in a general ward — more than $2,600 more for heart failure patients and nearly $5,000 more for heart attack patients. This is probably because of the additional testing and procedures that mark ICU care, but also potentially because of the higher chance of developing infections there. COPD patients didn't have a significant difference in cost between the two care settings.

"We found that the ICU may not always be the answer," says Valley. "Now we need to help doctors decide who needs the ICU and who doesn't."

Building on previous work

Valley and his co-authors on the new paper previously applied their model to older patients admitted with pneumonia and found that those who were "on the bubble" between needing ICU care or a general bed were more likely to survive if they were admitted to an ICU. The acute nature of pneumonia, compared with the chronic nature of heart failure and COPD, may have something to do with this difference, the researchers think.

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They've also showed that hospitals that send higher percentages of their heart patients to the ICU perform worse on measures of health care quality.

Valley and the senior author of the new paper, Colin Cooke, M.D., M.Sc., M.S., wrote a commentary last year about how doctors decide where to send these patients.

After their latest research, the authors conclude: "These findings suggest that the ICU may be overused for some COPD, heart failure or acute myocardial infarction patients with an uncertain indication for intensive care, and opportunities exist to decrease health care costs by reducing ICU admissions for certain patients." 

Future studies, they say, should help define which patients with these conditions would benefit from the ICU and which can be treated elsewhere in the hospital.

The study was funded by the National Institutes of Health, the Department of Veterans Affairs and the Agency for Healthcare Research and Quality. Valley, Cooke and co-authors Michael W. Sjoding, M.D., M.Sc., Andrew M. Ryan, Ph.D., and Theodore J. Iwashyna, M.D., Ph.D., are all members of the U-M Institute for Healthcare Policy and Innovation, and all except Sjoding are members of the Michigan Center for Integrative Research in Critical Care.