Published in the September 2008 issue of Today’s Hospitalist
IF YOU THINK YOU HAD A ROUGH SUMMER, consider Mitchell Levy, MD.
Dr. Levy is lead author of a controversial analysis published in June that found that mortality rates in ICUs rose when patients were cared for by critical care physicians. Those findings fly in the face of several previous studies that found compelling evidence for the benefits of being managed by critical care physicians in ICUs.
As medical director of the ICU at Rhode Island Hospital in Providence, director of critical care services for Brown University and president-elect of the Society of Critical Care Medicine (SCCM), Dr. Levy was stunned by the results.
His study “a retrospective database analysis published in the June 3, 2008, Annals of Internal Medicine “found that after adjusting for severity of illness, very sick patients had an 18% increased likelihood of in-hospital mortality when managed by critical care specialists. And when it came to the least sick ICU patients, their risk of dying was more than two-and-a-half times greater with critical care management than without.
In an interview with Today’s Hospitalist, Dr. Levy discussed those findings and underscored some of the clinical and practice unknowns that may help give hospitalists an edge in ICU care.
Q: How surprised were you by the results?
A: It was a complete surprise. The data are counterintuitive to all the published literature.
Q: What exactly did you find?
A: We used an SCCM-designed database, which included 123 ICUs and more than 100,000 patients, with data from 2000-04.
We also identified three types of ICUs: those in which patients were managed by critical care physicians almost all of the time; those that used them none of the time; and those that used critical care specialists some time.
The study found that patients managed by critical care physicians were, not surprisingly, sicker. But when we looked at the standardized mortality ratio, which is actual mortality over predicted mortality, patients managed by critical care physicians had a 9% increase in mortality ratio compared to patients not managed by critical care physicians.
Q: How did you control for confounders?
A: We used an expanded SAPS II disease-severity score. We also developed our own propensity score based on a list of factors that seem to be associated with critical care management, such as tracheostomy or ventilation at ICU admission, GI bleeding and cerebrovascular event. The score ranged from 1, for the lowest number of factors, to 4.
What was surprising was that all the odds ratios for patients managed by critical care physicians, except one category, were above one. That means the risk of dying was higher for almost every group when managed exclusively by critical care physicians. Even when we looked at subgroups of patients “for example, patients with a respiratory diagnosis and on ventilation “they were 22% more likely to die when managed by critical care physicians.
We also looked at the effect that critical care management had on what we called “no-choice” hospitals. Those are hospitals in which all patients are managed for their entire ICU stay by trained critical care physicians vs. hospitals in which no patients were managed by critical care physicians or only partially managed. Most of the patients in the study received care in choice hospitals.
When we compared those two kinds of hospitals, those in the no-choice hospitals, who were managed by critical care physicians, had a 47% higher risk of death than patients managed by non-critical care physicians in the ICU.
That is why the article is so damaging. No matter how you slice and dice this, it really does look like the risk of death is higher with management by critical care specialists.
Q: Why are your results so different from the literature?
A: This study clearly has raised more questions than it answered. The whole study hinges on the accuracy of our severity score and whether there remain unrecognized markers of severity that aren’t accounted for. Those could include unreported comorbidities and whether or not ICUs were following protocols.
Q: If the difference isn’t due to severity, what are some other hypotheses?
A: One is that maybe critical care physicians are doing too much, especially in the least sick patients. According to the database, the critical care physicians did do more as far as interventions, IV drugs, mechanical ventilation and continuous sedation. Perhaps some routine critical care practices and procedures may not be beneficial, or maybe the cumulative use of more interventions may take a toll in terms of complications and infections.
It is also possible that as trained critical care physicians, we may use our own judgment to manage patients instead of using standardized protocols that may be associated with better outcomes. Maybe in units that are doing well without a specialist, the communication between nursing and physicians is more in sync. Transfers among physicians may cause more disruptions and lead to more miscommunication.
Q: Is the study good news or bad news for hospitalists?
A: One limitation of the database is that we don’t know to what extent hospitalists played a role in the care of these patients. But the study results certainly suggest that hospitalists and other nonspecialists do pretty well.
Q: The accompanying editorial was entitled “Are Intensivists Safe?” Are they?
A: The database didn’t distinguish between critical care physicians who see patients in their office and true intensivists, who are hospital-based. That said, these results should cause us to reflect on “but not necessarily change “our practice. I think the findings do require further follow-up. At the end of the day, with all the flaws that I just described in the study, if my loved one came into the ICU, I would want them to be taken care of by an intensivist.
Cornelia Kean is a freelance health care writer based in Montclair, N.J.