The impact of intensivists on patient death rates: a complex picture

In recent years, the conventional wisdom behind staffing intensive care units (ICUs) with intensivists, sometimes referred to as critical care physicians, has been “if you hire them, they will heal,” to very loosely paraphrase Field of Dreams.

Many hospitals have been pushing to hire more intensivists in hopes of improving decreasing mortality and improving other patient outcomes, motivated by previous research suggesting that hospitals with ICUs staffed by board-certified intensivists have lower mortality rates than those that do not, as well as endorsements of the value of intensivist staffing models by the Leapfrog Group, a large coalition of healthcare purchasers, and the Society for Critical Care Medicine.

Now, the results of a new U-M led study that uses a novel approach to examine the effect of these physicians on patient death rates in ICUs across the country – and specifically looks at outcomes among hospitals making the transition to intensivist staffing – challenges the assumption that simply implementing intensivist models will lead directly to lower mortality, and, more broadly, has implications for the context and culture of how critical care teams are established and integrated.

Care for the critically ill

Intensivists are medical doctors with extensive training and experience with treating critically ill or injured patients. Rather than focusing on specific body systems such as cardiologists or pulmonologists, intensivists provide a comprehensive approach to caring for ICU patients, and are often available around the clock to manage critical issues that may arise.

The new analysis, published in Medical Care by U-M’s Amir Ghaferi, M.D., M.S., the study’s senior author and an assistant professor of surgery, and colleagues, used Medicare data over an eight-year period to compare mortality rates among older adult patients between hospitals that were intensivist staffed throughout this time period, those that were never intensivist staffed, and those that transitioned to intensivist staffing sometime during the period.While the connection between lower mortality rates and intensivist-staffed hospitals has been well documented, the limitations of prior studies have made it difficult to understand the true impact on patient well-being of transitioning to an intensivist staffing model.

They also looked at how mortality rates improved over those years with each of the three groups, and were also able to analyze the effect of intensivist staffing on mortality among the group of hospitals that transitioned to this model during the period. More than one-quarter of the hospitals in the study were in this “transition” group.

The study included data on 2,916,801 Medicare patients across 488 U.S. hospitals. The type of hospitals’ intensivist staffing was characterized by Leapfrog survey responses.

Their results paint a not-so-simple picture of the influence of intensivists on patient morality.

Implications for organizational culture

The first important finding is that hospitals currently utilizing an intensivist staffing model had lower mortality than those without, which is consistent with a large body of previous research.

A more intriguing result was that the hospitals making a transition to intensivist staffing were unable to accelerate their improvement or catch up with previously intensivist-staffed hospitals in decreasing mortality, a finding that sheds new light on the importance of adequate implementation of intensivist staffing.

“With respect to hiring intensivists, you cannot simply flip a switch and expect to have better outcomes immediately,” Ghaferi says. “Intensivists provide an invaluable service, but hospitals also need to make sure they are strategically and adequately integrated, and adapt the organizational culture in how they care for patients.” 

Ultimately, the hospital context in which intensivist staffing is implemented may be just as important, if not more than, the actual transition itself. Hospitals transitioning to intensivist-led teams will likely be able to improve mortality outcomes eventually, Ghaferi postulates, so long as adequate attention is given to integrating these specialists.

Ghaferi notes that the idea of an “ideal integrated intensive care system” requires that hospitals invest resources into building an appropriate critical care team around the intensivist if they hope to make a significant impact in how their patients fare. They would also do well to recognize that modifiable organizational dynamics, such as teamwork, leadership, culture, and communication practices are integral to improving ICU outcomes.

“Intensive care is a team sport, and hiring an intensivist is only one piece of that puzzle,” Ghaferi says.

The findings also suggest that the lower mortality rate previously observed at hospitals with intensivist staffing may be attributable to other, unmeasured factors – that there’s something qualitatively different about these hospitals that have long favored this kind of critical care model. Ghaferi’s ongoing research aims to identify these factors and how they contribute to success in patient outcomes.

Ghaferi’s study also did not examine patient outcomes beyond mortality, and there may be other benefits to intensivist staffing - such as length of stay, adherence to evidence-based protocols, or patient and family satisfaction with care – that have yet to be elucidated.

The bottom line for patients: hospitals supported by intensivists do have consistently better outcomes, and choosing an intensivist-staffed hospital will likely lead patients to a lower mortality hospital. But insomuch as intensivist staffing serves primarily as a proxy for other hospital attributes, “quality improvement will require identifying the precise factors that directly affect mortality,” the authors note.

Additional Authors: Nagendran, Myura MA, BMBCh; Dimick, Justin B. MD, MPH; Gonzalez, Andrew A. MD, MPH, JD; Birkmeyer, John D. MD; Ghaferi, Amir A. MD, MS