Examining the Impact on Outcomes of Structure & Process in Cancer Surgery

John D. Birkmeyer, MD
Professor of Surgery
University of Michigan Medical School
Ann Arbor, Michigan
jbirkmey@umich.edu

What's the problem?

Every year thousands of Americans die or experience serious complications when they have elective cancer surgery. The rates of complications and excess mortality vary widely across hospitals and surgeons, with some having very low rates and others much higher rates.

This variation in mortality rates suggests that the safety of cancer surgery could be improved substantially, but quality improvement efforts are hampered because of gaps in our current knowledge about the mechanisms that underlie variations in hospital performance. For example, do high mortality rates at these hospitals occur because of surgical or medical complications? Or do hospitals with high mortality rates just have higher complication rates? Or, are these hospitals less proficient at managing complications once they have occurred? Answers to questions like these have obvious implications for the types of interventions that are likely to result in meaningful quality improvement in cancer surgery.

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How does this research address the problem?

In this new grant, surgeon Dr. John Birkmeyer is using data from the 2006-2007 National Cancer Database to study 50 hospitals. Twenty hospitals will have among the lowest cancer surgery mortality rates in the United States (approximately 1.5%) and 30 hospitals will have the highest mortality rates (approximately 10%). Dr. Birkmeyer and his research team are looking at two big questions. What causes excess operative deaths at hospitals that have high rates of cancer surgery mortality? What resources and processes of care are responsible for differences in complications rates and mortality across hospitals?

To answer the first question, the researchers are conducting a clinical chart review to compare cause-specific mortality rates at the low and high mortality hospitals. Evidence that excess mortality is attributable primarily to surgical site complications would imply the need for interventions aimed at ensuring surgeon proficiency. On the other hand, variations in specific medical complications would suggest that the hospital needs to focus on processes related to care during the time period after the surgery.

With a better understanding of the clinical causes of excess deaths at high mortality hospitals, Dr. Birkmeyer and his team will then examine specific structural variables and processes of care that underlie differences in outcomes between the low mortality hospitals and the high mortality hospitals. They will look at factors that may reduce the incidence of complications, such as adherence to evidence-based practices in perioperative care. They also will examine factors that help hospitals improve rescue rates in patients with complications.

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Significance of the research & results

This innovative study promises to identify practical targets and strategies for improving the quality of cancer surgery. Previous studies, including those assessing correlations between surgical volume and complications or mortality rates, have highlighted the problem of variation in hospital outcomes. However, these studies have been based primarily on administrative data and are ill-suited for “getting under the hood” of the variation problem. In examining detailed clinical data, this study will be the first to identify the clinical causes of excess deaths at hospitals with high mortality rates. It also will be unique in assessing structural factors and processes of care that determine differences in hospital complication rates, and differences in how successfully hospitals “rescue” patients once a complication has occurred.

Developing a better understanding of clinical mechanisms underlying variation in outcomes will be invaluable in efforts to identify best practices and inform quality improvement efforts at all hospitals performing cancer surgery.

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Recent related publications of interest

Hollenbeck BK, Ye Z, Dunn RL, Montie JE, Birkmeyer JD. Provider treatment intensity and outcomes for patients with early-stage bladder cancer. J Natl Cancer Inst 2009 Apr 15;101(8):571-80. [View Abstract]

Birkmeyer JD, Dimick JB. Understanding and Reducing Variation in Surgical Mortality. Annu Rev Med 2009;60:1-11. [View Abstract]

Birkmeyer JD. Improving outcomes with lung cancer surgery: selective referral or quality improvement? Ann Surg Oncol 2009 Jan;16(1):1-2. [View Reference Information]

Waljee JF, Windisch S, Finks JF, Wong SL, Birkmeyer JD. Classifying cause of death after cancer surgery. Surg Innov 2006 Dec;13(4):274-9. [View Abstract]

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