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Association Between Anesthesiologist Volume and Short-term Outcomes in Complex Gastrointestinal Cancer Surgery

Educational Objective
To identify whether anesthesiology volume is associated with short-term outcomes in patients undergoing complex gastrointestinal surgery.
1 Credit CME
Key Points

Question  Is there an association between anesthesiologist volume and adverse perioperative outcomes?

Findings  In this cohort study of 8096 adults who underwent esophagectomy, pancreatectomy, or hepatectomy for cancer, care provided by anesthesiologists with high procedure volume (≥6 procedures per year) vs care by anesthesiologists with low procedure volume was independently associated with a lower risk of combined major morbidity and readmission over 90 days.

Meaning  Results of this study support organizing perioperative care to increase anesthesiologist volume and decrease the risk of adverse postoperative outcomes.


Importance  Intraoperative anesthesiology care is crucial to high-quality surgical care. The clinical expertise and experience of anesthesiologists may decrease the risk of adverse outcomes.

Objective  To examine the association between anesthesiologist volume and short-term postoperative outcomes for complex gastrointestinal (GI) cancer surgery.

Design, Setting, and Participants  This population-based cohort study used administrative health care data sets from various data sources in Ontario, Canada. Adult patients who underwent esophagectomy, pancreatectomy, or hepatectomy for GI cancer from January 1, 2007, to December 31, 2018, were eligible. Patients with an invalid identification number, a duplicate surgery record, and missing primary anesthesiologist information were excluded.

Exposures  Primary anesthesiologist volume was defined as the annual number of procedures of interest (esophagectomy, pancreatectomy, and hepatectomy) supported by that anesthesiologist in the 2 years before the index surgery. Volume was dichotomized into low-volume and high-volume categories, with 75th percentile or 6 or more procedures per year selected as the cutoff point.

Main Outcome and Measures  The primary outcome was a composite of 90-day major morbidity (with a Clavien-Dindo classification grade 3-5) and readmission. Secondary outcomes were individual components of the primary outcome. The association between exposure and outcomes was examined using multivariable logistic regression models, accounting for potential confounders.

Results  Of the 8096 patients included, 5369 were men (66.3%) and the median (interquartile range [IQR]) age was 65 (57-72) years. Operations were supported by 842 anesthesiologists and performed by 186 surgeons, and the median (IQR) anesthesiologist volume was 3 (1.5-6) procedures per year. A total of 2166 patients (26.7%) received care from high-volume anesthesiologists. Primary outcome occurred in 36.3% of patients in the high-volume group and 45.7% of patients in the low-volume group. After adjustment, care by high-volume anesthesiologists was independently associated with lower odds of the primary outcome (adjusted odds ratio [aOR], 0.85; 95% CI, 0.76-0.94), major morbidity (aOR, 0.83; 95% CI, 0.75-0.91), unplanned intensive care unit admission (aOR, 0.84; 95% CI, 0.76-0.94), but not readmission (aOR, 0.87; 95% CI, 0.73-1.05) or mortality (aOR, 1.05; 95% CI, 0.84-1.31). E-values analysis indicated that an unmeasured variable would unlikely substantively change the observed risk estimates.

Conclusions and Relevance  This study found that, among adults who underwent complex gastrointestinal cancer surgery, those who received care from high-volume anesthesiologists had a lower risk of adverse postoperative outcomes compared with those who received care from low-volume anesthesiologists. These findings support organizing perioperative care to increase anesthesiologist volume to optimize patient outcomes.

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CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.

Article Information

Accepted for Publication: December 26, 2020.

Published Online: March 17, 2021. doi:10.1001/jamasurg.2021.0135

Corresponding Author: Julie Hallet, MD, MSc, Department of Surgery, University of Toronto, 2075 Bayview Ave, Toronto, ON M4N 3M5, Canada (

Author Contributions: Mr Dharma had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Hallet, Turgeon, McIsaac, Eskander, Zuk, Sohail, Dharma, Coburn, Sutradhar.

Acquisition, analysis, or interpretation of data: Hallet, Jerath, Turgeon, McIsaac, Eskander, Zuckerman, Zuk, Darling, Dharma, Coburn, Sutradhar.

Drafting of the manuscript: Hallet, Jerath, McIsaac, Sohail, Coburn, Sutradhar.

Critical revision of the manuscript for important intellectual content: Hallet, Jerath, Turgeon, McIsaac, Eskander, Zuckerman, Zuk, Darling, Dharma, Coburn, Sutradhar.

Statistical analysis: Hallet, Jerath, McIsaac, Eskander, Zuckerman, Dharma, Coburn, Sutradhar.

Obtained funding: Turgeon.

Administrative, technical, or material support: Hallet, Jerath, Eskander, Zuckerman, Zuk, Sohail, Coburn.

Supervision: Hallet, Coburn, Sutradhar.

Conflict of Interest Disclosures: Dr Hallet reported receiving personal fees from Ipsen Biopharmaceuticals Canada, speaking honoraria and personal fees from Advanced Accelerator Applications, and speaking honoraria from Novartis Oncology outside the submitted work. Dr Eskander reported receiving grants from Merck and personal fees from Bristol-Myers outside the submitted work. No other disclosures were reported.

Funding/Support: This study was supported by grant FRN 154131 from the Canadian Institute of Health Research and by ICES, which is funded by an annual grant from the Ontario Ministry of Health and Long-term Care (MOHLTC).

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Disclaimer: The opinions, results, and conclusions expressed herein are those of the authors and do not reflect the official policy or position of the funding sources. No endorsement by ICES or the Ontario MOHLTC is intended or should be inferred. Parts of this manuscript were based on data and information compiled and provided by the Canadian Institute for Health Information (CIHI). However, the analyses, conclusions, opinions, and statements expressed herein are those of the authors and do not reflect the official policy or position of CIHI. Parts of this manuscript were based on data and information provided by Cancer Care Ontario (CCO). The opinions, results, views, and conclusions expressed herein are those of the authors and do not reflect the official policy or position of CCO. No endorsement by CCO is intended or should be inferred.

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