In a Canadian study reported in JAMA Surgery, Hallet et al found that higher anesthesiologist volume was associated with reduced risk of short-term adverse postoperative outcomes in patients undergoing complex surgery for gastrointestinal cancer.
Study Details
The population-based cohort study included 8,096 adult patients who underwent esophagectomy, pancreatectomy, or hepatectomy in Ontario from January 2007 to December 2018. Primary anesthesiologist volume was defined as the annual number of these procedures supported by an anesthesiologist in the 2 years prior to the index surgery.
The primary outcome measure was a composite of 90-day major morbidity (Clavien-Dindo classification grades 3–5) and hospital readmission. Risk of outcomes was assessed in multivariable logistic regression models.
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.— Hallet et al
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Key Findings
The 8,096 patients were treated by 842 anesthesiologists and 186 surgeons. The median anesthesiologist volume was three procedures (interquartile range = 1.5–6 procedures) per year. The 75th percentile of volume (≥ 6 procedures per year) was selected as the cutoff for high volume. A total of 2,166 patients (26.7%) were treated by high-volume anesthesiologists.
The composite primary outcome occurred in 36.3% of patients in the high-volume group and 45.7% of patients in the low-volume group (unadjusted odds ratio [OR] = 0.81, 95% confidence interval [CI] = 0.73–0.90).
In multivariate analysis including adjustment for surgeon volume and institutional volume, care by a high-volume anesthesiologist was associated with significantly reduced risk of the primary outcome (adjusted OR = 0.85, 95% CI = 0.76–0.94). Higher anesthesiologist volume was also independently associated with reduced risk of the primary outcome when analyzed as a continuous variable (adjusted OR = 0.990, 95% CI = 0.980–0.999).
On multivariate analysis, treatment by a high-volume anesthesiologist was also associated with reduced risk of 90-day major morbidity (adjusted OR = 0.83, 95% CI = 0.75–0.91) and unplanned intensive care unit admission (adjusted OR = 0.84, 95% CI = 0.76–0.94), but not hospital readmission (adjusted OR = 0.87, 95% CI = 0.73–1.05) or 90-day mortality (total of 402 events; adjusted OR = 1.05, 95% CI = 0.84–1.31).
The investigators concluded, “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.”
Julie Hallet, MD, MSc, of the Department of Surgery, University of Toronto, is the corresponding author for the JAMA Surgery article.
Disclosure: The study was supported by a grant 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. For full disclosures of the study authors, visit jamanetwork.com.
