Variation in anesthesiology provider-volume for complex gastrointestinal cancer surgery: a population-based study

Objective — Examine between-hospital and between-anesthesiologist variation in anesthesiology provider-volume (PV) and delivery of high-volume anesthesiology care.

Summary Background — Data Better outcomes for anesthesiologists with higher provider-volume (PV) of complex gastrointestinal cancer surgery have been reported. The factors linking anesthesiology practice and organization to volume are unknown.

Methods — We identified patients undergoing elective esophagectomy, hepatectomy, pancreatectomy using linked administrative health datasets (2007–2018). Anesthesiology PV was the annual number of procedures done by the primary anesthesiologist in the 2 years before the index surgery. High-volume anesthesiology was PV>6 procedures/year. Funnel plots to described variation in anesthesiology PV and delivery of high-volume care. Hierarchical regression models examined between-anesthesiologist and between-hospital variation in delivery of high-volume care use with variance partition coefficients (VPC) and median odds ratios (MOR).

Results — Among 7,893 patients cared for at 17 hospitals, funnel plots showed variation in anesthesiology PV (median ranging from 1.5, IQR 1-2 to 11.5, IQR 8–16) and delivery of HV care (ranging from 0 to 87%) across hospitals. After adjustment, 32% (VPC 0.32) and 16% (VPC 0.16) of the variation were attributable to between-anesthesiologist and between-hospital differences, respectively. This translated to an anesthesiologist MOR of 4.81 (95%CI 3.27–10.3) and hospital MOR of 3.04 (95%CI 2.14–7.77).

Conclusions — Substantial variation in anesthesiology PV and delivery of high-volume anesthesiology care existed across hospitals. The anesthesiologist and the hospital were key determinants of the variation in high-volume anesthesiology care delivery. This suggests that targeting anesthesiology structures of care could reduce variation and improve delivery of high-volume anesthesiology care.