Do Busier Surgeons Have Lower Intraoperative Costs? An Analysis of Anterior Cervical Discectomy and Fusion Using Time-Driven Activity-Based Costing

Abstract

Study Design: The present study is a single-center, retrospective cohort study of patients undergoing neurosurgical anterior cervical discectomy and fusion (ACDF). Objective Our objective was to use time-driven activity-based costing (TDABC) methodology to determine whether surgeons’ case volume influenced the true intraoperative costs of ACDFs performed at our institution. Summary of Background Data: Successful participation in emerging reimbursement models, such as bundled payments, requires an understanding of true intraoperative costs, as well as the modifiable drivers of those costs. Certain surgeons may have cost profiles that are favorable for these “at-risk” reimbursement models, while other surgeons may not. Methods: Total cost was divided into direct and indirect costs. Individual costs were obtained by direct observation, electronic medical records, and through querying multiple departments (business operations, sterile processing, plant operations, and pharmacy). Timestamps for all involved personnel and material resources were documented. All surgeons performing ACDFs at our primary and affiliated hospital sites from 2017 to 2022 were divided into four volume-based cohorts: 1–9 cases (n=10 surgeons, 38 cases), 10–29 cases (n=7 surgeons, 126 cases), 30–100 cases (n=3 surgeons, 234 cases), and > 100 cases (n=2 surgeons, 561 cases). Results: The average total intraoperative cost per case was $7,116 +/− $2,945. The major cost contributors were supply cost ($4,444, 62.5%) and personnel cost ($2,417, 34.0%). A generalized linear mixed model utilizing Poisson distribution was performed with the surgeon as a random effect. Surgeons performing 1–9 total cases, 10–29 cases, and 30–100 cases had increased total cost of surgery (P < 0.001; P < 0.001; and P<0.001, respectively) compared to high-volume surgeons (> 100 cases). Among all volume cohorts, high-volume surgeons also had the lowest mean supply cost, personnel cost, and operative times, while the opposite was true for the lowest-volume surgeons (1–9 cases). Conclusion: It is becoming increasingly important for hospitals to identify modifiable sources of variation in cost. We demonstrate a novel use of TDABC for this purpose. Level of Evidence: Level—III.