244 Does Surgeon Case Volume Influence Intraoperative Costs? An Analysis of Anterior Cervical Discectomy and Fusion Using Time-Driven Activity-Based Costing

INTRODUCTION: 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. Unfortunately, neurosurgeons are often unaware of the true costs of surgery. METHODS: Total cost was divided into direct and indirect costs. All surgeons performing ACDFs at our institution 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). Software was developed to automate the extraction of all intraoperatively utilized personnel and material resources from the electronic medical record (EMR). Total costs were determined through direct observation, EMR extraction, and inter-departmental collaboration (business operations, sterile processing, pharmacy, and plant operation). 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%). Generalized linear model utilizing Poisson distribution was performed with 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). CONCLUSIONS: 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.