Introducing the operative value index for glioma surgery: an integration of quality-adjusted life years with time-driven activity-based costing

Background Although many studies have examined outcomes after glioma surgery, few have explored the factors driving variation in the cost-effectiveness of surgical care. In this study, we integrate granular time-driven activity-based costing (TDABC) methodology with quality-adjusted life years (QALYs) to measure the true "value" (outcomes achieved per dollar spent) of glioma surgery. Methods 176 glioma surgeries performed at a single institution were reviewed. Process maps were designed to identify all resources utilized in the intraoperative episode. Costing software was developed to automate the extraction of this data from the electronic medical record (EMR). QALYs were calculated based on progression-free survival (PFS) and 6-month postoperative Karnofsky Performance Status (KPS) scores. The Operative Value Index (OVI) was defined as the QALYs achieved per $1,000 spent intraoperatively. Multivariable regression models were performed to examine factors driving variability in both costs and OVI. Results The median total cost of surgery was $6,987, most of which was driven by the cost of supplies ($3,804, 53%) and personnel ($1,635, 23%). The median QALY was 0.96, PFS was 403 days (1.1 years), and the OVI was 0.14. Multivariable regression analysis revealed that awake surgery was associated with $2,540 of additional cost compared to surgery under general anesthesia, while World Health Organization Grade III (p < 0.001) and Grade IV (p < 0.001) gliomas were associated with significantly lower OVI. Conclusions This study establishes a scalable, EMR-based framework for evaluating surgical value by integrating cost with outcomes. We show that awake surgery is associated with significantly higher total cost, and that increasing glioma disease severity is associated with worse outcomes achieved per dollar spent.