Does Surgeon Experience and Case Volume Affect Cost and Outcomes of Lumbar Fusions? A Time-driven Activity-based Cost Analysis

Introduction: As healthcare systems transition to value-based care models, understanding the factors influencing costs and outcomes in neurosurgery is crucial. This study utilizes Time-Driven Activity-Based Costing (TDABC) to assess the impact of surgeon experience and case volume on costs, clinical outcomes, and operative value in lumbar fusions. While TDABC has been applied in various surgical specialties, its use in neurosurgery, particularly in analyzing surgeon-specific factors, remains limited.

Methods: A retrospective cohort study was conducted at a single center, analyzing lumbar instrumented arthrodesis procedures from 2017 to 2019. Primary variables included surgeon experience (years) and case volume (annual procedures). Confounding variables such as patient demographics, comorbidities, surgery type, and levels fused were considered. Intraoperative cost data were sourced from electronic medical records and departmental sources. Clinical outcomes were measured using the Oswestry Disability Index (ODI), and operative value was defined by the Operative Value Index (OVI), representing the percent improvement in ODI per $1000 spent intraoperatively. Analysis of covariance examined the relationships between surgical costs, surgeon experience, case volume, and clinical outcomes.

Results: Among 291 surgeries, surgeons with ≥15 years of experience had lower mean surgery costs ($16,072 vs $22,260, p< 0.001) and higher OVI scores (2.03 vs 1.06, p=0.033) compared to less experienced surgeons. High-volume surgeons (≥100 cases) showed greater ODI improvements (8.70 vs 5.93, p=0.022) and higher OVI scores (2.22 vs 1.01, p=0.016) compared to lower-volume surgeons. Procedure type and levels fused significantly influenced surgery costs (p < 0.001) and OVI (p < 0.001).

Conclusion : This study is among the first to apply TDABC in evaluating the impact of surgeon experience and case volume on costs and outcomes in lumbar fusion procedures. Findings suggest that surgeons with ≥15 years of experience and high case volumes (≥100 cases) enhance operative value by reducing costs and improving ODI respectively. Encouraging specialization and maintaining high case volumes may enhance cost-effectiveness and patient outcomes in healthcare systems.