Defining the value of elective lumbar fusion: a systematic review of existing methodologies and framework for the Operative Value Index.

BACKGROUND

Despite wide variation in the outcomes and costs of lumbar fusion, few studies have integrated these domains together within a single metric to assess "value" (outcomes achieved per dollar spent). In this review, we sought to 1) characterize existing metrics of cost-effectiveness for lumbar fusion, 2) evaluate all applications of time-driven activity-based costing (TDABC) in spine surgery, and 3) outline the conceptual foundation for a standardized Operative Value Index (OVI).

METHODS

Two PRISMA-concordant systematic reviews were performed on PubMed and Scopus databases. The first review examined all studies which reported a cost-effectiveness metric for lumbar fusion. The second review examined all applications of TDBAC in spine surgery.

RESULTS

Among 366 screened studies, 40 (21 for cost-effectiveness in lumbar fusion, 19 for TDABC in spine surgery) fulfilled inclusion criteria. The incremental cost-effectiveness ratio (ICER) was the most common metric, followed by OVI. Costs were frequently defined as reimbursement or charges; few studies assessed actual costs or TDABC. TDABC studies consistently demonstrated that costs were driven primarily by surgeon-level and procedure-specific factors, not patient characteristics. OVI studies uniformly used TDABC costs combined with disease-specific outcomes, but were limited to short-term follow-up and primarily intraoperative costs.

CONCLUSIONS

Current value assessments in lumbar fusion are limited by heterogeneous outcomes and imprecise costing. A standardized framework integrating pathology-specific outcomes with episode-level costing (not charges or reimbursement) may enable more generalizable and accurate comparisons of operative value.