Incremental Cost-effectiveness Analysis on Length of Stay of an Enhanced Recovery After Spine Surgery Program: A Single-center, Retrospective Cohort Study

Background:Enhanced recovery after spine surgery (ERAS) is increasingly utilized to improve postoperative outcomes and reduce cost. There are limited data on the monetary benefits of ERAS when incorporating the costs of developing, operationalizing, and maintaining ERAS programs. The objective of this study was to calculate the incremental cost-effectiveness of a spine surgery ERAS program, modeling hospital and operational cost and length of stay (LOS). Methods:The study included adult patients undergoing spine surgery before and after implementation of an ERAS program. Variables included individual patient-level and ERAS personnel costs, with LOS as the outcome utility of interest. Propensity score matching was used to create a quasi-experimental design to equate the standard care and ERAS groups. Results:Four hundred and nine patients were included in the unmatched group, with 54 patients each in the standard care and ERAS groups after matching. In the matched cohort, the only imbalance in predictors (standard mean difference [SMD] >0.2) were race (SMD, 0.21), American Society of Anesthesiologist (ASA) physical status (SMD, 0.32), fluid balance in the operating room (SMD, 0.21), median (interquartile range) LOS (standard care, 2.0 [1.0, 3.75] days vs. ERAS, 4.0 [3.0, 5.0]; SMD, 0.81) and mean (+/- SD) total cost (standard care, $19,291.57 +/- 13,572.24 vs. ERAS, $24,363.45 +/- 26,352.45; SMD, 0.24). In the incremental cost effectiveness analysis, standard care was the dominant strategy in both 1-way and 2-way sensitivity analysis. Conclusions:We report a real-world, cost-effectiveness analysis following implementation of an ERAS program for spine surgery at a quaternary medical center. Our study demonstrated that considering LOS as the sole determinant, standard care is the dominant cost-effective strategy compared with the ERAS protocol.