Cost-Utility Analysis of Anterior Vertebral Body Tethering versus Spinal Fusion in Idiopathic Scoliosis from a US Integrated Healthcare Delivery System Perspective

Abstract

Anterior vertebral body tethering (VBT) is a non-fusion, minimally invasive, growth-modulating procedure with some early positive clinical outcomes reported in pediatric patients with idiopathic scoliosis (IS). VBT offers potential health-related quality of life (HRQoL) benefits over spinal fusion in allowing patients to retain a greater range of motion after surgery. We conducted an early cost-utility analysis (CUA) to compare VBT with fusion as a first-choice surgical treatment for skeletally immature patients (age >10 years) with moderate to severe IS, who have failed nonoperative management, from a US integrated healthcare delivery system perspective. Patients and Methods: The CUA uses a Markov state transition model, capturing a 15year period following index surgery. Transition probabilities, including revision risk and subsequent fusion, were based on published surgical outcomes and an ongoing VBT observational study (NCT02897453). Patients were assigned utilities derived from published patient-reported outcomes (PROs; SRS-22r mapped to EQ-5D) following fusion and the above VBT study. Index and revision procedure costs were included. Probabilistic (PSA) and deterministic sensitivity analyses (DSA) were performed. Results: VBT was associated with higher costs but also higher quality-adjusted life years (QALYs) than fusion (incremental costs: $45,546; QALYs gained: 0.54). The subsequent incremental cost-effectiveness ratio for VBT vs fusion was $84,391/QALY gained. Mean PSA results were similar to the base case, indicating that results were generally robust to uncertainty. The DSA indicated that results were most sensitive to variations in utility values. Conclusion: This is the first CUA comparing VBT with fusion in pediatric patients with IS and suggests that VBT may be a cost-effective alternative to fusion in the US, given recommended willingness-to-pay thresholds ($100,000-$150,000). The results rely on HRQoL benefits for VBT compared with fusion. For improved model accuracy, further analyses with longer-term PROs for VBT, and comparative effectiveness studies, would be needed.

Cost‐effectiveness of a novel, fluoroscopy‐based robotic‐assisted total hip arthroplasty system: A Markov analysis

“…The $50 000 threshold was selected to promote a more conservative analysis, 2,18 while the $100 000 threshold was chosen to align with recommendations from the World Health Organization (WHO) for cost-effectiveness analyses. [38][39][40] One-way deterministic sensitivity analysis (OSA) was performed to assess the outcome sensitivity of individual model parameters. A parameter was considered to be sensitive if a variation of �20% in its value changed the preferred treatment strategy.…”

“…2,18,40,41 Results of OSA were presented using tornado diagrams. 2,40 Probabilistic sensitivity analysis (PSA) modelling of 10 000 microsimulations was conducted as a means to predict the variance and distribution of treatment costs, utilities and ICER in a generalised population setting for both RA-THA and mTHA. 18 Treatment costs and utilities were modelled using gamma distributions, while transition probabilities were modelled using beta distributions.…”

Consolidated Health Economic Evaluation Reporting Standards (CHEERS) 2022 Explanation and Elaboration: A Report of the ISPOR CHEERS II Good Practices Task Force

“…If a primary outcome is prespecified, authors should cite a protocol or clinical study publication from which it is derived and justify excluding any other outcomes that were prespecified. Authors are encouraged to describe the nature Example of Item 9: Time horizon 87 "A 15-year time horizon was chosen for the base case of the analysis, beginning with the index procedures. A long-term time horizon (lifetime) was not considered appropriate due to the immaturity of utility data available for the analysis; extensive extrapolation over such a time horizon would be associated with considerable uncertainty.…”

Perioperative Outcomes of Open Anterior Vertebral Body Tethering and Instrumented Posterior Spinal Fusion for Skeletally Immature Patients With Idiopathic Scoliosis

“…[18][19][20][21][22] From a cost-utility standpoint, few studies have directly compared the direct costs of AVBT with IPSF. 26 Polly and colleagues found that direct costs were substantially greater for AVBT at $96,897 and $51,351 for IPSF. Our study found higher costs in supplies and OR services for IPSF but similar total direct costs at $50,891 for AVBT and Mean and SDs are provided for continuous variables.…”

“…From a cost-utility standpoint, few studies have directly compared the direct costs of AVBT with IPSF 26. Polly and colleagues found that direct costs were substantially greater for AVBT at $96,897 and $51,351 for IPSF.…”