Cost-utility Analysis Comparing Bracing Versus Observation for Skeletally Immature Patients with Thoracic Scoliosis

Abstract

Study design: Cost-utility analysis.

Objective: This study aimed to investigate the cost-utility of bracing versus observation in patients with thoracic scoliosis who would be indicated for bracing.

Summary of background data: There is high-quality evidence that bracing can prevent radiographic progression of spinal curvature in adolescent idiopathic scoliosis (AIS) patients with curves between 25° and 40° and Risser 0 to 2 skeletal maturity index. However, to our knowledge, the cost-utility of bracing in AIS has not been established.

Methods: A decision-analysis model comparing bracing versus observation was developed for a hypothetical 10-year old girl (Risser 0, Sanders 3) with a 35° main thoracic curve. We estimated the probability, cost, and quality-adjusted life years (QALY) for each node based on comprehensive review of the literature. Costs were adjusted for inflation based on Consumer Price Index and reported in terms of 2020 real dollars. Incremental net monetary benefit (INMB) was calculated based on a probabilistic sensitivity analysis using Monte Carlo simulations of 1000 hypothetical patients. One-way sensitivity analyses were performed by varying cost, probability, and QALY estimates.

Results: Our decision-analysis model revealed that bracing was the dominant treatment choice over observation at $50,000/QALY willingness to pay threshold. In simulation analysis of a hypothetical patient cohort, bracing was associated with lower net lifetime costs ($60,377 ± $5,340 with bracing vs. $85,279 ± $4543 with observation) and higher net lifetime QALYs (24.1 ± 2.0 with bracing vs. 23.9 ± 1.8 with observation). Bracing was associated with an INMB of $36,093 (95% confidence interval $18,894-$55,963) over observation over the patient's lifetime. The model was most sensitive to the impact of bracing versus observation on altering the probability of requiring surgery, either as an adolescent or an adult.

Conclusion: Cost-utility analysis supports scoliosis bracing as the preferred choice in management of appropriately indicated AIS patients with thoracic scoliosis.Level of Evidence: 5.