210. Cost-utility analysis of bracing vs observation for adolescent idiopathic scoliosis

Abstract

<h3>BACKGROUND CONTEXT</h3> High quality evidence has shown that bracing can prevent radiographic progression of spinal curvature in skeletally immature adolescent idiopathic scoliosis (AIS) patients with curves between 25° -45°. Despite popular use, the cost-utility of bracing has not been established. <h3>PURPOSE</h3> This study aimed to determine the cost-utility of bracing in AIS. <h3>STUDY DESIGN/SETTING</h3> Cost-utility analysis. <h3>PATIENT SAMPLE</h3> Hypothetical cohort of skeletally immature (Risser 1) AIS patient with a 35° right main thoracic curve. <h3>OUTCOME MEASURES</h3> Incremental cost utility ratio (ICUR) and incremental net monetary benefit were calculated. <h3>METHODS</h3> A decision-analysis model comparing bracing vs observation was developed for a hypothetical skeletally immature AIS patients. We estimated the probability, cost, and quality-adjusted life years (QALY) for each event based on comprehensive review of the AIS literature. Costs were adjusted for inflation based on Consumer Price Index and reported in terms of 2020 real dollars. QALYs were discounted at 3%. Incremental net monetary benefit (INMB) was calculated based on a probabilistic sensitivity analysis using Monte Carlo simulations of 1,000 hypothetical patients. One-way sensitivity analyses were performed by varying cost, probability, and QALY estimates. <h3>RESULTS</h3> Our decision-analysis model revealed that bracing was the dominant treatment choice over observation at $50,000/QALY willingness to pay threshold. The net lifetime costs were $57,908 ± $5,443 with bracing and $79,079 ± $4,281 with observation. The net lifetime QALYs were 24.1 ± 1.9 with bracing and 23.8 ± 1.8 with observation. Bracing was favored in 99.6% of the simulations with a median INMB of $32,854 (95% CI, $13,695 to $45,689). The model was most sensitive to the impact of bracing vs observation on the probability of requiring surgical treatment as an adolescent or adult spinal deformity treatment later in life. <h3>CONCLUSIONS</h3> Cost-utility analysis demonstrates that bracing for AIS is dominant over observation, with a positive INMB. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.