Cost-Utility Analysis Comparing Bracing Versus Observation for Skeletally Immature Patients With Thoracic Scoliosis

Ijezie Ikwuezunma, BS, BA; Kevin Wang, BS; Adam Margalit, MD; Paul Sponseller, MD, MBA; Amit Jain, MD

Disclosures

Spine. 2021;46(23):1653-1659. 

In This Article

Abstract and Introduction

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

Introduction

Studies exploring the natural history of adolescent idiopathic scoliosis (AIS) have demonstrated the consequences of untreated disease, including progressive deformity, cosmetic dissatisfaction, increased back pain, and pulmonary complications for large thoracic curves.[1] Treatment of AIS focuses on halting curve progression and preventing future complications, reducing pain, and improving quality of life.[2] Bracing has emerged as an important treatment strategy, after the BrAIST (Bracing in Adolescent Idiopathic Scoliosis Trial) study published in 2013 provided high-quality evidence that bracing significantly decreased the radiographic progression of high-risk curves in skeletally immature adolescents.[3]

Economic evaluation of AIS treatment interventions have become increasingly relevant in this contemporary era of value-based care, particularly as rising trends in procedural and hospital costs have come under much scrutiny due to lacking evidence of proportional improvements in patient-centered outcomes.[4,5] Cost-utility analysis (CUA) represents one method of health economic modeling by which value may be assessed from a patient-centered perspective in terms of both quantity and quality of life improvement.[6] A recent study demonstrated that surgical treatment of thoracic scoliosis in adolescents was more cost-effective than observation, and fell below the $50,000/quality-adjusted life-year (QALY) threshold for patients whose curvature fell within operative range.[7] However, majority of patients with scoliosis are not surgical candidates, and many are treated with observation or bracing, especially if at risk for curve progression. To our knowledge, the cost-utility of bracing in AIS (for the appropriately indicated patient) has not been established.

The primary aim of this study was to investigate the cost-utility of bracing versus observation in the treatment of skeletally immature patients with thoracic scoliosis who would be indicated for bracing. In addition, we aimed to identify factors that influence cost-utility estimates through sensitivity analyses. We hypothesized that bracing in thoracic AIS is cost-effective compared to observation for the appropriately indicated patient.

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