To Scan or Not to Scan—A Cross-Sectional Analysis of the Clinical Efficacy and Cost-Effectiveness of Audiometric Protocols for Magnetic Resonance Imaging Screening of Vestibular Schwannomas

Abstract

Introduction: Vestibular schwannomas (VS) are a rare cause of asymmetrical hearing loss, and routine screening with magnetic resonance imaging (MRI) can be costly. At present, no consensus exists on what qualifies as “asymmetrical sensorineural hearing loss” (ASNHL) and when a patient should be referred for screening. Objectives: 1) Evaluation of published audiometric protocols on the basis of sensitivity and specificity when applied to local clinical cohort of patients with ASNHL; 2) determination of clinical risks of missing VS and potential wastes in screening “radiologically normal” cases; 3) assessment of the cost of MRI screening. Methods: Cross-sectional study with chart review in a 2-year (2015–2016) cohort of 1059 patients who underwent MRI screening and audiometry indicating sensorineural hearing loss. Fourteen previously published audiometric protocols were assessed for their sensitivity and specificity in guiding radiological diagnosis of VS, and cost analysis was performed. Results: 6/14 audiometric protocols had a sensitivity greater than 85%. Diagnostic specificity ranged from 22.91 to 82.76%, clinical risks from 0 to 50%, and potential wastes from 17.24 to 77.09%. Average annual cost of screening was £64,069. Application of proposed local screening protocol had a projected cost saving of 32.19%. Cost of screening patients that benefit from treatment was compared with a utility function that quantified expected benefit. Conclusions: Development of an easy-to-apply algorithm incorporating high-sensitivity audiometric protocols may result in significant cost saving, with minimal clinical risk of missing cases. There was disparity between screening costs and monetary “benefit” of hearing.

Multiple Audiometric Analysis in the Screening of Vestibular Schwannoma

“…During our analysis, it was found that asymmetry of ≥20 dB at two adjacent frequencies when the average at 250 to 8,000 Hz was >30 dB in the better ear, showed the highest specificity of all (68.37%); however, the sensitivity was very low (55.56%), so it could not be considered an ideal screening test for VS. This high specificity has been previously published by other authors [ 25 ]. Unfortunately, in a screening test, the sensitivity needs to be prioritized.…”

Hear me out: rethinking internal auditory meatus magnetic resonance imaging in primary care. A cohort evaluation

“…4 Studies argue against imaging unilateral tinnitus, suggesting that acoustic neuroma can be reliably and more cost-effectively identified by asymmetric sensorineural hearing loss audiometric protocols. 11,41,42 In view of the harms of over-testing, the 2020 NICE guideline committee recommended to ‘consider’ but not ‘offer’ imaging for unilateral tinnitus. It is unclear what impact this semantic advice will have, considering the current ubiquitous unindicated imaging overuse.…”

Hipoacusia sensorineural asimétrica en el diagnóstico de schwannoma vestibular

“…El valor diagnóstico de los PEATC estándar sigue cuestionándose y genera controversia en cuanto a solicitar IRM de primera intención, lo que a su vez se ve limitado por su alto costo [1,2,37].…”

“…En el estudio de la hipoacusia asimétrica no solo encontramos valor intrínseco en su rehabilitación auditiva y tratamiento, sino un indicador temprano de patología retrococlear. El costo que implica el tratamiento de tumores en el ángulo pontocerebeloso en sus fases avanzadas es mucho mayor aparentemente que los costos implicados en una batería de estudios completa [1][2][3].…”

“…La audiometría tonal sigue siendo el estudio más útil y de más bajo costo para identificar la población en riesgo de padecer schwannoma vestibular (SV) y definir quién debe someterse a potenciales evocados auditivos de tallo cerebral (PEATC) o estudio de imagen (IRM) [2,7].…”