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

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 pound. 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.