Supplementary Material for: Audiological performance, complications and compliance of the ADHEAR Bone Conduction Device in a paediatric patient cohort.

Introduction: The ADHEAR is a non-surgical Bone Conduction Device (BCD) that makes use of an adhesive adapter. While clinical trials have demonstrated its efficacy with regards to audiological performance, safety and compliance, data on real-world paediatric cohorts is scarce. Methods: This retrospective cohort study analysed data from paediatric patients fitted with ADHEAR at a tertiary centre between January 2017 and September 2024. Baseline characteristics such as hearing loss aetiology were recorded. Long-term free-field aided and unaided warble-tone audiometry was performed within a subsample of 19 patients. Compliance and reasons for discontinuation were recorded over a follow-up period of up to 78 months and based on the last recorded status. Results: A total of 111 children (mean age: 10.1 years) were included. Mean functional gain was 22.7 (95% CI: 18.3 – 27.1) decibels hearing loss (dB HL) and the mean effective gain was 20.3 dB HL (95% CI: 20.3 (16.4, 24.2). Skin complications were low and reported in 16 children (14.4%), of whom 7 needed to temporarily refrain from device use. Long-term compliance was 40.9% (median follow-up: 24 months). Key reasons for discontinuation included lack of perceived benefit (23.5%), appearance or social stigmatization issues (20.6%), and practical issues with adhesives (16.2%). Conclusion: For congenital malformation and chronic suppurative otitis media patients, the ADHEAR provides effective amplification, although air-bone gap closure is suboptimal. Complications associated with device use were relatively rare and mild in nature. Compliance rates were notably lower than observed in other studies. Appearance and social stigmatization issues should be addressed during consultation.