Systematic Review on the Trial Period for Bone Conduction Devices in Single-Sided Deafness : Rates and Reasons for Rejection

Objective: To systematically review the literature to evaluate the trial period of bone conduction devices (BCDs) for adult patients with single-sided deafness (SSD). Data Sources: The PubMed, Embase, and Cochrane Library databases were searched from their inception up to August 15, 2016 for SSD, BCD, and their synonyms. Study Selection: In total, 523 articles were retrieved, of which 12 satisfied the eligibility quality criteria. Our outcomes of interest were: 1) the BCD implantation rejection percentage, 2) reasons to reject BCD implantation, and 3) possible prognostic factors predicting the trial outcome. Data Extraction and Synthesis: At critical appraisal, six studies (n = 471 patients) scored a moderate to high directness of evidence and a medium or low risk of bias and were selected for data extraction. Due to heterogeneity between studies, pooling of data for meta-analysis was not feasible. Therefore, results of studies were summarized per outcome: 1) after the BCD trial, 32.0 to 69.6% of SSD patients rejected BCD implantation, 2) the three main reasons for rejection were experiencing limited benefit from the device, patients fearing or being unfit for surgery and cosmetic aspects, 3) no clear prognostic factors predicting the trial outcome could be identified. Conclusion: Roughly half of patients rejected BCD implantation after a trial period. From the current literature it is unclear which patients could benefit most from BCD implantation. High level of evidence studies should be conducted to investigate possible prognostic factors that predict the BCD trial outcome.