Physical outcome measures for conductive and mixed hearing loss treatment: A systematic review.

BACKGROUND: The number of potential options for rehabilitation of patients with conductive or mixed hearing loss is continually expanding. To be able to inform patients and other stakeholders, there is a need to identify and develop patient-centred outcomes for treatment of hearing loss. OBJECTIVE OF REVIEW: To identify outcome measures in the physical core area used when reporting the outcome after treatment of conductive and mixed hearing loss in adult patients. TYPE OF REVIEW: Systematic review. SEARCH STRATEGY: Systematic review of the literature related to reported physical outcome measures after treatment of mixed or conductive hearing loss without restrictions regarding type of intervention, treatment or device. EVALUATION METHOD: Any measure reporting the physical outcome after treatment or intervention of mixed or conductive hearing loss was sought and categorised. The physical outcome measures that had been extracted were then grouped into domains. RESULTS: The literature search resulted in the identification of 1434 studies, of which 153 were selected for inclusion in the review. The majority (57%) of papers reported results from middle ear surgery, with the remainder reporting results from either bone conduction hearing devices or middle ear implants. Outcomes related to complications were categorised into 17 domains, whereas outcomes related to treatment success was categorised into 22 domains. CONCLUSIONS: The importance of these domains to patients and other stakeholders needs to be further explored in order to establish which of these domains are most relevant to interventions for conductive or mixed hearing loss. This will allow us to then assess which outcome measures are most suitable for inclusion in the core set.

Digital processing technology for bone-anchored hearing aids: randomised comparison of two devices in hearing aid users with mixed or conductive hearing loss.

OBJECTIVE: This study compared the performance of two new bone-anchored hearing aids with older bone-anchored hearing aids that were not fully digital. METHODS: Fourteen experienced bone-anchored hearing aid users participated in this cross-over study. Performance of their existing bone-anchored hearing aid was assessed using speech-in-noise testing and questionnaires. Participants were then fitted with either a Ponto Pro or a BP100 device. After four weeks of use with each new device, the same assessments were repeated. RESULTS: Speech-in-noise testing for the 50 per cent signal-to-noise ratio (the ratio at which 50 per cent of responses were correct) showed no significant differences between the Ponto Pro and the BP100 devices (p = 0.1) However, both devices showed significant improvement compared with the participants' previous bone-anchored hearing aid devices (p < 0.001). There were no significant differences between the two new devices in the questionnaire data. CONCLUSION: Both fully digital bone-anchored hearing aids demonstrated superior speech processing compared with the previous generation of devices. There were no substantial differences between the two digital devices in either objective or subjective tests.

The role of stability measurements of the Baha® system in children.

OBJECTIVE: Percutaneous bone conduction hearing aids are an established treatment for selected children unable to use conventional hearing aids. Currently in children, loading the implant is delayed for 3-6 months following fixture placement, due to concerns regarding bone quality, bone thickness and subsequent implant stability. Traditionally, such concerns led to children undergoing 2-stage Baha(®) surgery, with a second operation to attach the abutment after 3-6 months. Bone conduction implant stability can be objectively measured using resonance-frequency analysis (RFA) to generate Implant Stability Quotients (ISQs). We aimed to assess implant stability in children undergoing 1-stage surgery using RFA measurements and investigate the possible implications for earlier loading following surgery. METHODS: We report a case series of consecutive children undergoing Baha(®) at our tertiary paediatric hospital. The interval to implant loading remained 3-6 months for the duration of this study. RFA measurements were taken peri-operatively, 1 week post-surgery, within 3 months of surgery and then subsequently at follow up appointments. RFA measurements were also measured at loading of the hearing processor and at follow up appointments after loading. RESULTS: Nine children received 10 Cochlear™ Baha(®) BI300 implants (8 unilateral and 1 bilateral) with a mean age of 9 years 4 months (4 years 9 months to 13 years 5 months). The mean time to loading of the hearing processor was 3.3 months (3 to 5 months, n=9) and mean follow up was 9 months (12 weeks to 23 months). Eight children had ISQs that were potentially sufficient to have loaded the implant earlier than 3 months. Implant stability was maintained after loading with the hearing processor. CONCLUSION: This study supports the potential use of RFA measurements to either, guide implant loading following 1-stage surgery in children, or to enable a larger prospective study of early loading (4-6 weeks) in children.