Cochlear Implantation in Single Sided Deafness and Asymmetrical Hearing Loss: a Cost/Utility Study.

Study Overview
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Brief Summary
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The investigators assume that cochlear implants in this indication are not only effective but also cost-effective. The investigators' experimental protocol relies on real life therapeutic strategy, where a cochlear implant may be proposed once CROS and bone conductions systems have failed. Thus, all subjects enrolled in our study will try CROS and bone conduction devices. If these trials are ineffective, the remaining subjects will be randomized between two arms (cochlear implantation vs 6 months abstention followed by cochlear implantation). A comparative cost-utility analysis between the two arms, of medical consequences measured in terms of quality of life will identify a preference for a strategy. Specific binaural hearing measurements with respect to each treatment option (abstention, CROS, bone conduction device, cochlear implant) will also be collected.

Detailed Description
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Single sided deafness and profound asymmetrical hearing loss are impairments that significantly alter quality of life. Behavioural problems and scholar delays have been reported in children. Speech recognition with background or competing noise and sound localization are both impaired. 1/1000 new borns are affected and the incidence tends to rise in the adult population. At the moment, there is no guideline regarding the treatment of single sided deafness and asymmetrical hearing loss. Some patients don't even receive any therapeutic proposition. Three treatment options are available : CROS (Contralateral Routing Of the Signal) systems that convey the auditory information from the deaf ear to the good ear using wi-fi bone conduction devices which use transcranial conduction to convey auditory information from the poor ear to the good ear cochlear implants that directly stimulate afferent fibers of auditory nerve in the poor ear Cochlear implantation is therefore the only treatment which restores stimulation in the poor ear. Its efficacy in single sided deafness associated with incapacitating tinnitus have been demonstrated by Pr Van de Heyning (Leeuven, Be) and colleagues. Its interest has been compared to CROS systems and bone conduction devices in a valuable study conducted by S. Arndt (Pr Laszig, Freibourg, Ger). Cochlear implants provided better speech in noise recognition scores in dichotic hearing, i.e when speech and noise sources are spatially separated. Their first publication involved 11 patients but to date, more than 110 patients with single sided deafness have been included in their protocol. The efficacy of cochlear implantation has thus been validated in the treatment of single sided deafness and asymmetrical hearing loss. The investigators assume that cochlear implants in this indication are not only effective but also cost-effective. The investigators' experimental protocol relies on real life therapeutic strategy, where a cochlear implant may be proposed once CROS and bone conductions systems have failed. Thus, all subjects enrolled in our study will try CROS and bone conduction devices. If these trials are ineffective, the remaining subjects will be randomized between two arms (cochlear implantation vs 6 months abstention followed by cochlear implantation). A comparative cost-utility analysis between the two arms, of medical consequences measured in terms of quality of life will identify a preference for a strategy. Specific binaural hearing measurements with respect to each treatment option (abstention, CROS, bone conduction device, cochlear implant) will also be collected.

Official Title
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Cochlear Implantation in Single Sided Deafness and Asymmetrical Hearing Loss: a Cost/Utility Study.

Conditions
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Major Cochlear Ossification or Malformation, Retrocochlear Pathology, Auditory Processing Disorder, Central

Intervention / Treatment
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* Other: 6 months initial abstention
* Device: cochlear implantation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Social security affiliation Single sided deafness or profound asymmetrical hearing loss confirmed using pure tone audiometry and auditory brainstem responses, with or without tinnitus Written consent to the protocol Exclusion Criteria: Retrocochlear pathology (vestibular schwannoma, severe central auditory processing disorder) Major cochlear ossification or malformation Subjects under juridical protections or tutelage measure

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: cochlear implantation<br>Our experimental protocol relies on real life therapeutic strategy, where a cochlear implant may be proposed once CROS and bone conductions systems have failed. Thus, all subjects enrolled in our study will try CROS and bone conduction devices. If these trials are ineffective, the remaining subjects will be randomized between two arms (cochlear implantation vs 6 months abstention followed by cochlear implantation). | Device: cochlear implantation<br> <br> |
| Other: 6 months initial abstention<br>Our experimental protocol relies on real life therapeutic strategy, where a cochlear implant may be proposed once CROS and bone conductions systems have failed. Thus, all subjects enrolled in our study will try CROS and bone conduction devices. If these trials are ineffective, the remaining subjects will be randomized between two arms (cochlear implantation vs 6 months abstention followed by cochlear implantation). | Other: 6 months initial abstention<br>* Our experimental protocol relies on real life therapeutic strategy, where a cochlear implant may be proposed once CROS and bone conductions systems have failed. Thus, all subjects enrolled in our study will try CROS and bone conduction devices. If these trials are ineffective, the remaining subjects will be randomized between two arms (cochlear implantation vs 6 months abstention followed by cochlear implantation).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| incremental cost-utility ratio |  | 6 months after cochlear implantation versus no treatment option | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Global score of EuroQoL-5D |  | before and after auditory rehabilitation (cochlear implantation, CROS system or bone conduction device): Day 0, Week 3, Week 6, Month 6 | 
| Global score of Nijmegen Cochlear implant Questionnaire (NCIQ) |  | before and after auditory rehabilitation (cochlear implantation, CROS system or bone conduction device): Day 0, Week 3, Week 6, Month 6 | 
| Nijmegen Cochlear Implant Questionnaire (NCIQ): score in advanced auditory perception section |  | before and after auditory rehabilitation (cochlear implantation, CROS system or bone conduction device): Day 0, Week 3, Week 6, Month 6 | 
| Speech Reception Thresholds | Signal to noise ratio that allows 50% words recognition) in diotic hearing, dichotic hearing and reverse dichotic hearing | before and after auditory rehabilitation (cochlear implantation, CROS system or bone conduction device): Day 0, Week 3, Week 6, Month 6 | 
| Mean error angle for sound localization |  | before and after auditory rehabilitation (cochlear implantation, CROS system or bone conduction device): Day 0, Week 3, Week 6, Month 6 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Tinnitus, single sided deafness, Asymmetrical hearing loss, Cost-utility, Cochlear implants, Bone conduction device, Dichotic hearing, Squelch effect.