Cochlear implantation as a treatment for single-sided deafness and asymmetric hearing loss: a randomized controlled evaluation of cost-utility.

Background: Single-sided deafness (SSD) and asymmetric hearing loss (AHL) have recently been proposed as a new indication for cochlear implantation. There is still no recommended treatment for these hearing deficits, and most options considered rely on the transfer of sound from the poor ear to the better ear, using Contralateral Routing of the Signal (CROS) hearing aids or bone conduction (BC) devices. In contrast, cochlear implantation allows the poor ear to be stimulated and binaural hearing abilities to be partially restored. Indeed, most recently published studies have reported an improvement in the spatial localisation of an incoming sound and better speech recognition in noisy environments after cochlear implantation in SSD/AHL subjects. It also provides consistent relief of tinnitus when associated. These encouraging hearing outcomes raise the question of the cost-utility of this expensive treatment in an extended indication.

Methods: The final endpoint of this national multicentre study is to determine the incremental cost-utility ratio (ICUR) of cochlear implantation in comparison to the current standard of care in France through simple observation, using a randomised controlled trial. Firstly, the study comprises a prospective and descriptive part, where 150 SSD/AHL subjects try CROS hearing aids and a BC device for three weeks each. Secondly, the choice is made between CROS hearing aids, BC implanted device and cochlear implantation. Hearing outcomes and quality of life measurements are described after 6 months for the subjects who chose CROS, BC or declined any option. The subjects who opt for cochlear implantation are randomised between one group where the cochlear implant is inserted without delay and one group of simple initial observation. Hearing outcomes and quality of life measurements are compared after 6 months.

Discussion: The present study was designed to assess the efficiency of cochlear implantation in SSD/AHL. A favourable cost-utility ratio in this extended indication would strengthen the promising clinical results and justify a reimbursement by the health insurance. The efficiency of other options (CROS, BC) will also be described.

Trial registration: This research has been registered in ClinicalTrials.gov (http://www.clinicaltrials.gov/), the 29th July 2014 under the n°NCT02204618.