Assessment of the clinical effectiveness of bilateral cochlear implantation compared with unilateral cochlear implantation or bimodal stimulation, in adults with severe-to-profound hearing loss. In 2007, the National Institute for Health and Clinical Excellence (NICE) in the U.K. conducted a systematic review on cochlear implantation. This study forms an update of the adult part of the NICE review.
The electronic databases MEDLINE and Embase were searched for English language studies published between October 2006 and March 2011.
Studies were included that compared bilateral cochlear implantation with unilateral cochlear implantation and/or with bimodal stimulation, in adults with severe-to-profound sensorineural hearing loss. Speech perception in quiet and in noise, sound localization and lateralization, speech production, health-related quality of life, and functional outcomes were analyzed.
Data extraction forms were used to describe study characteristics and the level of evidence.
The effect size was calculated to compare different outcome measures.
Pooling of data was not possible because of the heterogeneity of the studies. As in the NICE review, the level of evidence of the included studies was low, although some of the additional studies showed less risk of bias. All studies showed a significant bilateral benefit in localization over unilateral cochlear implantation. Bilateral cochlear implants were beneficial for speech perception in noise under certain conditions and several self-reported measures. Most speech perception in quiet outcomes did not show a bilateral benefit. The current review provides additional evidence in favor of bilateral cochlear implantation, even in complex listening situations.
*Department of Clinical and Experimental Audiology, Academic Medical Center, Amsterdam; †Radboud University Nijmegen Medical Centre, Department of Otorhinolaryngology–Head and Neck Surgery, Hearing and Implants, Donders Institute for Brain, Cognition and Behaviour; ‡Department of Otorhinolaryngology and Head and Neck Surgery, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht; §Dutch Cochrane Centre and Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Center, Amsterdam; and ∥Department of Otorhinolaryngology, University Medical Center Groningen, Groningen, The Netherlands
Address correspondence and reprint requests to Jelmer van Schoonhoven, M.Sc., Department of Clinical and Experimental Audiology, Academic Medical Center, PO Box 22660, 1100 DD Amsterdam, The Netherlands; E-mail: firstname.lastname@example.org
This study was financed by the Dutch Health Care Insurance Board (CVZ, project OP08/642/020).
The authors disclose no conflicts of interest.