Objective: To assess the clinical effectiveness of bilateral cochlear implantation compared with unilateral cochlear implantation alone or with a contralateral hearing aid (bimodal stimulation), in children with severe-to-profound hearing loss. Recently, the National Institute for Health and Clinical Excellence (NICE) in the U.K. has conducted a systematic review on cochlear implantation. We decided to update the pediatric part of the NICE review.
Data sources: The electronic databases MEDLINE and Embase were searched for European, North American, and Australasian studies published between October 2006 and June 2009. Reference lists of the included articles were also searched for relevant articles.
Study selection: Studies were included if they comprised data on comparisons between bilateral cochlear implantation and unilateral cochlear implantation and/or bilateral cochlear implantation and bimodal stimulation, in children with severe-to-profound sensorineural hearing loss. The following outcome measures were analyzed: audiological, speech perception, speech production, functional capacities, health-related quality of life, and/or educational outcomes.
Data extraction: Characteristics of the participants, interventions, outcomes, and methodological comments were entered into data extraction forms and the level of evidence was assessed.
Data synthesis: Results were standardized for each outcome measure by calculating a standardized mean difference (effect size).
Conclusion: Effect sizes could not be pooled because of the heterogeneity of the studies. Therefore, we presented the results qualitatively. Although the level of evidence was low, the advantages of bilateral cochlear implants corresponded with the primary benefits of bilateral hearing, that is, improved speech perception in quiet and noise. Localization results were less consistent. No data on audiologic, speech production, or educational outcomes were available.