Cochlear Implantation In Children Under 12 Months: A Systematic Review

Research Question: How does cochlear implantation in children under 12 months of age affect speech and language outcomes compared to children implanted after 12 months of age? Background: Cochlear implantation is indicated for children with significant hearing loss who demonstrate limited benefit from a conventional hearing aid trial. Although the FDA only permits implantation in children 12 months of age or older, off-label implantation has occurred in children under 12 months of age. While some studies do not find statistically significant results due to small sample sizes (Miyamoto et al., 2008), others offer support for implantation in the population in question by demonstrating significant speech and language benefit as compared to children implanted over 12 months of age (Dettman et al., 2016). The aim of the present systematic review is to assess the efficacy of cochlear implantation in children under 12 months of age with regard to speech and language outcomes. Methods: We conducted a search of the following databases: CINAHL, PubMed and PsychInfo. The search was limited to articles published between 1990-2017. Our search retrieved 128 articles of which 45 were from CINAHL, 57 from PubMed, and 26 from PsychInfo. Articles were accepted into the initial pool if the participants included infants implanted before 12 months of age who received follow-up evaluations assessing receptive and/or expressive language. Upon title and abstract review, 86 studies were eliminated. Forty-two studies were included for full-text review. Of those 42 articles, 27 were eliminated due to lack of control comparison group, lack of participants under 12 months of age, and/or lack of speech/language outcome follow-up. The articles were evaluated by two independent reviewers. Interrater reliability was calculated to be 96% while performing title and abstract review. Anticipated Results: This systematic review included 15 articles, including systematic reviews, retrospective cohort studies, and longitudinal cohort intervention studies. Quality appraisals of the included articles and data extraction are in progress at this time. Discussion: Although this systematic review is not yet complete, the potential contribution of the anticipated results above is evident. Current evidence is mostly composed of retrospective cohort studies, and the included studies suggest evidence that supports cochlear implantation before 12 months of age